EP1944400A1 - Sewing machine - Google Patents

Abstract

A first carrier unit clamps two pieces of sewing material in a position relative for sewing and relocates them at a rate of carrying speed from a preparation station to a sewing station while relocating them at a rate of sewing speed during a sewing process. A second carrier unit (18) relocates with at a further rate of carrying speed the two pieces of sewing material from the sewing station to a station for deposit. A carrier subunit (16b) is relocated for the first carrier unit so as to ensure a relative sewing position during relocation of the two pieces of sewing material.

Description

The invention relates to a sewing machine for automatically sewing a first fabric part with a second fabric part.

Such sewing machines are known by public prior use. Examples of such sewing machines are those of the types 2110/4, 2111/4, 2112/4 and 2211/4 Beisler GmbH, Hoesbach. Such sewing machines are designed for sewing of different types of Nähgutteil pairs, whereby not only the Nähgutteile within a Nähgutteil-pair vary greatly in size, but where very different sizes of workpieces can be used even with different Nähgutteil pairs. Examples of this are the Nähgutteil pairs pocket bag / Taschenbesetz and front trouser part / slot strip. The workpieces differ in particular in their weight, so that they make different demands on their transport in the sewing machine by the two transport units. These different requirements lead either to an undesirable reduction in the process speed or to a high design complexity of the transport units.

A generic sewing machine is known from the DE 90 02 008 U1 , From the DE 197 12 421 C1 an automatic sewing machine is known, which has two stepper motors for moving a workpiece holder.

It is an object of the present invention to further develop a sewing machine of the type mentioned above in such a way that different pairs of sewing material can be sewn together with a high process speed and at the same time good process reliability.

This object is achieved by a sewing machine with the features specified in claim 1.

According to the invention, it has been recognized that the use of a drive motor which is capable of defined transport displacement on the one hand with the sewing speed and on the other hand with the transport speed, leads to the possibility of the sewing machines to the different requirements that are put on the transport of different Nähgutteil pairs , optimized to adapt. This makes it possible to sew sewing parts with a high process speed and at the same time high process reliability. In the known sewing machines, the transport displacement was always reserved on the one hand in the sewing speed and on the other hand in the transport speed always two separate drives, which brought a correspondingly increased drive effort with it. Instead of two separate drives, the invention now uses a drive which is capable of displacement both in the sewing speed and in the transport speed.

A stepper motor according to claim 2 allows a defined drive displacement. Exactly the respective position of the displaced transport unit or transport subunit can be tracked over the number of steps, so that, if desired, an intermediate initialization of the position of the transport unit or transport subunit can be dispensed with.

A common carrier according to claim 3 reduces the structural complexity of the sewing machine. The transport subunit and the second transport unit can then be relocated with one and the same drive.

A toothed belt according to claim 4 leads to a robust and safe drive.

Controllable lifting rams according to claim 5 have been found to be gentle and at the same time safe displacement of the workpieces as particularly suitable.

Hubstempel numbers according to claims 6 and 7 are well adapted to the function of the transport subunit on the one hand and the second transport unit on the other hand. The triangular arrangement of the lifting ram according to claim 7 ensures a safe displacement of larger pieces of sewing material from the sewing station to the storage station.

A programmable drive unit according to claim 8 leads to the possibility of a variable programming of different displacement sequences, adapted to the requirements of the respective automated sewing method.

An embodiment according to claim 9 allows in particular a dosage of the contact pressure of the lifting ram. For this purpose, the drive unit is in particular connected to a proportional valve for contact pressure dosing. If the contact pressure is not to be metered, can also be dispensed with a proportional valve.

Fig. 1

eine Aufsicht auf einen erfindungsgemäßen Nähautomaten nach dem Ausrichten zweier zu vernähender Nähgutteile zueinander in eine Näh-Relativposition;

Fig. 2

in einer perspektivischen Ansicht schräg von oben ein Transportmodul des Nähautomaten nach Fig. 1 mit einer Transport-Untereinheit einer ersten Transporteinheit und mit einer zweiten Transporteinheit;

Fig. 3

das Transportmodul nach Fig. 2 in einer weiteren perspektivischen Ansicht schräg von oben;

Fig. 4

in einer zu Fig. 1 ähnlichen Darstellung den Nähautomaten in einer weiteren Momentanposition bei der Durchführung eines ersten Nähverfahrens, in der zueinander ausgerichteten Nähgutteile von einer Klemmeinrichtung zur Verlagerung der beiden Nähgutteile hin zu einer Nähstation geklemmt sind;

Fig. 5

in einer zu Fig. 1 ähnlichen Darstellung den Nähautomaten in einer Näh-Momentanposition;

Fig. 6

in einer zu Fig. 1 ähnlichen Darstellung den Nähautomaten in einer Momentanposition beim Ablegen der beiden miteinander vernähten Nähgutteile;

Fig. 7

in einer zu Fig. 1 ähnlichen Darstellung den Nähautomaten in einer weiteren Momentanposition beim Ablegen der beiden miteinander vernähten Nähgutteile;

Fig. 8

in einer zu Fig. 1 ähnlichen Darstellung den Nähautomaten nach dem Ablegen der miteinander vernähten Nähgutteile;

Fig. 9 bis 12

in einer zu Fig. 1 ähnlichen Darstellung den Nähautomaten bei der Durchführung eines zweiten Nähverfahrens mit anderen zu vernähenden Nähgutteilen.

An embodiment of the invention will be explained in more detail with reference to the drawing. In this show:

Fig. 1

a plan view of an automatic sewing machine according to the invention after aligning two Nähgutteile to be sewn each other in a sewing relative position;

Fig. 2

in a perspective view obliquely from above a transport module of the sewing machine after Fig. 1 with a transport subunit of a first transport unit and with a second transport unit;

Fig. 3

the transport module after Fig. 2 in a further perspective view obliquely from above;

Fig. 4

in one too Fig. 1 similar representation of the sewing machine in a further instantaneous position in the implementation of a first sewing method, are clamped in the aligned piece of fabric by a clamping device for moving the two workpieces towards a sewing station;

Fig. 5

in one too Fig. 1 similar representation of the sewing machine in a sewing momentary position;

Fig. 6

in one too Fig. 1 similar representation of the sewing machine in a momentary position when placing the two sewn together sewing material parts;

Fig. 7

in one too Fig. 1 similar representation of the sewing machine in a further instantaneous position when depositing the two sewn together sewing material parts;

Fig. 8

in one too Fig. 1 similar representation of the sewing machine after depositing the sewn together sewing material parts;

Fig. 9 to 12

in one too Fig. 1 Similar representation of the sewing machine in the implementation of a second sewing method with other sewing material to be sewn.

An automatic sewing machine 1 is used for automatically sewing a first fabric part 2, z. B. a pocket bag, with a second fabric part 3, z. B. a bag occupation. The sewing machine 1 has a Nähgutauflage 4, to which the two sewing material to be sewn together 2, 3 are placed. The Nähgutauflage 4 has a sliding plate 5 with a plurality of vacuum holes 6 (vg1 Fig. 5 ). The latter communicate with a vacuum source for the releasable fixing of the workpiece parts 2, 3 on the sewing material support 4.

For aligning the two Nähgutteile 2, 3 in a in the Fig. 1 shown sewing-relative position is an insertion and preparation station 7 of the automatic sewing machine 1. The loading and preparation station 7 has a supply table 8, on which the workpieces 2, 3 are stacked. Furthermore, the loading and preparation station 7 on the sliding plate 5 has several application marks 9, on which the first workpiece 2 aligned on the sliding plate 5 can be placed. The insertion and preparation station 7 further comprises a loading unit 10 for the second workpiece 3. The insert unit 10 has a stop bar 11, on which the second workpiece 3 can be created. Furthermore, the insertion unit 10 has two spaced-apart Zwickmesser 12. With the latter, if necessary, a seam projection of a seam for sewing the two Nähgutteile 2, 3 are cut edge.

For loading and preparation station 7 also includes a folding station, not shown in the drawing, which is inserted in the insertion unit 10 to the stop bar 11 second fabric part 3 in a in the Fig. 1 shown Näh-relative position to the first fabric part 2 transferred. In this sewing-relative position, the second workpiece 3 is positioned on the first workpiece 2 so that the two workpiece parts are aligned with respect to a portion 13 of the edge contour of the first workpiece 2.

For the clarification of positional relationships and directions of movement is in the Fig. 1 a Cartesian xyz coordinate system drawn. The x-direction runs in the Fig. 1 perpendicular to the drawing plane. The y-direction runs in the Fig. 1 to the left and the z direction in the Fig. 1 up.

For sewing the two Nähgutteile 2, 3 together, a sewing station 14, which has a trained in the usual way sewing machine 15 is used.

A first transport unit 16, 16a, 16b of the automatic sewing machine 1 serves to clamp and displace the two workpiece parts 2, 3, both of which are located in the sewing relative position to each other during the transfer, from the loading and preparation station 7 to the sewing station 14. This shift takes place at a transport speed. Furthermore, the first transport unit 16 serves for the displacement of the two workpieces 2, 3 during the sewing process in the sewing station 14, in which the workpieces 2, 3 maintain the sewing relative position, with a sewing speed. The first transport unit 16 has a stapling unit 16a formed in a known manner. In certain sewing methods of the automatic sewing machine 1, the first transport unit 16 additionally includes a transport subunit 16b. The latter is part of a total in the Subunit 16b. The latter is part of a total in the Fig. 2 and 3 17. In addition to the transport subunit 16b, the transport module 17 has a second transport unit 18. This is used to shift the two sewn together in the sewing station 14 Nähgutteile 2, 3 with a further transport speed of the sewing station 14 to a storage station 19 of the Sewing machines 1, which can be displaced in the y-direction sliding table 20 and a displaceable in the x-direction lift table 21 (see. Fig. 7 ) having.

The transport sub-unit 16b has two lifting rams 22, which are screwed via a connecting plate 23 with two lifting cylinders 24. The lifting cylinders 24 allow a Hubverlagerung the lifting ram 22 in the x direction. The distance between the two lifting rams 22 in the z-direction to each other can be predetermined and fixed by means of a slot 25 in the connecting plate 23. The two lifting cylinders 24 of the transport subunit 16b are in turn bolted to a bracket 26. The bracket 26 is a common carrier for the transport subunit 16 b and the second transport unit 18.

The second transport unit 18 has three lifting rams, of which two lifting rams 27 are offset in positive z-direction relative to the lifting rams 22 of the transport subassembly 16b as the lifting rams 22 are mounted on the bracket 26 via a connecting plate 23 and two lifting cylinders 24. The latter can be prevented by targeted blowing of the workpiece 2, 3 when lifting the lifting ram, especially when lifting the lifting ram 27, an undesirable adhesion of the fabric 2, 3 at the Hubstempeln or eliminated become. In addition to the two Hubstempeln 27, the second transport unit 18 still has the third Hubstempel 29. The latter is mounted on a cantilever plate 30 which is screwed to the connecting plate 23. The cantilever plate 30 extends obliquely both in the y-direction and in the z-direction, so that the Aufsetzpunkte the two lifting rams 27 and the third Hubstempels 29 specify the corners of a triangle.

The lifting rams 22, 27, 29 can each be displaced by means of the lifting cylinders 24 between an operating position lowered onto the sewing material support 4 and a rest position raised from the sewing material support 4.

The bracket 26 is mounted on a carriage 31 of a linear guide 32. The linear guide 32 allows a guided displacement movement of the carriage 31 in the z direction. The carriage 31 is driven by a drive motor 33, which is designed as a stepper motor. The stepping motor 33 and the lifting cylinder 24 are controlled by a central control device, not shown, of the sewing machine 1. This central control device or drive unit is programmable. For power transmission between the stepping motor 33 and the carriage 31 is a toothed belt 34. The latter runs around pulleys 35, of which only one is visible in the drawing and rotate about axes parallel to the x-axis. The deflection rollers 35 are mounted on the linear guide 32.

At the motor end of the linear guide 32, a reference switch 36 is arranged. This serves to initialize the z-position of the carriage 31 on the linear guide 32nd

The linear guide 32 is mounted on a support frame 37, which is supported on a frame of the automatic sewing machine 1.

Hereinafter, the function of the transport module 17 will be described in connection with a first automatic sewing method in which the pocket bag 2 is sewn to the pocket occupant 3. Fig. 1 shows the instantaneous position in which the alignment of the two Nähgutteile 2, 3 is completed in the sewing relative position to each other. Fig. 4 shows the situation in which the staple unit 16a has lowered to a transfer position in which it firmly clamps the fabric part 3 on the fabric part 2, so that in the subsequent displacement both fabric pieces 2, 3 maintain their relative position to each other. Fig. 5 shows the instantaneous position during the sewing of the two Nähgutteile 2, 3 with the sewing machine 15. Until the completion of sewing, the transport module 17 is still inactive. Once the sewing is completed, the lifting cylinder 24 of the second transport unit 18 in the in the Fig. 5 shown z-position of the second transport unit 18 is activated, so that the lifting rams 27, 29 of the second transport unit 18 from the rest position to the operating position on the sewn together workpiece parts 2, 3 lower. The staple unit 16a now lifts off from the workpiece parts 2, 3. The second transport unit 18 now moves, driven by the stepping motor 33, with respect to the sewing speed of high transport speed to a programmed z-position on the sliding table 20, which in the Fig. 6 is shown. Now, the sliding table 20 is displaced in the negative y-direction and the sewn together sewing parts 2, 3 fall from the Hubstempeln 27, 29 and in the positive x-direction on the lifting table 21. This is in the Fig. 7 shown. Now the lifting rams 27, 29 of the second transport unit 18 are retracted again and the second transport unit 18 moves, driven by the stepping motor 33, with high transport speed again in the in the Fig. 1 shown starting position back.

At the same time, the sliding table 20 moves in the positive y-direction in his in the Fig. 1 shown starting position back.

During this automated sewing process, the transport subunit 16b of the transport module 17 remains inactive. Since the transport subassembly 16b is fixedly connected to the second transport unit 18 via the holding bracket 26, it moves passively with it during the sewing process.

After return of the second transport unit 18 and the sliding table 20 in their initial positions, the instantaneous position of the automatic sewing machine 1 is after Fig. 8 reached. Now the sewing process can run again. Of course, it is also possible to pass through the sewing process in an overlapping manner, ie it is possible to insert new workpiece parts 2, 3 while the previously inserted workpiece parts 2, 3 are still being processed in the sewing station 14.

Based on Fig. 9 to 12 Now, a second automated sewing method for sewing a first fabric part 2 in the form of a front trouser part and a second fabric part 3 in the form of a slot strip will be described.

Fig. 9 again shows the position at which the two workpieces 2, 3 are present in their sewing relative position to each other. The front trouser part 2 has been aligned by means of a laser line 38, with which the sliding plate 5 is illuminated and which runs parallel to the z-direction. The fabric part 3 is before being taken over by the folding station, not shown, the loading and preparation station 7 with in the Fig. 9 upper Zwickmesser 12 cut at the edge. Accordingly, the first Sewing material part 2 by a Zwickmesser 39 in the same z-position edge cut, so that the incisions of the two Nähgutteile 2, 3 in the sewing relative position are superimposed. Overall, the Nähgutauflage 4 has two such Zwickmesser 39 at the same z-height as the two Zwickmesser 12th

After the alignment of the two workpieces 2, 3 to each other (vg1. Fig. 9 ) moves the staple unit 16a in the transfer position and clamps the two workpieces 2, 3 in the sewing relative position. At the same time, the lifting rams 22 of the transport subunit 16b also lower onto the first workpiece 2. The first transport unit 16, ie the staple unit 16a, together with the transport subassembly 16b now move the two workpiece parts 2, 3 in the sewing relative position from the loading and preparation station 7 to the sewing station 14. The two units 16a move, 16b of the first transport unit 16 in synchronism with each other. This synchronous movement happens with the high transport speed.

Due to the fact that the lifting rams 22 of the transport subunit 16b guide the first workpiece 2 in this displacement movement in a positive z direction, this first workpiece 2 is prevented from accelerating out of the rest position due to its own weight or due to mass inertia Sewing relative position in the high transport speed from the staple unit 16a pulls. The transport subunit 16b thus serves to secure the sewing relative position during the displacement of the two workpiece parts 2, 3 by the first transport unit 16. Fig. 10 shows the situation immediately after lowering the lifting ram 22 on the first workpiece 2 and before introducing the acceleration in the transport speed.

Fig. 11 shows the situation during the sewing of the two Nähgutteile 2, 3 with the sewing machine 15. During sewing, move the two units 16a, 16b of the first transport unit 16 in synchronism with each other with a sewing speed in the z-direction, which is about a factor of 10 lower as the transport speed. During the sewing, it is ensured that the first fabric part 2 does not pull out of the staple unit 16a. In addition, the synchronous movement of the transport subunit 16b with the stapling unit 16a ensures that a high-quality and precisely positioned seam for sewing the two workpiece parts 2, 3 is produced. Start and end points of the seam follow a programmed sequence, controlled by the central control device.

After sewing, the lifting cylinders 24 of the transport subunit 16b are activated and the lifting rams 22 lift off the first workpiece 2. The staple unit 16a also lifts off the workpiece parts 2, 3. The sewed together sewing material parts 2, 3 are blown out by a not visible in the drawing air nozzle, the function of the second transport unit for moving the two Nähgutteile 2, 3 from the sewing station 14 to a tray or to the storage station 19 in this automated sewing method ,

After blowing the transport module 17 moves back into the in the Fig. 9 shown starting position back. In turn, it is then possible to place two workpiece parts 2, 3 in the loading and preparation station 7, whereby this can also take place partially overlapping with the later processing steps in the sewing machine 1 in the second automated sewing method.

In the second automated sewing method described above, the second transport unit 18 remains inactive and is only moved passively with the transport subunit 16b.

The transport module 17 thus has the function of a second transport unit for moving the two Nähgutteile of the sewing station 14 to the storage station 19 and the second automated sewing method shown above, the function of a subunit of the first transport unit 16 for moving the two workpieces 2 in the first automated sewing method shown above 3 in the sewing relative position from the loading and preparation station 7 to the sewing station 14. The displacement of the transport module 17 in the first sewing process with the transport speed, which is at least 10 times as large as the displacement during sewing in the second sewing method with the sewing speed. The transport speed is about 1 m / s. The sewing speed is about 5 to 7 cm / s. The different displacement speeds are provided by the drive motor 33.

Among other things, the central control device controls the lifting cylinders 24 for metering the contact pressure in the operating position of the lifting rams 22, 27, 29.

Claims (9)

Automatic sewing machine (1) for automatically sewing a first fabric part (2) with a second fabric part (3), with a fabric support (4), - With an insertion and preparation station (7) for aligning the two workpieces (2, 3) to each other in a sewing relative position, - With a sewing station (14) with a sewing machine (15) for sewing the two Nähgutteile (2, 3) with each other, - With a first transport unit (16) for clamping and for displacement of the two Nähgutteile (2, 3) in the sewing relative position of the loading and preparation station (7) towards the sewing station (14) with a transport speed and the displacement of the two workpieces (2, 3) at a sewing speed during the sewing operation in the sewing relative position, - With a storage station (19) for receiving the sewn together workpiece parts (2, 3), - With a second transport unit (18) for shifting the two Nähgutteile (2, 3) of the sewing station (14) towards the storage station (19) with a further transport speed, characterized in that a displacement of a transport subunit (16b) of the first transport unit (16) for securing the sewing relative position during the displacement of the two Nähgutteile (2, 3) by the first transport unit (16) and / or a displacement of the second Transport unit (18) by means of a drive motor (33) which is designed such that a displacement by the drive motor (33) on the one hand in the sewing speed and on the other hand at a transport speed which is at least 10 times the sewing speed. Sewing machine according to claim 1, characterized by a stepping motor as drive motor (33). Sewing machine according to claim 1 or 2, characterized in that the transport subunit (16b) and the second transport unit (18) are connected to a common carrier (26). Sewing machine according to one of claims 1 to 3, characterized by a toothed belt (34) for transmitting power between the drive motor (33) and the transport subunit (16b) and / or the second transport unit (18). Sewing machine according to one of claims 1 to 4, characterized in that the transport subunit (16b) and / or the second transport unit (18) at least one controllable lifting ram (22, 27, 29), which is displaceable between a on the Nähgutauflage (4) lowered operating position and one of the Nähgutauflage (4) lifted rest position. Sewing machine according to claim 5, characterized in that the transport subunit (16b) has at least two lifting rams. Sewing machine according to claim 5 or 6, characterized in that the second transport unit (18) has at least three lifting rams (27, 29) whose bearing points on the Nähgutauflage (4) in the operating position Do not lie on a line, but pretend the vertices of a triangle. Sewing machine according to one of claims 1 to 7, characterized by a programmable drive unit for the drive motor (33). Sewing machine according to claim 8, characterized in that the lifting rams (22, 27, 29) are in signal communication with the programmable drive unit.

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