DE9113900U1 - Thread clamping and cutting device for the rear or lower thread of an embroidery machine - Google Patents

Description

S 1123-31-ku 24.10.1991 Applicant: Saurer Sticksysteme AG, CH-9320 Arbon

Thread clamping and cutting device for the rear or lower thread of an embroidery machine

The subject of the present innovation is a thread clamping and cutting device according to the generic term of claim 1. Such a device has become known, for example, from the subject matter of DE 20 65 264.

In this case, in a manner known per se, a shuttle is slidably mounted in a shuttle guide and the thread clamping and cutting device is slidably driven via a rotary mechanism, wherein the displacement direction of the clamping and cutting device extends perpendicular to the transport direction of the shuttle.

The disadvantage of the known arrangement is that each thread clamping and cutting device must be assigned its own motion drive in order to ensure separate control. However, this has the disadvantage that a relatively large amount of space is required for the separate drive for each clamping and cutting device. Such an arrangement cannot be used on the usual shuttle embroidery machine with 4/4 repeat due to the limited space required.

Another disadvantage of the known cutting and clamping device is

that the length of the cut thread is relatively large. This

the embroidery image on the back of the fabric is affected and

The result is high thread consumption.

-Z-

A further disadvantage of the known arrangement is that the known clamping and cutting device is arranged in the area of the shuttle guide, and therefore there is a risk that the thread path of the rear or lower thread is impaired, especially since the known clamping and cutting device penetrates the shuttle carrier.

A characteristic of this known design is that the cutting knife itself initiates the clamping process and that the clamping of the rear or lower thread is directly dependent on the cutting process itself. This means that after the rear or lower thread has been cut, it is clamped between a clamping surface of a leaf spring and the cutting knife itself. However, this has the disadvantage that when a new cutting process is required, the clamping is released and the cut rear or lower thread is released. In embroidery areas that are currently out of service on the needle side, the cut and freely hanging rear or lower thread then runs up and down with the shuttle and is rubbed off, which can lead to a thread break or dropped stitches when this embroidery area is embroidered again.

The present invention is therefore based on the object of developing an embroidery machine with a thread clamping and cutting device of the type mentioned at the beginning in such a way that when the embroidery point is switched manually or mechanically on the needle side, the rubbing of the idle rear or lower thread on the shuttle side is reliably avoided.

The technical teaching of claim 1 serves to solve the problem.

The key feature of this innovation is that clamping is independent of the cutting process of the rear or lower thread.

This means that the clamping is independent of the movement of the cutting blade of the cutting device. In the state of the art, as described above, the cutting blade was also a clamping element, which resulted in the disadvantage of the rear or lower thread coming free, as described above.

Since the present innovation provides for clamping to take place independently of the cutting process, this has the advantage that all shuttle threads are first cut off and then transported to a clamping device that works independently of the cutting process, where they are held, even when the cutting knife goes back and carries out a new cutting process.

This has the advantage that the cut back or lower thread is always secured in the clamping device and cannot be released by a renewed movement of the cutting blade.

The back or lower thread is then only released from this clamping by a corresponding pull on the back or lower thread when, when re-embroidering the corresponding embroidery point, the back or lower thread is tied into the front thread and the pull on the back or lower thread becomes so strong that it is pulled out of the clamping point according to the invention.

This ensures that when the embroidery station is idle and switched off on the needle side, the shuttle moving back and forth cannot damage or rub through the clamped back or bobbin thread.

In addition, it has been known to eliminate this disadvantage by stopping the shuttle itself in order to avoid rubbing through the rear or lower thread. However, stopping the shuttle drive involves considerable mechanical effort, which, according to the

this innovation is avoided.

Another significant advantage of the present innovation is that only a very small amount of space is required for the cutting and clamping device on the shuttle side, because there is no longer a separate movement drive for each cutting and clamping device, as in DE 20 65 264, but according to the present innovation all cutting and clamping devices are operated in parallel via a common actuating rail together and simultaneously.

The present innovation comprises two different embodiments, both of which are to be covered by the present innovation concept.

In a first preferred embodiment of the present innovation, it is provided that the cutting knife itself is provided as an actuating element for initiating the clamping. This means that the cutting knife brings the cut rear or lower thread into the clamping device according to the innovation and leaves it there. This means that when the cutting knife is retracted again, the rear or lower thread remains in the clamping device without it being able to be released again from this clamping device by a retraction movement of the cutting knife, as is disadvantageously the case with DE 20 65 264.

In a second embodiment, it is provided that the clamping process, which is to be initiated independently of the cutting process, is initiated by a separate actuating element, whereby this actuating element can be moved independently of the cutting blade. This actuating element therefore grips the cut rear or lower thread and brings it into a corresponding clamping device, where it is held in place.

Another significant advantage of the innovation is that the cutting movement is parallel to the shuttle movement, which allows

little space is required. The motion drives for the cutting and clamping mechanism in DE-PS 20 65 264 are arranged perpendicular to the shuttle carrier, which means that a lot of space is required, which is not necessary with the present innovation, because with the present innovation the cutting and clamping mechanism is integrated in the taphole plate, which is connected to the shuttle carrier.

In a preferred embodiment of the present innovation, it is provided that the clamping device is arranged in the immediate vicinity of the cutting device and that the cutting edge of the cutting device is approximately aligned with a part of the clamping device. This ensures that the thread is clamped and cut at the shortest possible distance.

It is also important that the new thread cutting and clamping device is positioned approximately flush with the needle hole in the needle plate, which also ensures that the cut back or bobbin thread is only a short length. This ensures that the rest of the back or bobbin thread remaining on the fabric is very short.

The fact that the cutting element is arranged in approximately flush position opposite the thread clamping element results in the additional advantage that the cutting element only has to perform a very short cutting stroke in order to cut the rear or lower thread as intended.

Due to the fact that the entire thread clamping and cutting device is arranged in the throat plate, the significant advantage is that a drive part on the throat plate can be accessed with an external drive and requires little space, which drive part takes over the movement drive for the thread clamping and cutting device.

In a preferred embodiment of the present innovation,

It is intended that the thread clamping device is fixed and the cutting knife is guided movably in the throat plate. Both parts are mounted in a corresponding sliding guide of the throat plate and can be pulled out of this guide of the throat plate as a whole part and replaced.

The subject matter of the present innovation arises not only from the subject matter of the individual protection claims, but also from the combination of the individual protection claims with one another.

All information and features disclosed in the documents - including the summary, in particular the spatial configuration shown in the drawings, are claimed as essential to the invention, insofar as they are new compared to the prior art, individually or in combination.

The innovation is explained in more detail below using drawings that simply show one way of implementing it. The drawings and their descriptions reveal further key features and advantages of the innovation.

Show it:

Figure 1: Section along line I-I in Figure 2 through a needle plate of an embroidery station,

Figure la: an enlarged section through the throat plate in the area of the thread hole,

Figure 2: Side view of the arrangement according to Figure 1 in the direction of arrow II in Figure 1 showing three different shuttle guides in three different drawing planes of Figure 1,

Figure 3: Section along line III-III through a thread clamping and cutting device in Figure 2,

Figure 4: Top view of an intermediate plate,

Figure 5: Top view of the front plate of the operating slide,

Figure 6: Section through the front plate according to Figure 5,

Figure 7: Top view of the back plate of the actuating slide,

Figure 8: Section through Figure 7.

Figure 1 shows a needle plate 2, along one surface of which the fabric web 1 is guided parallel. The needle plate is a plate-shaped part. Each needle plate extends over several embroidery points, e.g. over four embroidery points, and forms the shuttle guides 6, 6a, 6b for one shuttle 3 each.

On the throat plate 2, the shuttle guides 6,6a,6b are designed in the form of half-open channels, in the area of which the respective shuttle 3 is moved via a displacement drive (not shown in detail). In this case, the shuttle guides 6,6a,6b are arranged in an oblique arrangement on the throat plate 2 and the respective shuttle 3 is driven so as to be displaceable in the direction of arrow 4 in the shuttle guides 6,6a,6b.

An intermediate plate 37 is attached to the needle plate 2 as shown in Figure 3, in which recesses 13 are provided for several guide parts 11. The guide parts 11 are preferably designed as plastic parts and are held in these recesses 13 in a detachable and removable manner. The recesses 13 are designed as slot-shaped recesses open on one side as shown in Figure 4, in

the plastic guide part can be inserted through the one-sided opening.

Figure 1 shows that the plastic part 11 is held in the intermediate plate 37 and in the needle plate 2 by a locking holder 14. This makes it particularly easy to pull the entire guide part 11, which is preferably made of plastic, out of the intermediate plate.

The guide part 11 has an inner recess 21 in which an actuating slide 18 is slidably guided. The type of actuating slide is shown in more detail in Figure 1 and in Figure 2 on the right-hand side. The actuating slide 18 essentially consists of an actuating rod 26 which has a projection at its lower end, opposite which is a projection 7 arranged on the guide part 11. A spring 9 is provided between the two projections. The force of the spring 9 thus holds the actuating slide 18 in a lower, lowered position, which is shown in Figure 1.

The displacement drive for the actuating rod 26 and thus for the entire actuating slide 18 is carried out by a cylinder 34, which acts via a piston rod 33 on a pivot point 32, which is arranged in the area of a pivotably mounted lever 31.

The lever 31 is connected in a rotationally fixed manner to a shaft 30, whereby the length of the shaft extends over a certain number of embroidery points.

As soon as the piston rod 33 of the cylinder is suddenly driven, e.g. in the direction of arrow 41, the lever 31 pivots clockwise into its position 31' and thus lifts the projection 8 upwards against the force of the spring 9, whereby the entire actuating rod 26 is displaced upwards in the direction of arrow 4.

The actuating slide 18 is connected to the actuating rod 26 via screws 27. The actuating slide 18 essentially consists of a U-shaped part, which according to Figures 5 to 8 essentially consists of a front plate 19 and a rear plate. Both plates 19, 20 form a mutual distance and thus a recess 21 into which the guide part 11 engages with a corresponding projection 12. This ensures that the actuating slide 18 is guided straight in the area of the guide part 11.

A keyhole-shaped recess 22 is incorporated into the front plate 19, which essentially consists of a hole 23, which in its upper part turns into an elongated hole 24. According to Figure 5, it is important that the lower edge of the hole 23 is designed as a cutting edge 25, whereby it is sufficient that only the left-hand area according to Figure 6 has a cutting effect, while the remaining, rounded area of the cutting edge 25 does not have a cutting effect and is designed to protect the thread.

In alignment with the keyhole-shaped recess 22 in the front plate, an identical keyhole-shaped recess 22 is incorporated in the rear plate 22 as shown in Figures 7 and 8. However, the lower boundary of the hole 23 is not cutting and is designed to be clean, which also applies to all other boundary edges.

It is important that the counter knife 39 is locked in place and cannot be moved in the guide part 11 and can therefore be easily replaced.

In the non-cutting position, the bore 23 of the actuating slide 18 is exactly aligned with the needle hole 15 machined into the needle plate.

A thread clamping device 16 is formed which essentially consists of a clamping gap 17.

This clamping gap is formed by a clamping finger 38, which is spring-mounted on one side in the guide part 11 and preferably
is formed in one piece with the guide part 11 made of plastic and on the other hand the clamping gap 17 is formed by a counter clamping piece 40 which is inserted into the guide part 11. This inserted part (counter clamping piece 40) can be seen in Figure 1.

It is now important that the clamping gap 17 in the direction of movement of the
actuating slide (i.e. in the longitudinal direction of the shuttle guide - direction of arrow 4) and that the clamping gap 17 forms an upward extension of the tap hole 15.

From Figures 2 (right illustration) and Figure 1 it can be seen that the V-shaped cutting edge 42 of the counter knife 39 with
its V-tip exactly in the middle area of the clamping gap 17
lies.

It is also important that the counter knife 39 according to Figure 3 is designed as a C-shaped profiled metal blade, the two
lateral legs 43 are clipped onto the lateral surfaces of the guide part 11.

This special C-shaped design and the clipping on of the slanting inward-facing legs 43 have the advantage that the front surface 44 of the knife curves inwards and thus adapts to the boundaries of the holes for the needle hole 15 and fits snugly. This ensures that the cutting front surface 44 of the counter knife 39 fits snugly and positively to the hole 23 of the
Front plate 19.

From Figure 3 it can be seen that in the area of the
guide piece 11, within the recess 21, the two interconnected plates 19,20 of the actuating slide 18

are guided, with the counter clamping piece 40 being arranged between these plates. The clamping finger 38 is then arranged on the opposite side of the thread hole 15.

A clamping and cutting process according to the present innovation is described in more detail below.

According to Figure 1, the rear or lower thread 10 is pulled out of the thread hole 5 of the shuttle 3 and runs through the stitch hole 15 in the position shown.

To clamp and cut this 33 thread 10, the cylinder 34 is actuated so that the piston rod is suddenly pivoted into its position 31' by the lever 31. As a result, the actuating rod 26 is lifted upwards and the actuating slide 18 with its two plates 19, 20 is moved upwards, whereby the projection 12 in the guide part 11 penetrates more deeply into the recess 21.

As a result, the thread 10 to be cut comes into contact with the movable cutting edge 25 in the area of the lower edge of the bore 23 and is then cut off as soon as the thread is in opposition to the upper cutting edge 42 of the fixed counter knife 39. It is important here that during this feed movement of the actuating slide upwards in the direction of arrow 4, the thread is now already in the area of the clamping gap 17 and is already being cut there during clamping.

This ensures that the thread is cut in a guided manner and is held during cutting.

However, after the thread has been cut, the actuating slide 18 continues to move upwards in the direction of arrow 4, whereby the cut thread end is pushed into the upper area of the slot 24 in the

area of the keyhole-shaped recess 22 and still remains in the clamping gap 17.

The thread is thus reliably clamped and cannot be released from this clamping gap 17 even if the actuating slide 18 is moved backwards in the direction of arrow 4. This represents a significant advantage over the prior art, because in the prior art the movable cutting blade (which in the present innovation is provided by the front plate 19) simultaneously formed a clamping surface for the cut thread, which had the disadvantage that when this cutting blade was pulled back this clamping surface was given up and the thread was released.

This is avoided in any case thanks to the present innovation, because even when the front plate 19 is pulled back, the thread remains in the area of the clamping gap 17 and is held in place.

It is only possible to pull out this thread if, when this embroidery point is put into operation again, this cut thread is tied in with the front thread in such a way that there is sufficient tension on this cut back or bobbin thread, which is then sufficient to pull this cut thread out of the clamping gap 17.

In addition, it is also noted that the rail 35 has the bends previously referred to as levers 31 and that these bends serve to actuate the respective projection 8 for the respective actuating rod 26.

It is also important in the present invention that the entire actuating slide 18 is concealed and closed on all sides in the guide part 11, which guide part 11 is in turn held in the shuttle plate in the needle plate 2 and in the intermediate plate 37.

This protects the entire thread clamping device 16 against contamination.

Another significant advantage of the present innovation is that the entire actuating slide 18 with its actuating rod 26 is integrated in the throat plate 2 or in the intermediate plate 37 connected to the throat plate, which results in a compact, space-saving structure, in particular because the entire displacement movement takes place in the plane of the throat plate 2.

The advantage of this innovation is that an embroidery machine with stitch point deactivation can now be operated in a particularly advantageous manner. When the stitch points on the needle side are deactivated or when the needles are stopped manually, the shuttles no longer need to be stopped in order to avoid the previously undesirable rubbing of the back or bobbin thread.

Now, according to the present innovation, all shuttle threads are first clamped and then cut on the shuttle side with the cutting and clamping device according to the invention. The shuttle threads cut in this way are then transported further into the clamping gap 17 according to the technical teaching of the present innovation, so that when the cutting device moves upwards again, they can no longer be cut off again by this cutting device and, above all, can no longer be released. This has the advantage that the rear or lower thread is now clearly fixed in the needle plate in the area of the needle hole 15 and can no longer be rubbed despite an oscillating movement of the shuttle 3. The defined fixation of the rear or lower thread in the area of the thread hole therefore prevents the rear or lower thread from being rubbed off, even if the shuttle 3 continues to oscillate in the direction of the arrow 4.

The essence of the innovation lies in the fact that in the area of the tap hole a

Thread clamping and cutting device is arranged, wherein in extension of the cutting direction for the cutting knife a clamping gap 17 of a thread clamping device 16 is arranged, so that the thread previously clamped by the cutting device and subsequently cut off is then grasped and fixed in the clamping gap 17 behind it in the cutting direction.

By arranging the thread clamping and cutting device directly in the area of the stitch hole 15, the advantage is achieved that the part of the back or lower thread that remains on the fabric is cut extremely short.

Furthermore, it is essential that the cutting device initially transports the thread to be cut without cutting in a clamping gap 17 and only cuts it there and that after cutting has taken place, the cut rear or lower thread is transported further upwards in the clamping gap 17 in order to then finally fix this thread.

In one embodiment, it is provided that the cutting device is displaceably guided in the area of a guide part 11 made of plastic and essentially consists of a front plate and a rear plate, with both plates 19, 20 each having a keyhole-shaped recess 22 with a bore 23 and an elongated hole 24.

Figure 2 shows a shuttle guide, whereby various parts are covered for better clarity. The middle part of Figure 2 shows all parts of a finished shuttle guide with integrated thread clamping and cutting device.

The right part of Figure 2 shows the thread and clamping device according to the invention, wherein the front wall of the shuttle guide is removed and the left part of Figure 2 shows the clamping device according to the invention, wherein the actuating slide 18 is removed.

The aligned position of the keyhole-shaped recess 22 above the clamping gap 17 results in the advantage of better thread guidance into the clamping gap 17. The keyhole-shaped recess 22 in the front plate 19 and in the back plate 20 is therefore not necessary for the solution; it is only important that the clamping gap 17 lying in the keyhole-shaped recess 22 is long enough so that the thread is clamped and then cut in the front area of the clamping gap and is then transported further back into the clamping gap 17 by the cutting device.

The elongated hole 24 in the area of the keyhole-shaped recess 22 in the area of the front plate serves to prevent the cut thread 10 from being pushed out of the clamping gap 17 when the actuating slide 18 moves back.

The elongated hole 24 in the area of the recess 22 in the area of the back plate 20 serves the same purpose.

Throughout the above description, the term "back or bottom thread" has been used as a synonym for a "back or bottom thread".

However, the term "back or bobbin thread" is only valid in connection with the working method according to the invention and the described devices, insofar as it is an embroidery machine with a shuttle.

The more general term "back or bobbin thread" therefore refers not only to embroidery machines with corresponding shuttles and associated shuttle threads, but also to other embroidery processes such as double-chain embroidery machines and embroidery machines with circular loopers.

DRAWING LEGEND

1 fabric panel

2 Needle plate

3 boats

4 Arrow direction

5 thread hole

6 Shuttle guide 6a 6b

7 Approach

8 Approach

9 Spring

10 Back or bobbin thread

11 Guide part

12 Approach

13 Recess (intermediate plate 37)

14 Locking bracket

15 tap hole

16 Thread clamping device

17 Clamping gap

18 Actuating slide

19 Front plate

20 Back plate

21 Recess

22 keyhole recess

23 Bore

24 slot

25 Cutting edge

26 Operating rod

27 Screw 28

29 warehouses

30 Wave

31 lever 31'

32 Pivot point

33 Piston rod

34 cylinders

35 Rail 36

37 Intermediate plate

38 clamping fingers

39 Counter knife

40 Counter clamp

41 Arrow direction

42 Cutting edge

43 legs

44 Front surface

Claims (10)

Applicant : Saurer Sticksyster.ie AG 09.01.1992 Protection claims 1. Thread clamping and cutting device for the rear or lower thread of an embroidery machine, wherein a shuttle is slidably mounted in a shuttle guide and both a slidable thread clamping device and a cutting device are provided, characterized in that the cutting device in the form of the cutting knife with the cutting edge (25) is designed independently of the thread clamping device (16) of the rear or lower thread, wherein the thread clamping and cutting device is arranged in the area of the stitch hole and a clamping gap (17) of the thread clamping device (16) is arranged in extension of the cutting device for the cutting knife, wherein the thread previously clamped by the cutting device and subsequently cut off is grasped and fixed in the clamping gap (17) behind it in the cutting direction. 2. Device according to claim 1, characterized in that the clamping is initiated by a separate actuating element, whereby this is subject to a movement independent of the cutting blade, and in this case the cutting device initially conveys the thread to be cut into a clamping gap (17) without a cutting process and only cuts it there and that after cutting has taken place, the cut rear or lower thread is conveyed further upwards in the clamping gap (17) and then finally fixed. 3. Device according to claims 1 and 2, characterized in that the cutting device is guided displaceably in the region of a guide part (11) and consists essentially of a front plate (19) and a rear plate (20), wherein in the front and rear plates (19, 20) a keyhole-shaped recess (22) with a bore (23) and an elongated hole (24) is formed. -Z- 4. Device according to claims 1 to 3, characterized in that the cutting blade formed by the front plate (19) with the cutting edge (25) itself is designed as an actuating element for the clamping. 5. Device according to claims 1 to 4, characterized in that the rear or lower thread is released from the clamping device (16) by applying tension when the embroidery is restarted. 6. Device according to claims 1 to 5, characterized in that the cutting movement is in the throat plate plane. 7. Device according to claims 1 to 6, characterized in that the clamping device (16) is arranged in the immediate vicinity of the cutting device, the cutting and clamping device being approximately flush opposite the needle hole in the needle plate. 8. Device according to claim 1, characterized in that the entire thread clamping and cutting device is arranged in the needle plate (2). 9. Device according to one of claims 1 to 8, characterized in that the front plate (19) with the cutting edge (25) is designed to be movable, whereas the counter knife (39) and the thread clamping device (16) are designed to be fixed. 10. Device according to one of claims 1 to 9, characterized in that the entire guide part (11), in which the cutting and clamping device are integrated, can be easily replaced as a whole.