Double chain-switch sewing machine, and method for forming a stitch pattern in a multilayer sewing material

Abstract

The invention relates to a double chain-switch sewing machine, in particular a multi-needle double chain-switch sewing machine, comprising: a sewing material support for multilayer sewing material (28), in particular mattress panels or quilts; and sewing elements, namely at least one needle (31) for an upper thread (39), at least one looper (40) for a lower thread (42), and at least one spreader that is associated with the looper (40) and forms a thread triangle; and a thread delivery device (43), wherein the upper thread (39) is guided through the thread delivery device (43), and wherein a length of upper thread (39) to be supplied and / or a thread tension of the upper thread (39) is controlled via the thread delivery device (43) depending on the relative position of the sewing elements.

Description

[0001] Double chain sewing machine and method for forming a sewing pattern in a multi-layered sewing material

[0002] The invention relates to a double chain stitch sewing machine, in particular a double chain stitch multi-needle sewing machine with a fabric support for multi-layered materials, especially mattress panels or quilts, and sewing elements, namely at least one needle for an upper thread, at least one hook for a lower thread, and at least one spreader associated with the hook for creating a thread triangle, as well as a thread feeder. Furthermore, the invention relates to a method for forming a stitch pattern in a multi-layered material, in which at least one upper thread and one lower thread are joined as a chain stitch, in particular as a double chain stitch, by means of a plurality of sewing elements, namely at least one needle and one hook, wherein the upper thread is fed via a thread feeder.

[0003] Various multi-needle sewing machines are known from the prior art. A distinction must be made between multi-needle lockstitch machines and multi-needle chainstitch machines. For example, US patent 5,005,499 discloses a multi-needle lockstitch machine with one or more needle bars, each of which is equipped with a plurality of stitch-forming needles. In this previously known multi-needle lockstitch machine, individual needles can be moved back and forth between two positions by pneumatic cylinders, depending on the sewing pattern to be sewn. In the first position, these needles participate in the sewing process, and in the second position, they are raised so that they do not pierce the fabric during the sewing process.

[0004] In the chain stitch or double chain stitch, a needle brings an upper thread to the lowest point of its path and, during a subsequent upward movement, forms a thread loop. As the needle returns to its highest position after forming the thread loop, a looper engages the loop with a bobbin thread. The upper thread is also called the needle thread, and the bobbin thread is also called the looper thread. When the fabric is transported to the next stitch in the sewing direction and the needle moves downward again, the looper swings back to its starting position, while the needle pierces a thread triangle formed by the thread loop and the bobbin thread, thus creating a link in the chain stitch. Compared to the straight stitch, the chain stitch or double chain stitch...The double chain stitch has the advantage of producing smooth seams and largely avoiding so-called displacement puckering, since the interlocking of the upper and lower threads is not pulled into the fabric as with the straight stitch, but lies on the underside of the fabric. Furthermore, thinner sewing threads can be used when executing chain stitches and double chain stitches compared to the straight stitch. Additionally, the chain stitch and double chain stitch have the advantage that the upper thread is subject to far less abrasion compared to the straight stitch, which is due to the fact that less thread is pulled back and forth through the eye of the needle with each stitch in a double chain stitch. Overall, the chain stitch and double chain stitch are therefore stronger than the straight stitch. One disadvantage of the chain stitch is...The double chain stitch is characterized by the fact that even minor skipped stitches or a thread break in the area of ​​the upper and / or lower thread can easily cause the thread chain to open.

[0005] Various multi-needle chain stitch sewing machines with stitch-forming sewing units are known from the prior art. Typically, such multi-needle chain stitch sewing machines have one or more needle bars with attached needles, as well as a corresponding number of hook shafts to which hooks are attached. The needle bars and hook shafts are arranged on opposite sides of a fabric support, which is designed as a perforated plate, with a needle hole provided in the fabric support for each needle. Different stitch patterns can be created in a single piece of fabric using such multi-needle chain stitch sewing machines. These patterns can also consist of individual, identical or different stitch elements spaced apart from one another.To create such stitch patterns in a fabric, it is known to move the fabric on the fabric support not only in the main sewing direction, but also in the opposite direction and at least at right angles to it. However, when executing chain stitches and double chain stitches, it is essential that each stitch is executed cleanly, so the utmost care must be taken with regard to the formation of a stitch seam. If, for example, several stitch pattern elements are arranged at intervals within a fabric, the fabric is moved to the point where the next stitch pattern element is to be sewn after the first stitch pattern element has been completed. In this position, a needle bar carrying the needles is in a raised position, and a hook shaft carrying the hooks is in a swung-back position.In this procedure, the lower thread, which is pulled from a cone, is guided along the underside of the fabric without being attached to the fabric in this area.

[0006] Alternatively, it can be provided that, in multi-needle chain stitch sewing machines, the upper thread is cut by a cutting device after completion of a sewing pattern element and that a completely new sewing process is initiated at the beginning of the next sewing pattern element.

[0007] Another quality indicator in the production of quilts and mattress panels is the quality of the seams between the sewn layers of material. A high-quality seam is characterized by the absence of skipped stitches, sufficient strength, and a thread-to-bottom ratio of approximately 3:1. This ratio can vary depending on the thickness of the quilt or mattress panel. It is considered a disadvantage if the top thread is visible as a loop on the underside of the fabric. Ideally, and therefore indicating high quality, the top thread should only be visible at the point where the needle enters the fabric. The bottom thread should form a clear loop, connecting the individual needle points.To achieve this result, it is advantageous to use a thread feeder that, firstly, provides a sufficient supply of thread for the needle to pierce the fabric with the upper thread, thus forming a loop beneath the fabric. Secondly, after the upper thread has joined with the lower thread, the upper thread should be retracted far enough so that it forms no loop, or at most a very small one, beneath the fabric.

[0008] The invention is therefore based on the objective of further developing a generic double chain stitch sewing machine or a generic method for forming a sewing pattern in such a way that, through the interaction of the sewing elements, needle, gripper and fingers in combination with their relative movements to each other, a thread distribution can be achieved in which the upper thread forms as few loops as possible under the fabric being sewn, so that, moreover, increased consumption of the upper thread in the seam is reduced and the stitch is sufficiently strong.

[0009] The solution to this problem in a double chain stitch sewing machine according to the invention provides that the upper thread is guided through the thread feeder device and that a thread length of the upper thread to be supplied and / or a thread tension of the upper thread is controlled via the thread feeder device depending on the position of the sewing elements relative to each other.

[0010] The thread feeder device according to the inventive embodiment of the double chain stitch sewing machine thus makes it possible to provide a sufficient thread length when the needle enters the fabric below the fabric, so that a secure engagement of the gripper in the thread loop of the upper thread is ensured. After the gripper has been withdrawn from this thread loop and the needle is again in downward movement to form the next thread loop, the thread feeder device controls the thread length of the upper thread and / or the thread tension of the upper thread depending on the position of the sewing elements, so that the upper thread is withdrawn from the previously executed stitch via the thread feeder device to such an extent that the upper thread forms no or only a very small thread loop on the underside of the fabric.

[0011] The thread feeder device according to the inventive embodiment of the double chain stitch sewing machine thus enables control of the thread feed in a needle stitch, whereby first a sufficient thread length and thread tension is enabled for the formation of the thread loop of the upper thread below the fabric being sewn, before in a second control setting the upper thread previously connected to the lower thread is retracted into the fabric to such an extent that the upper thread is only visible in a small quantity below the fabric being sewn.

[0012] According to a further feature of the invention, the thread feeder device has three thread guides, at least one of which is translationally movable relative to the other two. This design allows for the achievement of two different thread feed directions. In the first thread feed direction, where a sufficiently large loop of the upper thread is to be provided in the area below the fabric being sewn, the upper thread essentially passes through the three thread guides of the thread feeder device directly. In the second position, where as little of the upper thread as possible should remain below the fabric being sewn, the upper thread takes a longer path through the three thread guides, insofar as one thread guide is translationally movable relative to the other two, thus providing a longer path for the upper thread.

[0013] Furthermore, the thread feeder is driven by an oscillating motion, with adjustable amplitudes. This design allows the thread feeder to be adjusted for different fabric layers, whose thickness and / or properties vary depending on the product being manufactured. Consequently, different amplitudes of the oscillating drive of the thread feeder can also be adjusted, thus allowing the size of the thread loop beneath the fabric to be adjusted, while simultaneously enabling the retraction of the upper thread by the thread feeder to be adjusted according to the needle's path through the fabric.

[0014] In a preferred embodiment of the double chain stitch sewing machine according to the invention, the thread feeder device has three parallel, strip- or tube-shaped elements, each of which has an opening for the passage of the upper thread belonging to the needle, wherein the openings in two outerly arranged elements are aligned with each other, and wherein the element arranged between the two outerly arranged elements is movable relative to the two outerly arranged elements, and the opening in the element arranged between the two outerly arranged elements is arranged in at least one specific position, preferably coaxially aligned with the openings in the two outerly arranged elements.However, it is also possible that the openings in the elements are arranged with an offset from each other in this specific position, whereby the upper thread is preferably guided through the openings with as little deflection as possible. The openings can be circular or elongated.

[0015] If the openings in the three elements are arranged coaxially, the shortest path for the upper thread through the thread guide is achieved, one that least adversely affects the upper thread, particularly by applying a force perpendicular to its longitudinal axis and / or by providing additional friction. In this way, the needle can guide the upper thread down to a point below the fabric layer, thus creating the thread loop for the subsequent engagement of the hook. After the hook has withdrawn from the upper thread loop and formed the chain stitch, the middle element is moved relative to the two outer elements in such a way that the thread is retracted by the movement of the middle element.The upper thread is retracted in such a way that the previously used thread loop is pulled back as far as possible to the underside of the fabric, so that the upper thread is only visible as a point. For a good sewing result, it may still be sufficient if the upper thread forms a small loop on the underside of the fabric. Overall, this reduces the consumption of upper thread. At the same time, a sufficiently strong seam is formed in the fabric. These advantages are particularly noticeable with double chain stitch sewing machines that allow fabric transport not only in the sewing direction but also at an angle to it, so that more complex seams and patterns can be created.

[0016] In addition to the embodiment described above, it is also possible that not the middle element, but an outer element is movable relative to the other two elements.

[0017] According to a further feature of the invention, the embodiment described above is further developed such that the element arranged between the two outer elements is movable in the direction of its longitudinal axis relative to the two outer elements. Such a direction of movement can be easily implemented structurally and ensures a reliable sewing process. The same applies to the embodiment with an outer element that is movable relative to the other elements.

[0018] Preferably, ring-shaped guides made of a wear-resistant and / or friction-reducing material, such as ceramic, are arranged in the openings. This significantly reduces the frictional stress on the upper thread, thus also considerably reducing the risk of thread breakage. Furthermore, a wear-resistant material for these guides prevents the formation of cuts in the guides. This reduces the risk of thread breakage and significantly increases the service life of the guides. Maintenance intervals and repair requirements are extended or reduced.

[0019] According to a further feature of the invention, the thread feeder for each needle has three pins arranged parallel to one another, wherein two pins are fixed and the third pin is movable relative to the two fixed pins, deflecting the upper thread guided between them. This embodiment represents an alternative to the embodiment already described above with the three elements movable relative to one another.

[0020] Preferably, in a sewing machine according to the invention, the thread feeder device has a drive, in particular a servo motor, which drives a shaft with levers, wherein the element arranged between the two outerly arranged elements or the third pin is connected directly or indirectly to one of the levers. A servo movement can be provided, whereby a signal from an incremental encoder of a rotary encoder is used. Overall, the drive and the thread feeder device can be arranged in the area of ​​an upper sewing system or an upper thread tensioning device.

[0021] It has also proven advantageous to move the element arranged between the two outer elements using a crank mechanism, the crank mechanism having at least two positions of a phase setting.

[0022] Finally, in a sewing machine according to the invention, the thread feeder interacts with a thread cutting device, so that, for example, after the completion of a sewing pattern, the upper thread is cut and the fabric is moved to an area where a further, subsequent sewing pattern is to be sewn. This design also serves to reduce upper thread consumption and, moreover, to avoid extensive post-processing steps for the fabric, namely the removal of unsewn upper thread. Thread cutting devices for the upper thread are known in the prior art. With the design according to the invention, namely the interaction of the thread feeder with the thread cutting device, the effectiveness of the thread cutting device can be enhanced.For example, the tension in the upper thread can be adjusted by the thread feeder so that the thread cutter reliably performs the cutting process. The interaction between the thread feeder and the thread cutter is therefore based on a control mechanism for the thread feeder that affects the thread tension and / or thread length to ensure the upper thread is cut as intended.

[0023] To solve the problem described above, a method according to the invention provides that the upper thread is guided by the thread feeder device in such a way that the length of the upper thread to be supplied and / or the thread tension of the upper thread is controlled via the thread feeder device depending on the position of the sewing elements relative to each other.

[0024] In the method according to the invention, the upper thread can thus be controlled with regard to its thread length or its thread tension by means of the thread feeder device, so that the two different requirements already described above, namely providing a sufficiently large thread loop and subsequently retracting the upper thread for a high-quality design of the thread chain, can be met.

[0025] Preferably, in the method according to the invention, the thread feeder device has three parallel, rib- or tube-shaped elements, each of which has an opening for the passage of the upper thread belonging to the needle, wherein the openings in two outerly arranged elements are aligned with each other and wherein the element arranged between the two outerly arranged elements is moved relative to the two outerly arranged elements, wherein the opening in the element arranged between the two outerly arranged elements is arranged in at least one certain position, in particular coaxially aligned with the openings in the two outerly arranged elements.It is also possible for the upper thread to be guided through the openings in the elements, which are arranged with an offset from one another in this specific position, with the upper thread preferably being guided through the openings as free as possible from deflections within the openings. According to a further feature of the method according to the invention, the element located between the two outer elements is moved in an oscillating motion relative to the two outer elements along its longitudinal axis. Finally, the method according to the invention provides that the thread feeder is driven in an oscillating motion, with the amplitude of the oscillating movement being adjusted depending on the stitch formation and / or thread arrangement on the material being sewn.

[0026] Further features and advantages of the invention will become apparent from the following description of the accompanying drawing. The drawing shows:

[0027] Fig. 1 shows a multi-needle chain stitch sewing machine in a schematically represented side view;

[0028] Fig. 2 shows the multi-needle chain stitch sewing machine according to Fig. 1 in a perspective view;

[0029] Fig. 3 shows a chain stitch of the desired quality; Fig. 4 shows a chain stitch of lower quality;

[0030] Fig. 5 is a schematic representation of the multi-needle chain stitch sewing machine according to Figures 1 or 2 with a thread feeder device;

[0031] Fig. 6 shows a part of the thread feeder device according to Fig. 5 in a first position and

[0032] Fig. 7 shows the part of the thread feeder device according to Fig. 6 in a second position. A multi-needle chain stitch machine according to Figures 1 and 2 has a machine frame in which a row of needles 2 is located in the upper part, with the individual driven needles 31 arranged next to each other essentially perpendicular to the plane of the image. Reference numeral 3 denotes a conventional presser foot and reference numeral 4 denotes a row of hooks corresponding to the row of needles 2. Below the layers of the fabric 28 brought together in the sewing area is a stitch plate 13 or a sewing table. This stitch plate 13 serves as a support for the fabric.

[0033] The material to be sewn 28 consists of an upper layer 6, for example, a top fabric, a mattress ticking, or the like, and is pulled from a storage roller 5 and guided under a platform for an operator around guide rollers 8, 9, 10, 11, and 12 into the sewing area, i.e., into the area between the presser foot 3 and the stitch plate 13 or the material support. The layer 6 of the material to be sewn 28 consists of non-elastic material. Furthermore, the material to be sewn 28 has another layer 15 made of elastic material, for example, foam, which is stored on a storage roller 14. Guide rollers 16, 17, 18, and 19 are also provided for this elastic layer 15.

[0034] The layer 15, made of elastic material, is sewn together in the sewing unit with the upper layer 6, made of inelastic material, and another layer 21. The finished sewn item 28 is then pulled out of the sewing unit in the direction of arrow 29. The feeding of layers 6, 15, and 21 is provided by the force acting on the finished sewn item 28. After leaving the sewing unit, the finished sewn item 28 passes through a section with deflection and guide rollers 25, 26, and 27, which, among other things, tighten the sewn item 28 in the exit area of ​​the sewing unit.

[0035] The lower layer 21, which is pulled off from a storage roller 20, is fed to the sewing unit via deflection or guide rollers 22, 23 and 24, whereby the lower layer 21 can also be fed together with the upper layer 6 and the layer 15 of the deflection roller 12 according to Fig. 1.

[0036] Opposite the deflection pulley 12, a support 30 is arranged, the distance to the outer circumference of the deflection pulley 12 and the support 30 being adjustable, i.e., either the deflection pulley 12 is movable relative to the support 30 or the support 30 is movable relative to the deflection pulley 12. Alternatively, it can be provided that both the support 30 and the deflection pulley 12 are adjustable in the vertical direction.

[0037] As shown in Fig. 2, the fabric 28 leaves the multi-needle chain stitch sewing machine with a stitch pattern 32. This stitch pattern 32 can have different designs, and in order to be able to sew a variety of stitch patterns 32, the support 30 is movable relative to the needle row 2 and in its longitudinal direction. For moving the support 30, an electric motor 35 is provided in the machine frame 1, which has a pinion 37 on its drive shaft 36. This pinion 37 meshes with the teeth of a rack 38, which is fixedly connected to the support 30.

[0038] Figure 2 further shows that the needles 31 are arranged in two parallel rows 2, one behind the other in the sewing direction. Each needle 31 is assigned a gripper 40 of a gripper row 4. The gripper row 4 is formed by a gripper shaft 33, which is moved in an oscillating motion by an eccentrically designed drive (not shown in detail). This oscillating motion is transmitted to the grippers 40 attached to the gripper shaft 33, which, in conjunction with the oscillating up-and-down movement of the needles 31, create double chain stitches in the fabric 28. For this purpose, each needle 31 brings an upper thread 39 to the lowest point of its path, which lies below the fabric 28 between the presser foot 3 and the stitch plate 13 in an area such that the gripper 40 arranged there, which is assigned to the needle 31, can grasp a thread loop 41 left there during the upward movement of the needle 31.While the needle 31 is moved back from its lowest position to its highest position, the gripper 40 moves towards the thread loop 41 and carries a lower thread into the thread loop 41 of the upper thread 39.

[0039] In the next step, the fabric 28 is transported in the direction of arrow 29 before the needle 31 is moved again from its highest to its lowest position. At this point, the hook 40 swings back to its starting position, forming a thread triangle from the thread loop 41 of the upper thread 39 and the lower thread 42, into which the needle 31 pierces. In this way, a double chain stitch is formed, consisting of an upper thread 39 lying on the top of the fabric 28 and penetrating it, and a lower thread 42 lying on the underside of the fabric 28.

[0040] A preferred embodiment of a chain stitch is shown in Fig. 3. The thread loop 41 of the upper thread 39 can be seen arranged below the fabric 28 in such a way that the upper thread 39 is not deflected by the lower thread 42 towards an underside 34 of the fabric 28.

[0041] In contrast, Fig. 4 shows an arrangement of the upper thread 39 on the underside 34 of the fabric 28 that should be avoided as much as possible, such that a large length of the upper thread 29, forming the thread loop 41, lies against the underside 34 of the fabric.

[0042] To prevent close-to-close stitching as shown in Fig. 4, or to create close-to-close stitching as shown in Fig. 3, the double chain stitch sewing machine has a thread feeder 43. The thread feeder 43 controls the length of the upper thread 39 to be fed, depending on the position of the sewing elements, namely the needles 31, the hooks 40, and the spreaders (not shown). For this purpose, the thread feeder 43 has three parallel, rib-shaped elements 44, 45, each with an opening 46 (Figs. 6 and 7) for each needle 31, allowing the upper thread 39 belonging to that needle 31 to pass through. The openings 46 in the two outermost elements 44 are aligned with each other. The element 45 located between the two outermost elements 44 is movable relative to them.The movement of element 45 to elements 44 takes place in the direction of the longitudinal axis of elements 44 and 45.

[0043] In a position of elements 44 and 45 shown in Fig. 6, all openings 46 are coaxially aligned, so that the upper thread 39 passes through all openings linearly and over a short path. In this position, the thread feeder 43 provides a length of upper thread 39 sufficient to form a sufficiently large thread loop 41 below the fabric 28 such that, after the needle 31 returns, the gripper 40, pivoting towards the thread loop 41, can engage the thread loop 41.

[0044] The gripper 40 then pivots back out of the thread loop 41 and, via the thread feeder device 43, the upper thread 39 is retracted after forming a chain link from the upper thread 39 and the lower thread 42, i.e., the thread loop 41 moves towards the underside 34 of the fabric 28 to assume a position as shown in Fig. 3.

[0045] For this purpose, element 45 is moved in the longitudinal axis direction relative to elements 44 of the thread feeder device 43, so that the openings 46 are changed from their coaxially aligned arrangement according to Fig. 6 to an arrangement according to Fig. 7. This movement lengthens the path of the upper thread 39 to the fabric 28, and since the upper thread 39 cannot be additionally drawn from a thread supply, the thread loop 41 necessarily shortens and is thereby pulled out of the fabric 28 through the needle hole until only a minimal portion of the upper thread 39 is located below, i.e., in the area of ​​the underside 34 of the fabric 28, as shown in Fig. 3.

[0046] In the openings 46, ring-shaped guides 47 made of a ceramic material are inserted to guide the upper thread 39 in the openings 46 with as little friction as possible.

[0047] For the movement of element 45 relative to elements 44, a crank drive 48 is arranged, which has a variable phase adjuster 49. The crank drive 48 has levers, namely a first link 50, which is arranged to pivot about a pivot point 51. The link 50 is connected to a connecting link 52, the free end of which is pivotably attached to one end of element 45. The connecting link 52 is pivotally arranged on the link 50, and the link 50 and connecting link 52 are moved about the pivot point 51 by means of a link 54 articulated to an eccentric drive 53.

[0048] The linkage 50 has three connection positions 55 at its end furthest from the pivot point 51. By changing the connection positions 55, the amplitude of the movement of the element 45 relative to the elements 44 can be adjusted. The entire crank drive 48 is displaceable relative to the machine frame 1 in the direction of the thread feeder 43. The displacement of the crank drive 48 is effected by a pneumatic cylinder 56, which is connected to the machine frame 1 via a threaded rod 57 for adjusting the working range of the crank drive. The displacement of the crank drive 48 can be set via the combination of the pneumatic cylinder 56 and the threaded rod 57. This adjustment can also be used to activate a thread cutter (not shown) that interacts with the thread feeder 43.Activation is effected via the pneumatic cylinder 56, whereby cutting elements for cutting the upper thread 39 may be provided. Thread cutting devices for the upper thread 39 are known per se from the prior art. With the embodiment according to the invention, namely the interaction of the thread feeder device 43 with the thread cutting device, the effectiveness of the thread cutting device can be enhanced. For this purpose, for example, the tension in the upper thread 39 can be adjusted by the thread feeder device 43 such that the thread cutting device reliably performs the cutting process.

[0049] Reference sign

[0050] 1. Machine frame

[0051] 2nd row of needles

[0052] 3. Push button foot

[0053] 4th row of grippers

[0054] 5. Memory roll

[0055] 6. upper layer

[0056] 7th podium

[0057] 8. Deflection pulley

[0058] 9. Pulley

[0059] 10. Pulley

[0060] 11. Deflection pulley

[0061] 12. Pulley

[0062] 13. Stitch plate

[0063] 14. Spool reel

[0064] 15. Location

[0065] 16. Pulley

[0066] 17. Deflection pulley

[0067] 18. Pulley

[0068] 19. Pulley

[0069] 20. Memory roll

[0070] 21. Location

[0071] 22. Deflection pulley

[0072] 23. Deflection pulley

[0073] 24. Deflection pulley

[0074] 25. Leadership role

[0075] 26. Leadership role

[0076] 27. Leadership role

[0077] 28. Sewing materials

[0078] 29. Arrow

[0079] 30th edition

[0080] 31. Needle

[0081] 32. Sewing pattern

[0082] 33. Gripper shaft 34. Underside

[0083] 35. Electric motor

[0084] 36. Drive shaft

[0085] 37th sprocket

[0086] 38. Rack

[0087] 39. Top thread

[0088] 40. Gripper

[0089] 41. Thread loop

[0090] 42. Bottom thread

[0091] 43. Thread feeder device

[0092] 44th element

[0093] 45th element

[0094] 46. ​​Opening

[0095] 47. Leadership

[0096] 48. Crank drive

[0097] 49. Phase adjuster

[0098] 50. Handlebars

[0099] 51. Pivot point

[0100] 52. Connecting link

[0101] 53. Eccentric drive

[0102] 54. Handlebars

[0103] 55. Connection position

[0104] 56. Pneumatic cylinder

[0105] 57. Threaded rod

Claims

Patent claims 1. Double chain stitch sewing machine, in particular a double chain stitch multi-needle sewing machine with a fabric support for multi-layered fabric, in particular mattress panels or quilts, and sewing elements, namely at least one needle for an upper thread, at least one gripper for a lower thread and at least one spreader associated with the gripper which opens a thread triangle, as well as a thread feeder device, characterized in that the upper thread (39) is guided through the thread feeder device (43) and that a thread length of the upper thread (39) to be supplied and / or a thread tension of the upper thread (39) is controlled via the thread feeder device (43) depending on the position of the sewing elements relative to each other.

2. Sewing machine according to claim 1, characterized in that the thread feeder device (43) has three thread guides, at least one of which is translationally movable relative to the two other thread guides.

3. Sewing machine according to claim 1 or 2, characterized in that the thread feeder device is driven in an oscillating manner, wherein the amplitudes of an oscillating movement are adjustable.

4. Sewing machine according to one of claims 1 to 3, characterized in that the thread feeder device (43) has three parallel, strip- or tube-shaped elements (44, 45) which have an opening (46) for each needle (31) for the passage of the upper thread (39) belonging to the needle (31), wherein the openings (46) are divided into two the externally arranged elements (44) are aligned with each other and wherein the element (45) arranged between the two externally arranged elements (44) is movable relative to the two externally arranged elements (44) and the opening (46) arranged in the element (45) arranged between the two externally arranged elements (44) is arranged in at least one position coaxially aligned with the openings (46) in the two externally arranged elements (44).

5. Sewing machine according to claim 4, characterized in that the element (45) arranged between the two outer elements (44) is movable in the direction of its longitudinal axis relative to the two outer elements (44).

6. Sewing machine according to claim 4 or 5, characterized in that ring-shaped guides (47) made of a wear-resistant and / or friction-reducing material, for example ceramic, are arranged in the openings (46).

7. Sewing machine according to one of claims 1 to 3, characterized in that the thread feeder device (43) for each needle (31) has three pins aligned parallel to each other, wherein two pins are fixed and the third pin is movable relative to the two fixed pins in such a way as to deflect the upper thread (39) guided between the fixed pins.

8. Sewing machine according to one of claims 1 to 7, characterized in that, that the thread feeder device (43) has a drive, in particular a servo motor, which drives a shaft (53) with levers (50, 52, 54), wherein the element (45) arranged between the two externally arranged elements (44) or the third pin is connected directly or indirectly to a lever (52).

9. Sewing machine according to one of claims 4 to 6, characterized in that the element (45) arranged between the two externally arranged elements (44) is movable by means of a crank mechanism (48) and the crank mechanism (48) has at least two positions of a phase adjuster (49).

10. Sewing machine according to one of claims 1 to 9, characterized in that the thread feeder device (43) cooperates with a thread cutting device.

11. Method for forming a sewing pattern in a multi-layered fabric, in which at least one upper thread and one lower thread are joined as a chain stitch, in particular as a double chain stitch, by means of a plurality of sewing elements, namely at least one needle and one gripper, wherein the upper thread is supplied via a thread feeder device, characterized in that the upper thread (39) is guided by the thread feeder device (43) in such a way and that a thread length of the upper thread (39) to be supplied and / or a thread tension of the upper thread (39) is controlled via the thread feeder device (43) depending on the position of the sewing elements relative to each other.

12. Method according to claim 11, characterized in that, that the thread feeder device (43) has three parallel, rib- or tube-shaped elements (44, 45) which have an opening (46) for each needle (31) for the passage of the upper thread (39) belonging to the needle (31) or a pin, wherein the openings (46) or pins are located in two externally arranged elements (44) are arranged in alignment with each other and wherein the element arranged between the two outer elements (44) (45) is moved relative to the two outer elements (44), wherein the opening (46) or pins arranged in the element (45) arranged between the two outer elements (44) are arranged in at least one position preferably coaxially aligned with the openings (46) or pins in the two outer elements (46).

13. Method according to claim 12, characterized in that the element (45) arranged between the two outer elements (44) is moved in the direction of its longitudinal axis oscillating relative to the two outer elements (44).

14. Method according to one of claims 11 to 13, characterized in that the thread feeder device (43) is driven in an oscillating manner, wherein amplitudes of an oscillating movement are set depending on a stitch formation and / or thread arrangement on the material to be sewn (28).

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