Portal Sewing Unit

Abstract

The portal sewing unit is used to sew workpieces in a sewing work area with a width exceeding 1 m. The portal sewing unit comprises a portal frame (2) having an upper bridge rail (3), a lower bridge rail (4), and two end-side portal supports (6, 7), and the end-side portal supports (6, 7) form a portal (5) of the portal frame (2). The upper drive (48) is used to move the upper sewing part (8) along the upper bridge rail (3), and the lower drive (49) is used to independently move the respective lower sewing parts (10, 11) along the lower bridge rail (4). Through the sewing part controller (50) of the drives (48, 49), the upper sewing part (8) selectively cooperates with one or the other of the two lower sewing parts (10, 11) to form stitches in the workpiece. Thereby, a portal sewing unit with increased workpiece throughput is obtained.

Description

Technical Field

[0001] This patent application claims the priority of German Patent Application DE 10 2022 206 251.5, the content of which is incorporated herein by reference.

[0002] The present invention relates to a portal sewing unit for sewing workpieces in a sewing work area with a width exceeding 1 m.

Background Art

[0003] Such portal sewing units are commercially known. Patent Documents 1, 2, 3, 4, 5, and 6 each disclose a portal sewing unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to develop a portal sewing unit of the type described at the beginning and increase the throughput of workpieces.

Means for Solving the Problems

[0006] According to the present invention, this object is achieved by a portal sewing unit having the features described in claim 1.

[0007] According to the present invention, it is recognized that by using a selectively usable lower sewing part, one of the lower sewing parts can be temporarily stopped. This can be used for various purposes, for example, by replacing each lower sewing part to change the lower thread. Also, for example, overheating of the lower sewing part that can be measured by a temperature sensor can be prevented by the replacement function. And when the lower sewing part has a lower thread supply device, replenishment can be performed during the temporary stop of the operation of the lower sewing part that is not currently used for sewing. Also, it is possible to change the color between different colors of the lower thread stored in each lower sewing part. It is also possible to change between different thread thicknesses and / or thread qualities. The portal sewing unit can be provided with a plurality of upper sewing parts, for example, two upper sewing parts.

[0008] The width of the sewing work area of the portal sewing unit can be 1.5 m or more, 2 m or more, 2.5 m or more, up to a maximum of 3 m. The width of the sewing work area can be further increased according to the sewing work to be performed. The portal sewing unit can be used, for example, for sewing a very wide range of cargo nets.

[0009] In the embodiment according to claim 2, both lower sewing parts can be driven by one drive source, but independently of each other. Alternatively, each of the two lower sewing parts can also be operably connected to a dedicated drive source.

[0010] In the embodiment according to claim 3, the change between the lower sewing parts cooperating with the upper sewing part can be carried out during replacement, so that the throughput of the workpiece can be increased.

[0011] The embodiment according to claim 4 is more efficient because sewing can be continued even during replacement.

[0012] The exchange performed by the automated method according to claim 5 is independent of the operator and can be carried out without manual intervention. Alternatively, the exchange can also be performed semi-automatically or manually.

[0013] By the synchronization according to claim 6, the operating reliability of the sewing unit is improved. In addition to synchronization, it is also possible to calibrate the positions of the respectively selected lower sewing part and upper sewing part. Such calibration can be performed using a sensor system and / or a stepper motor drive and / or a calibration stop part.

[0014] The synchronization accuracy or positioning accuracy according to claim 7 has actually been proven to be successful. This accuracy is less than 0.25 mm, less than 0.2 mm, less than 0.15 mm, and can be, for example, about 0.1 mm.

[0015] The rack according to claim 8 has been proven to be effective as a transmission member. When using the rack for this purpose, each lower sewing part can be equipped with a dedicated transmission gear.

[0016] Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the drawings.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

Figure 30

Figure 31

Figure 32

Figure 33

Figure 34

Figure 35

Figure 36

Figure 37

Figure 38

Figure 39

DETAILED DESCRIPTION OF THE INVENTION

[0018] The portal (gate-shaped) sewing unit 1 shown in its entirety in FIGS. 1 and 2 is used to sew a work piece (sewing object) in a work area with a width B greater than 1 m, which is 3 m in the illustrated embodiment. The sewing unit 1 includes a portal frame 2 having an upper bridge rail 3 and a lower bridge rail 4 (see also FIG. 10). Two opposing end-side portal supports 6 and 7 for forming a portal 5 for the work piece are also attached to the portal frame 2.

[0019] Hereinafter, in order to facilitate understanding of the positional relationship, a rectangular coordinate system xyz is used. In FIG. 2, the x-direction extends rightward along the extension line B in the width direction, the y-direction is perpendicular to the drawing plane of FIG. 2 and extends into the figure, and the z-direction extends upward in FIG. 2.

[0020] The portal plane of the portal 5 extends parallel to the xz plane.

[0021] The upper bridge rail 3 serves to guide an upper sewing part 8 having an upper stitch former 9 in the form of a sewing needle for guiding an upper thread (not shown). Depending on the design of the portal sewing unit 1, a plurality of upper sewing parts 8, for example two upper sewing parts, can also be used.

[0022] The lower bridge rail 4 serves to guide two lower sewing parts 10, 11 (see also FIG. 12). The two lower sewing parts 10, 11 each comprise a looper-shaped lower stitch former 12, 13 having a looper thread supply part in a bobbin-shaped looper thread supply container.

[0023] The loopers or lower threads of the lower sewing parts 10, 11 can be composed of different colors and different thread qualities.

[0024] The sewing unit 1 is used to sew a two-thread stitch, for example a two-thread lock stitch or a two-thread chain stitch.

[0025] At the end-side stop positions of the lower sewing parts 10, 11, it is possible to access the bobbins through the access windows 14, 15 of the unit housing 16 (see FIGS. 1 and 2).

[0026] During sewing, the workpiece holder 17 is at least partially placed on the work plate 18 of the work table 19 of the sewing unit 1 (see also FIG. 13). Two workpiece holders such as the workpiece holder 17 are stored intermediate for the purpose of loading the workpiece and taking out the sewn workpiece using the multi-stage lifting table 20 of the sewing unit 1. The workpiece holder gripping device 21 including the gripping rail 22 is used to move each mounted workpiece holder 17 from the storage position shown in FIG. 1 to the sewing position (see also FIG. 13). The gripping rail 22 is linearly guided at both ends via the respective guide rails 23, 24. This linear guidance is driven via the drive motors 25, 26. When the sewing area is small, only one motor at the center of the gripping rail can also be used.

[0027] The two bridge rails 3, 4 and the gripping rail 22 extend parallel to the x-axis. The two guide rails 23, 24 extend parallel to the y-axis.

[0028] The multi-stage lifting table 20 has two table plates 27, 28, which are arranged stacked at a plurality of heights and are fixedly connected to each other for accommodating the respective workpiece holders 17. The upper table plate 27 of the two table plates provides an upper workpiece holder arrangement position, and the lower table plate 28 of the two table plates provides a lower workpiece holder arrangement position.

[0029] The table plates 27, 28 and the work plate 18 extend horizontally, that is, parallel to the xy plane.

[0030] The multi-stage lifting table 20 is a workpiece holder arrangement device. The two table plates 27, 28 are thus part of the arrangement table. Further, this workpiece holder arrangement device is attached with a guide track 29 having two opposing guide flanges 30, 31 each provided with a track run (track groove) 32.

[0031] During operation, the sewing unit 1 cooperates with a plurality of workpiece holders 17 that can be configured similarly. Therefore, it is sufficient to describe one of the workpiece holders 17 in more detail below.

[0032] FIG. 3 shows the workpiece holder 17, the upper table plate 27, and the two guide flanges 30, 31 of the guide track 29.

[0033] The workpiece holder 17 has a holding frame 33, to which a workpiece 34 to be sewn in the form of an intersecting strap 35 is fixed. The holding frame 33 has a plurality of holding frame sections 36, 37, 38, 39, and in the illustrated embodiment, there are a total of four (see also FIG. 4). In each case, adjacent sections of the holding frame sections 36 to 39 are articulated to each other via section joints (partial joints) 40, 41, 42 (see, for example, FIG. 9). The articulation axes of these section joints 40 to 42 extend parallel to the x-axis.

[0034] Since the pivot points of the section joints 40 to 42 are within or near the neutral line of the workpiece 34, the workpiece 34 is neither stretched nor compressed unnecessarily while the holding frame sections 36 to 39 pivot relative to each other.

[0035] Alternative embodiments of the workpiece holder can also have a different number of such holding frame sections, specifically, 2, 3, 5 or more such holding frame sections. The design of such a workpiece holder usually has a maximum of 20 such holding frame sections that are articulated to each other.

[0036] In the direction perpendicular to the articulation axes of the section joints 40 to 42, i.e., in the y direction, the depth extension of the workpiece holder 17 is, in the illustrated embodiment, approximately 3 m and can reach at least 1 m, at least 1.5 m, at least 2 m, at least 2.5 m, depending on the design of the workpiece holder 17, and can also be made greater than 3 m. The depth extension of the workpiece holder in the y direction is usually at most 10 m.

[0037] Figure 3 shows the starting position of the workpiece holder 17 with the pre-loaded workpiece 34 that has been completely sewn by the sewing unit 1. Sewing is performed at the intersection point 43 where the straps 35 extending in the lateral and longitudinal directions of the workpiece 34 intersect.

[0038] The workpiece holder 17 has a holding base 44 on which the workpiece 34 is placed. In particular, in the region of the intersection point 43 to be sewn and, in some cases, in the further overlapping portions to be sewn, the holding base 44 has an opening through which the workpiece 34 can be freely accessed from above and below.

[0039] Fixing elements 45 for fixing the workpiece 34 are attached to the holding base 44. These fixing elements 45 can be tension elements and / or clamp elements. Alternatively or additionally, the workpiece 34 can also be fixed to the holding base 44 by frictional connection.

[0040] A part of the holding frame sections 36 to 39 are corresponding holding base sections 441 to 444, which are articulated to each other via the section joints 40 to 42.

[0041] The holding frame 33 has frame rails 46, which extend at least partially in the circumferential direction and, in the illustrated embodiment, extend in the entire circumferential direction to stabilize the holding frame 33. The frame rail portions 461, 462 extending along the y direction are both again divided into a plurality of rail portions that are articulated to each other by the section joints 40 to 42.

[0042] Each of the holding frame sections 36 to 39 has at least one guide body 47 for cooperating with the guide track 29 in a guiding manner when the workpiece holder 17 moves along the guide direction F (±y direction) perpendicular to the joint axes of the section joints 40 to 42. These guide bodies 47 project in the ±x direction above the holding frame sections 36 to 39 and are designed as guide pins that engage with the track runs 32 of the guide flanges 30, 31 facing each other.

[0043] In the illustrated embodiment of the workpiece holder 17, such guide bodies 47 are attached to the end of the workpiece holder 17 leading in the -y direction and the end of the workpiece holder 17 following in the +y direction, and in each case, are attached at the height of the section joints 40 to 42.

[0044] Figures 5 to 8 show the instantaneous position sequences of the workpiece holder 17 while the workpiece holder 17 moves in the guide direction F starting from the starting position in Figure 3.

[0045] At the instantaneous position in Figure 5, the holding frame section 36 leading in the guide direction F is located between the guide flanges 30, 31 in the working area of the operating position for releasing and removing the workpiece 34 from the holding frame section 36. At the instantaneous position in Figure 6, the holding frame section 37 following next in the guide direction F is likewise in the working area. At the instantaneous position in Figure 7, this is the next holding frame section 38, and at the instantaneous position in Figure 8, this is the last holding frame section 39.

[0046] With the aid of the guide track 29, in accordance with the progress of the guided movement of the workpiece holder 17, the holding frame sections 36 to 39 are successively pivoted and redirected from horizontal to vertical one after another in a manner similar to a sectional garage door.

[0047] The two guide holding frame sections 36 and 37 are rotated approximately 180° when the workpiece holder 17 is in the end positions of FIGS. 8 and 9, in which end position the holding frame section 39 is accessible to the operator of the working area and in which end position it is arranged approximately horizontally. The holding frame sections 36 - 38 are inclined by more than 45° during the turning operation starting from the starting position of FIG. 3, i.e., the horizontal arrangement position of the workpiece holder 17 on the table plate 27. The two holding frame sections 36, 37 are inclined by more than 90°, and furthermore by more than 150°.

[0048] In the sequence of FIGS. 5 - 8, the operator has access to all the holding frame sections 36 - 39 in order to remove the workpiece 34. In the reverse sequence, loading can be carried out on the holding frame sections 39 (position in FIG. 8), 38 (position in FIG. 7), 37 (position in FIG. 6), and 36 (position in FIG. 5). In this case, the movement of the workpiece holder 17 on the guide track 29 is carried out in a direction opposite to the guide direction F.

[0049] The movement along the conveying direction F and the movement in the opposite direction can be carried out by means of the workpiece holder drive device and / or manually.

[0050] The portal frame 2 of the sewing unit 1 with the upper and lower sewing parts 8, 10, 11 will be described in detail below with reference to FIGS. 10 - 12.

[0051] The upper drive device 48 serves to move the upper sewing part 8 along the upper bridge rail 3, i.e., in the + / -x direction. The lower drive device 49, independently of the upper drive device 48, serves to move the lower sewing parts 10, 11 along the lower bridge rail 4, i.e., again in the + / -x direction. The drive devices 48, 49 and further drive devices of the sewing unit 1 are controlled via a central control unit housed in the control cabinet 50 (see FIG. 1).

[0052] The upper drive device 48 and the lower drive device 49 are selectively controlled such that the upper workpiece portion 8 cooperates with one of the two lower sewing portions, for example, the lower sewing portion 10, or the upper sewing portion 8 cooperates with the other of the two lower sewing portions, for example, the lower sewing portion 11, in order to form stitches in the workpiece 34.

[0053] In the illustrated embodiment, the lower drive device 49 is designed to have exactly one drive source. Couplings for the respective lower sewing portions 10, 11, which are not shown in detail in the drawing, are used to separate one of each of the lower workpiece portions 10, 11 from the drive train of the lower drive device 49 designed as a chain or belt.

[0054] Alternatively, the lower drive device 49 can be designed to have two independent drive sources, one for each of the two lower sewing portions 10, 11.

[0055] By means of the lower drive device 49, the lower sewing portions 10, 11 can be moved to their stop positions independently of each other, at which positions the respective looper thread supply containers can be exchanged for replacement looper thread supply containers, in particular bobbins, via the access windows 14, 15.

[0056] This exchange is carried out in an automated manner without manual intervention. Alternatively, the exchange can also be carried out manually or semi-automatically.

[0057] The upper drive device 48 and / or the lower drive device 49 can comprise a toothed rack and / or transmission gears as transmission members. Each of the lower sewing portions 10, 11 can have its own transmission gear.

[0058] FIG. 10 shows the lower sewing portion 10 in the left stop position accessible via the access window 14. In FIG. 10, the lower sewing portion 11 is shown in the right stop position accessible via the access window 15. In FIG. 10, the upper sewing portion 8 is shown in the right stop position assigned to the lower sewing portion 11.

[0059] FIG. 11 shows a state where the upper sewing part 8 and the lower sewing part 11 are in the sewing position. At this position, these two sewing parts 8 and 11 can cooperate to form stitches on the workpiece 34. At this sewing position, synchronization is performed between the upper sewing part 8 and the lower sewing part (in this case, the lower sewing part 11) that is currently cooperating with it to form stitches. This synchronization is performed by the control unit. The driving displacement direction of the driving devices 48 and 49, that is, the three-dimensional synchronization accuracy along the x-axis, is better than 0.3 mm. This synchronization accuracy can be in the range of 0.1 mm. Since the needle and the looper need to be connected to separate driving devices, they need to be synchronized.

[0060] At the position of FIG. 11, the lower sewing part 10 that is not currently sewing is at the left stop position. In the case of the lower sewing part 10, while the upper sewing part 8 is performing a sewing operation with the lower sewing part 11, the looper thread supply container can be exchanged at the position of FIG. 11.

[0061] After the exchange, the lower sewing part 10 becomes operable. When the looper thread of the currently sewing lower sewing part 11 starts to run out, under the control of the control unit, the sewing process is temporarily stopped, and the lower sewing part 11 that has been sewing until then is moved to the right stop position of FIG. 12 by the lower driving device 49. Further, due to the interaction between the upper driving device 48 and the lower driving device 49, synchronization is performed between the upper sewing part 8 and the newly filled lower sewing part 10. Thereafter, the sewing unit 1 can continue sewing by the cooperation of the upper sewing part 8 and the lower sewing 10. During that time, in the lower sewing part 11, the looper thread supply container is exchanged, and the lower sewing part 11 is accessible through the access window 15.

[0062] When a new bobbin is loaded, the stopped lower sewing part moves close to the sewing lower sewing part. In this way, after the bobbin becomes empty, the sewing lower sewing part can be separated from the upper sewing part, and the stopped lower sewing part can be immediately connected and synchronization can be started. In this way, a considerable amount of time can be saved.

[0063] The multi-stage elevating table 20 of the sewing unit 1 will be described in more detail below with reference to FIGS. 13 to 39.

[0064] FIG. 13 shows the multi-stage elevating table 20 together with the portal frame 2 and the work table 19 which are the main components of the sewing unit 1. The elevating table frame 51 for supporting the multi-stage elevating table 20 on the ground is omitted in FIGS. 13 and later.

[0065] FIG. 13 shows the multi-stage elevating table 20 loaded with two workpiece holders 17. Hereinafter, the upper workpiece holder 17 at the top is also referred to as the workpiece holder 171, and the workpiece holder 17 at the bottom initially is also referred to as the workpiece holder 172 (see, for example, FIG. 16). The upper one of the two workpiece holders 171 is at the upper workpiece holder placement position on the upper table plate 27 of the multi-stage elevating table 20. The second workpiece holder 172 is at the lower workpiece holder placement position on the lower table plate 28.

[0066] The two table plates 27 and 28 are fixedly connected to each other via a total of six vertical support columns 521 to 526 and a support plate 53. The support plate 53 is vertically disposed between the table plates 27 and 28 and between the two support columns 523 and 524 which are at the positions farthest from the portal frame 2. The support columns 521, 523, 524, and 526 are located at the four corners of the table plates 27 and 28 arranged vertically in alignment. The support columns 522 and 525 are located at the centers between one pair of support columns 521 and 523 and between the other pair of support columns 524 and 526.

[0067] The multi-stage lifting table 20 has two pairs of roller conveyors 54, 55. The rollers of the roller conveyors of the pairs of roller conveyors 54, 55 can rotate freely. Of these two pairs of roller conveyors, the upper pair of roller conveyors 54 is located at the same height in the z direction and has two opposing roller conveyors 541, 542 arranged at intervals in the x direction. The lower pair of roller conveyors 55 also has two roller conveyors 551, 552 located at the same height in the z direction and arranged at intervals in the x direction. The roller conveyor 541 is above the roller conveyor 551 in the z direction. The roller conveyor 542 is above the roller conveyor 552 in the z direction. Only the roller conveyor 551 facing the observer is shown in either of the two roller conveyors 551 and 552.

[0068] The roller conveyors of the pairs of roller conveyors 54, 55 extend longitudinally along the y direction respectively. The roller conveyors 541, 542, 551, 552 are each interrupted in the y direction. Due to this interruption, a space for the support column 522 and a space for the support column 525 are formed respectively.

[0069] At the momentary positions from Figure 13 to Figure 15, the upper table plate 27 is between the two upper roller conveyors 541 and 542 of the upper pair of roller conveyors 54, and the lower table plate 28 is between the two roller conveyors 551, 552 of the lower pair of roller conveyors 55. The roller conveyors 541, 542, 551, 552 can be moved between the stored roller conveyor position (see Figure 17) and the extended roller conveyor position (see Figure 18) using the roller conveyor lifting drive device 56 (see Figure 2). At the stored roller conveyor position, the x-direction distance between one of the roller conveyors 541, 542 and the other roller conveyors 551, 552 is shorter than the x-direction extension of the workpiece holder 17. At the extended roller conveyor position in Figure 18, this x-direction distance between one of the roller conveyors 541, 542 and the other roller conveyors 551, 552 is longer than the x-direction extension of the workpiece holder 17.

[0070] Furthermore, the multi-stage lifting table 20 includes a plate lifting drive device 57 (see FIG. 2) for moving the table plates 27 and 28 up and down with respect to the lifting table frame 51.

[0071] The two pairs of roller conveyors 54 and 55 can move via a roller conveyor lifting drive device 56 between, for example, the lowered plate position shown in FIG. 16 and the plate position raised by vertical movement in the z direction as compared to the lowered plate position, for example, shown in FIG. 31.

[0072] In the lowered plate position, the roller conveyors of the two pairs of roller conveyors 54 and 55 are arranged on both sides of the table plates 27 and 28 respectively assigned to these two pairs of roller conveyors 54 and 55. With this arrangement, the upper roller planes 58 and 59 of the respective pairs of roller conveyors 54 and 55 are located below the table plate planes 60 and 61 of the assigned table plates 27 and 28.

[0073] In the raised plate position (see FIG. 31 for example), the upper roller planes 58 and 59 of the respective pairs of roller conveyors 54 and 55 are located above the table plate planes 60 and 61 of the assigned table plates 27 and 28. There is a z-direction distance d respectively between one of the roller planes 58 and 59 and the table plate planes 60 and 61 of the other assigned table plates 27 and 28 (see FIG. 31). In this raised plate position, the roller conveyors are simultaneously in the stored position (see FIG. 17), and the two roller conveyors of each pair of roller conveyors 54 and 55 are separated from each other by a distance in the x direction. On the condition that this distance in the x direction is smaller than the x-direction extension of the workpiece holder 17, roller guiding for moving the workpiece holder 17 from or to the respective storage positions of the table plates 27 and 28 is possible.

[0074] The plate lifting drive device 57 can move the respective table plate planes 60, 61 of the selected table plates 27, 28 to a lifted position aligned with the work plate plane 62 of the work plate 18 of the work table 19 (see, for example, FIG. 20).

[0075] One of the plate lifting drive devices 57 and the other roller conveyor lifting drive device 56 can be formed as a linear drive device or a lifting cylinder.

[0076] As already described in connection with FIGS. 3 to 9, the upper workpiece holder placement position can be used to load the workpiece 34 to be sewn on the workpiece holder 17 or to remove the sewn workpiece 34 from the workpiece holder 17.

[0077] Furthermore, the roller conveyor pairs 54, 55 can be displaced by the roller conveyor lifting drive device 56 along the z - direction relative to the table plates 27, 28 to a workpiece holder receiving position that is further elevated compared to the raised plate position. This workpiece holder receiving position is shown, for example, in FIG. 26. Each upper workpiece holder (in the case of the position in FIG. 26, the workpiece holder 172) is then received at a position above the upper workpiece holder placement position that is spaced apart from the upper table plate 27 by a distance A in the z - direction. This z - direction distance A is greater than the z - direction extension of the workpiece holder 17.

[0078] The lower roller conveyor pair 55 can be moved in the positive z direction by the roller conveyor lifting drive device 56 to such an extent that its lower roller plane 59 is positioned above the upper table plate plane 60 of the upper table plate 27. This instantaneous position in the z direction is shown in Fig. 28. The lower roller conveyor pair 55 can then guide, on its rollers, one of the workpiece holders 17 (in the example shown in Fig. 28, the workpiece holder 171) on or from the upper table plate 27 at the position where the roller conveyor is retracted for movement.

[0079] The workpiece holder gripper device 21 is used to move the workpiece holders 171, 172 between the storage position and the working position on the work plate 18 of the work table 19. It is shown, for example, in the neutral position outside the sewing work area in Fig. 1. In the gripping position not shown in the figure, the gripping tool of the workpiece holder gripper device 21 designed in the form of gripping pins 63, 64 (see Fig. 13) is aligned with the work plate 18 in the z direction, and in the multi-stage lifting table 20, it grips the end of the workpiece holder 17 at the storage position of one of the two table plates 27, 28 and transfers it to the workpiece holder position. This workpiece holder 17 is aligned with the work plate 18 in the z direction respectively and is in the storage position on one of the two table plates 27, 28 in the multi-stage lifting table 20 and is transferred to the workpiece holder position. This is done by the engagement of the gripping pins 63, 64 with the complementary bushes of the workpiece holder 17 to be gripped. The gripping pins 63, 64 can be pneumatically moved in their respective complementary bushes.

[0080] Hereinafter, the operation cycle of the sewing unit 1, particularly the multi-stage lifting table 20 and the workpiece holder gripper device 21, will be described with reference to Figs. 19 to 39.

[0081] Figure 19 shows the starting position of the multi-stage lifting table 20. The upper workpiece holder 171 is at the upper storage position on the table plate 27, and the lower workpiece holder 172 is at the lower storage position on the table plate 28. The roller conveyor pairs 54, 55 are shown in the lowered plate position. The lower table plate plane 61 is aligned with the work plate plane 62.

[0082] The sewing of the upper workpiece holder 171 is completed. The lower workpiece holder 172 is attached for sewing.

[0083] Figure 20 shows the next working step. The workpiece holder gripping device 21 grips the end of the workpiece holder 172 and pulls it in the positive y-direction through the portal 5 of the portal sewing unit 1. The control device synchronizes the looper drives 25, 26 with the workpiece drives 48, 49 so that the workpiece 34 is sewn on the workpiece holder 172.

[0084] In the position of Figure 20, the workpiece holder 171 is removed and attached in conjunction with the guide track 29 as described above.

[0085] Figure 21 shows the instantaneous position after the process of sewing the workpiece 34 on the workpiece holder 172 is completed. At this time, the workpiece holder 172 is completely placed on the work table 19 so as not to overlap with the multi-stage lifting table 20 in the y-direction.

[0086] In the instantaneous position of Figure 21, at the upper workpiece holder placement position, the workpiece 34 to be sewn is attached to the workpiece holder 171.

[0087] At the instantaneous position (first change position) of FIG. 22, the multi-stage elevating table 22 having table plates 27, 28 and associated roller conveyor pairs 54, 55 is moved in the negative z direction by the plate elevating drive device 57, and the entire upper work piece holder 171 is moved to a change position where it is located on the upper table plate 27 below the work plate plane 62.

[0088] FIG. 23 shows an instantaneous position (the position of FIG. 18) where the roller conveyor pairs 54, 55 are extended so that the x-direction distance between them increases, as compared with the position of FIG. 22. This is performed using the roller conveyor elevating drive device 56.

[0089] FIG. 24 shows a situation where the roller conveyor pairs are moved in the positive z direction with respect to the two table plates 27, 28 using the roller conveyor elevating drive device 56 and are at the work piece holder receiving position. The upper roller conveyor pair 54 thus passes through the z plane of the work piece holder 171 located at the upper work piece holder arrangement position. The roller conveyors of the roller conveyor pairs 54, 55 continue to extend at the position of FIG. 24.

[0090] FIG. 25 shows an instantaneous position achieved by the stored roller conveyors of the roller conveyor pairs 54, 55. The upper roller plane 58 is above the work piece holder 171 located at the upper work piece holder receiving position and is aligned with the work plate plane 62.

[0091] FIG. 26 shows an instantaneous position where the sewn work piece holder 172 is pushed in the negative y direction onto the roller conveyor of the upper roller conveyor pair 54 by the work piece holder gripping device 21.

[0092] FIG. 27 shows the next situation where, after the work piece holder 172 is completely received at the work piece holder receiving position, the entire multi-stage elevating table 20 is moved in the positive z direction by the plate elevating drive device 57 and the upper table plate plane 60 is aligned with the work plate plane 62.

[0093] Compared with the first change position in FIG. 22, the multi-stage lifting table 20 is at the second change position in FIG. 27.

[0094] FIG. 28 shows the next instantaneous position where the roller conveyor pairs 54, 55 are further moved in the positive z direction with respect to the table plates 27, 28 compared to the position in FIG. 27 by the roller conveyor lifting drive device 56. Since the lower roller plane 59 is located slightly above the upper table plate plane 60, the work piece holder 171 at the upper work piece holder arrangement position is located on the roller conveyor of the lower roller conveyor pair 55.

[0095] FIG. 29 shows the next instantaneous position where the work piece holder 171 is drawn onto the work plate 18 of the work table 19 through the portal 5 after being gripped by the work piece holder gripping device 21. Here, or at a later point as described below, this loaded work piece holder 171 can be sewn as described above in relation to the work piece holder 172 at the instantaneous position in FIG. 20. The other work piece holder 172 is still at the work piece holder receiving position on the roller conveyor of the roller conveyor pair 54.

[0096] FIG. 30 shows the next instantaneous position where the entire multi-stage lifting table 20 provided with the plate lifting drive device 57 is further moved in the positive z direction. At this position, the lower table plate plane 61 is aligned with the work plate plane 62.

[0097] The movement to the instantaneous position in FIG. 30 is performed after the work piece holder 171 is completely placed on the work table 19 and no longer overlaps with the multi-stage lifting table 20 in the y direction.

[0098] Figure 31 shows the next instantaneous position where the two roller conveyor pairs 54, 55 have been lowered to the rising plate position. In each case, there is a z-direction distance d between one of the two roller planes 58, 59 and the two table plate planes 60, 61. The lower table plate plane 61 continues to be aligned with the work plate plane 62.

[0099] Figure 32 shows the next instantaneous position where the sewn workpiece 34 can be removed from the workpiece holder 172.

[0100] Figure 35 shows, on the one hand, the instantaneous position where the workpiece holder 171 can be sewn at the instantaneous position of FIG. 29 when sewing is not being performed corresponding to the description given above with reference to FIG. 20. On the other hand, it shows the instantaneous position where the workpiece holder 172 is loaded as described above with reference to FIGS. 3 and after. The lower table plate plane 61 continues to be aligned with the work plate plane 62.

[0101] Figure 33 shows the instantaneous position where the workpiece holder 172, which has not yet been lowered, is completely pushed out onto the roller conveyor of the upper roller conveyor pair 54 and is at a position of distance d above the upper table plate 27.

[0102] Figure 34 shows the next instantaneous position where the two roller conveyor pairs 54, 55 have moved in the negative z direction to the lowering plate position, and the workpiece holder 172 is placed on the upper table plate 27.

[0103] Figure 36 shows the next instantaneous position where the sewn workpiece holder 171 is placed on the lower table plate 28 using the workpiece holder gripping device 21.

[0104] Figure 37 shows the next instantaneous position where the workpiece holder 171 is pulled out from the lower table plate 28 onto the work table 19 using the workpiece holder gripping device 21 for sewing.

[0105] Figure 38 shows the moment when the workpiece holder 171 is completely sewn by the sewing unit 1 and placed on the work table 19 in the y direction without being aligned with the multi-stage lifting table 20.

[0106] The moment in Figure 39 corresponds to the position in Figure 21. Only the workpiece holders 171 and 172 are exchanged, but the sewing and loading situations and the positions of the workpiece holders 171 and 172 relative to the sewing unit 1 are the same. The cycle from Figure 21 to Figure 39 can be continuously repeated.

[0107] When the looper thread of the lower sewing part 10 or 11 currently in use starts to decrease, this looper supply is exchanged as described above, particularly in connection with Figures 10 to 12. Compared with the exchange time of the looper supply, the sewing process during the exchange of the lower sewing parts 10 and 11 is interrupted only for a clearly short period, such as 25%, 20%, 10%, or less of the exchange time.

Explanation of Reference Signs

[0108] 1 Portal Sewing Unit 2 Portal Frame 3 Upper Bridge Rail 4 Lower Bridge Rail 5 Portal 6, 7 Portal Support 8 Upper Sewing Part 9 Upper Stitch Former 10, 11 Lower Sewing Part 12, 13 Lower Stitch Former 14, 15 Access Window 16 Unit Housing 17 Workpiece Holder 18 Work Plate 19 Work Table 20 Multi-stage Lifting Table 21 Workpiece Holder Gripping Device 22 Gripping Rail 23, 24 Guide Rail 25, 26 Driving Motor 27 and 28 table plates 29 guide track 30 and 31 guide flanges 32 track run 33 holding frame 34 workpiece 35 strap 36 - 39 holding frame sections 40 - 42 section joints 43 intersection 44 holding base 45 fixing element 46 frame rail 47 guide body 48 upper drive device 49 lower drive device 50 control cabinet 51 lifting table frame 53 support plate 54 upper roller conveyor pair 55 lower roller conveyor pair 56 roller conveyor lifting drive device 57 plate lifting drive device 58 upper roller plane 59 lower roller plane 60 upper table plate plane 61 lower table plate plane 62 work plate plane 63 and 64 gripping pins 441 - 444 holding base sections 461 - 462 frame rail parts 521 - 526 support struts 541, 542, 551, 552 roller conveyors

Claims

1. A portal sewing unit (1) for sewing a workpiece (34) in a sewing work area having a width (B) exceeding 1 m, having a portal frame (2), the portal frame comprising: - an upper bridge rail (3) for guiding at least one upper sewing part (8) comprising an upper stitch former (9) in the form of at least one sewing needle, - a lower bridge rail (4) for guiding at least two lower sewing parts (10, 11), each having a lower stitch former (12) in the form of a looper and comprising a looper thread supply part in a looper supply container, and - two end-side portal supports (6, 7) facing each other to form a portal (5) of the portal frame (2), having an upper drive device (48) for moving the upper sewing part (8) along the upper bridge rail (3), having a lower drive device (49) for independently moving each of the lower sewing parts (10, 11) along the lower bridge rail (4), having a sewing part controller (50) for the upper drive device (48) and the lower drive device (49), by which sewing part controller (50), optionally, -- the upper sewing part (8) cooperates with one (10) of the two lower sewing parts (10, 11), or -- the upper sewing part (8) cooperates with the other (11) of the two lower sewing parts (10, 11) to form stitches in the workpiece (35), a portal sewing unit.

2. The portal sewing unit according to claim 1, characterized in that the lower drive device (49) comprises exactly one drive source and at least one coupling for separating one of the lower sewing parts (10, 11) from the drive train of the lower drive device (49).

3. The portal sewing unit according to claim 1 or 2, characterized in that the lower sewing parts (10, 11) can be moved independently of each other to a stop position, in which a looper thread storage container can be exchanged with a replacement looper thread storage container.

4. The portal sewing unit according to claim 3, characterized in that the exchange can be carried out at one (10) of the lower sewing parts (10, 11) in the stop position during the sewing operation between the upper sewing part (8) and the other (11) of the lower sewing parts (10, 11).

5. The portal sewing unit according to claim 3 or 4, characterized in that the exchange can be carried out in an automated manner.

6. The sewing unit controller (50) is designed such that synchronization is performed between the upper sewing unit (8) and the lower sewing unit (10; 11) that is currently cooperating with it to form stitches, characterized in that the portal sewing unit according to any one of claims 1 to 5.

7. The synchronization accuracy and / or position accuracy of the upper sewing unit (8) with respect to the lower sewing unit (10, 11) that is currently cooperating with the upper sewing unit (8) to form stitches is less than 0.3 mm along the drive displacement direction (x), characterized in that the portal sewing unit according to claim 6.

8. The upper drive device (48) and / or the lower drive device (49) has a toothed rack as a transmission member, characterized in that the portal sewing unit according to any one of claims 1 to 7.

Images