EP0768418A1 - Embroidering machine, particularly of the Schiffli type, with a severing- and clamping device for the front yarn - Google Patents

Abstract

An embroidery machine, esp. a Schiffli machine, has a cutter and clamp for each needle thread. A blade (17) is rigidly attached to each fabric presser and works with a movable blade (21) and a yarn clamp (27). The blade (21) is constructed as a yarn catcher. There is a further yarn catcher (25) at some distance from the blade (21) and a clamp (27) is fitted between the blade (21) and the further yarn catcher (25).

Description

The present invention relates to an embroidery machine, in particular a Schiffli embroidery machine, with a front thread cutting and clamping device with a cutting edge fixedly arranged on the presser for each front thread to be cut, a knife movable against this cutting edge and a thread clamp for clamping the front thread.

DE-A-226 828 describes a device for facilitating the cutting of the front threads, in which holding devices are arranged close to the embroidery surface in such a way that they are able to hold the front threads running from the needles to the fabric when these threads are to be cut. The holding effect is imparted by forks or clamping levers, which can be moved in relation to the presser forks. The front threads are then held between the presser forks and the other forks, whereupon the threads can be cut off. The needle-side thread ends are then held until the embroidery needles are actuated again for embroidering. The threads can either be cut with a knife, with which a person walks along the machine and continuously cuts the threads opposing the knife, or a rotatable clamping lever is provided with each presser fork, which, when rotated, guides the presser fork against a knife edge to simultaneously cut the thread and hold the end of the thread. The clamping and cutting device, which requires an individually rotatable lever for each of the many embroidery points, is complicated and expensive and does not have the required long service life and reliability in operation. This also applies to the thread clamping and cutting device according to CH-A-683 785. This device is not used for cutting the front thread, but for cutting the back or loop thread. It therefore belongs to a genus other than the present invention. Furthermore, the device according to CH-A-683 785 has a pivotable angular one Entry and cutting element for the back or shuttle thread. The same type of cutting and clamping device with an angular entry and cutting element for the rear thread can also be found in the subject of EP 0 666 352. However, there is no use of such a mechanism for the front thread. Rather, a completely different mechanism, corresponding to the operating and space conditions prevailing in the area of the needle and drill, is provided for the front thread, as was previously proposed by EP-A-0 606 585.

EP-A-0 606 585 relates to one of the latest proposals for a cutting and clamping device for the front thread of an embroidery machine. This device has a mounting rail for cutting and clamping elements. Such a cutting and clamping element consists of a fixed knife, which is attached to the mounting rail with retaining bolts. A movable knife is guided in a longitudinally displaceable manner on the fixed knife via a parallel guide consisting of hollow rivets. Furthermore, a clamping spring is attached to the fixed knife. The clamping spring has the additional task of avoiding play between the movable knife and the fixed knife. In order to operate this cutting and clamping device, a complicated control mechanism is necessary. This has to perform complicated movements in different directions. The device is further complicated by the fact that a selection mechanism is provided for the working and non-working embroidery sites. A sliding piece must be moved to open the knife before the cutting process. Furthermore, a parallelogram-like displacement of all cutting and clamping elements with a pivoting movement is necessary. In addition, a movement towards the material level is required.

It is an object of the present invention to improve an embroidery machine of the type mentioned at the outset in such a way that a faultless and reliable cutting and clamping of the front threads of the embroidery machine is ensured with little effort.

Starting from the prior art according to DE-A-226 828, this is achieved according to the invention in that the knife is designed as a thread catcher, in that a further thread catcher is provided at a distance from the knife, and in that the thread clamp between the knife and the further thread catcher is arranged.

This training does not require individually rotatable levers or cutting elements and therefore has space in a small space. A large number of knives can also be formed on a piece of sheet metal. The illustration according to the invention allows the front thread to be gripped securely, reliably clamped and cut in a simple manner. In this way, jumping threads are avoided and later embroidering is possible. In contrast to the prior art, the front thread is gripped on two opposite sides of the thread clamp and securely inserted into it. In contrast to the prior art, there is no change in the direction of the front thread when clamping. This also contributes to secure clamping.

In the commercially available ship embroidery machines, the pressers are generally arranged on a presser ruler that can be pivoted about an axis. According to one exemplary embodiment of the invention, the knives and the further thread catchers are now fastened to a knife ruler, and the knife ruler is driven by at least one lever, one end of which is articulated on the knife ruler and the other end of which has a joint on which an actuating lever engages. wherein after cutting the threads the pivot point of the joint lies on the axis of rotation of a hinge, about which the presser ruler is pivoted during embroidery. With this training, unnecessary wear of the knife edges is avoided with simple means. It should be noted that when embroidering the presser is operated over 200 times per minute. In contrast, cutting only takes place at longer intervals. Since in the described design of the embroidery machine a relative movement of the knife edges when Embroidery is safely avoided, a long service life of the knife edges is guaranteed.

An advantageous embodiment of the embroidery machine provides that at least two actuating levers are connected to one another by a rod articulated on them. This ensures a safe parallel guidance of the knife ruler. The actuating levers are advantageously designed as angle levers.

The clamping gap of the thread clamp is advantageously practically in the same plane as the thread to be cut. This extends from the needle to the embroidery floor before cutting. The clamping gap can run practically at right angles to the surface of the sheet metal piece forming the presser and practically in the same direction as the movement of the movable knife when cutting the thread. In other words, this means that the clamping gap is arranged practically in the same plane as the thread running from the needle to the embroidery base and that the direction of movement of the knife is practically perpendicular to the thread. In contrast to the prior art, the thread is not deflected when it is clamped.

The thread clamp advantageously has a cutout for guiding the knife. The knife is thus safely guided between the presser plate and the thread clamp.

The thread clamp advantageously has a stationary part and a movable or resilient part. It thus represents its own organ. In contrast to the prior art, the presser or the knife is therefore not part of the thread clamp. Since it is a separate organ, it can be replaced independently of other organs if necessary. The thread clamp advantageously has teeth on one of the two surfaces forming the clamping gap. This ensures high reliability of thread clamping. The teeth are arranged on the knife side and advantageously engage in a recess on the side of the clamping gap. This has proven to be particularly advantageous. The thread clamp expediently consists of plastic. This allows one particularly Cost-effective production of thread clamps with optimal clamping properties. For example, the stationary part can be U-shaped, the resilient part being arranged between the legs of the U. The resilient part can also have an arc-shaped plastic spring, which enables the thread to be clamped particularly favorably.

The plastic spring expediently counteracts the opening of the clamping gap with a predetermined force after the resilient part has been inserted into the stationary part. This makes adjustment unnecessary.

A stop can be provided which limits the path by which the clamping gap can be opened. This prevents e.g. when threading, the threading tool is inadvertently inserted into the clamping gap and damages the thread clamp.

Fig.1

eine perspektivische Darstellung eines Ausführungsbeispiels der erfindungsgemässen Vorderfadenschneid- und -klemmeinrichtung, wobei im linken Teil der Figur die Stellung der Messer und der weiteren Fadenfänger vor dem Schneiden der Fäden dargestellt ist, während auf der rechten Seite die Stellung nach dem Schneiden und Festklemmen der Fäden dargestellt ist, die Fäden selbst aber nicht eingezeichnet sind,

Fig.2

eine Ansicht der Einrichtung von Figur 1 von hinten gesehen,

Fig.3

die Einrichtung von Figur 2 im Schnitt,

Fig.4

die Ansicht des federnden Teils des Fadenklemmers,

Fig.5

den federnden Teil von Figur 4 von oben gesehen,

Fig.6

den stationären Teil des Fadenklemmers,

Fig.7

den stationären Teil von Fig. 6 von oben her betrachtet,

Fig.8

den Fadenklemmer bestehend aus stationärem Teil und federndem Teil,

Fig.9

den am Stoffdrückerblech befestigten Fadenklemmer mit dem Fadenfänger und dem beweglichen Messer in der oberen Stellung bereit zum Einziehen des Fadens, und

Fig.10

die Ansicht des Zusammenbaus von Fig.9 von oben gesehen.

The invention will now be described with reference to the drawing. It shows:

Fig. 1

a perspective view of an embodiment of the front thread cutting and clamping device according to the invention, the position of the knives and the further thread catchers before cutting the threads is shown in the left part of the figure, while the position after cutting and clamping the threads is shown on the right side but the threads themselves are not shown,

Fig. 2

2 shows a view of the device of FIG. 1 from behind,

Fig. 3

the device of Figure 2 in section,

Fig. 4

the view of the resilient part of the thread clamp,

Fig. 5

the resilient part of Figure 4 seen from above,

Fig. 6

the stationary part of the thread clamp,

Fig. 7

the stationary part of FIG. 6 viewed from above,

Fig. 8

the thread clamp consisting of a stationary part and a resilient part,

Fig. 9

the thread clamp attached to the presser plate with the thread catcher and the movable knife in the upper position ready to pull in the thread, and

Fig. 10

the view of the assembly of Figure 9 seen from above.

The perspective view of the front thread cutting and clamping device from FIG. 1 shows the presser plates 13 fastened to a presser ruler 11 (FIG. 3) with the presser fingers 15. A cutting edge 17 is formed on the lower part of the presser fingers 15. A movable knife 19 is arranged on each presser finger 15. A large number of such knives 19 can be formed on a piece of sheet metal 20. Each knife 19 has a hook-shaped part 21 which on the one hand acts as a thread catcher and on the other hand has a cutting edge 22 which cooperates with the cutting edge 17 like scissors. The sheet metal pieces 20 with the knives 19 are carried by the knife ruler 23. Thread catchers 25 with angled edges 26 are also arranged on the knife ruler 23. It should now be noted that the hook-shaped parts 21 of the knives 19 also work as thread catchers, so that in this description the thread catchers 25 are referred to as further thread catchers. Thread clamps 27 are attached to the presser plate 13 and will be described in detail later. It should be noted that with each thread clamp 27, the knife 19 comes to rest on one side and the further thread catcher 25 on the other side, so that when the knife ruler 23 moves downward from the hook-shaped part 21 and the further thread catcher 25, the thread securely the clamping gap 29 of the Thread clamp 27 is pulled, the thread being cut simultaneously by the cooperation of the cutting edge 17 and the cutting edge 22 formed on the hook-shaped part 21.

In FIG. 1, a needle plunger 26 with a needle 28 and a drill plunger 30 with a drill 32 are shown, as are provided for each embroidery site. It can be seen that in the case of the described design of the front thread and clamping device, this does not stand in the way of the drill 32.

Further details of the front thread cutting and clamping device can now be seen from FIGS. 2 and 3. The device is shown in the position after cutting the thread. The knife ruler 23 with the knife 19 also acting as a thread catcher and the further thread catcher 25 is therefore in the lower position. The presser 13 is in the position in which the presser finger 15 rests on the embroidery base 31, that is to say the web of material.

Pins are arranged on the knife ruler 23 at intervals from one another, which guide the knife ruler 23. One of the pins 33 can be seen in FIG. 3. This pin 33 is slidably mounted in a sleeve 35 of the presser ruler 11. The presser ruler 11 can be pivoted about an axis 37 of the ball joints 39 (only one ball joint 39 is shown). The reference number 41 denotes the rod which belongs to the presser mechanism of an embroidery machine. The drive of the presser is known prior art.

The knife ruler 23 is carried by two pairs of levers 47, 51 (only one is shown). The drive unit 43 is used to drive the knife ruler 23, e.g. a hydraulic cylinder which engages the arm 45 of the angle lever 47. The arm 49 is articulated on the lever 51 via the ball joint 39. The lever 51 is coupled to the knife ruler 23 via the joint 53.

The parallel guidance of the knife ruler 23 is ensured by the lever pairs 47, 51 (only one is shown), the angle lever 47 of which is coupled to one another via a rod 55 are. It is advantageous if, after the threads have been cut, the fulcrum 40 lies on the axis of rotation 37. This prevents the lever 51 from moving when the presser fingers 15 are pivoted about the axis 37. This in turn prevents a relative movement between the movable knives 19 and the cutting edges 17, which could lead to premature wear.

As FIGS. 4 to 10, in particular FIG. 8, show, the thread clamp 27 consists, for example, of a stationary part 61 and a resilient part 63. In the assembled state, a screw 65 holds the parts 61 and 63 together. A screw hole 67 is provided for fastening the thread clamp 27 with the screw 72 (FIG. 9) on the presser plate 13. A pin 68 engaging in the bore 70 acts as a protection against rotation. As can be seen in particular from FIGS. 1 and 8, the thread clamp 27 has a clamping gap 29 which runs practically at right angles to the surface of the presser plate 13 and in the same direction as the movement of the movable knife 19 when cutting the thread. The thread clamp 27 has teeth 69 on the knife side on a surface forming the clamping gap 29. In the exemplary embodiment shown, the teeth 69 are arranged laterally on the clamping gap 29 and can engage in a recess 71 (FIG. 5) of the resilient part 63. The cutout 77 serves to guide the knife 19. The stationary part 61 is U-shaped. The resilient part 63 is arranged between the legs of the U. The arched plastic spring 73 formed on part 63 provides the spring action. A stop 75 limits the opening of the clamping gap 29. In order to ensure precise positioning of the resilient part 63, a wedge-shaped recess 76 is provided on the stationary part 61, into which a projection 78 of the resilient part 63 fits.

During normal operation of the embroidery machine, the device is in the position shown in FIGS. 2 and 3, but the presser fingers 15 are pivoted counterclockwise after each stitch around the axis 37 (FIG. 3) and are lifted off the embroidery base 31. If the thread is now to be cut, the presser is again in the Figure 3 location shown. The drive unit 43 then actuates the levers 47, 51 and thus also the knife ruler 23. The knife ruler 23 is therefore shifted upwards into the position shown on the left in FIG. The angled edge 26 of the further thread catcher 25 slightly presses the thread 74 (FIG. 10) stretched between the embroidery base 31 and the needle 28, whereupon the thread 74 springs back into the original position. During the subsequent downward movement of the knife ruler 23, the thread 74 is gripped both by the movable knife 19 and by the further thread catcher 25 and drawn into the clamping gap 29 and finally by the interaction of the cutting edge 22 on the hook-shaped part 21 and the cutting edge 17 (FIG. 1) cut. The cutting is done like with scissors. The thread end remains clamped in the thread clamp 27, so that embroidery can subsequently be carried out without any problems.

In summary, the following can be stated:

The embroidery machine has a presser ruler 11 which can be pivoted about the axis 37 and has the presser fingers 15. A cutting edge 17 is formed on the presser fingers 15. A knife ruler 23 is arranged on the presser ruler 11 and can be moved upwards from the position shown. Both the knives 21, which also serve as thread catchers, and further thread catchers 25 are arranged on the knife ruler 23. Between a knife 21 and a thread catcher 25 there is a thread clamp 27 attached to the presser plate 13. If the thread 74 is now to be cut, the knife ruler 23 is moved upwards and brought back into the position shown. The thread 74 running parallel to the clamping gap 29 is gripped by the knife 19 and the thread catcher 25 and pulled downward into the clamping gap 29 of the thread clamp 27. The thread 74 is cut like with scissors by the interaction of knife 19 and cutting edge 17.

Claims (15)

Embroidery machine, in particular a ship embroidery machine with a front thread cutting and clamping device with a cutting edge (17) arranged firmly on the presser (13) for each front thread to be cut, a knife (21) movable against this cutting edge (17) and a thread clamp (27) for clamping of the front thread, characterized in that the knife (21) is designed as a thread catcher, that a further thread catcher is provided at a distance from the knife (21) and that the thread clamp (27) between the knife (21) and the further thread catcher (25 ) is arranged. Embroidery machine according to Claim 1, in which the pressers (15) are arranged on a presser ruler (23) which can be pivoted about an axis (37), characterized in that the knives (21) and the further thread catchers (25) are arranged on a presser ruler ( 11) arranged knife ruler (23) are fastened so that the drive of the knife ruler (23) takes place via at least one lever (51), one end of which is articulated on the knife ruler (23) and the other end of which has a joint (39) to which an actuating lever (47) engages, the pivot point (40) of the joint (39) lying on the axis of rotation (37) about which the presser ruler (11) is pivoted during embroidery after the threads have been cut. Embroidery machine according to claim 2, characterized in that at least two actuating levers (47) are connected to one another by a rod (55) articulated thereon. Embroidery machine according to claim 2 or 3, characterized in that the actuating lever (s) (47) are angle levers. Embroidery machine according to one of claims 1 to 4, characterized in that the clamping gap (29) of the thread clamp (27) is practically in the same plane as the thread to be cut. Embroidery machine according to one of claims 1 to 5, characterized in that the clamping gap (29) practically at right angles to the surface of the sheet metal piece (13) forming the presser (15) and practically in the same direction as the movement of the knife (19) when cutting the Fadens runs. Embroidery machine according to one of claims 1 to 6, characterized in that the thread clamp (27) has a recess (77) for guiding the knife (19). Embroidery machine according to one of claims 1 to 7, characterized in that the thread clamp (27) has a stationary part (61) and a movable or resilient part (63). Embroidery machine according to claim 8, characterized in that the thread clamp (27) has teeth (69) on a surface forming the clamping gap (29). Embroidery machine according to Claim 9, characterized in that the teeth (69) engage laterally at the clamping gap (29) in a recess (71) in the other part of the thread clamp (27). Embroidery machine according to one of claims 1 to 8, characterized in that the thread clamp (27) consists of plastic. Embroidery machine according to one of claims 1 to 11, characterized in that the stationary part (61) is U-shaped, and that between the legs of the U the resilient part (63) is arranged, on which an arcuate plastic spring (73) is formed . Embroidery machine according to Claim 12, characterized in that the plastic spring (73) counteracts the opening of the clamping gap (29) with a predetermined force after the resilient part has been inserted. Embroidery machine according to claim 12, characterized in that a stop (75) is provided which limits the path by which the clamping gap (29) can be opened. Front thread clamp according to one of claims 5 to 14.

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