EP0294408B1 - Cross-winding device - Google Patents

Abstract

Known cross-winding devices have a strap that moves back and forth a support (5) with a thread guide (7). The support (5) has hydraulically or pneumatically driven clamping means. To obtain cross-wound bobbins, the gripper shuttle drive is provided with a spring (18) that goes through its dead centre when the gripper shuttles (10.L, 10.R) are moved. The gripper shuttle drive is actuated in the stroke reversal areas by fixed stops (23.L, 23.R). The fixed stops can be moved in the direction of the stroke, effecting an aspiration and an oscillation. The strap (1) can extend over several winding stations connected each to a support (5) and thread guide (7).

Description

The invention relates to a method according to the preamble of claim 1.

The method according to the preamble of claim 1 is referred to as "wobble". This method has the disadvantage that the winding speed, which is the geometric sum of the circumferential speed of the spool and the traversing speed, is changed by the mirror disturbance. Such a method is e.g. known from DE-OS 28 55 616 = US-4,296,889 (Bag. 1100).

From DE-PS 19 16 580 = US-3,730,448 (Bag. 666) it is known to periodically shorten the stroke when producing a package (breathing). In this process, an additional speed is superimposed positively or negatively on the traversing drive, a grooved roller that always travels over the same stroke length. The traversing thread guide therefore travels the stroke distance assigned to him with the same traversing frequency but with a changed traversing speed when the traversing stroke is changed. The process of periodically changing the stroke (breathing) also serves to build up an exactly cylindrical coil with straight faces or inclined faces (biconical coil). In this method, too, the change in the traversing speed results in a change in the winding speed and thus a change in the thread tension.

In order to avoid impermissible changes in the thread tension, EP 27 173 proposes that the mirror disturbance and breathing take place synchronously. As a result, the change in the traversing speed for the purpose of mirror interference is largely compensated for by the change in the traversing speed for the purpose of breathing. The latter method has been further developed to perfection by EP 85109799, so that uniformly cylindrical bobbins can be built up, from which the thread can be drawn off without error at speeds of more than 1000 m / min.

The invention has for its object to provide a method with which in the manufacture of packages with high winding and traversing speeds mirror disturbances can be achieved by changing the stroke length or the traversing speed without an unacceptable change in thread tension. It is solved in a method according to the preamble of claim 1 by the claim character.

The invention according to the characterizing part of claim 1 creates a method in which there is no change in the traversing speed due to mirror interference and breathing. Mirror disorder and breathing are mutually dependent. Therefore, measures for synchronization, which require considerable mechanical and electronic effort in the known methods and devices, are not necessary. The method according to claim 1 has the advantage that the thread can be wound with constant and optimized thread tension without the formation of mirrors. Any breathing method can be used, for example breathing according to EP-A 87 101028 (Bag. 1509).

For mechanical, electrical or textile reasons, it may be expedient or necessary to insert a rest cycle between the strokes of the stroke shortening in which there is no stroke shortening. There is a risk of mirror formation during these rest cycles. It is therefore proposed that a mirror disturbance occurs by changing the traversing speed during these rest cycles (claim 2).

A traversing device suitable for carrying out the method according to the invention is explained in more detail with reference to the attached drawing.

• Fig. 1 die schematische Darstellung einer mehrstelligen Aufspuleinrichtung mit Einrichtungen zur Spiegelstörung durch Atmung;
• Fig. 2 Schema einer mehrstelligen Aufspuleinrichtung mit einer Changiereinrichtung mit zwei getrennt antreibbaren endlosen Antriebsriemen;
• Fig. 3 die schematische Aufsicht auf eine einer Aufspulstelle nach Fig. 1 zugeordneten Changiereinrichtung;
• Fig. 4 Hub-Zeit-Diagramm für die Spiegelstörung durch Atmung der Changierung bei gleichbleibender Changiergeschwindigkeit;
• Fig. 5 Hub-Zeit-Diagramm für Spiegelstörung bei gleichbleibender Hublänge und zeitweiliger Änderung der Changiergeschwindigkeit.

Show it:

• Figure 1 is a schematic representation of a multi-digit winding device with devices for mirror disturbance through breathing.
• 2 shows a diagram of a multi-position winding device with a traversing device with two separately drivable endless drive belts;
• 3 shows the schematic plan view of a traversing device assigned to a winding unit according to FIG. 1;
• Fig. 4 stroke-time diagram for the mirror disturbance by breathing the traversing at a constant traversing speed;
• Fig. 5 stroke-time diagram for mirror disturbance with constant stroke length and temporary change in traversing speed.

1 and 2 are schematically shown winding machines with several winding positions. In Fig. 1, a plurality of threads 8 are fed from a delivery mechanism 47 and a thread guide 49 to their respective winding position. The endless belt 1 extends over three winding positions. The pulley 2 is driven by the motor 55. At a serving as a straight guide rod, which extends over the three winding positions, a carriage 5 with a traversing thread guide 7 are movably guided for each winding position. The gripper drive is switched by the stops 23.L and 23.R, which are each arranged on supports and can be driven by a threaded spindle 29. The threaded spindles are driven by motor 64 and a countershaft 65 and gear pairs 56. The thread is wound on the spool 57, which is freely rotatable. The coil is driven on its periphery by drive rollers 58. The drive rollers 58 of the three winding stations are driven together by motor 59. Otherwise, one of the exemplary embodiments of this invention can serve as the traversing device.

2 is a top view. The winding machine can essentially correspond to that of FIG. 1. Here, however, the traversing devices are not driven by one belt, but by two endless belts 1.1 and 1.2. Each of these belts is driven by a motor 55.1 and 55.2. Frequency generators 60, 61 can drive the motors at different speeds and the belts at different speeds. The carriages 5, which are assigned to each winding point, are each driven by one of the belt spaces, the two belt spaces intended for driving having opposite directions of movement 4.1 and 4.2. The fixed stops 23.L and 23.R are only shown in dashed lines as stop curves. For the rest, reference can be made to the description of FIG. 1.

3:

A circumferential belt 1 is stretched between two rollers 2 and 3 and rotates in direction 4. A carriage 5 is on straight guides 6 between the two parallel belt spaces straight and has a traversing thread guide 7, in which the thread 8, which runs perpendicular to the image plane, is guided.

The entrainment and reversing mechanism is attached to the carriage between the two belt spaces. A fixed gripping jaw 9.L is attached to the carriage 5 outside and closely adjacent to the belt piece running to the left. The toggle spring 11.L is clamped on one side on the bracket 10.L. The Bock 10.L is mounted on the sled in the area of the belt run to the right. The movable gripper 12.L is attached to the free end of the toggle spring 11.L. The toggle spring 11.L is shaped with a curve. It is so long that the movable gripper 12.L does not touch the belt drum in the rest position of the toggle spring 11.L. The same elements 9.R to 12.R are provided for clockwise rotation, but the sides are reversed.

On the central pin 13, which is located exactly in the middle between the driving elements 9 to 12 cited above, two disks are freely rotatable about the pivot axis 13. The eccentric disc 14 has a smaller diameter over an angle of almost 180 ° and a larger diameter over a further angle of almost 180 °. Both circumferential areas are constantly connected. These transitions from a smaller to a larger diameter form the two eccentrics of the eccentric disc, which cause the toggle springs 11.L and 11.R to stretch. A drive pin 15 sits on the eccentric disk 14. The drive pin 15 projects through a circular elongated hole 16 which is introduced into the second so-called switching disk 17. The elongated hole 16 extends over only a short circumferential area. The eccentric disc 14 is clamped by tension spring 18. The articulation point 19 of the tension spring 18 is attached to the slide in a plane that passes through the pivot pin 13 and is perpendicular to the belt space 1. From pivot point 19 on Viewed from the slide, the articulation point 15 lies on the eccentric disc beyond the pivot point 13 of the eccentric disc. Therefore, the cedar 18 passes through its dead center when the eccentric disc 14 is rotated.

The shift lever 17 is clamped by cedar 20. The cedar 20 is in turn clamped between the already mentioned clamping point 19 on the slide and on the other hand at a clamping point 21 of the shift lever, which is also beyond the pivot point 13 on a larger diameter than the clamping point of the spring 18 on the eccentric disc 14. The cedar 20 thus also passes over its dead position when the switching disk is pivoted. The switching disc 17 has a switching lug 22. The switching lug 22 interacts with stops 23.R and 23.L when the right and left end positions of the slide 5 are reached. Stops 24.L and 24.R are used to stop and guide the movable grippers 12.L and 12.R.

From Fig. 1 it can be seen that the belt 1 can have a great length and that between the rollers 2 and 3 a larger number of traversing devices, i.e. Stops 23.L and 23.R and carriage 5 can be arranged. The straight guides 6 can extend over only one winding point or also over a large number of winding positions. The traversing stroke length can be adjusted in the direction of the arrow by changing the position of at least one of the two stops 23.L, 23.R. Permanent magnets 63.L and 63.R are attached to the slide on both sides. These interact with fixed magnets 62.L and 62.R, which are attached in the stroke reversing areas.

The mode of action:

It can be seen from Fig. 3 that the traversing carriage 5 moves to the right, since the carriage 5 by the fixed gripping jaw 9.R and the movable gripper 12.R on the right moving belt belt is clamped. The carriage moves to the right until the switching lug 22 hits the right stop 23.R. The switching lug 22 is pivoted to the left relative to the carriage. The eccentric disk 14 initially does not take part in this pivoting movement, since the driving pin 15 slides on the eccentric disk in the slot 16 of the switching disk.

The pivoting movement of the switching lever 17 or the switching lug 22 is limited by the stops 25. L and 25. R attached to the slide 5.

In addition, it is shown that the stops 23.L and 23.R are mounted on a spindle 29.L and 29.R and secured against rotation. The spindles 29 are threaded. They are driven by the stepper motors 64.L and 64.R. The stepper motors are controlled by storage and control unit 66, both directions of rotation being possible.

The stepper motors 64.L and 64.R can be driven synchronously or individually so that the stops 23.L and 23.R individually or preferably both move synchronously towards the center of the stroke and back again. This movement can be controlled according to a predetermined program. Breathing follows. Suitable laws for control result e.g. from EP-A 85109799, but also from the as yet unpublished German application 36 02 853 (Bag. 1509). Reference is made to these pre-registrations and the subsequent registrations registered with their priority. With the breathing laws described there, a cylindrical cheese can be constructed with a precisely cylindrical circumference.

4 shows the largest traverse stroke H and the smallest traverse stroke h on the ordinate on. The abscissa is the time axis. The solid line shows the development of the traversing movement of the traversing thread guide over the total stroke H on the time axis. The dashed line shows the development of the traversing movement over the smallest stroke h on the time axis. A back and forth movement is called a double stroke. The number of double strokes per unit of time is referred to as the number of double strokes or _ in this application _ as the traversing frequency. The time period T or t for a back and forth movement is referred to as a double stroke time.

It can be seen that the double stroke times depend on the size of the stroke. Therefore, the traversing frequency 1 / T with a large stroke H is lower than the traversing frequency 1 / t with a small traversing stroke h. On the other hand, the diagram shows that the traversing speed dH / dT for a large stroke H is equal to the traversing speed dh / dt for a small stroke h. By breathing according to this invention, there is no change in the traversing speed. As a result, the winding speed and thus the thread tension during winding remain constant. On the other hand, the traversing frequency = double stroke rate is decisive for the creation of mirrors. A first-order mirror is created when the winding ratio (= the number of turns = the number of crossings), ie the ratio of the coil speed / double stroke number, is an integer. Low-order mirrors occur when the winding ratio deviates from the next integer winding ratio by a large fraction with an integer denominator (in particular 1/2, 1/3, 1/4). Due to the breathing movement according to this invention, the following alternatives to mirror disturbance or mirror avoidance are conceivable: By permanently shortening the traversing stroke, it is possible to avoid critical, mirror-prone winding conditions occurring during the winding travel. Alternatively, you can quickly run through critical, mirror-prone winding conditions. And another alternative is that one the winding ratio varies periodically or aperiodically in the manner of a wobble and avoids mirror symptoms in that the winding conditions, which are at risk of being mirrored, are passed through only briefly.

The diagram according to FIG. 5 shows on the one hand the time course of the traversing movement and on the other hand the time course of the traversing speed. Common to both diagrams is the abscissa, the time axis. The ordinate of the lower part of the diagram represents the stroke H or h. It should be noted that the slope of the curve shown represents the traversing speed. However, the changes in the traversing speed that result from the upper part of the diagram are not visible because of their relatively small size and because of the distorted representation of the lower part of the diagram.

From the lower part of the diagram it can be seen that the stroke shortening is carried out during the clock cycles TK, with first a linear shortening of the stroke from the maximum stroke H to the minimum stroke h and then a linear extension to the maximum stroke H again. There is no shortening of the stroke during the rest periods TR.

From the upper part of the diagram it can be seen that the traversing speed (with the dimension m / sec.) Remains constant during the cycle times with a shorter stroke. A wobble takes place during the rest periods TR. The traversing speed is changed periodically or non-periodically, but in any case repeatedly, with a change of up to 10% of the mean value.

Such a wobble for the purpose of mirror disturbance, i.e. to avoid the mirror symptoms is known per se. During the cycle times with stroke shortening, such a mirror fault _ as already described _ is not necessary.

Claims (2)

1. A method of ribbon breaking when winding a yarn into a cross-wound package with an angular deposit of more than 2° by temporarily varying the traversing frequency, characterised in that the traversing frequency is varied by shortening the stroke with the traversing speed unchanged.

2. A method as claimed in claim 1, characterised in that ribbon breaking is effected by varying the traversing speed during the periods in which the stroke is not shortened.

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