EP1918439B1 - Thread clamping and severing arrangement with thread assigning and removing device - Google Patents

Description

The invention relates to a clamping cutting device of a flat knitting machine with a plurality of clamping points for clamping a thread according to the preamble of claim 1.

In the case of clamping cutters which have a catching arm on their longitudinal side facing the fabric, which presses the thread to be clamped and cut to a level below the comb gap, and in which many clamping cutoffs are arranged next to one another, the problem frequently arises at the clamping cutting points, which have a greater distance to the tentacle, the thread is not introduced into the fishing needle so that it can be optimally clamped and optimally cut.

If at a clamping cutting device of this type at a remote from the fishing hook clamping cutting the expelled needle to dissolve the thread clamping, with their subsequent clamping cutting point but has clamped a thread that is already fed back to the knitting process, it may happen that the fishing needle detected on its toothed side of this thread and moved along in its advancing movement and then entrains in their retracting movement to the extent that this thread is clamped in that nip again, which has just released their thread. Such a double-clamped thread leads to disturbances, because of the controller A thread can only be released at the clamping cutting point, in the catching needle of which it has been inserted by the thread guide.

In many successively arranged clamping cutting points and many threads on the front side of the clamping cutter are present. In this case, stretched threads run from the clamping cutting point to the fabric. Furthermore, tension-free threads whose clamping has been solved exist. If the tensioned and the tensionless threads have the opportunity to be able to arrange themselves spatially, it is easy to interlock the threads that are clamped, and the threads whose clamping is solved. As a result, the yarn released from the clamping can not follow the pull-off movement of the knitted fabric and pulls together the edge stitches of the last knitting line that has been formed with it.

From the EP 0 990 724 A2 The Applicant is a clamping and cutting device is known in which a rotationally movable Fadenzuweisorgan feeds one or more threads by a pivoting movement of a clamping and cutting point.

Object of the present invention is to provide a clamping cutter of the type mentioned in such a way that the mentioned disadvantages avoided and as few moving elements are needed.

This object is achieved in a particularly simple and surprising manner by a clamping-cutting device with the features of claim 1. By this measure it is ensured that the between a yarn guide and a fishing hook in front of the front page Clamping device skewed thread is properly grasped by the fishing needle and clamped and cut reliably. In particular, it is ensured that the thread to be clamped and cut is not only clamped and cut in the upper region of the catching needle. More reliable clamping and cutting occurs when the thread is clamped in the lower part of the fishing needle. This lower portion of the fishing needle, which also has a primary cutting edge, the thread through the

Fed threading element.

In a particularly preferred embodiment, the thread-assigning element of the active device can be followed by at least one thread stripping element. A Fadenabstreifelement can also be provided independently of a Fadenzuweiselement. Therefore, the provision of a Fadenabstreifelements on a clamp-cutting device is also considered as an independent invention. By Fadenabstreifelement it is ensured that in a withdrawal movement of the fishing needle of the thread of an adjacent nip is stripped from the fishing needle and thus is not clamped between the teeth and the pinion of the fishing pin associated nip.

In one embodiment of the invention may also connect to the thread stripping element of the active device at least one thread guide. By a yarn guide ensures that the threads do not get tangled in front of the end face of the clamping cutter.

In particular, it is ensured that the threads take no spatial arrangement, but lie flat against the yarn guide. In a development, the thread guide element can be provided in a region below the clamping points.

It is particularly preferred if the thread guide elements are materially connected to the Fadenabstreifelementen. Thus, the thread guiding elements can be an integral part of the thread-applying and thread-wiping device.

In the clamp-cutting device according to the invention, when the thread-assigning element is arranged on the side of the clamping point facing the catch hook, the thread coming from the catch hook can thereby be correctly fed to the clamping point.

Particular problems with clamping and cutting may result at locations remote from the fishing hook. Therefore, it is advantageous if the clamping points are arranged side by side and at least the farthest from the fishing hook clamping point is associated with a Fadenzuweiselement.

A low-noise operation of a flat knitting machine can be ensured if a thread assigning element is assigned to several clamping points. The more nip points a thread assigning element is assigned, the more reliably the clamping and cutting can take place.

In a development, it can be provided that the plurality of clamping points to which a thread assigning element is assigned are arranged in the half of the clamping cutting device remote from the catch hook. In the half removed from the fishing hook comes It is particularly common for disturbances when no inventive thread-assigning element is used, since there is the most to be clamped and cut thread in its height position of the clamping points.

It when several Fadenzuweiselemente associated with different terminal points, are combined to form a unit and the unit is attached to the clamping cutter is particularly advantageous. By this measure, the manufacture and assembly of Fadenzuweiselemente is facilitated. Several thread guide elements can be mounted together. This results in a time saving in comparison to the installation of each individual thread assignment element. There may be one or more units, each having a plurality Fadenzuweiselemente be provided. For example, in a clamp-type clamp having 16 nips, eight units with two filament fasteners, four with four filament fasteners, two with eight filament fasteners, or one with 16 filament fasteners may be provided. It may also be sufficient to provide a unit with, for example, four thread assigning elements in the area of the clamping cutter remote from the catching hook.

It is particularly preferred if all thread assignment elements are combined into one unit. This unit can also be designed so that they are fixed by the catch needles and blades of the clamping points on the clamping cutter in the vertical direction. For this purpose, the unit may have a bar.

Further advantages result if the thread assignment elements at least at the height of an upper region, in particular in the height range of a Secondary cutting edge, a fishing needle of each associated clamping point are arranged. By this measure, during a retraction movement of the jaw needle, the thread to be clamped abuts the thread guide element and a surface adjoining the secondary cutting edge, and slide on this surface, which is usually oriented obliquely to the direction of movement of the jaw needle, and the thread guide element downward in the direction of the primary cutting edge ,

An improved thread allocation results when the thread assignment elements are oriented at least in sections obliquely from an upper to a lower height region of the nip.

The stripping of the yarn from a fishing needle is particularly effective when the Fadenabstreifelement is arranged in a lower region relative to the height of the clamping points.

It is particularly advantageous if a respective thread stripping element is provided on both sides of a clamping point. This ensures that the thread below the fishing needle is not inclined and is reliably stripped from the fishing needle.

A thread is reliably led away from the lower portion of a fishing pin when the Fadenabstreifelemente run obliquely downwards or bent.

If in each case a thread stripping element and a thread guide element are materially connected to one another, the manufacture is simplified. In addition, the Fadenabstreifelement and Fadenzuweiselement not individually on the clamping cutter but can be mounted together. In a simplest embodiment, a thread stripping element and a thread-joining element connected in a material-locking manner can form a thread-assigning and thread stripping device. Preferably, however, a plurality of thread stripping elements and thread guide elements are each materially connected to each other and combined to form a comb-like unit. They thereby form a Fadenzuweis- and Fadenabstreifvorrichtung. Advantageously, only a single Fadenzuweis- and Fadenabstreifvorrichtung comprising a plurality of Fadenzuweiselemente and Fadenabstreifelemente must be mounted on the clamping cutter. In a clamp-cutting device according to the invention a low-noise operation is possible. Therefore, more clamping points can be used than before. In particular, twice as many clamping points, for example 16 clamping points, can be provided with the same length of the clamping cutting device.

If the thread guide elements are narrower than the thread stripping elements, it is ensured that a thread to be cut is fed to a blade at a correct angle, in particular not too steeply, so that reliable cutting is ensured.

The scope of the invention also includes a flat knitting machine with a clamping cutter as described above.

Further features and advantages of the invention will become apparent from the following detailed description of embodiments of the invention with reference to the figures of the drawing, which shows details essential to the invention, and from the claims.

In the schematic drawing embodiments of the invention are shown, which are explained in more detail in the following description.

Show it:

Fig. 1

a plan view of a clamp-cutting device;

Fig. 2

a plan view of the end face of the clamping cutter in the direction of arrow X of Fig. 1 ;

Fig. 3

an enlarged section of the clamping cutter on the side of the thread guide;

Fig. 4-6

in a slightly schematic representation of an enlarged partial view of Figure 3 in the direction of the arrow Y;

Fig. 7

the clamping cutter in the same position as in Fig.1 ;

Fig. 8

a detailed view of an edge region of the clamping cutting device with an extended fishing needle;

Fig. 9

a side view of the clamping-cutting device of Fig. 8 in the direction of arrow Y;

Fig. 10

a detailed representation of an edge region of the clamping cutting device with a fishing needle in a return movement;

Fig. 11

a side view of the clamping-cutting device of Fig. 10 in the direction of the arrow Y.

The Fig. 1 shows a clamp-cutting device 1, which, for example, sixteen clamping cutting points 2, which are arranged successively or juxtaposed, shown in plan position. The clamp-cutting device 1 is equipped with a Fadenzuweis- and Fadenabstreifvorrichtung 6.

This Fadenzuweis- and Fadenabstreifvorrichtung 6 has for each clamping cutting point 2 or only for selected clamping cutting points 2 an even closer to describing device 61st

The guide plate 3 is the supporting body of all functional elements. In the grooves 31, the fishing needles 21 are mounted longitudinally displaceable. Not shown are movement-introducing elements, which are acted upon by the lock parts of a carriage and cause the propulsion and retraction movement of the fishing needles 21.

At the knitted 200 facing the longitudinal side of the guide plate 3, a cover 4 is attached. It covers the mechanism, not shown, which converts a translational movement initiation of the fishing hook 5 in a pivoting movement of the fishing hook 5. The fishing hook 5 is pivotally mounted in the guide plate 3. In the groove 41, which is formed by a cutout in the guide plate 3 and the cover 4, the elements not shown are displaceable stored, which cause the movement of the fishing hook 5 and are acted upon by the lock parts of the carriage.

The clamping cutting points 2 each comprise a catching needle 21, which has incorporated in its thread catching area on one side a toothing, a clamping pinion 22 which is rotatably mounted on a pivot bearing 23, and a blade 24 which is pivotally mounted on the guide plate 3. The inside of the thread catching area of the catching needle 21 has a cut edge.

The thread-assigning and thread-stripping device 6 is formed integrally in a preferred embodiment. At each clamping cutting point 2 there is preferably an associated active device 61, which comprises a thread-assigning element 62, a thread-stripping element 63 and a thread-guiding element 64. This threading and Fadenabstreifvorrichtung 6 is connected by screws 65 with the guide plate 3. From a bar 6 'are the active devices 61 from. The strip 6 'fixes at least some of the movable elements of the clamping points 2 in their height position with respect to the guide plate. 3

The Fadenzuweis- and Fadenabstreifvorrichtung 6 could also consist of as many individual active devices 61, as clamping cutting points 2 are present. In addition, the active devices 61 could be interconnected in smaller numbers than in the preferred embodiment. It is also possible to arrange the active devices 61 only at the clamping cutting points 2, which are located in a remote position to the fishing hook 5.

The thread 150, which has the last stitch of the knitted fabric 200 connection, has been deducted from the yarn guide 100 so far from the spool that it can be clamped and cut from the furthest removed from the fishing hook 5 clamping cutting point 2.

The thread 150, after the yarn guide 100 has passed the fishing hook 5, detected by this and pressed to the lowest possible level. From this level, the yarn center 150 'rises continuously up to the outlet opening 101 of the yarn guide 100 and then passes as yarn center 150 "through the yarn guide 100 to the yarn package.

The Fig. 2 shows the clamp-cutting device 1 in the direction of the arrow X of the Fig.1 , The yarn center 150 'has its lowest position on the fishing hook 5 and constantly increases up to the outlet opening 101 of the yarn guide 100. The further a clamping cutting point 2 is removed from the fishing hook 5, the less likely it is that the thread 150, which of the last Knitting series comes, which was formed with this thread, at the position on the thread catching area or hook of the fishing needle 21 is applied, in which the thread 150 is optimally clamped and cut.

In the clamping cutting device 1 shown by way of example, 2 threads can be clamped in a maximum of sixteen clamping cutting points. In the area of the front side of the clamping cutting device 1, threads may be located which are held down by the fishing hook 5 coming from their knitting and detected by a fishing pin 21 and clamped and cut at the respective clamping cutting point 2, or coming from the clamping cutting point 2 held down by the fishing hook 5 and fed to their first row of knitting.

So that all knitting threads can arrange themselves in a plane to the end face of the clamping cutting device 1, each active device 61 has a thread guide element 64 following the thread wiping element 63. The thread guide elements 62 are narrower than the thread wiping elements 63. In this way, a recess is realized which is a flatter Supplying the thread 150 to the blade 24 allows.

The Fig. 3 shows in an enlarged detail of the Fig.1 the thread insert into the catching needle 21 of the fishing hook 5 farthest clamping cutting point 2. The fishing pin 21 is driven out into its thread catching position, and the yarn guide 100 has the yarn center 150 'inserted into the fishing needle 21. In the retraction movement of the fishing pin 21 in its basic position, the thread 150 is clamped between the teeth 210 of the fishing needle 21 and the teeth of the pinion 22 and then cut off with the blade 24 on the opposite side of the toothed needle 21. As a result, the thread 150 between the knit 200 and the thread guide 100 is separated.

The FIGS. 4 to 6 show in a slightly schematic representation of an enlarged partial view of Figure 3 in the direction of the arrow Y, as well as the mode of action of the thread-assigning element 62 of the active device 61 of the thread-assigning and thread-stripping device 6.

Evidently the Fig. 4 the thread 150 has been inserted through the yarn guide 100 in the fishing needle 21. The fishing needle 21 is in its return movement in the direction of the arrow Z. The thread 150 is in the upper region of the inclined surface 212, which forms the inner contour of the fishing needle 21 with the straight surface 211.

The surface 212 forms with the toothing 210 opposite outside of the fishing needle 21, the secondary cutting edge, and the surface 211 forms with the outside of the primary cutting edge.

Evidently the Fig. 5 the catching needle 21 is retracted so far in the direction of the arrow Z that the thread 150 rests against the threading element 62 of the active device 61 of the threading and thread stripping device 6.

In the Fig. 6 The threading element 62 of the active device 61 of the threading and thread stripping device 6 has brought the thread 150 into a position on the inner contour of the catching needle 21, on which it is securely clamped and securely cut off can be. The FIGS. 5, 6 one takes that the thread 150 between the obliquely downward pointing in the direction of nip 2 thread assigning element 62 and also obliquely downward, facing away from the nip 2 surface 212 and is forced downwardly by these, wherein the thread 150 at the Fadzuuweiselement 62 and the surface 212 slides down.

The Fig. 7 shows the clamp-cutting device 1 in the same position as in Fig.1 , For example, the fishing needle 21 'of the clamping cutting point 2', which has the second largest distance from the knitted fabric 200, has been expelled to release the thread which it had clamped. In their Austriebsbewegung there is a risk that their teeth 210 ', the thread 155, which is clamped in the subsequent clamping cutting point 2 "and has already been fed back to the knitting process detected and this thread 155 at least part of the Austriebsbewegung the fishing needle 21' pulled along becomes.

Since the catching needle 21 'of the clamping cutting point 2' is withdrawn after its ejection movement to release its clamped thread back to its basic position, the already in the clamping cutting point 2 "clamped thread 155 can be additionally clamped in the clamping cutting point 2 ' ,

Since the system which controls the clamping cutter 1 can always only cause a thread to be released at the clamping cutting point at which it has been inserted through the thread guide into its catching needle, a double clamping of a thread leads to disturbances.

Such disturbances are prevented by the thread stripping element of the active device of the clamping point, in which the thread is clamped, and the thread stripping element of the active device of the clamping point, which has released its thread. In the example, these are the clamping points 2 'and 2 "with their active devices 61' and 61" and their Fadenabstreifelemente 63 'and 63 ", which are arranged on both sides of the nip 2'.

The Fig. 8 shows in an enlarged detail of the Figure 7 the expelled fishing needle 21 ', which has released by the Austriebsbewegung the thread, which was located in the clamping cutting point 2'. In this Austriebsbewegung the fishing needle has 21 'with its toothed side 210', the thread 155 detected, which is already clamped in the subsequent nip 2 ", and has taken him in their expulsion direction.

The Fig. 9 shows in a slightly schematic representation of an enlarged partial view of Figure 8 in the direction of the arrow Y. The expelled fishing needle 21 'has with its toothed side 210' the thread 155 detected, which is already clamped in the subsequent nip, and taken him in their Austriebsrichtung.

The Fig. 10 shows in one of the Figure 8 corresponding representation of the fishing needle 21 'in the moment of their retraction movement, in which they applied to the Fadenabstreifelemente 63' and 63 "of the active means 61 'and 61" of the Fadenzuweis- and Fadenabstreifvorrichtung 6 in their toothing 210' detected thread 155.

During the further retraction movement of the catching needle 21 ', the thread 155' is stripped off by the two stripping elements 63 'and 63 "from the catching needle 21' and thus can not be trapped between its toothing 210 'and the pinion 22'.

The Fig. 11 shows in a slightly schematic representation of an enlarged partial view of Figure 10 in the direction of the arrow Y. The thread detected by the toothing 210 'of the catching needle 21' lies against the visible stripping element 63 "of the active device 61" and on the behind it and therefore not visible stripping element 63 'of the active device 61'. It is in the further retraction movement of the fishing needle 21 'by the stripping 63' and 63 "stripped from the fishing needle 21 '.

Claims (18)

1. Clamping and cutting device (1) of a flat bed knitting machine with several clamping points (2, 2', 2") for clamping a thread (150, 155), wherein a knitting device (61) with a thread allocation element (62) is assigned to at least one clamping point (2, 2', 2"), which thread allocation element allocates the thread (150, 155) to be clamped to a cutting edge, in particular a primary cutting edge, of a tuck needle (21, 21') of the clamping point (2, 2', 2"), characterized in that the clamping and cutting device (1) has a catch hook (5) and the thread allocation element (62) is arranged on the side of the clamping point (2, 2', 2") facing towards the catch hook (5).
2. Clamping and cutting device (1) according to claim 1, characterized in that a thread stripper element (63) adjoins the thread allocation element (62) of the knitting unit (61).
3. Clamping and cutting device (1) according to claim 2, characterized in that a thread guide element (64) adjoins the thread stripper element (63) of the knitting unit (61).
4. Clamping and cutting device according to one of the preceding claims, characterized in that the clamping points (2, 2', 2") are arranged next to one another and a thread allocation element (62) is assigned at least to the clamping point (2, 2', 2") furthest removed from the catch hook (5).
5. Clamping and cutting device according to one of the preceding claims, characterized in that a thread allocation element (62) is assigned to several clamping points (2, 2', 2").
6. Clamping and cutting device according to claim 5, characterized in that the several clamping points (2, 2', 2"), to which a thread allocation element (6) is assigned, are arranged in the half of the clamping and cutting device (1) situated furthest from the catch hook (5).
7. Clamping and cutting device according to one of the preceding claims, characterized in that several thread allocation elements (62), which are assigned to different clamping points (2, 2', 2"), are combined to form a unit, and the unit is attached to the clamping and cutting device (1).
8. Clamping and cutting device according to one of claims 5 through 7, characterized in that all of the thread allocation elements (62) are combined to form a unit.
9. Clamping and cutting device according to one of claims 5 through 8, characterized in that the thread allocation elements (62) are arranged at least at the height of an upper region, in particular in the height region of a secondary cutting edge, of a tuck needle (21, 21') of the respectively assigned clamping point (2, 2', 2").
10. Clamping and cutting device according to one of claims 5 through 9, characterized in that the thread allocation elements (62) at least in some sections are aligned obliquely from an upper to a lower height region of the clamping point (2, 2', 2").
11. Clamping and cutting device according to one of claims 2 through 10, characterized in that the thread stripper device (63, 63', 63") is arranged in the lower height region of the clamping points (2, 2', 2").
12. Clamping and cutting device according to one of the preceding claims, characterized in that respectively one thread stripper element (63, 63', 63") is provided on both sides of a clamping point (2, 2', 2").
13. Clamping and cutting device according to one of claims 11 through 12, characterized in that the thread stripper elements (63, 63', 63") are embodied running obliquely downwards or in a curved manner.
14. Clamping and cutting device according to one of the preceding claims, characterized in that respectively one thread stripper element (63, 63', 63") and a thread allocation device (62) are connected to one another by adhesive force.
15. Clamping and cutting device according to one of claims 5 through 14, characterized in that the thread allocation elements (62) are narrower than the thread stripper elements (63, 63', 63").
16. Clamping and cutting device according to one of claims 3 through 15, characterized in that the thread guide element (64) is provided in a region below the clamping points (2, 2', 2").
17. Clamping and cutting device according to one of claims 12 through 16, characterized in that the thread guide elements (64) are connected to the thread stripper elements (63, 63', 63") by adhesive force.
18. Flat bed knitting machine with a clamping and cutting device (1) according to one of the preceding claims.

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