Device and method for feeding weft yarns to a rapier head of a weaving machine

Description

[0001] The invention relates to a device for feeding at least first and second weft yarns to a weaving machine comprising at least one rapier head, wherein the weft yarns can be fed to the rapier head in the weft direction.

[0002] WO 2011 / 015173 A1 discloses a device for the sequential transfer of two preferably ribbon-shaped weft yarns, also called tapes, from a feed unit assigned to each weft yarn to a rapier head of a weaving machine. By appropriately controlling the feed units, either one or the other weft yarn is fed to the rapier head and subsequently inserted into the shed. For this purpose, the two feed units are arranged one above the other and aligned in the weft direction. Each feed unit has a clamping device for clamping a free end of the respective weft yarn, wherein the respective clamping device is movable essentially in the weft direction between at least two different operating positions.Furthermore, each clamping device can be moved by means of a pivoting unit driven by a drive, preferably a servo motor, which each comprises two parallel pivoting arms connected by a coupling element, wherein the clamping device is arranged on the coupling element.

[0003] Because each clamping device moves only in a vertical plane, which also includes the weft insertion line, the respective ribbon-shaped weft material follows a largely twist-free and deflection-free path in the warp direction from the feed unit to its transfer to the rapier head. Shear forces that could damage the respective weft yarn do not occur. There is therefore no deflection in the direction of the width of the ribbon-shaped weft material. If the respective clamping device can be moved in the aforementioned vertical plane, which also includes the weft insertion line, various feed movements can be carried out using the device, whereby no deflection in the direction of the width of the ribbon-shaped weft material occurs.To transfer a ribbon-shaped weft yarn, its free end is first clamped in the corresponding clamping device, then transferred to the rapier head, and then the clamping device is opened and the weft material is inserted.

[0004] However, this known device has the disadvantage of being relatively complex and cost-intensive. It also requires a relatively large amount of space. Last but not least, due to the pivoting kinematics, when the clamping device moves in the weft direction, an undesirable vertical movement of the respective weft yarn occurs, i.e., in the vertical direction relative to the plane in which the weft insertion line lies. This has a negative impact on the accuracy of the delivery of the respective weft yarn to the rapier head, as well as on the cutting position of the weft yarn after its insertion into the shed.

[0005] JP 2983531 A describes a weaving machine that allows a color choice between two weft yarns. For this purpose, either a first weft yarn from a first bobbin or a second weft yarn from a second bobbin, which is arranged next to the first bobbin in the warp direction, is inserted into the open shed, and then the inserted and cut first or second weft yarn is pushed to the selvage. This design requires that the weft yarn inserted further from the selvage, in particular, must be moved a relatively long distance to the selvage, which can lead to undesirable friction problems. The corresponding equipment complexity is also relatively high.

[0006] EP 3 425 094 B1 describes a device in which a pivoting coupling unit has several clamps arranged on a circular arc, each for a single weft thread. By pivoting the coupling unit, a selected clamp, including the weft thread, is brought close to the fabric edge. There, after the clamp is released, the weft thread is pulled by a rapier head through the open shed into the fabric.

[0007] It is an object of the present invention to provide a device for feeding at least first and second weft yarns, preferably ribbon-shaped weft yarns, to a weaving machine comprising at least one rapier head, which at least partially eliminates the above-mentioned disadvantages.

[0008] This object is achieved by a device and a method having the features of the independent claims.

[0009] The device according to the invention comprises a coupling unit which, when installed, can be moved linearly back and forth in the warp direction laterally on the weaving machine. This coupling unit connects at least a first and a second feed unit to one another, which are arranged next to one another in the warp direction and are designed such that they can feed at least a first and a second weft yarn to the rapier head. Furthermore, the device according to the invention comprises a positioning unit for positioning the coupling unit linearly in or against the warp direction in at least a first and a second position, wherein the first feed unit is designed to feed the first weft yarn to the rapier head in the first position of the coupling unit and the second feed unit is designed to feed the second weft yarn to the rapier head in the second position of the coupling unit.

[0010] The advantages of the invention can be seen in particular in the fact that the coupling unit, in interaction with the positioning unit, positions at least the first and second feed units linearly in or against the warp direction in order to - after suitable positioning - enable the first or second weft yarn to be passed to the rapier head. For example, in the first position of the coupling unit, the first feed unit transfers the first weft yarn to the rapier head, which then introduces the first weft yarn into the open shed of the weaving machine. After this first weft yarn has been fed into the shed, its free end, close to the device according to the invention, is cut off, the first feed unit is retracted and subsequently the coupling unit is moved in the warp direction into the second position such that the second feed unit is transferred into a position in which it can transfer the second weft yarn to the rapier head.

[0011] In this way, at least two weft yarns, for example of different material types, can be quickly and easily inserted into a fabric.

[0012] The solution according to the invention has several advantages over the solution described in WO 2011 / 015173 A1. Firstly, the weft yarn to be inserted can be fed linearly to the rapier head. During this feed movement - unlike the pivoting kinematics according to WO 2011 / 015173 A1 - there is no movement of this weft yarn in the vertical direction, i.e. the weft yarn is always in the same vertical position. This feature also achieves a high degree of flexibility with regard to feed movements or the possibilities for reaching the weft yarn to be transferred to the rapier head. The device according to the invention also requires little space.

[0013] Since the invention makes it possible to move the weft yarn, which is presented to the rapier head for weft insertion and then drawn through the shed, only in a horizontal and linear direction, i.e., without a vertical movement component, the control unit can be freely programmed with respect to the presentation movement of the respective weft yarn. This allows for greater precision in presentation and a more precise cutting of the respective weft yarn after its insertion into the shed. A simultaneous vertical offset, as in WO 2011 / 015173 A1, does not need to be considered.

[0014] The advantages of a linear feed with weft yarn selection (color selection) using lateral feed units, i.e., movable in and against the warp direction, are that both feed units can be constructed identically and thus exhibit the same behavior during the feed movement. For the same reason, the two feed units are easily adjustable and positionable, as they are positioned at the same height.

[0015] It is preferred that the coupling unit can be positioned such that during each weft insertion the position of the first feed unit in the first position of the coupling unit and the position of the second feed unit in the second position of the coupling unit coincide in the warp direction. In this case the first and second feed units assume the previous position of the other feed unit at different times, for example one after the other, in order to supply the corresponding weft yarn to the rapier head, which can be moved through the open shed, in this position. Despite the linear adjustment of the coupling unit in or against the warp direction for the purpose of color selection, the weft yarn to be inserted is therefore always located in the ideal insertion axis, while the other weft yarn is slightly deflected laterally in or against the warp direction.

[0016] It should be noted that the rapier head can be moved through the shed from one selvedge to the other or the respective weft yarn can be transferred, for example, halfway to a second rapier head, which then pulls the weft yarn the second distance through the shed.

[0017] According to an advantageous embodiment, the at least two feed units each comprise carriages that can be moved in the weft direction. The carriages are preferably linearly movable in and against the weft direction, while both can be moved back and forth in the warp direction by means of the coupling unit, also linearly according to the invention.

[0018] It is advantageous if at least one, and preferably exactly one, drive, and in this case preferably a servo motor, is coupled to the at least two carriages in such a way that the drive can only move one of the at least two carriages in and against the weft direction. Accordingly, the drive moves both carriages, but not at the same time, but only one of the two at a time. So while one carriage is moved in the weft direction, for example, to transfer the corresponding weft yarn to the rapier head, the other carriage remains in place. This means that only a small amount of mass (namely the respective feed unit) is moved, unnecessary mechanical disturbances are avoided, and the space required on the side of the weaving machine is used optimally. If only the said one drive is used to advance and retract the two carriages (at staggered times), this represents a cost-effective and space-saving solution.

[0019] Each carriage preferably has a clamp that can be closed and opened by electrical or pneumatic control for clamping and releasing the respective weft yarn. It is preferred that each clamp has guide elements that are arranged upstream, as seen in the weft direction, and that guide the respective weft yarn on the top, bottom and sides, and that are also part of the respective carriage. In this way, the free end of the weft yarn to be transferred does not hang freely downwards immediately after the clamp, but advantageously only after the guide elements - as seen in the weft direction - and is guided by the carriage in a defined manner in the weft direction to the rapier head, where it is then taken over. The at least one drive can preferably be controlled in such a way that the respective carriage and preferably its respective guide elements can be guided to different degrees of proximity to or even into the rapier head.This adapted reaching movement can be achieved preferably through flexible programming of the drive. Mechanical adjustments for different weft yarns—especially for materials with low flexural rigidity—are advantageously not necessary.

[0020] Specifically, this embodiment relates to a device for feeding at least one first weft yarn to a weaving machine comprising at least one rapier head, comprising at least one first feed unit with which the at least one weft yarn can be fed to the rapier head in the weft direction, wherein the first feed unit has a first clamp with which at least a portion of the at least one first weft yarn can be force-fittedly guided during the feeding of this weft yarn to the rapier head. This device is characterized in that the portion of the at least first weft yarn guided by the first clamp can be conveyed linearly in and against the weft direction with respect to the rapier head by means of the first feed unit, wherein this linear movement of said portion of the at least first weft yarn takes place along the weft insertion line.

[0021] With such a design, for example, relatively slack weft yarn can be inserted further into the open rapier head, ensuring a secure transfer of the weft yarn. In other words, the sufficiency of the weft yarn to be inserted is flexible. With appropriate control of the feed unit, various parameters can be taken into account in the control unit's programming.

[0022] In this exemplary embodiment, as in the embodiment with the at least two feed units described above, the at least first feed unit comprises a first carriage that can be moved in and against the weft direction by means of a drive, preferably a servomotor. Advantageously, said clamp can also be closed and opened by electrical or pneumatic control, wherein guide elements are advantageously provided upstream of the clamp, as seen in the weft direction, that guide the first weft yarn on the top and bottom sides as well as laterally. The clamp and the guide elements of the first carriage can be guided by the drive to varying degrees of proximity to or into the gripper head.

[0023] By means of the aforementioned aspect of the invention, it is particularly possible to insert not only the weft yarn itself into the rapier head, but also—which is particularly advantageous with relatively pliable weft yarns—the front part of the feed unit. In this way, the pliable weft yarn, which projects beyond the feed unit in the weft direction and is reliably guided by it, reaches behind the clamping area of the rapier head and is not held up in front of the clamping area, for example by parts of the rapier head facing the feed unit. During this so-called overfeeding, the feed unit therefore briefly moves between the clamping area and then back against the weft direction, whereby the weft yarn to be clamped projects so far beyond the feed unit that it remains in the clamping area despite the feed unit moving back and is clamped when the rapier head is subsequently closed.

[0024] In the described embodiment, in addition to the first feed unit with the first carriage, a second feed unit with a second carriage is provided, wherein both feed units can be controlled as described above in order to enable in particular the described overfeeding, i.e. the immersion of the front part of the feed unit or its carriage into the clamping area.

[0025] Returning to the construction according to the invention with coupling unit, at least two feed units and positioning unit, in an alternative embodiment to the above carriages, the at least two feed units can each comprise a belt conveyor unit. Each belt conveyor unit comprises two circulating belt conveyors that can be positioned relative to one another, between which the respective weft yarn can be conveyed with frictional engagement at least in the weft direction. If the belt conveyors of the respective feed unit come into frictional engagement with the respective weft yarn, the clamped weft yarn is conveyed in the weft direction by driving the belt conveyors in opposite directions in order to present its free end to the rapier head. In this embodiment, the belt conveyors preferably remain in their position with respect to the weft direction, i.e. always at the same distance from the longitudinal edge of the fabric.However, as in the above embodiment of the carriages, according to the invention the belt conveyors are moved back and forth in the warp direction by their coupling with the coupling unit in order to position the at least first or second weft yarn for transfer to the rapier head.

[0026] The positioning unit preferably comprises a drive for positioning the coupling unit, preferably a motor (e.g., a servo motor) or a pneumatic cylinder, wherein this drive can move to positions corresponding to the first and second positions of the coupling unit. If the drive is configured, for example, as a pneumatic cylinder, its two end positions can correspond to the first and second positions of the coupling unit. This results in an extremely simple and easy-to-control design.

[0027] The coupling unit, which is movable in the warp direction, is particularly preferably coupled to a fixed, i.e., stationary, guide part. This advantageously has first guide structures, while the coupling unit has guide elements corresponding to these first guide structures. The first guide structures and the guide elements interact in such a way that the coupling unit can be positioned exclusively in and against the warp direction.

[0028] The first guide structures are preferably also designed such that they not only enable the coupling unit to be positioned linearly in or against the warp direction, but also simultaneously prevent one of the at least two feed units from moving in the weft direction, and that second guide structures are further provided on the guide part, which enable the other feed unit, which is not prevented from moving, to be moved in and against the weft direction. The first and second guide structures are preferably designed to run orthogonally to one another and to intersect, corresponding to the warp and weft directions running orthogonally to one another. As long as the coupling unit is moved linearly in or against the warp direction by means of the first guide structures, movement of the first or second feed unit in the weft direction is not possible.Only after positioning the coupling unit in the first or second position can the respective feed unit be moved.

[0029] According to an advantageous embodiment, the first and second guide structures are formed by grooves and / or elevations in the guide part. This allows the coupling unit to move back and forth only in the warp direction, while preventing movements in other directions, particularly those orthogonal thereto. On the other hand, after appropriate positioning of the coupling unit, it allows the corresponding feed unit to move only in the weft direction.

[0030] For feeding a first weft yarn to the lateral edge of the weaving machine, a first weft yarn storage unit is preferably provided, which is positioned further away and comprises a first bobbin that stores the first weft yarn. From here, the first weft yarn can be guided to the first feed unit. Likewise, for feeding a second weft yarn to the lateral edge of the weaving machine, a second weft yarn storage unit is preferably provided, which is positioned further away and comprises a second bobbin that stores the second weft yarn. From here, the second weft yarn can be guided to the second feed unit.

[0031] Preferably, a first guide element is arranged between the first weft yarn storage unit and the first feed unit, immediately upstream of the first feed unit. Furthermore, a second guide element is preferably arranged between the second weft yarn storage unit and the second feed unit, immediately upstream of the second feed unit. The first and second guide elements run alongside one another at least immediately upstream of the respectively associated first and second feed units. Preferably, said first and second guide elements are coupled to the first and second feed units, respectively, and are displaced back and forth therewith due to the movement of the coupling unit in the warp direction. Alternatively, the first and second guide elements are arranged stationary.

[0032] According to an advantageous embodiment, the first weft yarn storage is arranged above the second weft yarn storage, with the bobbin axis of the first weft yarn storage being located above the bobbin axis of the second weft yarn storage. This arrangement saves space. In this preferred embodiment, the two weft yarns emerge from their respective weft yarn storages running one above the other, while lying side by side for the purpose of reaching the rapier head.

[0033] Preferably, the first and second weft yarn storage devices are aligned in the weft direction, with the axes of the first and second bobbins then aligned in the warp direction. According to an alternative, the first and second weft yarn storage devices are aligned in the warp direction, with the axes of the first and second bobbins then aligned in the weft direction, and deflection means are provided for deflecting the first and second weft yarns in the weft direction. Specific space requirements on the weaving machine and in the weaving mill can be taken into account here.

[0034] The invention also relates to a weaving machine with at least one rapier head movable in and against the weft direction through the open shed and with a device as described above.

[0035] Furthermore, the invention also relates to a method for feeding at least first and second weft yarns during fabric production by means of a weaving machine having at least one rapier head, preferably using a device according to one of the preceding claims, wherein at least a first and a second weft yarn are placed next to one another in a plane in the warp direction on an edge of the fabric and are fed one after the other (not necessarily alternately) in the weft direction to the rapier head of the weaving machine, wherein the at least first and second weft yarns are positioned linearly in or against the warp direction for their respective weft insertion such that they are each pulled along the weft insertion line by the at least one rapier head through the open shed, wherein the weft yarn not currently to be inserted is drawn linearly in or against the warp direction from this weft insertion line to release the weft insertion line.is deflected against the warp direction.

[0036] The device and method according to the invention can particularly preferably be used for ribbon-shaped weft yarns or ribbon-shaped weft materials, for example those containing carbon, glass, and / or basalt fibers or filaments. Ribbon-shaped weft yarns or ribbon-shaped weft materials of various widths can be processed.

[0037] The invention is explained in more detail with reference to the figures. They show: Figure 1a-1f shows a schematic plan view of a device according to the invention (without weft yarns) with carriage-comprising feed units in different positions; Figures 2a-2c show a plan view of the schematically illustrated device of the Fig. 1a-1f with inserted weft yarns and weft yarn storage; Figure 2 shows a side view of the schematically illustrated device according to the Fig. 2a-2c; Figures 3a-3d show a bottom view of a schematically illustrated device according to the invention to illustrate the kinematics; Figure 4 shows a perspective top view of the front part of a carriage; Figures 5a-5f show a schematic side view of various approach positions of a carriage relative to a gripper head, and Figures 6a-6e show a schematic side view of a further embodiment of a feed unit.

[0038] In the top view of the Figures 1a-1f A device 1 according to the invention is shown very schematically, which is used for feeding first and second weft yarns S1, S2 (these are not shown in the diagram for the sake of clarity). Figure 1 shown, see Figures 2a-2d ) to a rapier head 82 of a weaving machine 80, which is only shown very schematically in the detail. For this purpose, the device 1 is arranged laterally of the weaving machine 80 and presents the first and second weft yarns S1, S2 to be inserted to the rapier head 82.

[0039] The device 1 comprises a coupling unit 10 on which a first feed unit 30 and a second feed unit 50 are provided, wherein the first feed unit 30 delivers the first weft yarn S1 and the second feed unit delivers the second weft yarn S2 to the rapier head 82. Using a rapier bar 84, the rapier head 82 draws the weft yarn, which is delivered to it and subsequently clamped, along the weft insertion line E through the open shed.

[0040] The two feed units 30, 50 are coupled to one another via the coupling unit 10. The coupling unit 10 can be moved along the fabric edge in and against the warp direction KR into two defined positions by means of a drive 15, which in this case is designed as a pneumatic cylinder 16 with a pushing or pulling cylinder rod 17. This movement of the coupling unit 10 also positions the two feed units 30, 50 in the warp direction KR.

[0041] Both the first feed unit 30 and the second feed unit 50 comprise carriages 31 and 51, respectively, which can be moved in and against the weft direction SR. The first and second carriages 31, 51 are driven by a jointly used drive 42, which is designed as a servomotor and which, like the pneumatic cylinder 15, is controlled by a control unit 5. Figure 1 the corresponding control lines are shown dotted.

[0042] In the Figure 1a the coupling unit 10 is in a first position. In this first position of the coupling unit 10, the first feed unit 30 in turn assumes a position in which the first weft yarn S1 lies in the weft insertion line E. According to the Figure 1bThe coupling unit 10 is still in the aforementioned first position, but the first feed unit 30 has advanced in the weft direction SR to the rapier head 82. In this position, the weft yarn S1 is delivered or transferred to the rapier head 82, whereupon the rapier head 82 moves through the open shed. After the first weft yarn has been delivered, the first feed unit 30 is returned to its starting position by means of the drive 42 against the weft direction SR.

[0043] According to the Figure 1c The weft yarn S1 can now be cut in the cutting plane SE by means of a cutting device 79 which is only shown schematically.

[0044] According to the Figure 1d the coupling unit 10 is then moved by means of the pneumatic cylinder 16 into its second position, in which the second weft yarn S2 presented in the second feed unit 50 is aligned with the weft insertion line E. Accordingly, according to the Figure 1eThe second feed unit is moved in the weft direction SR, again using the drive 42, to the rapier head 82, where the transfer of the weft yarn S2 takes place. Figure 1f the second feed unit 50 returns to its initial position and the second weft yarn S2 is cut by means of the cutting device 79. Subsequently, the coupling unit 10 can be returned to the position according to the Figure 1a be processed.

[0045] In the Figures 2a-2c the device 1 is according to the Figure 1 omitting some features and showing others, again shown in a schematic plan view. In the side view of the Figure 2dIt can be seen that the first weft yarn S1 is wound onto a spool 72 in an upper weft yarn storage 70. From there, the first weft yarn S1 is guided via a deflection roller 71 to the first feed unit 30. Below the first, upper weft yarn storage 70, a second, lower weft yarn storage 75 is arranged, which stores a second spool 77 with the weft yarn S2 wound thereon. From there, the second weft yarn S2 is guided via a deflection roller 76 to the second feed unit 50. The two weft yarn storages 70, 75 are aligned with each other in plan view (see Figures 2a-2c ). The two weft yarns S1, S2 initially run essentially very close together, but then diverge slightly in the direction of the feed units 30, 50, as shown below with reference to the Figures 2a-2c is explained.

[0046] According to the top view of the Figure 2athe first feed unit 30 with the carriage 31 is located - by appropriate positioning of the coupling unit 10 (not shown) - in a position in which its weft yarn S1 can be inserted along the weft insertion line E by means of the rapier head 82. The second feed unit 50 is deflected slightly against the warp direction KR. To illustrate this, the central axis D2 of the second weft yarn S2 is extended as far as the weft yarn stores 70, 75. This clearly shows that there is a slight angle between the weft insertion line E and the central axis D2 of the second weft yarn S2. This is not critical, however, since the second weft yarn S2 is not being inserted into the shed at this moment.

[0047] In the Figure 2b It is shown again how the first feed unit 30 brings the weft yarn S1 to the rapier head 82. According to the Figure 2cthe coupling unit 10 (not shown) has been moved into the second position in which the second weft yarn S2 is aligned with the weft insertion line E. In this case, the first feed unit 30 is positioned outside the weft insertion line E, with the central axis D1 of the weft yarn S1 forming a small angle therewith.

[0048] The Figures 3a-3d show a special embodiment of the Figures 1 and 2 only schematically shown device 1. In contrast to the Figures 1 and 2 represent the Figures 3a-3d a bottom view of a device 1. The pneumatic cylinder 16 with its cylinder rod 17 can be seen. The cylinder rod 17 is connected to the coupling unit 10 so that the pneumatic cylinder 16 can move the coupling unit 10 back and forth in the warp direction KR.

[0049] In the present case, the coupling unit 10 is essentially U-shaped in the bottom view, with elevations 11 pointing downwards (i.e., here towards the viewer) provided on both of its leg ends. These elevations 11 engage with a first guide structure 21 designed as a guide groove, which is provided in a guide part 20. The guide part 20 is fixed, i.e., stationary, just like the pneumatic cylinder 16. The guide part 20 is configured in the present case as a flat cuboid, which essentially serves to guide the coupling unit 10 and the two feed units 30, 50. The said first guide structure 21 in the guide part 20 runs in the warp direction KR, so that the coupling element 10 with its elevations 11 is positively guided by the first guide structure 21 in and against the warp direction KR when it is set in motion by the pneumatic cylinder 16.

[0050] The two carriages 31, 51 of the first and second feed units 30 and 50 are arranged on the coupling element 10. Both carriages 31, 51 can be moved in and against the weft direction SR. For this purpose, a drive mechanism is provided, which in the present case consists of a drive 42 designed as a servomotor with a planetary gear, a pivoting lever 43, and a sliding block 45 arranged stationary on the pivoting lever but rotatable by means of a pivot joint 44. Each of the two carriages 31, 51 has a recess 46 for the sliding block 45 on its underside (i.e., facing the viewer). The two recesses 46 are aligned with one another when the two carriages 31, 51 are at the same height in the weft direction SR ( Figure 3a, Figure 3c ).

[0051] Furthermore, a guide element 41 in the form of a raised portion is provided on the underside of the first carriage 31, and a guide element 56, also in the form of a raised portion, is provided on the underside of the second carriage 51. These raised portions 41, 56 can slide in a positively guided manner in and against the firing direction SR in a second guide structure 22, which is configured as a guide groove in the guide part 20, when the coupling unit 10 is suitably positioned, namely in its first and second positions, respectively.

[0052] In the Figure 3aThe coupling unit 10 is shown in its first position, in which the first carriage 31 is positioned such that it can be moved in the firing direction SR due to its elevation 41. The elevation 56 of the second carriage 51, however, abuts the edge of the second guide structure 22, so that a movement of the second carriage 51 in the firing direction SR is prevented. In order for the second carriage 51 to slide in the firing direction SR, the coupling unit 10 must be brought into its second position by the pneumatic cylinder 16 (see the discussion below on Fig. 3c and 3d ).

[0053] In the Figure 3b It is shown how - driven by the drive 42 and the pivoting mechanism including the sliding block 45 - the first carriage 31 was advanced in the firing direction SR, ie in the direction of the gripper head 82 (not shown), and was thereby positively guided by the elevation 41 running in the second guide structure 22.

[0054] In the Figure 3c the first and second carriages 31, 51 are again at the same height. However, the pneumatic cylinder 16 has now moved the coupling unit 10 in the warp direction KR into its second position. The sliding block 45 has slipped into the recess 46 of the second carriage 51. Subsequently, as shown in the Figure 3d As shown, the second carriage 51 is moved by the drive 42 in the weft direction SR in order to deliver the second weft yarn S2 to the gripper head 82 or to transfer it to it.

[0055] In the Figure 4the carriage 31 of the feed unit 30 is shown in more detail (the carriage 51 of the feed unit 50 is preferably of identical construction). In cross-section, the carriage 31 has a U-shaped, closed plate 40. The two upwardly projecting side legs of this plate 40 serve as laterally guiding guide elements 39 for the weft yarn (not shown), while the base of the plate 40 serves as the lower guide element 36. In the central region of the plate 40, a clamp 32 is provided, which presses the weft yarn downwards with the aid of a pneumatically loaded pressure rod 33 (only partially shown here). Upstream of the clamp 32 in the weft direction SR is an upper guide element 35 coupled to the clamp 32, which has an open cross-section and presses the weft yarn downwards against the lower guide element 36 of the plate 40.Thus, the weft yarn is safely guided to the rapier head 82 both laterally by the guide elements 39 and on its upper and lower sides by the guide elements 35, 36.

[0056] To the rear, ie opposite to the weft direction SR, the clamp 32 is also followed by an upper guide surface 34, which is aligned with the U-shaped plate, for the weft yarn, which passes between the plate 40 and the upper guide surface 34.

[0057] Further back, in this embodiment, in the direction of the weft yarn storage unit 70, there is a first guide element 28, also U-shaped, which is optional. This serves to guide the weft yarn S1 in an orderly manner to the first feed unit 30. The first guide element 28, together with the first feed unit 30, is displaced linearly in or against the warp direction KR (by means of the coupling unit 10). Furthermore, it is advantageous, but not mandatory, if it is also displaced back and forth in the weft direction SR by means of the drive 42.

[0058] In summary, in the described embodiments, the weft yarn S1 or S2 to be inserted is selected from the two adjacent weft yarns S1, S2 by means of a lateral displacement of the coupling unit 10 in and against the warp direction KR. The linear displacement of the coupling unit 10 in or against the warp direction KR is triggered pneumatically in the present case, while a drive 42 designed as a servomotor takes over the delivery of the selected weft yarn S1 or S2 to the rapier head 82 in the weft direction SR. By selecting the aforementioned drive, the device according to the invention can be implemented cost-effectively, since only one servo drive can be used for the feed movement and one pneumatic drive for the color selection. In WO 2011 / 015173 A1, however, two servo drives are necessary for the pivoting kinematics.The color selection by switching between the two weft yarns S1, S2 can be done by the relatively inexpensive pneumatic cylinder 16.

[0059] In the Figures 5a-5f a transfer or delivery of a first weft yarn S1 (the second weft yarn S2 could equally well be selected) to a rapier head 82 is shown in chronological order. Figures 5a-5fdemonstrate the exemplary embodiment of a device for feeding at least one first weft yarn S1 to a weaving machine comprising at least one rapier head 82, wherein a coupling unit 10, at least two feed units 30, 50 and a positioning unit 15 are provided. Shown is the first feed unit 30, with which the at least one weft yarn S1 can be fed to the rapier head 82 in the weft direction SR, wherein the first feed unit 30 has a first clamp 32 with which at least a portion of the at least one first weft yarn S1 can be guided in a force-fitting manner during the feeding of this weft yarn S1 to the rapier head 82.This device is characterized in that the section of the at least first weft yarn S1 guided by the first clamp 32 can be conveyed linearly in and against the weft direction SR with respect to the rapier head 82 by means of the first feed unit 30, this linear movement of said section of the at least first weft yarn S1 taking place along the weft insertion line E.

[0060] According to the Figure 5a The weft yarn S1 is clamped by the schematically illustrated clamp 32 and guided in the direction of the rapier head 82 on the upper and lower sides by guide elements 35, 36. The weft yarn S1 is relatively flexible and should be securely clamped by the rapier head 82. For this purpose, an overtravel strategy is selected. According to the Figure 5bThe gripper head 82 opens, which has an upper gripping part 85 with an upper clamping part 86 and a lower gripping part 87 with a lower clamping part 88. The carriage 31, together with the weft yarn S1, is now moved between the two clamping parts 86, 88 by moving the first feed unit 30 in the weft direction SR. This ensures that the weft yarn S1 actually reaches the gripper head 82, i.e. the free end of the weft yarn S1 does not, for example, strike the front side of the lower clamping part 88 when the carriage 31 is moved in the weft direction SR and can then no longer be conveyed into the gripper head 82.

[0061] According to the Figures 5c and 5dThe feed unit 30 is then moved out of the gripper head 82, whereby the free end of the weft yarn S1 remains between the upper and lower clamping parts 86, 88. This ensures that the pliable weft yarn S1 is actually moved behind the two clamping parts 86, 88. Now, as in Figure 5e As shown, the gripper head 82 is closed, whereby the upper and lower clamping parts 86, 88 clamp the free end of the weft yarn S1. Now opens according to Figure 5f the clamp 32, which also lifts the upper guide part 35.

[0062] The rapier head 82 can then be moved in the weft direction SR through the open shed, taking the weft yarn S1 with it.

[0063] If the weft yarn S1 has a relatively high bending stiffness, the step in Fig. 5b, ie the insertion of the carriage 31 between the two clamping parts 86, 88 is omitted. In this case, a safe transfer of the weft yarn S1 can be safely realized due to its higher flexural rigidity even without overrunning the carriage 31, ie inserting the carriage 31 in the weft direction beyond the clamping area between the two clamping parts 86, 88.

[0064] In the Figures 6a-6e An alternative embodiment for the feed units 30, 50 is shown. Instead of a carriage, the feed units 30, 50 in this embodiment each comprise a belt conveyor unit 60, each of which comprises two circulating belt conveyors 62 that can be positioned relative to one another, between which the respective weft yarn S1 or S2 can be conveyed in a force-locking manner in the weft direction SR. In the present case, each belt conveyor 62 comprises three rollers, at least one of which is actively driven.

[0065] In the Figure 6ais shown, the two belt conveyors 62 clamp, for example, a weft yarn S1 between them. When the gripper head 82 is open, the Figure 6b the weft yarn S1 is advanced between the two clamping parts 86, 88, whereupon the gripper head 82 closes and the weft yarn S1 is clamped ( Figure 6c ). Now the two belt conveyors 62 are moved away from each other so that the rapier head 82 can pull the weft yarn S1 through the shed. The following follows according to Figure 6d the cut of the inserted weft yarn S1 with the belt conveyors 62 previously moved back into the clamping position. Subsequently, the free weft yarn end can be moved back by the belt conveyors 62 against the weft direction SR to its starting position (see Figure 6a ) can be driven.

[0066] In brief summary, according to the invention, the weft yarns S1, S2 to be fed to the rapier head 82 lie next to one another in front of the fabric edge in the warp direction KR. They preferably come from weft yarn stores 70, 75 arranged one above the other. The selection of the weft yarn S1, S2 to be inserted in each case takes place by lateral movement of the coupling unit 10 together with the feed units 30, 50, which are designed here as a carriage (reaching carriage) or as a belt conveyor unit 60. The coupling unit 10 is moved linearly laterally in or against the warp direction KR such that, during the weft insertion, the weft yarn S1 or S2 to be inserted is preferably inserted without deflection, while the weft yarn S2 or S1 not to be inserted in each case is deflected laterally in or against the warp direction KR by a small amount on its way from the weft yarn store 75 or 70 to the feed unit 50 or 30. This has no negative effect on this weft yarn S2 orS1, since it is not moved in the firing direction SR during this phase.

[0067] The device and the method according to the invention can easily be extended to more than two weft yarns.

[0068] In addition to the advantages outlined at the beginning, the process presented here makes it possible to precisely produce a wide variety of weaving patterns. For example, weft yarns of different widths and / or materials and / or with different pre-treatment can be used to achieve a corresponding structure and / or pattern. Two (or more) identical weft yarns can of course also be used. A further advantage of using identical weft yarns is that the machine does not have to be stopped if the supply of one weft yarn is first inserted into the fabric and then switched to the other weft yarn without a break. While this weft yarn is being inserted, the previously used weft yarn can be replaced in the corresponding weft yarn storage. In general, longer running times can be achieved with the same weft materials and changing weft yarn storages. List of reference symbols

[0069] 1 Device 5 Control unit 10 Coupling unit 11 Elevations 15 Positioning unit 16 Pneumatic cylinder 17 Cylinder rod 20 Guide part 21 First guide structure 22 Second guide structure 28 First and second guide element 30 First feed unit 31 First carriage 32 Clamp 33 Pressure rod 34 Guide surface 35 Upper guide elements 36 Lower guide elements 39 Lateral guide elements 40 Sheet 41 Guide element 42 Drive (servo motor) 43 Pivot lever 44 Joint 45 Sliding block 46 Recess 50 Second feed unit 51 Second carriage 56 Guide element 60 Belt conveyor unit 62 Belt conveyor 70 First weft yarn storage 71 Deflection roller 72 First spool 75 Second weft yarn storage 76 Deflection roller 77Second bobbin 79Cutting device 80Loom 82Gripper head 84Gripper bar 85Upper gripping part 86Upper clamping part 87Lower gripping part 88Lower clamping part S1First weft yarn S2Second weft yarn GFabric SRWeft direction KRWarp direction SECutting plane EWat insertion line

Claims

1. Device (1) for feeding at least first and second weft yarns (S1, S2) to a weaving machine (80) comprising at least one gripper head (82), wherein the weft yarns (S1, S2) can be fed to the gripper head (82) in the weft direction (SR), wherein the device (1) comprises: - a coupling unit (10) which, in the installed state of the device (1), can be moved back and forth laterally on the weaving machine (80) in the warp direction (KR), and - at least one first and one second feeding unit (30, 50), wherein the first and the second feeding unit (30, 50) are arranged next to one another in the warp direction (KR) on the coupling unit (10) and are configured to feed a first and a second weft yarn (S1, S2), respectively, to the gripper head (82), and a positioning unit (15) for linearly positioning the coupling unit (10) in and counter to the warp direction (KR) in at least one first and one second position, wherein the first feeding unit (30) is configured to feed the first weft yarn (S1) to the gripper head (82) in the first position of the coupling unit (10) and the second feeding unit (50) is configured to feed the second weft yarn (S2) to the gripper head (82) in the second position of the coupling unit (10).

2. Device (1) according to claim 1, characterized in that the coupling unit (10) is positionable in such a way that, during the respective weft insertion, the position of the first feeding unit (30) in the first position of the coupling unit (10) and the position of the second feeding unit (50) in the second position of the coupling unit (10) coincide in the warp direction (KR).

3. Device (1) according to claim 1 or 2, characterized in that the at least two feeding units (30, 50) comprise slides (31, 51) which can be moved in the weft direction (SR).

4. Device (1) according to claim 3, characterized in that at least one or exactly one drive (42), preferably a servomotor, is coupled to the at least two carriages (31, 51) in such a way that the drive (42) is able to move the at least two carriages (31, 51) in and counter to the weft direction (SR), but not at the same time.

5. Device (1) according to claim 3 or 4, characterized in that each carriage (31, 51) has a clamp (32), which is to be closed and opened by electrical or pneumatic control, for clamping and releasing the respective weft yarn (S1, S2), wherein, for each clamp (32), guide elements (35, 36, 39) are provided which are arranged upstream as seen in the weft direction (SR) and guide the respective weft yarn (S1, S2) on the upper and lower side and laterally.

6. Device (1) according to claim 4 and 5, characterized in that the at least one drive (42) can be controlled in such a way that the respective carriages (31, 51) can be guided differently close to or into the gripper head (82).

7. Device (1) according to claim 1 or 2, characterized in that the at least two feeding units (30, 50) each comprise a belt conveyor unit (60), wherein each belt conveyor unit (60) comprises two circulating belt conveyors (62) which can be positioned relative to one another and between which the respective weft yarn (S1, S2) can be conveyed in a force-fitting manner at least in the weft direction (SR).

8. Device (1) according to at least one of the preceding claims, characterized in that the positioning unit (15) comprises a drive, preferably a motor or a pneumatic cylinder (16), wherein the drive can approach positions which correspond to the first and the second position of the coupling unit (10).

9. Device (1) according to at least one of the preceding claims, characterized in that the coupling unit (10) is coupled to a stationary guide part (20), wherein the guide part (20) has first guiding structures (21) and the coupling unit (10) has guiding elements (41, 56) which correspond to these first guiding structures (21), wherein the coupling unit (10) can be positioned exclusively in and counter to the warp direction (KR) in the interaction of the first guiding structures (21) with the guiding elements (41, 56).

10. Device (1) according to claim 9, characterized in that the first guiding structures (21) are configured in such a way that they enable the positioning of the coupling unit (10) in and counter to the warp direction (KR) and at the same time prevent the movement of in each case one of the at least two feeding units (30, 50) in the weft direction (SR), and in that, furthermore, second guiding structures (22) are provided on the guide part (20) and enable the respective other feeding unit (50, 30), which is not prevented from moving, to be moved in or counter to the weft direction (SR).

11. Device (1) according to claim 10, characterized in that the first and the second guiding structures (21, 22) are formed by grooves and / or elevations in the guide part (20).

12. Device (1) according to at least one of the preceding claims, characterized in that a first weft yarn storage (70) with a first bobbin (72) is provided for the storage of the first weft yarn (S1), wherein the first weft yarn (S1) is guided from the first weft yarn storage (70) to the first feeding unit (30), and in that a second weft yarn storage (75) with a second bobbin (77) is provided for the storage of the second weft yarn (S2), wherein the second weft yarn (S2) is guided from the second weft yarn storage (75) to the second feeding unit (50).

13. Device (1) according to claim 12, characterized in that the first weft yarn storage (70) is arranged above the second weft yarn storage (75), so that the first weft yarn (S1) in the first weft yarn storage (70) and the second weft yarn (S2) in the second weft yarn storage (75) leave the respective weft yarn storage (70, 75) running one above the other.

14. Device (1) according to claim 12 or 13, characterized in that - the first and the second weft yarn storage (70, 75) are aligned in the weft direction (SR), wherein the axes of the first and the second bobbin are aligned in the warp direction (KR), or - the first and the second weft yarn storage are aligned in the warp direction (KR), wherein the axes of the first and the second bobbin are aligned in the weft direction (SR) and deflecting means are provided for the deflection of the first and second weft yarn (S1, S2) in the weft direction (SR).

15. Weaving machine (80) with at least one gripper head (82) which can be moved through the open shed in and counter to the weft direction (SR) and with a device (1) according to one of the preceding claims.

16. Method for feeding at least first and second weft yarns (S1, S2) during the production of woven fabric by means of a weaving machine (80) having at least one gripper head (82), preferably using a device (1) according to one of claims 1 to 14, wherein at least one first and one second weft yarn (S1, S2) are placed next to one another on an edge of the woven fabric (G) in a plane in the warp direction (KR) and are fed to the gripper head (82) of the weaving machine (80) in succession in time in the weft direction (SR), wherein the at least first and second weft yarn (S1, S2) are positioned linearly in or counter to the warp direction (KR) for their respective weft insertion in such a way that they are in each case pulled through the open shed along the weft insertion line (E) by the at least one gripper head (82), wherein the weft yarn (S2, S1) currently not to be inserted is deflected linearly in or counter to the warp direction (KR) from this weft insertion line (E) in order to release the weft insertion line (E).