Multi-layer lifting table for providing at least two workpiece holders for sewing unit

Abstract

A multi-layer lifting table (20) for providing at least two workpiece holders for a sewing unit. The multi-layer lifting table (20) is provided with a lifting table frame and two table plates (27 and 28), and the two table plates (27 and 28) are placed at multiple heights one above the other and fixedly connected with one another for storing the workpiece holders. The two roller conveyor pairs (54, 55) are displaceable by lifting via a roller conveyor lifting drive between a lowered plate position and a lifted plate position compared thereto. In the lowered plate position, the roller planes of the roller conveyor pair (54, 55) lie below the respective platen planes of the assigned platen (27, 28). In the raised plate position, the roller plane lies on the platen plane in order to guide the workpiece holder by means of the rollers from a respective storage position or to a respective storage position on the platen (27, 28). Panel lift drive means for lift displacement of the platen (27, 28) relative to the lift table frame (51). This enables the multi-layer lift table to be used to increase the workpiece yield of the sewing unit.

Description

[0001] This patent application claims the priority of German patent application 10 2022 206 255.8, the content of which is incorporated herein by reference. Technical Field

[0002] The invention relates to a multi-level lifting table for providing a sewing unit with at least two workpiece holders. Background Art

[0003] A conveyor table for providing a workpiece holder for a sewing unit is known in the industry. This type of conveyor table is used to load workpieces onto the workpiece holder, or to remove sewn workpieces from the workpiece holder. DE 23 18 189 A1 discloses a device for removing and placing two-dimensional objects, in particular textiles. WO 2018 / 202898 A1 discloses a system for ironing and sewing pockets on cloth. US 4,708,073 discloses a method for processing cloth pieces in cutting and sewing operations. DE 37 34 659 A1 discloses a method and device for producing multi-layer single-piece garments. DE 35 22 498A1 discloses a device for guiding textile workpieces. DE 2 102 610 A discloses a device for aligning and holding cloth pieces stacked together. Summary of the invention

[0004] The object of the invention is to develop a conveyor table of this type in such a way that the tool output of a sewing unit is increased.

[0005] This object is achieved according to the invention by a multi-level lifting table having the features of claim 1 .

[0006] According to the present invention, it has been recognized that a multi-layer lifting table is constructed, which has a plurality of tabletops placed one above the other at multiple heights and capable of being displaced by lifting, and a pair of roller conveyors that can move independently of the tabletops, which can achieve substantially automated replacement between two workpiece holders. That is, while one of the workpiece holders is loaded or unloaded, the other workpiece holder is sewing in the sewing unit. Compared with the situation where the sewing unit is stationary when the workpiece holder is loaded, this greatly reduces the occupancy time of the sewing unit. With the help of a plate lifting drive, the tabletop plane of the tabletop can be selectively lifted to a position flush with the working plate plane of the working plate of the sewing unit, thereby facilitating the replacement of the workpiece holder between the tabletop and the working plate. These lifting drives can be designed as linear drives and / or lifting cylinders. Using a roller conveyor lifting drive, the roller conveyor pair can be made to reach different plate positions. The roller conveyor lifting drive can be designed to be independent of the plate lifting drive. The upper workpiece holder placement position can be used to load workpieces to be sewn onto the workpiece holder and / or to remove sewn workpieces from the workpiece holder.

[0007] The additional displaceability of at least the uppermost roller conveyor pair according to claim 2 makes it possible to realize additional workpiece holder receiving positions, so that in a multi-level lifting table with two tabletops, a total of at least three positions can be used for corresponding workpiece holders, in particular two workpiece holder storage positions on the two tabletops and an additional workpiece holder receiving position. This improves the logistics of the workpiece holders when changing between completely sewn workpiece holders and workpiece holders to be sewn, or between workpiece holders to be loaded and loaded workpiece holders.

[0008] According to the multi-stage lifting table of claim 3, the flexibility of use options is further improved when changing between workpiece holders.

[0009] The spacing increase in the roller conveyor lifting drive according to claim 4 makes it possible to move around a workpiece holder placed on the corresponding platen. The spacing is increased transversely to the rolling direction of the roller conveyors of the roller conveyor pair. The spacing can be increased by means of one or more cylinders. As an alternative to a linear increase in the spacing, the increase in the spacing can also be achieved by pivoting the roller conveyors outwards.

[0010] The interruption of the roller conveyor and the resulting use of additional support rods increases the rigidity of the platen structure.

[0011] Another object of the present invention is to provide a sewing unit that can take advantage of such a multi-layer lifting table.

[0012] This object is achieved according to the invention by a sewing unit having the features of claim 6 .

[0013] The workpiece holder gripping device makes it possible to displace the workpiece holder in a driven manner between the multi-layer lifting table and the working plate of the sewing unit. The pin of the gripping device can be used as a gripping tool, for which purpose it engages with a complementary bushing of the workpiece holder. As an alternative or in addition, the gripping tool can also include a bushing that cooperates with the pin of the workpiece holder.

[0014] The advantages of the multi-layer lifting table and the workpiece holder clamping device are particularly evident in the embodiment of the inlet sewing unit according to claim 7. The inlet sewing unit can have a sewing work area with a width of more than 1 meter, more than 1.5 meters, more than 2 meters, more than 2.5 meters or even more than 3 meters.

[0015] According to the clamping rail of the workpiece holder clamping device according to claim 8, the workpiece holder clamping device is stable and safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Exemplary embodiments of the present invention are explained in more detail below with reference to the accompanying drawings. In the drawings:

[0017] Figure 1 A perspective view of a portal sewing unit is shown, which is used for sewing workpieces in a sewing work area with a width of more than 1 meter, including a multi-level lifting table for receiving a plurality of segmented workpiece holders, which are used to fix the workpieces to be sewn;

[0018] Figure 2 Shows Figure 1 An end view of the sewing unit as seen from direction II in FIG.

[0019] Figure 3 Shows the available Figure 1 A perspective view of a segmented workpiece holder of a sewing unit, also in the Figure 1 The starting position shown, in which a sewn workpiece in the form of a cargo net is fixed to the workpiece holder, wherein, in addition, two guide flanges of the guide rail for guiding the steering movement of the workpiece holder from the starting position are shown;

[0020] Figure 4 show Figure 3 Side view from the middle direction IV;

[0021] Figures 5 to 8shows the momentary positions of a segmented workpiece holder during a turning movement in the guiding direction of a guide rail, wherein in each momentary position a workpiece can be removed from the holding frame section of the respective workpiece holder facing the operator;

[0022] Fig. 9 In with Figure 4 A similar diagram shows the Figure 8 A side view of the workpiece holder as seen in direction IX, with the workpiece holder turned to the maximum extent;

[0023] Fig.10 An inlet frame of an inlet sewing unit is shown, having an upper sewing part with an upper stitch forming tool and two lower sewing parts, the upper sewing part having an upper stitch forming tool, each lower sewing part having a lower stitch forming tool, the lower sewing parts being selectively used in conjunction with the upper sewing part, wherein the two lower sewing parts and the upper sewing part are each in an edge side parking position;

[0024] Fig.11 Shows Fig.10 An end view of the inlet frame shown, wherein one of the two lower sewing parts is in a parked position, wherein the other lower sewing part is in a stitching position together with the upper sewing part, cooperating to form a seam;

[0025] Fig.12 In with Fig.11 A similar diagram is shown with Fig.11 a complementary situation in which the other lower sewing part is now in the parked position;

[0026] Fig.13 Shows Figure 1 the main components of an inlet sewing unit, in particular an inlet frame with an upper sewing part and two lower sewing parts, the main components of a multi-level lifting table with two workpieces, the two workpieces being placed on tabletops arranged at different heights relative to each other, a working plate of the sewing unit for placing the workpieces to be sewn in the workpiece holders, and a workpiece holder holding device for transferring the respective workpiece holder from a storage position to a sewing position;

[0027] Fig.14 From Fig.13 The corresponding view shows the multi-level lift table without the workpiece holder;

[0028] Fig.15 Display from Fig.14 Side view of the multi-level lifting platform seen from center direction XV;

[0029] Fig.16 The same Fig.15A side view of a similar multi-stage lift table with two workpiece holders positioned thereon, each in a position to position the workpiece holder on one of the two decks of the multi-stage lift table;

[0030] Fig.17 Shows Fig.16 A top view of the multi-level lifting table seen in the direction XVII in FIG. 1 , wherein the roller conveyor pairs are in the retracted plate position, wherein the two roller conveyors of each roller conveyor pair are each assigned to one of the platens of the multi-level lifting table;

[0031] Fig.18 and Fig.17 Similarly, multiple lifts and Fig.17 Compared to the roller conveyors of the extended roller conveyor pairs, the space between the roller conveyors of the individual roller conveyor pairs is Fig.17 Compared to being enlarged;

[0032] Fig.19 Shows the view from direction XIX Fig.13 a side view of the access frame and multi-level lift table in the arrangement shown;

[0033] Figures 20 to 39 Shows Fig.19 The multi-layer lifting table and workpiece plate in the sewing unit use two workpiece holders for the momentary position during sewing, loading and removal. DETAILED DESCRIPTION

[0034] Figure 1 and Figure 2 The sewing unit 1 is shown as a whole, which is used for sewing workpieces in a working area with a width B greater than 1 meter, and in the embodiment shown the width B is 3 meters. The sewing unit 1 comprises an upper bridge rail 3 and a lower bridge rail 4 (see also Fig.10 ) of the inlet frame 2. The inlet frame 2 also includes two opposite edge side inlet brackets 6 and 7 to form an inlet 5.

[0035] In order to facilitate understanding of positional relationships, the Cartesian xyz coordinate system is used below. Figure 2 In the figure, the x direction extends to the right along the width extension B. The y direction is perpendicular to Figure 2 The drawing plane extends into this figure. Figure 2 , the z direction extends upward.

[0036] The inlet plane of the inlet 5 extends parallel to the xz plane.

[0037] The upper bridge rail 3 is used to guide the upper sewing part 8, which has an upper stitch forming tool 9 in the form of a needle, which is used to guide the upper thread (not shown in the figure). According to the design of the inlet sewing unit 1, more than one upper sewing part 8, such as two upper sewing parts, can also be used.

[0038] The lower bridge rail 4 is used to guide the two lower sewing parts 10, 11 (see Fig.12 ). The two lower sewing parts 10, 11 each have a lower stitch forming tool 12, 13, each in the form of a looper with a looper thread supply located in a looper thread supply container in the form of a bobbin.

[0039] The loopers or lower threads of the lower sewing parts 10, 11 may comprise different colors and different thread qualities.

[0040] The sewing unit 1 is used for sewing a two-thread stitch, such as a lockstitch or a chain stitch.

[0041] In the edge-side parking position of the lower sewing parts 10, 11, the bobbin can be accessed through the access windows 14, 15 of the unit housing 16 (see Figure 1 and Figure 2 ).

[0042] During the sewing process, the workpiece holder 17 is at least partially located on the working plate 18 of the working table 19 of the sewing unit 1 (see Fig.13 ). Two workpiece holders similar to the workpiece holder 17 are temporarily (intermediately) stored for loading workpieces, and the sewn workpieces are removed by means of the multi-layer lifting table 20 of the sewing unit 1. The workpiece holder clamping device 21 includes a clamping rail 22, and the workpiece holder clamping device 21 is used to remove the workpiece holders 17 loaded respectively from the sewing unit 1. Figure 1 The storage position shown is shifted to the sewing position (see also Fig.13 ). The two ends of the clamping track 22 are linearly guided via respective guide tracks 23, 24. This linear guidance is driven via drive motors 25 and 26. In the case of a small sewing area, it is also possible to use only one motor in the middle of the clamping track.

[0043] The two bridge rails 3, 4 and the gripper rail 22 extend parallel to the x-axis. The two guide rails 23, 24 extend parallel to the y-axis.

[0044] The multi-layer lifting table 20 has two table plates 27 and 28, which are placed one above the other at different levels and fixedly connected to each other for storing respective workpiece holders 17. The upper table plate of the two table plates, that is, the table plate 27, provides a placement position for the upper workpiece holder, and the lower table plate of the two table plates, that is, the table plate 28, provides a placement position for the lower workpiece holder.

[0045] The platens 27 and 28 and the working plate 18 extend horizontally, ie parallel to the xy plane.

[0046] The multi-layer lifting table 20 is a workpiece holder placement device. Therefore, the two table plates 27, 28 are part of the placement table. In addition, the workpiece holder placement device includes a guide rail 29, which has two opposite guides or flanges 30, 31, each of which has a track run 32.

[0047] During operation, the sewing unit 1 is used in conjunction with a plurality of workpiece holders 17 , which may be constructed in the same manner, so that only one of the workpiece holders 17 will be described in more detail below.

[0048] Figure 3 The workpiece holder 17 and the upper platen 27 as well as the two guide flanges 30 , 31 of the guide rail 29 are shown.

[0049] The workpiece holder 17 has a holding frame 33, which is fixed relative to a workpiece 34 to be sewn in the form of a cross-belt 35. The holding frame 33 has a plurality of holding frame sections 36, 37, 38, 39, a total of four in the illustrated embodiment (see also FIG. Figure 4 ). In each case, adjacent ones of the retaining frame segments 36 to 39 are connected to one another in an articulated manner via segment joints 40 , 41 and 42 (see, for example, Fig. 9 ). The articulation axes of the segment joints 40 to 42 are parallel to the x-axis.

[0050] The pivot points of the segment joints 40 - 42 are located at or near the neutral strand of the workpiece 34 , so that the workpiece 34 is neither accidentally stretched nor accidentally compressed during the process of retaining the frame segments 36 - 39 pivoting relative to each other.

[0051] Other embodiments of the workpiece holder can also have different numbers of such holding frame segments, specifically two, three, five or more such holding frame segments. Such a workpiece holder design generally has at most twenty such holding frame segments connected to each other in an articulated manner.

[0052] The depth of the workpiece holder 17 in the direction perpendicular to the articulation axis of the segment joints 40 to 42 (i.e., in the Y direction) is about 3 meters in the illustrated embodiment, and can reach at least 1 meter, at least 1.5 meters, at least 2 meters, at least 2.5 meters, or even more than 3 meters, depending on the design of the workpiece holder 17. The depth of the workpiece holder 17 is generally at most 10 meters.

[0053] Figure 3 The starting position of the workpiece holder 17 is shown, the previously loaded workpiece 34 having been completely sewn by the sewing unit 1. The sewing takes place at the intersection point 43, where the transversely and longitudinally extending strips 35 of the workpiece 34 cross.

[0054] The workpiece holder 17 has a holding base 44 on which the workpiece 34 is located. In the region of the intersections 43 to be sewn, and in other possible overlapping portions to be sewn, the holding base 44 has an aperture into which the workpiece 34 can freely enter from above and below.

[0055] Fixing elements 45 for fixing the workpiece 34 are attached to the holding base 44. These fixing elements 45 can be tensioning elements and / or clamping elements. As an alternative or in addition, the workpiece 34 can also be fixed to the holding base 44 by a friction connection.

[0056] Part of the holding frame segments 36 to 39 is a corresponding holding base segment 441 to 444 , which are connected to one another in an articulated manner via segment joints 40 to 42 .

[0057] The holding frame 33 has a frame rail 46 which extends at least partially in the circumferential direction, in the illustrated embodiment completely in the circumferential direction, thereby stabilizing the holding frame 33. The two frame rail sections 461 and 462 extending in the Y direction are again divided into a plurality of rail sections which are connected to one another in an articulated manner via segment joints 40 to 42.

[0058] When the workpiece holder 17 is moved along the guide direction F (+ / -y direction) perpendicular to the joint axis of the segment joints 40 to 42, each holding frame segment 36 to 39 has at least one guide body 47, which cooperates in a guiding manner with the guide rail 29. These guide bodies 47 are designed as guide pins, protrude above the holding frame segments 36 to 39 in the + / -x direction, and engage with the opposing rail slideways 32 of the guide flanges 30 and 31.

[0059] In the embodiment of the workpiece holder 17 shown in the figures, such guide bodies 47 are attached to the end of the workpiece holder 17 leading in the −y direction and to the end of the workpiece holder 17 trailing in the +y direction and are each located at the level of the segment joints 40 to 42 .

[0060] Figures 5 to 8 The workpiece holder 17 is shown Figure 3 The starting position is a sequence of instantaneous positions of the workpiece holder 17 during the movement along the guide direction F.

[0061] exist Figure 5 In the instantaneous position of , the holding frame segment 36 guided in the guide direction F is located between the guide flanges 30 and 31 in the working area of ​​the operating position for releasing and removing the workpiece 34 from the holding frame segment 36. Figure 6 At the instantaneous position of the guide frame, the retaining frame section 37 following it in the guiding direction F is correspondingly in the working area. Figure 7 The instantaneous position of the next holding frame segment 38 is Figure 8 , which is the last retaining frame segment 39.

[0062] Depending on the progress of the guided movement of the workpiece holder 17 with the aid of the guide rails 29 , the holding frame segments 36 to 39 are pivoted one after the other first from the horizontal direction and turned into the vertical direction in a manner similar to a sectional garage door.

[0063] When the workpiece holder 17 is in Figure 8 and Fig. 9 In the end position, the two guided holding frame sections 36 and 37 are turned almost 180°, wherein the operator can access the holding frame section 39 in the working area, so that in the end position they are almost horizontal. Figure 3 Starting from the starting position of the workpiece holder 17, i.e. from the horizontal orientation of the workpiece holder 17 on the table 27, during the turning movement, the holding frame sections 36 to 38 are tilted by more than 45°. The two holding frame sections 36 and 37 are tilted by more than 90°, even more than 150°.

[0064] exist Figures 5 to 8 In the reverse order, the operator can access all the holding frame segments 36 to 39 in order to remove the workpiece 34. In the reverse order, the holding frame segments 39 ( Figure 8 ), 38( Figure 7 ), 37( Figure 6 position) and 36( Figure 5In this case, the workpiece holder 17 moves on the guide rail 29 in a direction opposite to the guide direction F.

[0065] The displacement in the conveying direction F and in the opposite direction can be realized by means of a workpiece holder drive and / or manually.

[0066] The following will be combined Figures 10 to 12 The inlet frame 2 and the upper sewing parts 8 and the lower sewing parts 10 and 11 of the sewing unit 1 are described in detail.

[0067] The upper drive 48 is used to shift the upper sewing element 8 along the upper bridge rail 3 (i.e., in the + / -x direction). The lower drive 49 is used to shift the lower sewing elements 10, 11 along the lower bridge rail 4 (i.e., again in the + / -x direction), and is independent of the upper drive 48. The drives 48, 49 and other drives of the sewing unit 1 are controlled by a central control unit, which is installed in a control cabinet 50 (see Figure 1 ).

[0068] The upper drive device 48 and the lower drive device 49 are controlled to selectively enable the upper workpiece part 8 to cooperate with one of the two lower sewing parts (i.e., for example, the lower sewing part 10), or to enable the upper sewing part 8 to cooperate with the other of the two lower sewing parts (i.e., for example, the lower sewing part 11), thereby forming a stitch on the workpiece 34.

[0069] In the illustrated embodiment, the lower drive 49 is designed as just one drive source. In order to decouple the transmission system of the lower drive 49 designed as a chain or belt from the corresponding one of the lower sewing parts 10, 11, a coupling of the corresponding lower sewing parts 10, 11 is used, which is not shown in detail.

[0070] As an alternative, the lower drive device 49 can also be designed with two independent drive sources, one drive source for each of the two lower sewing parts 10 and 11.

[0071] By means of the lower drive 49 , the lower sewing parts 10 and 11 can be moved independently of one another into a parking position, wherein the respective looper thread supply container can be replaced by an alternative looper thread supply container, in particular a replacement bobbin, via the inspection windows 14 and 15 .

[0072] This replacement can be performed automatically without human intervention. Alternatively, the replacement can be performed manually or semi-automatically.

[0073] The upper drive 48 and / or the lower drive 49 may comprise a rack and / or a transmission gear as a transmission assembly. Each lower sewing part 10, 11 may have its own transmission gear.

[0074] Fig.10 The sewing element 10 is shown in the left parking position, wherein it can be accessed through the inspection window 14. Fig.10 In the figure, the lower sewing part 11 is located in the right parking position, which can be accessed through the inspection window 15. Fig.10 In FIG. 8 , the upper sewing part 8 is shown in the right parking position assigned to the lower sewing part 11 .

[0075] Fig.11 The upper sewing part 8 and the lower sewing part 11 are shown in a sewing position, wherein the two sewing parts 8 and 11 can cooperate to form a stitch on the workpiece 34. In this sewing position, the upper sewing part 8 is synchronized with the lower sewing part (in this case, the lower sewing part 11) that is currently cooperating to form the stitch. This synchronization is provided by the control unit. The three-dimensional synchronization accuracy along the drive displacement direction of the drive devices 48 and 49 (i.e. along the x-axis) is better than 0.3 mm. This synchronization accuracy can be within the range of 0.1 mm. Since the separate drive devices must be coupled, the sewing needle and the curved needle must be synchronized.

[0076] exist Fig.11 The lower sewing part 10 which is not currently sewing is in the left parking position. When the upper sewing part 8 and the lower sewing part 11 are sewing, the lower sewing part 10 can be Fig.11 Replace the needle thread supply container in the position

[0077] After replacement, the lower sewing part 10 is ready for operation. Once the looper thread of the lower sewing part 11 currently being sewn begins to run out, the sewing process will be temporarily terminated under the control of the control unit until the lower sewing part 11 that has been sewn to this point is shifted to the lower drive device 49. Fig.12 Furthermore, the upper sewing part 8 is synchronized with the now newly filled lower sewing part 10 by means of the interaction of the upper drive 48 and the lower drive 49. The sewing unit 1 can then continue sewing by means of the cooperation of the upper sewing part 8 with the lower sewing part 10, while at the same time, the looper thread supply container is replaced in the lower sewing part 11, which can be accessed through the inspection window 15.

[0078] After a new bobbin is installed, the parked lower sewing part is moved close to the lower sewing part being sewn. In this way, after the bobbin is empty, the lower sewing part being sewn can be separated from the upper sewing part and the parked lower sewing part can be coupled and started synchronously immediately. This saves a lot of time.

[0079] Combined with the following Figures 13 to 39 The multi-layer lifting table 20 of the sewing unit 1 is explained in more detail.

[0080] Fig.13 A multi-level lifting table 20 is shown together with an inlet frame 2 and a work table 19 , which are the main components of the sewing unit 1 . Fig.13 The following drawings omit the lifting platform frame 51 that supports the multi-layer lifting platform 20 on the ground.

[0081] Fig.13 A multi-layer lifting table 20 is shown with two workpiece holders 17 loaded thereon. Hereinafter, the initial upper workpiece holder 17 is also referred to as workpiece holder 171, and the initial lower workpiece holder 17 is also referred to as workpiece holder 172 (see, for example, Fig.16 ). The upper one of the two workpiece holders 171 is located at an upper workpiece holder placement position on the upper platen 27 of the multi-layer lifting table 20. The second workpiece holder 172 is located at a lower workpiece holder placement position on the lower platen 28.

[0082] The two platens 27 and 28 are fixedly connected to each other via a total of six vertical support rods 521 to 526 and via a support plate 53. The support plate 53 is located vertically between the platens 27 and 28 and between the two support rods 523 and 524 farthest from the inlet frame 2. The support rods 521, 523, 524 and 526 are located at the four corners of the platens 27 and 28 placed one above the other in an aligned manner. The support rods 522 and 525 are located centrally between the support rods 521 and 523 and 524 and 526.

[0083] The multi-level lifting platform 20 has two roller conveyor pairs 54 and 55. The rollers of the roller conveyors of the roller conveyor pairs 54 and 55 can rotate freely. The upper roller conveyor pair 54 of the two roller conveyor pairs has two roller conveyors 541 and 542 facing each other, which are at the same height in the z direction and are spaced apart from each other in the x direction. The lower roller conveyor pair 55 has two roller conveyors 551 and 552, which are also at the same height in the z direction and are spaced apart from each other in the x direction. Roller conveyor 541 is located above roller conveyor 551 in the z direction. Roller conveyor 542 is located above roller conveyor 552 in the z direction. Of the two roller conveyors 551 and 552, only the roller conveyor 551 facing the observer can be seen in the figure.

[0084] The roller conveyors of the roller conveyor pairs 54 and 55 extend longitudinally in the y direction respectively. The roller conveyors 541, 542, 551, 552 are respectively interrupted in the y direction. Such interruptions provide spacing for the support rods 522 and 525 respectively.

[0085] exist Figures 13 to 15The upper platform 27 is located between the two upper roller conveyors 541 and 542 of the upper roller conveyor pair 54, and the lower platform 28 is located between the two roller conveyor pairs 551 and 552 of the lower roller conveyor pair 55. The roller conveyors 541, 542, 551, 552 can be lifted by means of the roller conveyor lifting drive 56 (see Figure 2 ) in the roller conveyor retracted position (see Fig.17 ) and roller conveyor extended position (see Fig.18 ). In the retracted position of the roller conveyors, the x-distance between the roller conveyors 541, 542 and 551, 552 is less than the extension of the workpiece holder 17 in the x-direction. Fig.18 In the extended roller position shown, the distance between the roller conveyors 541 , 542 and 551 , 552 in the x direction is greater than the extension of the workpiece holder 17 in the x direction.

[0086] In addition, the multi-layer lifting platform 20 also has a plate lifting drive device 57 (see Figure 2 ) is used for lifting displacement of the table plates 27 and 28 relative to the lifting table frame 51.

[0087] Via the roller conveyor lifting drive 56, the two roller conveyor pairs 54 and 55 can be in a lowered plate position (e.g. Fig.16 shown) and (for example, Fig.31 The plate position shown in Figure 1 is shifted between the lowered plate position and the lowered plate position. Fig.31 The plate position shown is raised by a lifting displacement in the z direction.

[0088] In the lowered plate position, the roller conveyors of the roller conveyor pairs 54, 55 are each placed on opposite sides of the tabletop 27, 28 assigned to these roller conveyor pairs 54, 55, in such a way that the upper roller plane 58, 59 of the respective roller conveyor pairs 54, 55 is located below the tabletop plane 60, 61 of the assigned tabletop 27, 28.

[0089] In the raised plate position (see, for example, Fig.31 ), the roller planes 58, 59 of the upper part of each roller conveyor pair 54, 55 are located above the platen planes 60, 61 of the assigned platens 27, 28. The roller planes 58, 59 are respectively spaced apart from the platen planes 60, 61 of the assigned platens 27, 28 by a z-direction distance d (see Fig.31 In this raised position, if the roller conveyor is simultaneously in the retracted position (see Fig.17 ), the rollers can guide the workpiece holder 17 to shift from or to the corresponding storage positions of the table plates 27, 28, wherein the x-distance between the two roller conveyors of each roller conveyor pair 54, 55 is smaller than the x-extension of the workpiece holder 17.

[0090] By means of the plate lifting drive 57, the respective platen plane 60, 61 of the selected platen 27, 28 can be brought into a lifting position aligned with the working plate plane 62 of the working plate 18 of the working table 19 (see Fig. 20 ).

[0091] The plate lifting drive 57 and the roller conveyor lifting drive 56 may form linear drives or lifting cylinders.

[0092] As above combined Figures 3 to 9 As explained, the placement position of the upper workpiece holder can be used to load the workpiece holder 17 with the workpiece 34 to be sewn, or to remove the sewn workpiece 34 from the workpiece holder 17 .

[0093] In addition, by means of the roller conveyor lifting drive 56, the roller conveyor pairs 54 and 55 can be lifted and displaced relative to the platens 27 and 28 in the z direction to a workpiece holder receiving position, which is still further raised relative to the lifting position. Fig.26 As shown. Each upper workpiece holder, in Fig.26 The workpiece holder 172 is in the middle position and is then received into a position above the upper workpiece holder placement position, thereby being spaced apart in the z-direction relative to the upper platen 27 by a z-direction distance A that is greater than the z-direction extension of the workpiece holder 17 .

[0094] By means of the roller conveyor lifting drive 56 , the lower roller conveyor pair 55 can be displaced in the positive z-direction so that its lower roller plane 59 comes to be located above the upper deck plane 60 of the upper deck 27 . Fig.28 This instantaneous Z position is shown. The lower roller conveyor pair 55 in the roller conveyor retracted position can then guide one of the workpiece holders 17 on its rollers ( Fig.28 In the example, the workpiece holder 171 is moved onto or out of the upper platen 27 .

[0095] In order to shift the workpiece holders 171, 172 between the storage position and the working position on the working plate 18 of the workbench 19, it is necessary to use a workpiece holder gripping device 21, such as Figure 1 As shown, the workpiece holder clamping device 21 is in a neutral position outside the sewing work area. In the clamping position not shown in the figure, the clamping tool of the workpiece holder clamping device 21 is designed in the form of clamping pins 63, 64 (see Fig.13), gripping and holding the edge of the workpiece holder 17 (keeping the workpiece holder 17 aligned with the worktable 18 in the Z direction and in the storage position of one of the two table plates 27, 28 in the multi-layer lifting table 20) so as to be transferred into the workpiece holder position. This is achieved by the engagement of the gripping pins 63, 64 with the complementary bushings of the workpiece holder 17 to be gripped. The gripping pins 63 and 64 can be moved into their respective complementary bushings in a pneumatic manner.

[0096] Next, combine Figures 19 to 39 The operating cycle of the sewing unit 1, in particular the multi-layer lifting table 20 and the workpiece holder gripping device 21, will be described.

[0097] Fig.19 The starting position of the multi-level lifting table 20 is shown, with the upper workpiece holder 171 located in the upper storage position of the platen 27 and the lower workpiece holder 172 located in the lower storage position of the platen 28. The roller conveyor pairs 54 and 55 are shown in the lowered platen position. The lower platen plane 61 is aligned with the work platen plane 62.

[0098] The sewing of the upper workpiece holder 171 has just been completed. The lower workpiece holder 172 has been loaded for sewing.

[0099] Fig. 20 The next working step is shown. The workpiece holder gripper 21 grips the edge of the workpiece holder 172 and pulls it in the positive y-direction through the inlet 5 of the inlet sewing unit 1. The control synchronizes the gripper drives 25, 26 with the workpiece drives 48, 49 so that the workpiece 34 is sewn on the workpiece holder 172.

[0100] exist Fig. 20 position, as described above, the workpiece holder 171 interacts with the guide rail 29 for unloading and loading.

[0101] Fig.21 The instantaneous position after the termination of the process of sewing a workpiece 34 on a workpiece holder 172 which is completely located on the worktable 19 is shown, so that the workpiece holder 172 does not overlap with the multi-level lifting table 20 in the y direction.

[0102] exist Fig.21 The workpiece holder 171 is then loaded with the workpiece 34 to be sewn in the instantaneous position of the upper workpiece holder placement position.

[0103] exist Fig. 22The multi-layer lifting table 20 together with the table plates 27, 28 and the related roller conveyor pairs 54, 55 are shifted to the replacement position along the negative z direction using the plate lifting drive device 57, wherein the upper workpiece 171 is located as a whole below the working plate plane 62 on the upper table plate 27.

[0104] Fig.23 Shown is Fig. 22 Compared to the instantaneous position in the position in, the roller conveyor pairs 54, 55 are extended in such a way that the x-direction distance of the roller conveyor pairs 54, 55 relative to each other increases ( Fig.18 This is achieved by means of the roller conveyor lifting drive 56.

[0105] Fig.24 The roller conveyor pairs are shown displaced relative to the two platens 27 and 28 in the positive z-direction to the workpiece holder receiving position with the aid of the roller conveyor lifting drive 56. As a result, the upper roller conveyor pair 54 passes through the z-plane of the workpiece holder 171 in the upper workpiece holder placement position. The roller conveyors of the roller conveyor pairs 54 and 55 are still Fig.24 Extended in position.

[0106] Fig.25 The instantaneous position achieved when the roller conveyors of roller conveyor pairs 54 and 55 are retracted is shown. The upper roller plane 58 is located above the workpiece holder 171 in the upper workpiece holder receiving position and is aligned with the work plate plane 62.

[0107] Fig.26 The instantaneous position is shown in which the completely sewn workpiece holder 172 is pushed by the workpiece holder gripping device 21 in the negative y-direction onto the roller conveyor of the upper roller conveyor pair 54 .

[0108] Fig. 27 The following situation is shown: after the workpiece holder 172 is fully received by the workpiece holder receiving position, the entire multi-level lifting table 20 is displaced in the positive z-direction by means of the plate lifting drive device 57, so that the upper table plane 60 is aligned with the working plate plane 62.

[0109] and Fig. 22 Compared with the first replacement position in Fig. 27 The second replacement position in .

[0110] Fig.28 The following instantaneous positions are shown: Fig. 27Compared to the position of the upper workpiece holder, the roller conveyor pairs 54, 55 are further displaced in the positive z direction relative to the tabletops 27, 28 by means of the roller conveyor lifting drive 56. The lower roller plane 59 is slightly higher than the upper tabletop plane 60, so that the workpiece holder 171 in the upper workpiece holder placement position is now located on the roller conveyor pair of the lower roller conveyor pair 55.

[0111] Fig.29 The following instantaneous position is shown, in which the workpiece holder 171 is pulled onto the work plate 18 of the workbench 19 through the inlet 5 after the workpiece holder gripping device 21 has gripped the workpiece holder 171. Now, or at a later time explained below, the workpiece holder 171 can be pulled onto the work plate 18 of the workbench 19 as described above in conjunction with the workpiece holder gripping device 21. Fig. 20 As explained in the instantaneous position of the workpiece holder 172, the loaded workpiece holder 171 is sewn. Another workpiece holder 172 is still in the workpiece holder receiving position on the roller conveyor of the roller conveyor pair 54.

[0112] Fig.30 The following instantaneous position is shown, wherein the entire multi-layer lifting table 20 and the plate lifting drive 57 are further displaced in the positive z direction. In this position, the lower table plane 61 is aligned with the working plate plane 62.

[0113] When the workpiece holder 171 is completely located on the workbench 19 and no longer overlaps with the multi-layer lifting table 20 in the y direction, it is shifted to Fig.30 The instantaneous position in .

[0114] Fig.31 The instantaneous position is shown in which the two roller conveyor pairs 54 , 55 have been lowered into the platen lifting position, with a z-distance d being present between the two roller planes 58 and 59 and the two platen planes 60 and 61 , respectively. The lower platen plane 61 continues to be aligned with the working plate plane 62 .

[0115] Fig.32 The following instantaneous position is shown during which the completely sewn workpiece 34 is removed from the workpiece holder 172.

[0116] Fig.35 shows the instantaneous position, on the one hand, where if Fig.29 If no sewing is performed in the instantaneous position of Fig. 20 On the other hand, wherein the workpiece holder 172 is loaded, with reference to the above Figure 3 The lower deck plane 61 continues to be aligned with the working plate plane 62.

[0117] Fig.33The instantaneous position is shown in which the still loaded workpiece holder 172 is pushed completely onto the roller conveyor of the upper roller conveyor pair 54 and is located at a distance d above the upper work table 27 .

[0118] Fig.34 The instantaneous position is shown in which the two roller conveyor pairs 54 and 55 are displaced in the negative z-direction into a lowered plate position in which the workpiece holder 172 is placed onto the upper platen 27 .

[0119] Fig.36 Shown is the instantaneous position in which the completely sewn workpiece holder 171 is placed on the lower platen 28 by means of the workpiece holder gripping device 21 .

[0120] Fig.37 The instantaneous position is shown in which, for sewing, the workpiece holder 171 is pulled from the lower table 28 onto the worktable 19 by means of the workpiece holder gripping device 21 .

[0121] Fig.38 Shown is the instantaneous position in which the workpiece holder 171 is completely sewn by means of the sewing unit 1 and is placed on the work table 19 without being aligned in the y direction with the multi-layer lifting table 20 .

[0122] Fig.39 The instantaneous position of Fig.21 The instantaneous position of Fig.21 Only the workpiece holders 171 and 172 are exchanged in the present embodiment, otherwise the sewing and loading situation and the positioning of the workpiece holders 171 and 172 relative to the sewing unit 1 are identical. Figures 21 to 39 cycle.

[0123] Once the looper thread of the currently used lower sewing part 10 or 11 begins to run out, as described above, especially in conjunction with Figures 10 to 12 The described replacement of this curved needle feeder, wherein, compared with the replacement time of the curved needle feeder, the interruption time of the sewing process during the replacement of the lower sewing parts 10, 11 is significantly shorter, for example, only lasting 25%, 20%, 10% or a shorter part of the replacement time.

Claims

1. A multi-layer lifting table (20) for providing at least two workpiece holders (171, 172) for a sewing unit (1) - having a lifting platform frame (51), - having at least two table plates (27, 28) which are placed one above the other at multiple heights and fixedly connected to each other for storing workpiece holders (171, 172), wherein an upper table plate (27) of the two table plates (27, 28) provides an upper workpiece holder storage position, and a lower table plate (28) of the two table plates (27, 28) provides a lower workpiece holder storage position, - having at least two roller conveyor pairs (54, 55) capable of being displaced by lifting between a lowered plate position and a plate position lifted relative to the lowered plate position, - in the lowered plate position, each roller conveyor pair (54, 55) is placed on opposite sides of the platen (27, 28) assigned to this roller conveyor pair (54, 55) so that the roller plane (58) of the upper part of the respective roller conveyor pair (54, 55) is located below the platen plane (60, 61) of the assigned platen (27, 28), - in the plate position raised relative to the lowered plate position, each roller conveyor pair (54, 55) is placed on opposite sides of the table (27, 28) assigned to this roller conveyor pair, so that the roller plane (58, 59) of the upper part of the corresponding roller conveyor pair (54, 55) is located above the table plane (60, 61) of the assigned table (27, 28) in order to guide the workpiece holder (171, 172) by the rollers to be displaced from the corresponding storage position or to the corresponding storage position on the table (27, 28), - having a plate lifting drive device (57) for lifting and displacing the table plates (27, 28) relative to the lifting table frame (51), - A roller conveyor lifting drive (56) is provided for lifting and displacing the roller conveyor pair (54, 55) relative to the platform (27, 28).

2. The multi-layer lifting platform according to claim 1, characterized in that: The uppermost roller conveyor pair (54) of the roller conveyor pairs (54, 55) can be shifted to a workpiece holder receiving position by means of the roller conveyor lifting drive device (56), and the workpiece holder receiving position is further lifted relative to the raised plate position for receiving one of the workpiece holders (171, 172) at a position above the upper workpiece holder storage position.

3. The multi-layer lifting platform according to claim 2, characterized in that: At least one roller conveyor pair (55) is capable of being shifted by means of the roller conveyor lifting drive (56) from below the uppermost roller conveyor pair (54) to a workpiece holder receiving position which is still further lifted relative to its plate position, wherein the plate position is raised compared to the table plane (61) of the assigned table (28), in which the upper roller plane (59) of this roller conveyor pair (55) is located above the table plane (60) of the table (27) above the assigned table (28).

4. The multi-layer lifting platform according to any one of claims 1 to 3, characterized in that: The roller conveyor lifting drive (56) is designed so that during displacement between a plate position and a workpiece holder receiving position at the height of a workpiece holder storage position, the distance between the roller conveyors (541, 542; 551, 552) of the respective roller conveyor pair (54, 55) increases.

5. The multi-layer lifting platform according to any one of claims 1 to 4, characterized in that: The roller conveyors (541, 542; 551, 552) of at least one roller conveyor pair (54, 55) are interrupted, wherein the interruption creates a space for support rods (522, 525) for interconnecting the platens (27, 28).

6. A sewing unit (1) for sewing workpieces (34) in a sewing work area, - having a work plate (18) for placing the sewing workpiece (34), - having a seam forming tool (9, 12) for producing a seam, - having a multi-layer lifting platform (20) as claimed in any one of claims 1 to 5, - having a workpiece holder clamping device (21), which can be shifted between a neutral position and a clamping position outside the sewing work area via a clamping drive device (25, 26), in which the clamping tool (22) of the workpiece holder clamping device (21) clamps the edge of the workpiece holder (171, 172) in the storage position on one of the table plates (27, 28) of the multi-layer lifting table (20) to transfer it to the workpiece holder sewing position.

7. The sewing unit according to claim 6, characterized in that Designed as an entry-type sewing unit.

8. The sewing unit according to claim 6 or 7, characterized in that: The workpiece holder clamping device (21) comprises a clamping rail (22) as a clamping tool, both ends of which are linearly guided via respective guide rails (23, 24).

Images