WO1998028481A1

WO1998028481A1 - Embroidery machine with changing hook

Info

Publication number: WO1998028481A1
Application number: PCT/EP1997/006621
Authority: WO
Inventors: Hans-Rainer Gessmann; Karl Helgert; Rolf Zieschang
Original assignee: Zsk Stickmaschinen Gmbh
Priority date: 1996-12-20
Filing date: 1997-11-27
Publication date: 1998-07-02
Also published as: AU5656098A; DE19653296C1

Abstract

The invention relates to an embroidery, stitching or sewing machine with an upper and lower thread system and a device for changing a hook that is arranged on the working area underneath the needle plate. Said machine has several hooks assigned to the same working area and which are fitted to a hook support, which can be displaced in such a way that the hooks can be individually positioned underneath the needle plate, the hooks (3) being linearly arranged in an axis on the hook support (7) which can be displaced linearly in the direction of said axis (6).

Description

Embroidery machine with change of hook

The invention relates to an embroidery, quilting or sewing machine with upper and lower thread system and with a device for changing a looper mounted at the work station below the throat plate, the machine having several grippers assigned to the same work station, which are arranged on a looper carrier which can be moved such that the grippers can be positioned individually below the throat plate.

In addition to the manufacturing costs, the economic viability of these machines is largely determined by their speed, particularly when changing the thread and when troubleshooting accidents such as thread breakage. Not only the upper thread, but also the lower thread is of crucial importance.

In conventional machines, changing the bobbin is a complex and lengthy process that the operator usually has to do by hand. In detail, the bobbin case with the bobbin must first be removed from the hook. Then the lower thread spool stored in it is exchanged for a new thread spool. Then the bobbin case with the new bobbin must be inserted into the hook and locked.

While performing these steps, the machine must be stopped, at least at the affected job. Such downtimes make the processing of textile goods considerably more expensive. Various devices for automatically changing the bobbin case have therefore been proposed. A sewing machine is known from DE-OS 17 60 106, which has a magazine for several bobbin cases with bobbin bobbins. During a change, a bobbin carrier that moves back and forth transports a bobbin case from the magazine to the looper, where a gripper device removes the old bobbin case with the empty bobbin from the looper and inserts the new bobbin case with the full bobbin into the looper.

To simplify this very complex device, it was proposed in DE 40 25 475 AI to provide a tubular magazine for a plurality of bobbin cases with an ejection device and a device for removing bobbin cases from the gripper. This combination of two devices for removing and inserting bobbin cases from or into the gripper is also structurally very complex and changing the bobbin case takes a relatively long time. In addition, the capacity of the magazine is limited, so that after a corresponding number of bobbin capsule changes, a longer machine downtime is required to reload the magazine.

Also in this machine, a bobbin case change is only provided when a bobbin is empty. It is not possible to change the bobbin case several times according to the program with different colored bobbin threads to achieve certain embroidery or sewing patterns.

In order to avoid these disadvantages, it was proposed in JP 59-166187 to design an embroidery machine with the features mentioned at the outset. Several grippers are supported over the circumference of a drum-shaped auxiliary body, which can each position a gripper below the throat plate by rotation. Such a drum especially in the case of a large number of grippers, requires a large installation space which extends not only to the sides but also downwards. To control the rotary movements of the drum, a complex coupling mechanism is required, which causes high manufacturing costs.

From DE 3515627 C2 a non-generic chain stitch embroidery machine is known which works according to the single thread system with only one embroidery thread. Therefore, there can be no problem in this machine that the lower thread needs to be changed. A gripper is therefore not required for this stitch formation, but a loop former that swings back and forth as a thread layer. In order to enable the embroidering of a multi-colored pattern on this machine, it was proposed to arrange a plurality of loop formers in a movable manner next to one another. For each color, the thread is drawn off from a large thread cone or thread bobbin, so that the thread supply is used up much less frequently than with the comparatively much smaller bobbin threads in the grippers of a two-thread embroidery machine. The removal of thread breaks is not possible with a machine according to DE 3515627 C2.

The object of the invention is to provide an inexpensive to manufacture and easy-to-use machine of the type mentioned which, with simple controllability, enables a rapid, preferably automatic change of the grippers and which, with a simple and compact construction, requires only a small installation space. The change should be possible both when the bobbin is empty and when the thread breaks or when the bobbin changes color.

This object is achieved in that the grippers are linearly mounted on the gripper carrier in one axis are, and the gripper carrier is linearly movable in the direction of this axis.

In this way, a particularly compact and space-saving design is achieved, which enables the grippers to be changed quickly with short travel distances. Exact positioning of the grippers in the working position below the throat plate is possible in a simple manner. The gripper change can be triggered manually or automatically. Thanks to an automatic gripper change, the machine is ready for use again very quickly, with the machine's workstation being replaced during a change, i.e. is only stopped for a very short time during the movement of the gripper carrier. The textile is therefore inexpensive to work with, even with different colored bobbins.

The time required for an operator to operate and control the machine can be reduced to a minimum. An operator can operate and supervise several machines according to the invention at the same time, since production interruptions due to empty bobbin bobbins or breakage of the bobbin can be eliminated automatically. After an automatic looper change has taken place, the operator has sufficient time to determine whether a new bobbin has to be inserted into a looper in a park position or whether the same bobbin can continue to be used after a yarn break.

The changer device according to the invention is inexpensive to manufacture and easy to handle and control. It is structurally simple, easy to assemble and is characterized by a compact design and low space requirements. Two or more grippers can be arranged on the movable gripper carrier and moved simultaneously. The movement of the gripper carrier can be controlled via a control unit.

It is particularly advantageous if a single drive is provided for all grippers, by means of which the gripper positioned below the throat plate in the working position can be driven via a coupling. The drive by an electric motor and coupling means that can be coupled in a form-fitting manner is particularly favorable.

It is also advantageous if the grippers, which are not currently driven, are locked in a rotationally fixed manner on the gripper carrier in parking positions. As a result, both additional wear and noise generation due to rotating but not currently required grippers can be avoided without each individual gripper having to be drivable by its own motor, which has led to further high costs. The locking can be done easily over half of the coupling, a positive coupling is particularly inexpensive.

In preferred embodiments, the gripper carrier can be moved via a toothed belt, via a cable pull, via a toothed rack with pinion or via a spindle, preferably a trapezoidal thread or ball roller spindle. Electrical, pneumatic, hydraulic and / or magnetic drive means can preferably be used.

In order to be able to separate the currently processed lower thread from the textile material when changing the thread, it is advantageous if at least one thread cutting device is provided below the needle plate. A first thread cutting device can consist of two movable knives exist, which can be actuated by a control unit in particular when an intended change of bobbin thread.

A second, particularly simple thread cutting device can be formed by two fixed knives arranged laterally below the throat plate and in the direction of travel of the looper, on which the lower thread is cut when the looper is moved.

Likewise, a thread monitor with a sensor, preferably a wire bracket, can be provided below the throat plate, by means of which a thread break or an empty bobbin can be detected and which transmits the corresponding signals to the control unit of the looper carrier.

The gripper carrier with the grippers and optionally the thread cutting device (s) and the thread monitor can advantageously be combined to form a working head. A particularly efficient way of working can be achieved in that the machine has several working heads. However, the gripper changing device according to the invention can also be used in a machine with only one working head.

With several working heads, a particularly space-saving construction of the machine with very small working head distances can be achieved in that the gripper carrier can be moved vertically up and down and can be swiveled or rotated during the process. In order to avoid collisions with very small working head distances during the rotational movement of the gripper carriers, the gripper can be changed in two passes in succession only on every second working head, or the rotational movements of the individual gripper carriers are carried out in succession so that two adjacent gripper carriers do not rotate at the same time. In this way, the smallest possible Working head spacing is not determined by the length, width or diameter of the changing device, but by the narrower working head width. In addition, grippers that are not involved in the embroidery process are more accessible due to the vertical arrangement for changing the bobbin, because they are no longer in the table top level. There is also more installation space for other components, especially for thread cutters, thread monitors and for the X and Y pantograph drives.

If the machine has several working heads, each individual gripper carrier can be moved by its own drive, preferably a stepper motor, or a single drive can be provided, which over all gripper carriers, in particular via a drive spindle, via a rack and pinion combination a cable or via a toothed belt, moved at the same time. This type of drive is particularly advantageous when a large number of identical embroidery patterns with differently colored lower threads are to be carried out next to one another.

It is advantageous if one or more gripper carriers can be moved into an intermediate position in which all grippers of this / these gripper carrier (s) are locked in a rotationally fixed manner. This reduces the wear on the grippers when only certain working heads are working, especially when the patterns are large, and the working heads that are not required are switched off.

A further automation of the workflow of the machine can be achieved in that at least one bobbin capsule changing device known per se is provided for changing the bobbin capsules with bobbin bobbins stored therein from the hooks. Such devices for changing the bobbin case can for the entire machine or be arranged for a single working head as well as fixed or movable. Fitting the changing devices with new bobbin cases is only necessary after a relatively long period of time, so that the time required for an operator to operate and control the machine can be reduced even further.

If the bobbin thread currently being processed is to be changed, the machine is first stopped. The currently processed lower thread is then separated from the textile material and the looper carrier moves until the looper with the desired lower thread is in the working position below the needle plate. Then the work process can be continued immediately with the new bobbin thread.

In addition to such a change of the gripper, which is predetermined by the embroidery or sewing program, a change can also take place if the lower thread is broken or the lower thread bobbin is empty, which can be easily determined, in particular, by a thread monitor.

Further advantages and features of the invention emerge from the subclaims and from the following description and the exemplary embodiments illustrated in the drawings.

Show it:

Figure 1: View of a job with two grippers

Figure 2: Top view of the work station from Figure 1 (throat plate is not shown) Figure 3: Side view of the workplace from Figure 1

Figures 4a and 4b: enlarged view of the area Z from

Figure 3 with two different embodiments of the clutch for the gripper drive

Figure 5a and 5b: two different embodiments of a gripper locked in a parking position

Figure 6: View of four jobs, whose

Gripper carriers can be moved by a common motor

Figure 7: View of four jobs, each

Gripper carrier can be moved by its own motor

FIG. 8: View of a work station from FIG. 7, in which the gripper carrier has moved into an intermediate position (gripper switch-off)

Figure 9: Schematic arrangement of the grippers on a gripper carrier

Figure 10: Schematic representation of a vertically movable and pivotable gripper carrier

Figure 11: Side view of a work station with a bobbin case changing device

The work station 1 shown in FIGS. 1 to 3 of an embroidery machine has two grippers 3, each one - IC -

Have bobbin case 4 with bobbin 5 stored therein. The two grippers 3 are rotatably mounted on a gripper carrier 7 which can be moved back and forth in the direction 6.

The gripper carrier 7 can be moved in such a way that the grippers 3 can be positioned individually in a working position A below the needle plate 8 and the needle 9. The gripper carrier 7 is driven by a stepper motor 10 and via a spindle 11, on which a spindle nut 12, which is non-rotatably attached to the gripper carrier 7, is mounted.

If the machine has several work stations 1, the gripper carrier 7 of each individual work station 1 can be moved by its own stepper motor 10 (FIG. 7), or all gripper carriers 7 are moved by a single stepper motor 10 at the same time, the individual spindles 11 via couplings 13 and intermediate shafts 14 are connected to one another in a rotationally fixed manner (FIG. 6).

The gripper carrier 7 is movably supported in a rail 15 which is fastened to the machine frame 17 via a base plate 16. Beneath the base plate 16 and behind the gripper carrier 7 is a gripper drive shaft 18, which extends over all work stations 1 of the machine and is driven by an electric motor. The gripper drive shaft 18 drives a gripper clutch 29, which is mounted at the working position A of the work station 1 and can be coupled in a form-fitting manner (detail Z from FIG. 3), via a gear (not shown in more detail).

The gripper clutch 29 can be formed by a first coupling part 19a formed with a groove, into which the web-shaped flattened end of the gripper shaft 20 can be inserted as a second coupling part 20a (FIG. 4a). In a second variant of the gripper coupling 29, the end of the gripper shaft 20 can be designed as a second coupling part 20b with a groove which can be pushed onto the web-shaped, flattened first coupling part 19b (FIG. 4b).

When the grippers 3 are in a parking position B or in an intermediate position C, they are locked in a rotationally fixed manner via the second coupling part 20a on a holding rail 21a (FIG. 5a) or via the second coupling part 20b on a holding rail 21b (FIG. 5b). The holding rails 21a and 21b are arranged in particular in their vertical orientation corresponding to the first coupling parts 19a and 19b, so that a problem-free coupling of the gripper coupling 29 when moving the gripper carrier 7 is possible if the groove or the web of the first coupling part 19a or 19b is aligned horizontally.

In the case of a machine with a plurality of work stations 1, it may happen with large patterns extending over several work stations 1 that certain work stations 1 cannot be used. In the machine shown in FIG. 7, only work stations la and lc work, while work stations lb and ld are not used. Since the first coupling part 19a or 19b of the gripper coupling 29 of each work station 1 is driven permanently via the gripper drive shaft 18 which extends over the entire machine during operation of the machine, the gripper carriers 7 of the work stations 1b and 1d not currently used are moved in such a way that the Both grippers 3 of each gripper carrier 7 are each in an intermediate position C, in which the grippers 3 are switched off and locked in a rotationally fixed manner via the second coupling parts 20a and 20b and the holding rails 21a and 21b. Not one at the moment Used work station 1b or 1d with the two grippers 3 locked in an intermediate position C is shown enlarged in FIG. 8 (gripper switch-off).

The bobbin cases 4 with the lower thread bobbins 5 stored therein are held in a rotationally fixed manner in each looper 3 by a holding finger 22.

At the working position A of the work station 1 there is a thread cutting device 25 consisting of a hook knife 23 which can be moved back and forth and a fixed counter knife 24 under the needle plate 8. In addition, a wire bracket 26 is arranged below the needle plate 8 as a sensor for a bobbin thread guard, which resiliently counteracts bears the bobbin thread stretched between textile and bobbin 5. In the event of a possible lower thread break, the wire bow 26 springs back into its rest position, so that the thread break can be recognized by the lower thread monitor.

In addition, two fixed cutting knives 27 can be provided below the needle plate 8, which automatically cut the lower thread stretched between the textile material and the lower thread spool 5 when the gripper 3 is moved from the working position A to a parking position B. Three or more grippers 3 can also be arranged linearly on each gripper carrier 7 (FIG. 9).

FIGS. 10a to 10e show different snapshots during a gripper change, the gripper carrier 7 being vertically movable and pivotable. First, the gripper carrier 7 is moved downward (FIG. 10a). The gripper carrier is pivoted through 180 ° in the lower region (FIGS. 10b to 10d). Finally, the gripper carrier 7 is moved up again, so that the gripper 3b, which was first in the parking position B, is now in the - 15 -

Working position A is located. The gripper 3a has been moved from the working position A to the parking position B (FIG. 10e). A gripper switch-off is also easily possible in this embodiment if the gripper carrier 7 is moved vertically into its lower position (FIG. 10c) and remains there. Swiveling the gripper carrier 7 is not necessary, but can also be carried out.

At the work station 1 shown in FIG. 11, a bobbin capsule changing device 28, which can be moved parallel to the looper carrier 7, is provided, in which a plurality of bobbin capsules 4 with lower thread bobbins 5 are mounted. The bobbin capsule changing device 28 can be moved to the parking positions B of the grippers 3 in order to insert a new bobbin capsule 4 into the locked gripper 3 here. This bobbin case change can also be done while the machine is embroidering. One or more bobbin case changing devices 28 can also be arranged to be stationary or movable over all work stations 1 of the machine.

Claims

claims

1. embroidery, quilting or sewing machine with upper and lower thread system and with a device for changing a stored at the job below the needle plate gripper, the machine having several the same job associated grippers, which are arranged on a gripper carrier ger that It is movable that the grippers can be positioned individually below the throat plate, since you are marked by the fact that the grippers (3) are linearly mounted on the gripper carrier (7) in an axis (6), and the gripper carrier (7; in the direction of this axis (6 ) can be moved linearly.

2. Machine according to claim 1, characterized in that a single drive, in particular an electric motor, is provided for all grippers (3), through which the gripper (3) positioned below the needle plate (8) in the working position (A) via a Coupling (29) can be driven.

3. Machine according to claim 2, so that the non-driven grippers (3) are locked in a parking position (B), in particular via a coupling (20, 21), in a rotationally fixed manner on the gripper carrier (7).

4. Machine according to one of the preceding claims, characterized in that the Gripper carrier (7) can be moved by an electrical, pneumatic or hydraulic drive (10).

5. Machine according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the

The gripper carrier (7) can be moved via a toothed belt, a toothed rack with pinion or a spindle (11).

6. Machine according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that at least one thread cutting device (25, 27) is provided below the needle plate (8).

7. Machine according to claim 6, d a d u r c h g e k e n n z e i c h n e t that a pivotally mounted knife (23) and a fixed counter knife (24) comprising first thread cutting device (25) and a two fixed cutting knife (27) comprising second thread cutting device is provided.

8. Machine according to one of the preceding claims, that a thread monitor is provided below the needle plate (8) with a sensor (26) for actuating the looper carrier (7).

9. Machine according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the

The gripper carrier (7) with the grippers (3) and optionally the thread cutting device (25, 27) and the thread monitor (26) are arranged on a working head (1).

10. Machine according to claim 9, d a d u r c h g e k e n n z e i c h n e t that the machine has several working heads (1).

11. Machine according to claim 10, d a d u r c h g e k e n n z e i c h n e t that the gripper carrier (7; vertically up and down and can be pivoted or rotated during the process.

12. Machine according to claim 10 or 11, so that each gripper carrier (7) can be driven by its own drive (10), preferably by a stepper motor.

13. Machine according to claim 10 or 11, so that all gripper carriers (7) can be driven and simultaneously moved by a single drive (10), in particular via a drive shaft (14).

14. Machine according to one of claims 10 to 13, so that one or more gripper carriers (7) can be moved into an intermediate position (C) in which no gripper (3) is driven.

15. Machine according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the

Machine has at least one bobbin capsule changing device (28) for changing the bobbin capsules (4) with lower thread bobbins (5) from the grippers (3) stored therein,