EP1460161B1 - Device for cutting the rear thread in shuttle embroidery machines - Google Patents

Abstract

A shuttle embroidery loom produces numerous loose threads that arise from needle insertions distributed over the lower face of the cloth which rests against a needle plate. A shuttle (27) presents a rear thread (33) behind the plate, The shuttle is moved back alongside a pushrod (11). The rear thread cutting assembly (21) has a shuttle (35) that moves back and forth on a T-shaped track rod (20) alongside the pushrod (11). The shuttle (35) has a blade carrier (27) and cutting blade (41). The shuttle has a slip-interface (52) that simultaneously opens the upper driver (17) during the cutting movement, allowing removal of the shuttle (27). As the slide (35) moves, the rear thread (33) is picked up first by the leading edge (43) and slightly withdrawn from the shuttle (27) until it is cut by the knife edge (41). Enough thread then remains for the next stitch. A spacer (49) ensures that, after the loose thread end has been detached from the fabric, enough thread still remains for appliqu stitching.

Description

The present invention relates to a device for cutting the underwires in shuttle embroidery machines, which have a plurality of embroidery sites, wherein each of these embroidery sites is assigned behind a stitch plate to the back thread supplying shuttle, which is movable by a driver bar back and forth. In the 1909 published DE 226 828 It is described that one can cut the back threads by walking along the machine with a knife or a pair of scissors, thereby cutting off the hundreds of threads in succession that are opposite the knife. This must be done very carefully, so that the scissors or the knife does not hurt the embroidery floor. Another disadvantage is that it depends heavily on the craftsmanship of the executing person, whether the cut is made at the desired distance from the embroidery floor. Especially for application work the back thread should not be cut too close to the embroidery bottom. Finally, it is also disadvantageous that only relatively short thread lengths are available for piecing after cutting with the knife or the scissors.

The dating from 1972 dating DE 2 226 791 shows a stationary device; with which the needle threads used for embroidery on the front side of the embroidery base can be cut. This device has a guide extending along the entire length parallel to the gate, on which a knife carrying carriage is slidably guided. The movement of the carriage with the knife is effected by a rope which is connected at both ends of the gate with pulling devices (page 5, lines 9 to 21). In the event of a yarn change, the gate must be raised so that the needle threads are skewed relative to the cutting edge of the knife. Then all needles are moved back. This will be devices operated, which prevent the withdrawal of the needle threads from the needle tubes. With the cable then the knife is moved quickly along its lead and cuts the tensioned between the embroidery bottom and the needle tubes needle threads close to the embroidery bottom. The lifting of the gate not only serves to give the needle threads the already mentioned skew, but above all to the length of the hanging after the cutting process of the needles thread lengths so that the subsequent embroidering can be safely initiated (p , Lines 1 to 28, page 7, lines 1 to 3).

This document shows only a cutting device for the front or needle threads, but not for the rear or shuttle threads. On the boat side of the machine just completely different conditions prevail than on the needle side. For example, the available during the cutting process length of the shuttle thread between the embroidery plate and the embroidery bottom is substantially smaller than the length of the needle thread between the embroidery bottom and the needle eye. Also, the cutting device can not be mounted stationary above the up and down movable driver bar, without thereby reducing the usable embroidery height, because in the lowermost position of the gate, the upper fabric wave is close to the driver bar. Already the first mentioned DE 226 828 from 1908 as well as later EP 0 638 682 from 1965 therefore provide cutting devices for the shuttle thread, which are arranged when embroidering below the boat and must be moved to cut in the cutting position between the embroidery plate and the embroidery bottom. These cutting devices are accordingly complicated and expensive.

Cutting the back thread is necessary, for example, if the shuttle should be replaced, for example, when they are virtually empty. To remove the boats, therefore, the back thread is cut first and then the upper drivers are opened individually by hand, whereupon the boats can be removed. Instead of opening the boats by hand, the sees GB 1,063,070 a slide, which can be moved parallel to the driver bar and thereby detects the upper driver and moves them to the extent that they release the shuttle for removal. After filling the new boats, the slide can also be used to bring the upper drivers back into the closed position. However, this device has the disadvantage that the guidance of the carriage is performed by the heads of the clamping screws for the tension springs of the upper driver, which does not allow good guidance of the carriage. This disadvantage is due to the new driver bar unit according to the EP 1,055,761 has been corrected, which has no clamping screws. In this driver bar unit, the driver bar consists of a profile, in which the driver nails are inserted into holes. The profile is provided above a T-shaped guide. Thus, if a shuttle change is to be made, the carriage can be placed on the driver bar and slid onto it to open the drivers. The T-shaped guide allows a virtually play-free guidance of this carriage.

It is an object of the present invention to provide a device for cutting the back threads in shuttle embroidery machines, which allows a uniform cutting all the back threads. Also, the thread ends projecting from the embroidery bottom and, if possible, the thread ends protruding from the stitch holes of the throat plate should have the desired length.

The solution of this object is achieved by a device of the type mentioned above, which is characterized according to the invention by a carriage, which is guided by a guideway slidable along the driver bar, arranged on the carriage or trained knife carrier, located in the area in front of the stitch holes for Stitch plate extends, and arranged on the knife carrier Knife which has a cutting edge for cutting the back thread in the area in front of the stitch holes of the throat plate.

Since the knife is passed through a carriage, the cutting of all the end threads takes place at the same point in the space between the embroidery bottom and throat plate. In contrast to manual cutting of the back threads there is therefore no risk of damage to the embroidery base by the knife. A particular advantage consists in the fact that according to a preferred embodiment, the slide sliding surfaces for opening, or closing, the upper driver may have. This allows cutting the threads and opening the drivers in a single operation.

Advantageously, the cutting edge, viewed in the cutting direction, arranged at a distance behind the front edge of the knife carrier. After cutting, the thread length projecting from the stitch hole is twice the distance between the cutting edge and the front edge of the knife carrier. This thread length is large enough to allow easy re-staking.

The knife carrier may have a foot whose free end is located at a distance from the cutting edge. This ensures that the cutting edge never comes into contact with the embroidery base and damages it.

Conveniently, a slot for holding the knife is arranged in the foot of the knife carrier. This ensures a stable support of the knife.

An advantageous embodiment provides that fixedly or adjustably a spacer is arranged on the knife carrier, which extends beyond the cutting plane of the cutting edge. Through this spacer, the embroidery bottom is moved out of the stitching plane slightly, so that it is, for example, 3 mm from the cutting edge is removed. This distance corresponds to the length of the protruding from the embroidery bottom thread ends after cutting the back threads.

Preferably, the knife is adjustable mounted on the knife carrier and provided with predetermined breaking points. Such knives are commercially available and prove to be very practical, because when dulling the cutting edge of the blunt section can be stopped and readjusted the knife.

The front edge of the knife carrier may have a recess as a thread catcher. This ensures that the thread is reliably detected.

Conveniently, the guide floor is formed, e.g. with T-shaped cross-section, that lifting or lateral tilting of the carriage is prevented during the displacement along the driver bar.

If the carriage has sliding surfaces for opening or closing the upper driver, the knife carrier is advantageously arranged releasably on the carriage. The carriage can then also be used to open the upper driver without cutting at the same time. It has proven to be practical to design the knife carrier such that it can be slipped over the handle of the slide.

Figur 1:

in perspektivischer Darstellung die Vorrichtung beim Schneiden während der Verschiebung auf dem Trägerbalken, wobei auch ein Teil des Stöcklis mit den Schifflibahnen und der Stichplatte sichtbar sind,

Figur 2:

den Messerträger mit dem Messer,

Figur 3:

eine Teilansicht von oben auf den Messerträger, welche die Befestigung des Messers am Messerträger darstellt

Figur 4:

ein weiteres Ausführungsbeispiel der Vorrichtung zum Schneiden und

Figur 5:

eine Ansicht der Vorrichtung von rechts ,

Embodiments will now be described with reference to the drawings. They show:

FIG. 1:

a perspective view of the device during cutting during the displacement on the support beam, whereby also a part of the Stöcklis with the Schifflibahnen and the needle plate are visible,

FIG. 2:

the knife carrier with the knife,

FIG. 3:

a partial view from above of the knife carrier, which represents the attachment of the knife on the knife carrier

FIG. 4:

a further embodiment of the device for cutting and

FIG. 5:

a view of the device from the right,

In FIG. 1 is a part of the driver bar 11 and the so-called Stöcklis 13 a shuttle embroidery machine can be seen. The Stöckli 13 includes the Schifflibahnen 25 along which the Schiffli 27 (only one is shown) by the drivers 19,17 can be moved up and down. Also stitch plates 29 are part of Stöcklis 13. The throat plates 29 have stitch holes 31, in which the needles can penetrate. The stitching plane, that is to say the plane in which the embroidery bottom to be embroidered is arranged, is located directly in front of the stitch plates 29 during embroidering, so that the embroidery bottom lies against it.

Fig.1 but shows the Stöckli 13 and the driver bar 11 in a position in which they were moved away from the Stickebene. There is thus a gap between the embroidery bottom and the throat plate 29, to allow cutting of the end threads 33. so that the apparatus 21 for cutting the back thread can be placed on the driver bar 11. The embroidery bottom is not visible in the drawing. However, it runs in a plane practically parallel to the throat plate 29. The tail threads 33 to be cut extend from the throat plate 29 to the embroidery bottom, not shown, and protrude where they seem to end in the drawing, from the embroidery floor.

Like in the EP 1 055 761 described, the driver bar 11 consists of an aluminum profile 15, in which the upper driver 17 and the lower driver 19 are arranged. At the top of the profile 15 is a guide track 20 with preferably T-shaped cross-section. The carriage 35, which is advantageously made of plastic, has a guide with a corresponding cross section (as in Fig. 5 20 ') and can be slid for cutting along the guideway 20 on the driver bar 11 in the direction of the arrow 23.

The cutting device 21 consists essentially of a carriage 35, a blade carrier 37 arranged on the carriage 35 and the blade 39. The blade carrier 37 is made of sheet metal, e.g. Shaped sheet steel. But it would also be a construction made of plastic possible. The cutting edge 41 of the knife is, viewed in the cutting direction 23, arranged at a distance behind the front edge 43 of the knife carrier 37. The knife carrier 37 has a foot 45 which extends against the embroidery bottom and whose free end is arranged at a distance from the cutting edge 41. The foot 45 has a slot 47 for holding the knife 39. On the blade carrier 37, a spacer 49 is fixed or adjustable, which extends beyond the cutting plane of the cutting edge 41 and rests against the embroidery bottom. As a result, the embroidery floor is kept at the desired distance from the cutting edge 41.

The knife 39 is adjustable with the screw 51 (FIG. Fig. 3 ), the nut 53 and the U-profile 55 attached to the knife carrier 37. It can find a commercial knife use, which has a number of sections which are defined by predetermined breaking points from each other.

The knife carrier 37 has an opening 57 with which it can be slipped over the handle 59 of the carriage 35.

At the in Fig. 1 The cutting device shown serves the carriage 35 not only the exact guidance of the cutting edge 41, but also the opening and closing of the upper driver 17. For this purpose, the carriage 35 has the sliding surfaces 52 and 54, respectively.

To open the upper driver 17 and cutting the back threads 33, the cutting device 21 is placed on the driver bar 11 and moved along the guide track 20 in the direction of arrow 23. The tabs 18 of the upper driver 17 are detected by the sliding surface 52 and the driver from the right in Fig. 1 located position in the left in Fig. 1 shown position. At the same time the respective rear thread is detected by the front edge 43 and pulled something out of the boat 27 until it is cut by the cutting edge 41.

To close the upper driver 17 of the carriage 35 is turned by 180 degrees and moved along the guide track 20. In this case, the tabs 18 are detected by the inner sliding surface 54, and the drivers 17 are in the left in Fig. 1 shown returned position.

In 4 and 5 an embodiment is shown, which only serves to cut the back threads, but otherwise substantially the same design, as with reference to the FIGS. 1 to 3 has been described.

• Die Schneidvorrichtung 21 für Hinterfäden besitzt einen Schlitten 35, der von der T-förmigen Führungsbahn 20 sicher geführt längs zum Treiberbalken 11 verschiebbar ist. Am Schlitten 35 ist der Messerträger 37 mit dem Messer 39 angeordnet. Der Schlitten 35 weist eine Gleitfläche 52 auf, um beim Schneiden gleichzeitig die oberen Treiber 17 zu öffnen, damit die Schiffchen 27 entnommen werden können. Beim Verschieben des Schlittens 35 wird der Hinterfaden 33 zuerst von der Vorderkante 43 erfasst und etwas aus dem Schiffchen 27 herausgezogen, bis er von der Schneide 41 geschnitten wird. Es steht dann eine genügende Fadenlänge zum Wiederansticken zur Verfügung. Der Abstandhalter 49 bewirkt, dass das nach dem Schneiden aus dem Stoffboden ragende Fadenstück eine genügende Länge aufweist, wie sie beispielsweise bei Applikationsarbeiten benötigt wird.

In summary, the following can be stated:

• The tailing device 21 has a carriage 35 which is guided by the T-shaped guideway 20 securely slidable along the driver bar 11. On the carriage 35 of the knife carrier 37 is arranged with the knife 39. The carriage 35 has a sliding surface 52 to simultaneously open the upper driver 17 when cutting, so that the boats 27 can be removed. When moving the carriage 35 of the back thread 33 is first detected by the leading edge 43 and pulled something out of the boat 27 until it is cut by the cutting edge 41. It is then a sufficient length of thread for Wiederansticken available. The spacer 49 causes the projecting after cutting from the fabric bottom thread piece has a sufficient length, as required for example in application work.

Claims (11)

1. Device to cut the rear threads on Schiffli-type embroidery machines which are equipped with a plurability of embroidery stations, each embroidery station being associated behind a stitch plate (29) with a shuttle (27) being movable back and forth by a driver bar (11) characterized by
   a sledge (35) being movable along a guide way (20) extending along the driver bar (11),
   a knife carrier (37) located or formed on the sledge (35) in the region of the needle holes (31) of the stitch plate (29), and
   a knife located on the knife carrier (37), said knife comprising in the region in front of the stitch plate (29), a cutting edge (41) to cut the rear thread.
2. Device according to claim 1, characterized in that, seen in direction of cutting, the cutting edge (41) is located at a distance from the front edge (43) of the knife carrier (37).
3. Device according to claim 1 or 2, characterized in that the knife carrier (37) has a foot (45) having a free end located at a distance from the cutting edge (41).
4. Device according to one of the claims 1 to 3, characterized in that the foot (45) has a slot (47) to hold the knife (39).
5. Device according to one of the claims 1 to 4, characterized in that a distance holder (49) is located fix or adjustable on the knife carrier (37) and extending beyond the cutting plane of the cutting edge (41).
6. Device according to one of the claims 1 to 5, characterized in that the knife (39) is adjustably mounted on the knife carrier (37) and provided with preset breaking lines.
7. Device according to one of the claims 2 to 6, characterized in that the front edge (43) of the knife carrier (37) has a recess acting as thread catcher.
8. Device according to one of the claims 1 to 7, characterized in that the guide way (20) is formed in such a way, e.g. having a T-profile, as to prevent lifting-off or lateral tilting of the sledge (35) when it is moved along the driver bar (11).
9. Device according to one of the claims 1 to 8, characterized in that the sledge (35) has glide planes (52, 54) for opening or closing, respectively, of the upper driver pins (17).
10. Device according to one of the claims 1 to 9, characterized in that the knife carrier (37) is removably connected to the sledge (35).
11. Device according to claim 10, characterized in that the knife carrier (37) can be put over the grip (59) of the sledge (35).

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