WEFT FEED DEVICE WITH CLAMPING DISC

Description

[0001] The invention relates to a weft thread feeder for providing several weft threads in a weaving machine and for selectively feeding a weft thread to a gripper for a weft insertion, as well as a weaving machine with a weft thread feeder.

[0002] In weaving machines, especially rapier looms, the weft threads are inserted into the shed from one side of the machine using a gripper. Typically, several weft threads are held in place, which are inserted alternately according to the respective weaving pattern.

[0003] From WO 2020 / 052 822 A1, a weaving machine with a weft thread color selection device is known, by means of which several weft threads can be fed to a gripper in a selected sequence. For this purpose, the weft thread color selection device has a thread guide which has thread guide lugs on its outer circumference. The required weft thread is fed to the gripper by a feeding needle.

[0004] The weft threads are held in place, for example, by a tack strip. However, tack strips have the disadvantage that they must be removed from the finished textile and therefore represent a waste product. This increases the amount of material required for the fabric's production.

[0005] Furthermore, a weft thread handling device for a rapier loom is known from EP 3 425 094 A1. Each of the supplied weft threads is guided through a closed eyelet of a selection arm, by means of which it is fed to the rapier. A clamping rapier is mounted on a carrier for each weft thread, the carrier being pivotable about a rotational axis. The weft threads converge from the respective selection arms towards a convergence point before diverging again in a fan shape towards the corresponding clamps on the carrier. The rotational axis of the carrier passes through the convergence point of the weft threads.

[0006] CN 101 314 881 B describes a weft color selection device in which weft threads of different colors or types are guided through eyelets arranged side by side in a color selection disc. The color selection disc with its individual eyelets allows the weft thread to be positioned by moving it so that a feeder needle can transfer the weft thread to a gripper. Since the gripper runs below the color selection device, the feeder needle must push or guide the respective weft thread downwards towards the gripper immediately after it exits the color selection disc, so that the gripper can take over the thread. This inevitably involves a sharp deflection of the weft thread, potentially damaging it.

[0007] In contrast, the task is to provide a weft thread feeder that reduces the deflection of the weft threads during feeding and also the thread waste.

[0008] The problem is solved by a weft thread feeder according to the invention and a weaving machine with such a weft thread feeder according to the main claims. Preferred embodiments of the present invention are set forth in the respective dependent claims.

[0009] The weft thread feeder for providing multiple weft threads in a weaving machine and for selectively feeding an active weft thread to a gripper, according to the invention, comprises a rotatably driven color selector disc with several eyelets arranged on its outer circumference for receiving at least one weft thread each. Furthermore, the weft thread feeder according to the invention includes a rotatably driven clamping disc with several clamps arranged on its outer circumference for holding at least one weft thread each in their closed position. A feed needle is arranged between the color selector disc and the clamping disc, via which the at least one active weft thread to be fed can be transferred to the gripper in a transfer position from a feed position—into which the at least one active weft thread can be brought by rotating the color selector disc and an active clamp together with the clamping disc into a feed-rotation position.In addition, the active clamp can be moved into an open position to release the active weft thread, in which it is located after the weft thread has been transferred to the gripper.

[0010] Typically, only one weft thread is picked up from each eyelet. However, depending on the weave pattern, it may be possible to feed two or more weft threads from one eyelet to the looper using a passing needle and insert them during a weft insertion. This is only possible, however, if the position of the individual weft threads in the fabric does not need to be free of twisting during weft insertion. In such a case, each eyelet of the color selector can hold more than one weft thread. For the sake of simplicity, however, the invention will be described below with only one weft thread per eyelet, although the descriptions are also intended to apply to multiple weft threads, i.e., a set of weft threads, per eyelet. Double wefts can be inserted easily using this type of weft thread guide.

[0011] If, however, two weft threads are to be inserted without twisting in a double weft, they are preferably guided in separate eyelets. In such a case, the feed needle has a double receiving eyelet, i.e., a double depression for the separate receiving of two weft threads. Thus, a single weft thread from each of the two eyelets is presented to the gripper in one stroke with a single feed needle. A gripper for inserting two weft threads in a double weft without twisting is described, for example, in DE 10 2018 222 722 B3. The two active weft threads for the double weft are held in a single active clamp of the clamping disc and are clamped again in the same active clamp after the weft insertion. Thus, the clamping disc typically has only half as many clamps as the color selection disc has eyelets. Usually, two weft threads are taken from adjacent eyelets, i.e.,Two adjacent weft threads, grouped and held in a clamp. This means that the combination of weft threads inserted in a double weft is predetermined by the thread guide.

[0012] The color selector dial is designed as a multi-part color selector dial with several sub-discs, in particular with two sub-discs. The two sub-discs are typically rotatable independently of each other about a common axis of rotation. For this purpose, each sub-disc usually has its own drive. The sub-discs can be arranged axially one behind the other or be located in the same plane. For example, the sub-discs are arranged axially one behind the other, and the preferably two sub-discs have different pitch circle diameters on which the eyelets are arranged. Thus, for example, a rear, first sub-disc has a larger pitch circle diameter than a second, front sub-disc.To guide the weft threads held in the eyelets of the second sub-disc, the first sub-disc has a curved groove, for example, on the pitch circle diameter of the eyelets of the second disc, and a radial groove extending outwards from this groove to guide the active weft thread. If the two sub-discs are arranged in one plane, the eyelets of both sub-discs can pivot in a common pivot plane. If the sub-discs can pivot about a common pivot axis, the two sub-discs can have a crank so that the bearings of the two sub-discs are axially offset from each other, yet the eyelets are still located in a common pivot plane. A color selection disc with several sub-discs is described, for example, in the aforementioned publication WO 2020 / 052 822 A1.

[0013] The eyelets of the color selector dial are preferably designed as open eyelets. In this context, an open eyelet is understood to mean, in particular, that the weft thread can be removed radially outwards from the eyelet, i.e., the open eyelet is designed, in particular, as a radial notch on the outer circumference of the color selector dial. Preferably, only the at least one weft thread to be fed, which can also be referred to as the active weft thread, is removable from the corresponding eyelet in the forward rotation position. The remaining weft threads are fixed in the respective open eyelets. The open eyelet of the active weft thread, which is in the forward rotation position, is also referred to as the active eyelet. All eyelets except the active eyelet can be closed, for example, mechanically by a latch in the form of a cam disc.The eyelets are preferably arranged on the same, predefined pitch circle diameter around the pivot point of the color selector dial and are open radially outwards. The cam disc has a circumferential recess on the pitch circle diameter around the pivot point of the color selector dial. Only in the area of ​​the forward rotation position does the cam disc have a radially outward-facing recess that extends to the outer edge of the cam disc and releases the active weft thread. In an alternative embodiment, for example, each open eyelet has its own closure, which closes the respective eyelet in the normal state and only opens the active eyelet when rotating to the forward rotation position. Instead of being open eyelets, the eyelets can also be designed as closed eyelets. With a closed eyelet, the active weft thread is guided by and held in the eyelet even during feeding to the gripper and during weft insertion.

[0014] The clamping disc typically has a number of clamps corresponding to the total number of eyelets on the color selector disc or sub-discs, or, in the case of a twist-free double weft, to half the total number of eyelets. Each weft thread to be supplied thus runs from a thread storage unit or a pre-winding device, through an eyelet on the color selector disc, to a corresponding clamp on the clamping disc. Between the color selector disc and the clamping disc, the weft thread runs directly, without any deflection. The clamp in which the active weft thread to be supplied is located is also called the active clamp, analogous to the active eyelet in which the same active weft thread is located.To select the active weft thread from the multiple available weft threads, the color selector disc and the clamping disc are rotated into a position in which the active clamp and the active eyelet are in the forward-reaching position, thus placing the active thread in a forward-reaching position. The rotational position of the clamping disc and the color selector disc differs for the forward-reaching position of each clamp or eyelet, because the weft thread held by the respective clamp and eyelet must always be brought into the same forward-reaching position for pickup by the forward-reaching needle. The forward-reaching position is defined by a pickup position of the forward-reaching needle and is identical for each of the multiple available weft threads when using a forward-reaching needle with a single drop. With a double fork with two drops, there is one forward-reaching position each for the first and second active weft threads.

[0015] After rotating the color selection disc and the clamping disc into the rotational position in which the at least one active weft thread to be fed is in the feed position, the feed needle picks up the at least one active weft thread between the color selection disc and the clamping disc and moves the at least one active weft thread into its transfer position, from which the gripper picks up the active weft thread. For this purpose, a recess or a double recess is preferably formed on the front of the feed needle, which picks up the weft thread or weft threads and guides them securely. The feed needle can be moved translationally or rotationally in a circular path from a pick-up position of the feed needle to pick up the active weft thread in the feed position to a delivery position of the feed needle to move the at least one weft thread into the transfer position to the gripper.

[0016] After the active weft thread is transferred to the gripper, the active clamp is moved to an open position to release at least one active weft thread for weft insertion. The clamp can open during or after the transfer to the gripper.

[0017] The clamps are preferably actuated by an actuator. In particular, the clamps can be moved by the actuator from a closed position, in which the weft thread is securely clamped, to an open position. In a first embodiment, the actuator is fixedly arranged on the weft thread feed device. It is designed such that the active clamp, which is in the forward rotation position, can be actuated. The actuator can move the clamp from the closed position to the open position and / or from the open position to the closed position. The embodiment with a fixed actuator comprises at least one actuator. The clamps rotate relative to the fixed actuator when the clamping disc is turned. In the forward rotation position, the active clamp is at least opened so that the weft thread can be released and fed in.With a single actuator, the clamp's forward rotation position corresponds to its receptive rotation position, so that the active clamp is moved to the open position by the single actuator to release the active weft thread before insertion and to receptive it after insertion. The forward and receptive rotation positions are located near the binding point so that the active weft thread can be picked up by the clamp after insertion.

[0018] Preferably, the weft thread feeder has a second, stationary actuator. The second stationary actuator is preferably arranged such that the receiving clamp, located in a receiving position that differs from the reaching position, can be actuated. The receiving position is rotated relative to the reaching position in the direction of the fabric's binding point or along a straight line through the fabric's binding point. In the two-actuator configuration, the reaching position of the active clamp is optimized and rotated away from the fabric's binding point in the direction of the gripper's path of movement. After insertion, the active weft thread is picked up by the active clamp in the receiving position. This is the same clamp from which the weft thread was taken in the reaching position before insertion.During weft insertion, the active clamp is rotated towards the binding point of the fabric. This optimized rotation position, where the active clamp is positioned closer to the gripper during the transfer of the active weft thread, reduces the distance between the active clamp and the gripper clamp, thus minimizing thread protrusion at the gripper clamp. This, in turn, reduces thread waste in the form of excess thread, which is transferred from the receiving gripper to the receiving gripper with the active weft thread and pulled beyond the fabric during weft insertion.

[0019] When using a single, stationary actuator, it is sufficient to open the active clamp before the weft insertion and close it after the insertion, once the active weft thread has been picked up, to securely clamp it. When using at least two stationary actuators to operate the clamps, the active clamp is opened and closed in the forward rotation position before the weft insertion to release the weft thread, and then opened again in the retrieval rotation position to pick up the weft thread after insertion, and closed again to clamp the picked-up weft thread.

[0020] In an alternative design, each terminal has its own actuator. The actuators are fixed to the terminal disc and rotate with the terminals when the terminal disc is turned. The number of actuators corresponds to the number of terminals. This design with a separate actuator for each terminal offers the advantage that actuation of the respective terminal is not limited to discrete rotational positions of the terminal disc or the terminals themselves, particularly the reaching position and / or the receiving position, but rather allows for actuation of the terminal even while the terminal disc is rotating.Furthermore, a clamp can also be held open during a twisting process, for example between the release before the shot entry and the reception after the shot entry, which reduces the number of opening and closing operations and thus the mechanical stresses on the individual components and possibly the cycle time.

[0021] Preferably, the clamps are designed as normally closed clamps. These are also commonly referred to as "normally-closed" clamps. A preload force is applied to the clamp such that it remains closed and securely clamps the weft thread. Preferably, the clamp is held in the closed position by a spring, in particular a helical spring. The clamping force of the clamp is adjustable via the spring force or preload of the spring. By changing the spring preload, the clamping force can be adjusted, which may be necessary, especially with different weft threads, materials, and thicknesses. Adjusting the clamping force may also be necessary if two or more weft threads need to be securely held per clamp instead of just one.

[0022] The at least one actuator operates the terminals preferably pneumatically, electrically, mechanically, or magnetically. The type of actuator and the method of actuating the terminals are independent of whether the actuator is stationary or non-rotating. In the case of non-rotating actuators, these can be integrated into the terminal.

[0023] Preferably, a thread retrieval device is provided for returning the weft thread to the active clamp after it has been inserted, i.e., the clamp from which the weft thread was taken. In particular, the thread retrieval device is a device that guides the weft thread securely into the clamp after it has been inserted, specifically into a clamping area of ​​the clamp, so that it is securely clamped. For this purpose, the thread retrieval device has, for example, a crescent-shaped section in which the weft thread is received and guided. The crescent-shaped section can be arc-shaped or, for example, U- or V-shaped. During the retrieval process, the receiving section moves, in particular, in the direction of the clamp.The receiving area of ​​the thread retriever moves, for example, back and forth along a circular or elliptical path, whereby the inserted weft thread is only guided over a portion of the path.

[0024] In a preferred embodiment, the weft thread feeder has a clamp blow-off for clearing the clamps after the weft thread is discharged or before it is received. Accordingly, the clamp blow-off is arranged such that it can be actuated in the open position of the clamp and clears the clamp in this position. The clamp blow-off, like the actuator, can be fixed in place within the weft thread feeder. Preferably, the clamp blow-off is arranged such that the active clamp can be cleared in the forward rotation position or the receiving rotation position of the clamp disc. If the forward rotation position differs from the receiving rotation position, the clamp blow-off can be configured to operate in either the forward rotation position or the receiving rotation position. Alternatively, the clamp blow-off is fixed to the clamp disc or each individual clamp.Each clamp is equipped with a clamp blow-off device, allowing for blow-out in the open position of the active clamp between weft thread delivery and weft thread reception. The clamp blow-off device is particularly preferably combined with pneumatic actuation of the clamps, i.e., at least one pneumatic actuator. The compressed air supplied to the actuator can then be used for the clamp blow-off. The clamp blow-off device is preferably designed to be stationary or rotationally fixed, depending on the actuator's configuration. During the clamp blow-off, contaminants, such as thread remnants or lint, are removed from the clamp, ensuring secure clamping of the weft thread.

[0025] Preferably, the color selector disc and the clamping disc are arranged parallel to each other. Furthermore, preferably, the axes of rotation of the color selector disc and the clamping disc are congruent to each other, i.e., the color selector disc and the clamping disc are arranged concentrically with respect to a common axis of rotation. Preferably, the clamps of the clamping disc and the eyelets of the color selector disc are arranged on a pitch circle diameter, which is further preferably identical.

[0026] In a preferred embodiment, the weft threads run parallel to each other between the color selector disc and the clamping disc. In any case, the individual weft threads run directly and straight from the eyelet of the color selector disc to the clamp of the clamping disc, i.e., without deflection, provided they are passive weft threads, which, unlike active weft threads, are not involved in the current weft insertion. For example, the active weft thread is deflected around the lowering of the infeed needle when it is moved into the transfer position by means of the infeed needle.

[0027] Preferably, the clamping disc and / or the color selection disc are driven rotaryally by an electric motor, in particular a stepper motor or a servo motor. Preferably, both the clamping disc and the color selection disc have their own drive, i.e., in particular their own electric motor. More preferably, the color selection disc is driven or rotated synchronously with the clamping disc. This reduces the deflection of the weft threads and thus also the stress on the weft threads, which leads to a reduction in defects in the fabric.

[0028] Alternatively, a synchronous drive of the color selector and the clamping disc can be achieved with a single drive unit that powers both. The color selector and the clamping disc are typically rotated at least when a different weft thread is required for the subsequent weft insertion than for the previous one. Preferably, the color selector is rotated between two consecutive weft insertions. Furthermore, with a clamping disc, it may be necessary to rotate it between the weft thread delivery and the weft thread pickup if the weft thread is to be picked up in a different position than when it was delivered. This occurs when the delivery rotation position differs from the pickup rotation position.

[0029] The invention further comprises a weaving machine with a weft thread feed device as described above. Preferably, the clamping disc of the weft thread feed device is arranged parallel to the warp threads of the fabric.

[0030] Preferably, a weft thread cutter is arranged between the clamping disc and the warp threads, and further preferably parallel to the warp threads. The weft thread cutter is controlled, in particular, electronically or mechanically. Preferably, the control is achieved via its own drive, especially a separate electric motor, or via a mechanical gearbox, for example, as a secondary drive from the main drive of the weaving machine.

[0031] A preferred embodiment and details of the present invention are described below with reference to the figures. These show: Figure 1: a first embodiment of a weft thread feeder according to the invention in a weaving machine; Figure 2: a detailed view of the weft thread feeder according to the invention made of Figure 1 Figure 3: a first embodiment of a clamping disc according to the invention; Figure 4: a second embodiment of a clamping disc according to the invention; Figure 5: a second embodiment of a weft thread feeder according to the invention; Figure 6: a third embodiment of a weft thread feeder according to the invention for twist-free insertion of a double weft; and Figure 7: a fourth embodiment of a weft thread feeder according to the invention with a double disc.

[0032] Figure 1 and 2 show an area of ​​a weaving machine 1 with a fabric 3 and a weft thread feed device 10 according to the invention wherein Figure 2 a section of the weaving machine Figure 1in a second state. An active weft thread 2, selected from a plurality of weft threads 2a-h, is fed to a gripper 50 via the weft thread feeder 10 and inserted by the gripper 50 into a shed 4 to produce the fabric 3. In this example, the weft thread feeder 10 holds eight weft threads 2a-h, which can be selectively fed to the gripper 50. The various weft threads 2a-h are, in particular, weft threads made of different materials, colors, and / or thicknesses. By using a predefined feeding sequence for the weft threads 2a-h in conjunction with a predefined closed or open shed position of the individual shafts of a weaving machine 1, the fabric 3 can be woven with a predefined structure or pattern.

[0033] The weft thread feeder 10 has a color selection disc 20, a clamping disc 40, and a feeding needle 30 arranged between them for selective feeding. The color selection disc 20 has eight outwardly open loops 21a-h on its outer diameter. The number of loops corresponds at least to the number of weft threads 2a-h or weft thread bundles that are to be fed individually to the gripper 50. The open loops 21a,ch are closed by a latch in the form of a cam disc 22, so that the weft threads 2a,ch cannot be pulled out of the corresponding open loops 21a,ch. Here, the color selection disc 20 is in the rotation position 12b, so that the open loop 21b is in the feeding rotation position 12 and represents the active, open loop 21, which is not closed by the cam disc 22.For this purpose, the cam disk 22 has an arc-shaped cam groove 25, the outer edge of which has an opening for releasing the active weft thread 2. Thus, the active weft thread 2 to be introduced, in the case shown the weft thread 2b, can be picked up by the guiding needle 30 located in the receiving position 31 - as in . Figure 1 shown - and guided from the feed needle to a delivery position 32 for transfer to the gripper 50. For this purpose, the feed needle 30 has a recess 33 on its front side to receive the weft thread to be inserted. The active weft thread 2, which has been brought to the delivery position 32, can be grasped by the gripper 50 by means of its gripper clamp 51 and inserted into the shed 4.

[0034] The clamping disc 40 of the weft thread feed device 10 comprises, on a pitch circle diameter, a number of clamps 41a-h corresponding to the number of open loops 21a-h of the color selection disc 20. In this case, the color selection disc 20 comprises eight open loops 21a-h and the clamping disc 40 comprises eight clamps 41a-h, with each of the open loops 21a-h and each of the clamps 41a-h being occupied by one of the weft threads 2a-h, respectively. Thus, each of the weft threads 2a-h passes through an associated open loop 21a-h and is clamped in an associated clamp 41a-h. The clamping disc 40, like the color selection disc 20, is shown in the rotation position 12b, so that the clamp 41b and the eyelet 21b are in the reach rotation position 12 and the weft thread 2b is in the reach position 11.

[0035] The weft thread feeder 10 further comprises two stationary actuators 49, 49', wherein the first actuator 49 is arranged such that the active clamp 41 in the forward rotation position 12 can be actuated, and the second actuator 49' is arranged such that the active clamp 41 in the receiving rotation position 14 can be actuated. Because the forward rotation position 12 differs from the receiving rotation position 14 due to the two actuators 49, 49', it is optimized in the direction of the gripper 50. The thread overhang 6 at the gripper 50 is thus reduced, as this shortens the distance between the active clamp 41 and the gripper 50.

[0036] By securing the weft threads 2a-h in the clamps 41a-h of the clamping disc 40, the individual weft threads 2a-h can be held without retaining bars and provided to the feed needle 30 under a defined pretension. The color selection disc 20 is rotaryally driven by a first servo motor 23. The clamping disc 40 is rotaryally driven by a third servo motor 46 as a clamping disc drive. The feed needle 30 is translationally driven by a second servo motor 34, enabling it to move the active weft thread 2 from the feed position 11 to the transfer position 13.

[0037] In the illustrated embodiment, the clamping disc 40 is arranged parallel to the warp threads 5 of the fabric 3. The pitch circle diameter on which the weft threads 2a-h are held on the clamping disc 40 by the clamps 41a-h corresponds essentially to the pitch circle diameter on which the open eyelets 21a-h of the color selection disc 20 are located. The axis of rotation 24 of the color selection disc 20 forms a skew line with respect to the axis of rotation 42 of the clamping disc 40.

[0038] To select and insert one of the weft threads 2a-h into the shed 4, both the color selector 20 and the clamping disc 40 are first moved to one of the rotation positions 12a-h, so that the active weft thread 2 to be inserted is in a reaching position 11. The color selector 20 and the clamping disc 40 are rotated synchronously. The individual clamps 41a-h are mounted on the clamping disc 40 at a predefined angle to each other. The spacing between the individual clamps 41a-h can be constant or vary. To move the weft thread 2a-h, held in one of the clamps 41a-h, into the reaching position 11, the clamping disc must be rotated to the respective rotation position 12a-h. This applies analogously to the color selector 20 and the eyelets 21a-h. Figure 1 and 2The weft thread 2b is the active weft thread 2 and both the color selection disc 20 and the clamping disc 40 are shown as being in the rotation position 12b.

[0039] The weft thread 2 to be inserted is moved from the forwarding position 11 to a transfer position 13 by means of the forwarding needle 30. In the transfer position 13, the weft thread 2 to be inserted is picked up by the gripper 50. For this purpose, the gripper 50 grasps the weft thread 2 to be inserted with the gripper clamp 51 open, whereupon this is closed and the gripper clamp 51 securely guides the weft thread 2. After the transfer of the active weft thread 2 to the gripper 50, the active clamp 41 is opened by means of the actuator 49 and releases the weft thread 2 for insertion into the shed 4. Such a position of the gripper 50 after the transfer is in Figure 2The weft thread 2 to be inserted is fixed in the gripper clamp 51. The gripper 50 shown is a feeder gripper, which picks up the weft thread 2 on the left side of the fabric 3 as the entry side and transfers it to the center of the fabric. There, the weft thread 2 is transferred to the right-hand taker gripper (not shown). The gripper clamp of the taker gripper engages the gripper clamp 51 of the gripper 50 and fixes the active weft thread 2. The active weft thread 2 is then transported through the entire shed 4. After the weft thread insertion, the weft thread 2 to be inserted is placed in the corresponding active clamp 41 from which it was taken and clamped. The weft thread 2 is also inserted back into the active eyelet 21 from which it was taken.To pick up the inserted weft thread 2, the active clamp 41 is rotated clockwise into the receiving position 14 for the weft thread 2b. After the weft thread 2 is clamped in the corresponding active clamp 41, it is cut by a weft thread cutter 60. Additionally, the active weft thread 2 is released from the clamp of the receiving gripper.

[0040] After the weft insertion has been completed, the same weft thread 2b or one of the other weft threads 2a,ch can be selected for the subsequent weft insertion via the weft thread feed device 10 and transferred to the gripper 50.

[0041] Figure 3Figure 1 shows a first embodiment of a clamping disc 40 according to the invention. The clamping disc 40 has eight clamps 41a-h on a pitch circle diameter. The individual clamps 41a-h are offset from each other by the same angle α. Clamp 41b is shown open, and the clamping disc 40 is in the rotation position 12b, so that clamp 41b is in the reaching rotation position 12. The number of clamps 41a-h can vary depending on the embodiment and depends in particular on the number of different weft threads 2a-h required for a fabric 3.

[0042] Terminals 41a-h are identical in design. The construction of terminals 41a-h is described using terminal 41a as an example. Terminal 41a comprises a base body 44, which is fixed to the terminal disc 40 and in which the clamping element 45 is mounted. The clamping element 45 has a shaft that is translationally mounted in a bushing in the base body 44. Terminal 41a is designed as a "normally closed" terminal and is closed in its normal state. For this purpose, the clamping element 45 is pre-tensioned against the base body 44 by a helical spring 48. The clamping force of terminal 41a is adjustable via the force of the helical spring 48.

[0043] To move the clamps 41a-h from the closed position to the open position, the weft thread feeder 10 comprises two actuators 49, 49' for actuating the clamping element 45. In the Figure 3In the embodiment shown, two actuators 49, 49' are arranged stationary in the weft thread feed device 10. Stationary here means that the actuators 49, 49' do not rotate with the clamping disk 40. The first actuator 49 is arranged such that the active clamp 41, which is in the forward rotation position 12, can be actuated. Figure 3 The clamping disc is shown in the rotation position 12b. For this purpose, the actuator 49 actuates the terminal 41b and moves it from the closed position against the spring force of the helical spring 48 to the open position. The actuator 49 comprises a drive. The embodiment according to Figure 3The assembly further comprises a second actuator 49'. The second actuator 49' is fixedly arranged such that the active clamp 41 can be actuated in a receiving rotary position 14. The reaching rotary position 12 is rotated relative to the receiving rotary position 14 away from the weft line of the active weft thread 2 or the binding point in the direction of a weft insertion line. In the illustration shown, the reaching rotary position 12 is rotated counterclockwise relative to the receiving rotary position 14.

[0044] The different rotational positions during the transfer of the active weft thread 2 to the gripper 50 and the reception of the active weft thread 2 after the weft insertion allow the thread protrusion 6 or the waste length on the right side, i.e. on the side of the fabric 3 opposite the weft thread feed device 10, to be reduced.

[0045] In the embodiment according to Figure 4is, in contrast to the embodiment according to Figure 3 Each terminal 41a-h is assigned its own actuator 49a-h. For this purpose, the actuators 49a-h are not fixed in position, but are rotationally fixed to the terminal disc 40, i.e., they rotate with the terminal disc 40. Thus, the actuators 49a-h, like the terminals 41a-h, rotate with the terminal disc 40. Assigning one actuator 49a-h to each terminal 41a-h increases the flexibility when opening and closing the active terminal 41 and can also result in time savings. Figure 4 Terminal 41b is moved to the open position by actuator 49b and represents the active terminal 41. In the embodiment according to Figure 3The active clamp 41 is opened twice for a weft insertion. First, the clamp is opened and closed again by the actuator 49 to allow the weft thread to be released before the insertion, i.e., in particular when the gripper 50 has clamped the active weft thread 2. Second, the active clamp 41 is opened and closed again by the actuator 49 to receive the weft thread. In contrast, according to the embodiment, the active clamp 41 can be operated as described in Figure 4 The opening is shown between the release before the weft insertion and the reception of the active weft thread 2 after the weft insertion, since the actuators 49a-h rotate with the terminals 41a-h. Furthermore, in the embodiment according to Figure 3 the actuation of terminals 41a-h is limited to two discrete rotational positions, whereas in the embodiment according to Figure 4Terminals 41a-h can be actuated in any rotational position. For example, terminals 41a-h can also be actuated while the terminal disc 40 is being rotated.

[0046] In Figure 5 Figure 1 shows a second embodiment of a weft thread feeder 10 according to the invention, with a clamping disc 40 and clamps 41a-h. The clamps 41a-h are analogous to those shown in Figure 1. Figure 4 The terminal disc 40 is fixed to the terminal disc 40 in a rotationally fixed manner in the embodiment shown. The design and function of the terminals 41a-h essentially correspond to those shown in Figure 3In the illustrated embodiment, the weft thread feeder 10, in contrast, has only one stationary actuator 49. The forward rotary position 12 thus also corresponds to the receiving rotary position 14. The weft thread feeder 10 additionally has a clamp blow-out 47, by means of which any remaining thread remnants or lint remaining in the clamping area of ​​the active clamp 41 are blown out by means of compressed air, so that secure clamping of the active weft thread 2 is always possible. The clamp blow-out 47 is shown by way of example in the area of ​​the clamp 41b in the form of a blow-out tube. Here, the clamp blow-out 47 is arranged stationary in the area of ​​the receiving rotary position 14, which in the illustrated embodiment also represents the forward rotary position 12.

[0047] Furthermore, in the embodiment according to Figure 5A thread returner 15 is shown. The thread returner is arranged such that the active weft thread 2, after being inserted into the fabric 3, is reliably brought into the clamping area of ​​the active clamp 41, here clamp 41b. The thread returner 15 interacts with a reed 7, so that together they bring the inserted active weft thread back into the active clamp 41. The thread returner has a drive 16. The movement of the thread returner 15 and the reed 7 is schematically indicated by two arrows.

[0048] Figure 6Figure 1 shows a third embodiment of a weft thread feeder 10 according to the invention for the twist-free insertion of a double weft. The color selection disc 20 comprises eight open eyelets 21a-h, and the clamping disc 40 has four clamps 41a-d. Each of the clamps 41a-d can be actuated by a rotationally fixed actuator 49a-d, i.e., one that rotates with the clamping disc 40. Two weft threads guided in adjacent eyelets are held in each clamp. Thus, weft thread 2a from eyelet 21a and weft thread 2b from eyelet 21b are held in clamp 41a. The two weft threads 2a and 2b therefore fan out from clamp 41a to eyelets 21a and 21b. The same applies to the weft threads 2c,d, 2e,f and 2g,h, which are guided in the eyelets 21c,d, 21e,f and 21g,h and held in the clamps 41b, 41c and 41d. The pass-through needle 30 is designed with a double fork and has two recesses 33.The two recesses 33 are spaced apart such that two adjacent active weft threads 2 can be picked up by the feed needle 30 in the receiving position 31 and moved to the delivery position 32. In the illustration shown, the weft threads 2a, b are the active weft threads 2, which are located in the transfer position 13, and the feed needle 30 is located in the delivery position 32. The gripper 50 is designed such that the two active weft threads 2 are clamped in the gripper clamp 51 and inserted into the shed 4 without twisting. After the double weft is inserted, the two active weft threads 2 are moved by the reed 7 (not shown) back into the active clamp 41 and clamped by it.

[0049] In Figure 7A fourth embodiment of a weft thread feeder 10 according to the invention is shown, with a color selection disc 20 having two partial discs 20', 20". Such an arrangement with two partial discs 20', 20" is also commonly referred to as a double disc. The weft thread feeder 10 has, analogous to the embodiment according to Figure 1A clamping disc 40 with eight clamps 41a-h, each holding one of the weft threads 2a-h, and two stationary actuators 49, 49'. In contrast, the color selection disc 20 consists of two sub-discs 20', 20", which are independently rotatable and each has its own sub-disc drive 23', 23". The two sub-discs 20', 20" are arranged parallel to each other and can be pivoted in parallel pivot planes about a common axis of rotation 24. If the insertion side is defined as the left side and the opposite side of the fabric 3 as the right side, the weft insertion occurs from left to right. The first sub-disc 20' in the weft insertion direction faces away from the left side of the fabric 3 and is also referred to as the rear sub-disc. The second sub-disc 20" faces the left side of the fabric 3 in the weft insertion direction and is referred to as the front sub-disc.The first sub-disc 20` has a larger diameter than the second sub-disc 20". Eight open loops 21'ah of the first sub-disc 20` are arranged on a pitch circle diameter D. Four open loops 21"ad of the second sub-disc 20" are arranged on a pitch circle diameter d. The pitch circle diameter D is larger than the pitch circle diameter d. The color selection disc 20 has a total of twelve open loops, of which only eight are covered with one of the eight weft threads 2a-h each. The number of open loops on the color selection disc 20, i.e., here the sub-discs 20', 20", and also the number of covered loops can generally vary depending on the embodiment and application.

[0050] The first partial disk 20' also has a passage 26 for the weft threads held in the open loops 21"ad of the second partial disk 20". The passage 26 is designed as an arc-shaped groove and has a radially outwardly extending outlet to allow the active weft thread 2, when held in one of the open loops 21"ad, to be passed from the passing needle 30 to the gripper 50. In the illustrated embodiment, the outlet is located centrally in the first partial disk 20' between the two open loops 21'd and 21'e. In addition to the arc-shaped cam groove 25 for the weft threads of the first partial disk 20', the cam disk 22 also has a second arc-shaped cam groove 25' for the weft threads of the second partial disk 20".By designing the color selection disc 20 with two sub-discs 20', 20" the maximum angular range over which the color selection disc 20 must be rotated to select the active weft thread 2 is reduced, or, with a constant rotation angle, the number of eyelets is increased. This can be particularly advantageous with a weft thread feed device 10 for the twist-free insertion of a double weft. Reference symbol list

[0051] 1 Weaving machine 2 Active weft thread 2a-h Weft threads 3 Fabric 4 Shed 5 Warp threads 6 Thread overhang 7 Reed 10 Weft thread feeder 11 Active weft thread delivery position 12 Delivery rotation position 12a-h Rotation positions 13 Active weft thread transfer position 14 Pick-up rotation position 15 Thread take-up 16 Thread take-up drive 20 Color selection disc 20' First divider disc 20" Second divider disc 21 Active eyelet 21a-h Open eyelets 21'a-h Open eyelets of the first divider disc 21"a-d Open eyelets of the second divider disc 22 Bar in the form of a cam disc 23 First servo motor 23' First divider disc drive 23" Second divider disc drive 24 Rotation axis of the color selection disc 25, 25'Slide groove 26Grid 30Reaching needle 31Reaching needle pickup position 32Reaching needle delivery position 33Lowering 34Second servo motor 40Terminal disc 41Active terminal 41a-hTerminals 42Rotation axis of the terminal disc 44Base body 45Clamping element 46Third servo motor 47Terminal blowout 48Coil spring 4949'Stationary actuators 49a-hRotational actuators 50Gripper 51Gripper clamp 60Weft thread cutter,

Claims

1. Weft yarn feeding device (10) for providing a plurality of weft yarns (2a-h) in a weaving machine (1) and for selectively feeding an active weft yarn (2) to a gripper (50), comprising a. a rotationally drivable color selection disc (20) having a plurality of eyelets (21a-h) arranged on its outer circumference, each one for receiving at least one weft yarn (2a-h), b. a feeding needle (30) by means of which the active weft yarn (2) is being able to be transferred from a feeding position (11) to the gripper (50) in a transfer position (13), characterized in that c. there are a rotationally drivable clamping disc (40) with a plurality of clamps (41a-h) arranged on its outer circumference, each one for holding at least one weft yarn (2a-h) in its closed position, and d. the hand over needle (30) arranged between the color selection disc (20) and the clamping disc (40), via which the at least one active weft yarn (2) to be fed is passed from the feed position (11), into which the active weft yarn (2) is able to be brought by rotating the color selection disc (20) and an active clamp (41) together with the clamping disc (40) into a feeding rotational position (12), is able to be transferred to the gripper (50) in a transfer position (13) and the active clamp (41) is brought into an open position after the transfer.

2. Weft yarn feeding device (10) according to claim 1, characterized in that the clamps (41a-h) are able to be actuated via at least one actuator (49, 49a-h, 49').

3. Weft yarn feeding device (10) according to claim 2, characterized in that the actuator (49) is arranged in a stationary manner and each one of the active clamps (41) located in the feeding rotational position (12) is actuated.

4. Weft yarn feeding device (10) according to claim 2 or 3, characterized in that the active clamp (41) located in a pick-up rotational position (14) is able to be actuated via a second actuator (49').

5. Weft yarn feeding device (10) according to claim 2, characterized in that each clamp (41a-h) is assigned to with its own actuator (49a-h), the actuators (49a-h) being fixed to the clamping disc (40) in a rotationally fixed manner.

6. Weft yarn feeding device (10) according to one of claims 2 to 5, characterized in that the clamps (41a-h) are designed as clamps which are closed in the normal state.

7. Weft yarn feeding device (10) according to claim 6, characterized in that the clamps (41a-h) are each held in the closed position by a spring (48) and the clamping force of the clamps (41a-h) is adjustable via the spring force of the respective spring (48).

8. Weft yarn feeding device (10) according to one of claims 2 to 6, characterized in that the at least one actuator (49, 49a-h, 49') actuates the clamps (41a-h) pneumatically, electronically, mechanically or magnetically.

9. Weft yarn feeding device (10) according to one of the preceding claims, characterized in that a yarn retriever (15) is provided for fed back the at least one active weft yarn (2) after a weft insertion into the active clamp (41) out of which the at least one active weft yarn (2) has been taken out.

10. Weft yarn feeding device (10) according to one of the preceding claims, characterized in that a clamp blow-out (47) is provided for blowing out the clamps (41a-h) after the transfer of the at least one active weft yarn (2) to the gripper (50).

11. Weft yarn feeding device (10) according to one of the preceding claims, characterized in that the colour selection disc (20) and the clamping disc (40) are arranged parallel to each other, in particular concentrically to a common axis of rotation (24, 42).

12. Weft yarn feeding device (10) according to one of the preceding claims, characterized in that the weft yarns (2a-h) run parallel to each other between the colour selection disc (20) and the clamping disc (40).

13. Weft yarn feeding device (10) according to one of the preceding claims, characterized in that the clamping disc (40) can be rotationally driven by an electric motor, in particular a stepper motor or a servomotor.

14. Weft yarn feeding device (10) according to one of the preceding claims, characterized in that the colour selection disc (20) is driven synchronously with the clamping disc (40).

15. Weaving machine (1) with a weft yarn feeding device (10) according to one of the preceding claims.

16. Weaving machine (1) according to claim 15, characterized in that the clamping disc (40) is arranged parallel to the warp threads (5).

17. Weaving machine (1) according to claim 15 or 16, characterized in that a weft yarn cutter (60), which is electronically or mechanically controlled, is arranged between the clamping disc (40) and the warp threads (5), parallel to the warp threads (5).