Patent Application
20240200241
The invention relates to a device for feeding at least first and second weft threads to a loom which has at least one gripper head, the weft threads being feedable to the gripper head in the weft direction.
WO 2011/015173 A1 discloses a device for temporally successively transferring two preferably strip-type weft threads, which are also referred to as tapes, from a respective feed unit associated with a weft thread to a gripper head of a loom. By suitably controlling the feed units, either the first weft thread or the other weft thread is fed to the gripper head and subsequently inserted into the shed. The two feed units are arranged one above the other and oriented in the weft direction for this purpose. Each feed unit has a clamping device for clamping a free end of the respective weft thread, the clamping device being movable essentially in the weft direction between at least two different operating positions. Furthermore, each clamping device is movable by means of a swivel unit which is driven by a drive, preferably a servomotor, and includes two parallel swivel arms which are connected by a coupling element, the clamping device being arranged on the coupling element.
Due to the movement of each clamping device only in a vertical plane, in which the weft insertion line is also situated, the strip-type weft material takes a course which is largely twist-free and does not deflect in the warp direction from the feed unit until transferred to the gripper head. As a result, shear forces which could damage the weft thread do not arise. Deflection therefore does not take place in the direction of the width extension of the strip-type weft material. If the clamping device is movable in the aforementioned vertical plane, in which the weft insertion line is also situated, various feed movements can be carried out by means of the device, a deflection not being carried out in the direction of the width extension of the strip-type weft material. In order to transfer a strip-type weft thread, its free end is initially clamped in the associated clamping device then transferred to the gripper head and, thereafter, the clamping device is opened and the weft material is inserted.
This known device has the disadvantage, however, that it is relatively complex and costly. It also requires a relatively large amount of space. Last but not least, due to the swivel kinematics during the movement of the clamping device in the weft direction, an undesired movement of the weft thread upward also takes place, i.e., in the vertical direction with respect to the plane, in which the weft insertion line is also situated. This negatively affects the accuracy of presenting the weft thread to the gripper head and also the cutting position of the weft thread once it is inserted into the shed.
JP 2983531 A describes a loom, in which a color selection between two weft threads is made possible. For this purpose, either a first weft thread from a first bobbin or a second weft thread from a second bobbin, which is arranged next to the first bobbin in the warp direction, is inserted into the open shed and, thereafter, the inserted and cut first or second weft thread is pushed onto the selvedge. This design requires, in particular, that the inserted weft thread situated farther away from the selvedge must be moved a relatively great distance to the selvedge, wherein undesired friction-related problems can arise. The apparatus-related complexity is also relatively high in this case.
A problem addressed by the present invention is that of providing a device for feeding at least first and second weft threads, preferably strip-type weft threads, to a loom which has at least one gripper head, the device at least partially eliminating the aforementioned disadvantages. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
The objects are provided by a device and a method having the features set forth herein.
The device according to the invention has a coupling unit which is movable back and forth in the warp direction when the device is installed laterally on the loom. This coupling unit connects at least a first feed unit and a second feed unit to one another, the feed units being adjacently arranged in the warp direction and designed such that they enable at least a first and a second weft thread, respectively, to be fed to the gripper head. Furthermore, the device according to the invention has a positioning unit for positioning the coupling unit in or counter to the warp direction in at least a first position and a second position, wherein the first feed unit is designed to feed the first weft thread to the gripper head when the coupling unit is in the first position and the second feed unit is designed to feed the second weft thread to the gripper head when the coupling unit is in the second position.
The advantages of the invention are, in particular, that the coupling unit, in connection with the positioning unit, positions the at least first feed unit and second feed unit in or counter to the warp direction such that, after suitable positioning, the first weft thread or the second weft thread can be presented to the gripper head. For example, in the first position of the coupling unit, the first feed unit transfers the first weft thread to the gripper head which subsequently inserts the first weft thread into the open shed of the loom. Once this first weft thread has been inserted into the shed, its free end close to the device according to the invention is cut, the first feed unit is moved back and, thereafter, 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 thread to the gripper head.
In this way, at least two weft threads, for example, each made from a different type of material, can be quickly and easily inserted into a woven fabric.
The approach according to the invention has multiple advantages over the approach described in WO 2011/015173 A1. On the one hand, the weft thread to be inserted can be fed to the gripper head in a linear manner. In this feed movement, in contrast to the swivel kinematics according to WO 2011/015173 A1, this weft thread does not move in the vertical direction, i.e., the weft thread is always located in the same vertical position. Due to this feature, high flexibility with respect to feed movements and possibilities for presenting the weft thread which is to be transferred to the gripper head is also achieved. The device according to the invention also requires only a small amount of installation space.
Since the invention makes it possible to move the weft thread, which has been presented and transferred to the gripper head and then drawn through the shed, only in the horizontal and linear directions, i.e., without a vertical movement component, for weft insertion, the control unit can be freely programmed with respect to the presentation movement of the weft thread. As a result, greater presentation accuracy and a more precise cut of the weft thread once it is inserted into the shed can be achieved. A height offset taking place at the same time, as in WO 2011/015173 A1, does not need to be taken into consideration.
The advantages of a presentation which takes place only in the linear direction with a weft-thread selection (color selection) by means of laterally, i.e., in and counter to the warp direction, displaceable feed units is that the two feed units can be identically designed and then also exhibit the same behavior in the presentation movement. Good adjustability and positionability of the two feed units results for the same reason, since these have an identical position with respect to height.
It is preferred that the coupling unit is positionable such that the position of the first feed unit when the coupling unit is in the first position and the position of the second feed unit when the coupling unit is in the second position match in the warp direction during weft insertion. In this case, the first and the second feed units take the previous position of the other feed unit at different times, for example, one after the other, in order—in this position—to present the corresponding weft thread to the gripper head which is movable through the open shed. Despite the displacement of the coupling unit in or counter to the warp direction for the purpose of selecting color, the weft thread to be inserted therefore always lies on the ideal insertion axis, while the other weft thread is slightly deflected laterally in or counter to the warp direction.
It is to be noted that the gripper head can be movable from the one selvedge to the other selvedge through the shed or the weft thread can be transferred to a second gripper head, for example, half-way through, the second gripper head then pulling the weft thread along the second half of the path through the shed.
According to one advantageous embodiment, the at least two feed units each have slides that are movable in the weft direction. The slides are preferably linearly movable in and counter to the weft direction, whereas they are both movable back and forth, preferably also linearly, in the warp direction by means of the coupling unit.
It is advantageous when at least one and preferably exactly one drive, preferably a servomotor, is coupled to the at least two slides such that the drive is capable of moving only one of the at least two slides in and counter to the weft direction. The drive therefore moves both slides, but not at the same time, and, instead, moves only one of the two. Whereas the one slide is therefore moved, for example, in the weft direction in order to transfer the associated weft thread to the gripper head, the other slide remains in place. Therefore, only little mass (specifically the particular feed unit) is moved, unnecessary mechanical imbalance is avoided and the space required at the side of the loom is optimally utilized. When only the aforementioned one drive is used to move the two slides forwards and backwards (at different times), this is a cost-effective and space-saving approach.
Each slide preferably has a clamp which is to be closed and opened via electrical or pneumatic control for clamping and releasing the weft thread. It is preferred that each clamp, as viewed in the weft direction, has upstream guide elements which guide the weft thread on the top side and the underside and laterally, the guide elements also being part of the slide. In this way, the free end of the weft thread to be transferred does not freely hang down directly after the clamp, but rather advantageously only—as viewed in the weft direction—after the guide elements and is guided by the slide in a defined manner in the weft direction to the gripper head in order to be received by the gripper head.
The at least one drive is preferably controllable such that the slide and preferably its guide elements are guidable to different distances away from or even into the gripper head. This possibility for presenting a weft thread in an individually variable manner is also a standalone aspect of the invention, which can be realized regardless of the claimed design of the coupling unit, the feed units and the positioning unit. This adapted presentation movement can preferably be realized by means of a flexible programming of the drive. Mechanical adjustments for different weft threads, in particular for materials having low bending stiffness, are advantageously not necessary.
Specifically, this aspect of the invention, which is also to be considered as a standalone invention, relates to a device for feeding at least one first weft thread to a loom which has at least one gripper head, the device having at least one first feed unit, with which the at least one weft thread is feedable to the gripper head in the weft direction, wherein the first feed unit has a first clamp, with which at least one portion of the at least one first weft thread can be guided in a force-locked manner when this weft thread is fed to the gripper head. This device is characterized in that the portion of the at least first weft thread which is guided by the first clamp is linearly conveyable by means of the first feed unit in and counter to the weft direction with respect to the gripper head, this linear movement of the aforementioned portion of the at least first weft thread taking place along the weft insertion line.
With such an embodiment, for example, a relatively flexible weft thread can continue to be inserted into the open gripper head, thereby ensuring that the weft thread is reliably transferred. In other words, the presentation of the weft thread to be inserted is flexible. Various parameters can be taken into account in the programming of the control unit by suitably controlling the feed unit.
In this aspect of the invention, which is also to be considered as a standalone invention, the at least first feed unit has a first slide which is movable by means of a drive, preferably a servomotor, in and counter to the weft direction, which also applies for the above-described embodiment having the at least two feed units. The aforementioned clamp can also be advantageously closed and opened via electrical or pneumatic control, wherein guide elements are advantageously provided, the guide elements being situated upstream of the clamp as viewed in the weft direction and guiding the first weft thread on the top side and the underside and laterally. The clamp and the guide elements of the first slide are guidable to different distances away from or into the gripper head by means of the drive.
By means of the aforementioned aspect of the invention, it is possible, in particular, to not only insert the weft thread itself into the gripper head, but also into the front part of the feed unit, which is advantageously made use of, in particular, with relatively flexible weft threads. In this way, the flexible weft thread, which projects beyond the feed unit in the weft direction and is securely guided thereby, arrives behind the clamping region of the gripper head and is not stopped ahead of the clamping region, for example, by parts of the gripper head facing the feed unit. In this over-insertion, the feed unit therefore travels briefly between the clamping region and then back counter to the weft direction, the weft thread to be clamped projecting beyond the feed unit to such an extent that it remains in the clamping region despite the feed unit having been moved back and is clamped when the gripper head is subsequently closed.
In the above-described aspect of the invention, which is also considered as standalone, it is preferred that a second feed unit having a second slide is provided in addition to the first feed unit having the first slide, both feed units being controllable as described above, in order to enable, in particular, the above-described over-insertion, i.e., also dipping the front part of the feed unit or its slide into the clamping region.
Referring back to the design according to the invention having a coupling unit, at least two feed units and a positioning unit, the at least two feed units can each have a strip-conveying unit in an embodiment which is an alternative to the aforementioned slides. Each strip-conveying unit has two revolving strip conveyors which are positionable in relation to each other and between which the weft thread is conveyable with frictional engagement at least in the weft direction. If the strip conveyors of the feed unit enter into frictional engagement with the weft thread, the clamped weft thread is conveyed in the weft direction by driving the strip conveyors in the opposing directions in order to present the free end of the weft thread to the gripper head. In this embodiment, the strip 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 woven fabric. As is the case with the aforementioned embodiment of the slides, the strip conveyors, however, according to the invention, are moved back and forth in the warp direction due to the coupling with the coupling unit, in order to position the at least first or second weft thread for transfer to the gripper head.
Preferably, the positioning unit has a drive, preferably a motor (for example, a servomotor) or a pneumatic cylinder, for positioning the coupling unit. This drive can move to positions that correspond to the first and the second positions of the coupling unit. When the drive is, for example, a pneumatic cylinder, its two end positions can correspond to the first and the second positions of the coupling unit. An extremely simple and easily controlled design results.
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, whereas the coupling unit has guide elements which correspond to these first guide structures. The first guide structures and the guide elements interact in such a way that the coupling unit is positionable exclusively in and counter to the warp direction.
The first guide structures are preferably also designed such that they not only allow the coupling unit to be positioned in and counter to the warp direction, but also simultaneously prevent one of the at least two feed units from moving in the weft direction, and such that two guide structures are provided on the guide part, which permit the other feed unit, which is not prevented from moving, from moving in and counter to the weft direction. The first and the second guide structures preferably extend orthogonally to each other and cross each other, corresponding to the warp direction and the weft direction which extend orthogonally to each other. Provided the coupling unit is moved by means of the first guide structures in and counter to the warp direction, the first feed unit or the second feed unit cannot move in the weft direction. The feed unit can be moved only once the coupling unit has been positioned in the first or second position.
According to one advantageous embodiment, the first and the second guide structures are formed by grooves and/or protrusions in the guide part. As a result, it is made possible for the coupling unit to move back and forth only in the warp direction, whereas movements in other directions, in particular directions which are orthogonal thereto, are prevented. On the other hand, once the coupling unit has been suitably positioned, it is made possible for the corresponding feed unit to move only in the weft direction.
In order to feed a first weft thread at the lateral edge of the loom, a first weft thread storage unit is preferably provided, which is set up farther away and has a first bobbin which stores the first weft thread. The first weft thread is guidable from here to the first feed unit. Similarly, in order to feed a second weft thread at the lateral edge of the loom, a second weft thread storage unit is preferably provided, which is set up farther away and has a second bobbin which stores the second weft thread. The second weft thread is guidable from here to the second feed unit.
Preferably, between the first weft thread storage unit and the first feed unit, a first guide element is arranged directly ahead of the first feed unit. Furthermore, between the second weft thread storage unit and the second feed unit, a second guide element is preferably arranged directly ahead of the second feed unit. The first and the second guide elements extend next to one another at least directly ahead of the associated first and second feed units, respectively. Preferably, the aforementioned first guide element and the second guide element are coupled to the first feed unit and the second feed unit, respectively, and are displaced back and forth in the warp direction due to the movement of the coupling unit. Alternatively, the first and the second guide elements are stationary.
According to one advantageous embodiment, the first weft thread storage unit is arranged over the second weft thread storage unit, the bobbin axis of the first weft thread storage unit being situated above the bobbin axis of the second weft thread storage unit. This arrangement is space-saving. In this preferred embodiment, the two weft threads therefore emerge from their respective weft yarn storage units extending one above the other, while they are situated next to one another for the purpose of being presented to the gripper head.
Preferably, the first and the second weft thread storage units are aligned in the weft direction, the axes of the first and the second bobbins then being aligned in the warp direction. According to one alternative, the first and the second weft thread storage units are aligned in the warp direction, the axes of the first and the second bobbins then being aligned in the weft direction and deflection means are provided for deflecting the first weft thread and the second weft thread in the weft direction. Specific space requirements for the loom and in the weaving mill can be taken into account here.
The invention also relates to a loom having at least one gripper head which is movable through the open shed in and counter to the weft direction, and to an above-described device.
The invention further relates to a method for feeding at least first and second weft threads during the production of woven fabric by means of a loom having at least one gripper head, preferably utilizing a device of one of the preceding claims, wherein at least one first weft thread and one second weft thread are located in a plane in the warp direction next to one another at an edge of the woven fabric and are fed sequentially in time (not necessarily alternatingly) in the weft direction to the gripper head of the loom, wherein the at least first and second weft threads are positioned in and counter to the warp direction for their weft insertion such that they are each drawn through the open shed along the weft insertion line by at least one gripper head, wherein the weft thread which is not to be inserted at the moment is deflected out of the weft insertion line (E) in or counter to the warp direction in order to clear the weft insertion line.
Particularly preferably, the device according to the invention and the method according to the invention can be used for strip-type weft threads and strip-type weft materials, for example, those that contain carbon filaments, glass filaments and/or basalt fibers or filaments. Strip-type weft threads and strip-type weft materials having various widths can be processed.
The invention is explained in greater detail in the present case with reference to figures, wherein:
Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.
The top view from
The device 1 has a coupling unit 10, on which a first feed unit 30 and a second feed unit 50 are provided, the first feed unit 30 presenting the first weft thread S1 to the gripper head 82 and the second feed unit presenting the second weft thread S2 to the gripper head 82. The gripper head 82 pulls the weft thread, which has been presented thereto and subsequently clamped, through the open shed along the weft insertion line E by means of the gripper rod 84.
The two feed units 30, 50 are motion-coupled to each other via the coupling unit 10. The coupling unit 10 is movable by means of a drive 15, which is a pneumatic cylinder 16 having a pushing and pulling cylinder rod 17 (
In the present case, the first feed unit 30 and the second feed unit 50 include slides 31 and 51, respectively, which are movable in and counter to the weft direction SR. The first and the second slides 31, 51 are driven by means of a commonly used drive 42 which is a servomotor in the present case and is controlled by a control unit 5, the pneumatic cylinder 15 also being controlled by the control unit 5. The corresponding control lines are shown as dotted lines in
In
According to
According to
According to the top view in
The coupling unit 10 is essentially U-shaped in the underside view in the present case, protrusions 11 being provided on its two limb ends, the protrusions pointing downward (i.e., toward the observer in this case). These protrusions 11 are engaged with a first guide structure 21 which is formed as a guide groove and is provided in a guide part 20. The guide part 20 is installed in a fixed, i.e., stationary, manner, which is also the case for the pneumatic cylinder 16. The guide part 20 is a flat cuboid in the present case, which is used essentially for guiding the coupling unit 10 and the two feed units 30, 50. The aforementioned first guide structure 21 in the guide part 20 extends in the warp direction KR, such that the coupling element 10 with its protrusions 11 is forcibly guided via the first guide structure 21 in and counter to the warp direction KR when it is set into motion by the pneumatic cylinder 16.
The two slides 31, 51 of the first and the second feed units 30, 50, respectively, are arranged on the coupling element 10. Both slides 31, 51 can be moved in and counter to the weft direction SR. A drive mechanism is provided for this purpose, which is composed in this case of a drive 42 formed as a servomotor having a planetary transmission, a pivot lever 43 and a sliding block 45 which is stationarily arranged on the pivot lever but is rotatable by means of a rotational joint 44. Each of the two slides 31, 51 has on its underside (i.e., directed toward the observer) a recess 46 for the sliding block 45. The two recesses 46 are aligned with each other when the two slides 31, 51 are located at the same level in the weft direction SR (
A guide element 41 in the form of a protrusion is also provided on the underside of the first slide 31 and a guide element 56 which is also in the form of a protrusion is provided on the underside of the second slide 51. When the coupling unit 10 has been suitably positioned, specifically in its first or second position, these protrusions 41, 56 can slide, being forcibly guided, in and counter to the weft direction SR in a second guide structure 22 which is formed as a guide groove in the guide part 20 in the present case.
In
In
In
Toward the rear, i.e., counter to the weft direction SR, the clamp 32 is also adjoined by an upper guide surface 34 for the weft thread, which is also oriented toward the U-shaped metal sheet, the weft thread passing between the metal sheet 40 and the upper guide surface 34.
In this embodiment, a first guide element 28, which is also U-shaped and which is optional, adjoins even farther toward the rear, in the direction of the weft thread storage unit 70. This is used for guiding the weft thread S1 to the first feed unit 30 in an ordered manner. The first guide element 28 is moved together with the first guide element 30 in and counter to the warp direction KR (by means of the coupling unit 10). It is also advantageous, although not necessary, when it is also moved back and forth in the weft direction SR by means of the drive 42.
In summary, in the described embodiments, the weft thread S1 or S2 to be inserted is selected from the two adjacently situated weft threads S1, S2 via a lateral displacement of the coupling unit 10 taking place in and counter to the warp direction KR. The displacement of the coupling unit 10 in and counter to the warp direction KR is initiated pneumatically in the present case, whereas a drive 42 in the form of a servomotor carries out the presentation of the selected weft thread S1 or S2 to the gripper head 82, the presentation taking place in the weft direction SR. Due to the selection of the aforementioned drive, the device according to the invention can be cost-effectively realized, since only one servodrive may be used for the feed movement and one pneumatic drive may be used for selecting the color. In WO 2011/015173 A1, however, two servodrives are necessary for the swivel kinematics. The color can be selected by switching between the two weft threads S1, S2 by means of the relatively cost-effective pneumatic cylinder 16.
In
According to
According to
If the weft thread S1 has a relatively great bending stiffness, the step in
In a brief summary, according to the invention, the weft threads S1, S2 to be fed to the gripper head 82 are situated next to each other ahead of the woven-fabric edge in the warp direction KR. They preferably come from weft thread storage units 70, 75 which are arranged one above the other. The weft thread S1, S2 to be inserted is selected by laterally moving the coupling unit 10 together with feed units 30, 50 which are in the form of slides (presentation slides) or a strip-conveying unit 60 in this case. The coupling unit 10 is moved laterally in or counter to the warp direction KR such that the weft thread S1 or S2 is preferably inserted without deflection during the weft insertion, while the weft thread S2 or S1 which is not to be inserted is laterally deflected in or counter to the warp direction KR by a small amount on its way from the weft thread storage unit 75 or 70, respectively, to the feed unit 50 or 30, respectively. This does not negatively affect this weft thread S2 or S1, since it is not moved in the weft direction SR in this phase.
The device according to the invention and the method according to the invention can also be readily expanded to include more than two weft threads.
In addition to the advantages which were initially described, the presented method makes it possible to precisely produce highly diverse weave patterns. For example, weft threads having various widths and/or materials and/or having different pretreatment can be used in order, for example, to obtain a suitable structure and/or pattern. Two (or more) identical weft threads can also be used, of course. One further advantage of using identical weft threads is that the machine does not need to be stopped when the supply of one weft thread has been initially inserted into the woven fabric and then a switch to the other weft thread is carried out without a pause. While this weft thread is being inserted, the weft thread that previously ran out can be replaced in the appropriate weft thread storage unit. In general, longer runtimes can be achieved with identical weft materials and by exchanging the weft thread storage units.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 203 879.4 | Apr 2021 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/057579 | 3/23/2022 | WO |
