EP0235557B1 - Method to take up a thread onto a cross-wound bobbin - Google Patents

Abstract

1. A chuck adapted to be cantilever-mounted for rotation about a longitudinal axis thereof in a winding machine for threads such as synthetic plastics filament, glass fibre etc., the chuck comprising an element movable radially thereon between retracted and extended positions under the action of centrifugal force when the chuck is rotated about its longitudinal axis at or above a predetermined operating speed in use, the element having a head portion which projects radially outwardly from the bobbin tube receiving surface of the chuck when the element is in its extended position, and is located inwardly of that surface when the element is in its retracted position, the head portion either including thread catching means adapted to receive and catch a thread to secure the thread to the chuck for winding into a package thereon or being adapted to co-operate in use with a part carried by the chuck in order to form such a thread catching means.

Description

The invention relates to a method for. Production of a cylindrical cheese in a wild winding from a thread, in particular from a textured, in particular false-twisted, textured thread. The end faces of such cylindrical cross-wound bobbins can lie in a normal plane (winding with straight end faces) or can be erased relative to this normal plane (biconical winding).

In this application, a cross-wound bobbin is referred to as a bobbin in a wild winding, the winding ratio of which is constant or variable in the course of the winding travel. "Spool ratio" refers to the ratio of the spool speed NS (revolutions of the spool per minute) to the traversing speed DH (number of double strokes per minute).

Coils of the type defined at the outset are described in DIN 61 800. They are manufactured on cross winding devices of texturing machines. Because of their treatment, in particular false twist texturing treatment, the threads have curl-elastic properties there.

The current technical development is aimed at larger spools and at increasing the running speed in the further processing machines.

In order to avoid the beads at the coil ends, it is known to breathe the traverse stroke by breathing, i.e. Modify periodic shortening and lengthening in the end area of these beads.

It is also known that a mirror disturbance should occur in the production of cheese. The symptoms of such mirrors are usually avoided by constantly reducing and increasing the traversing speed, which is specified as the number of back and forth movements (double strokes) of the traversing thread guide per unit of time, between an upper and lower limit.

It is also known that the tensile force with which the thread has been wound onto the bobbin is a special criterion for good running properties. It depends in particular on the uniformity of this tensile force over the thread length and over the length of the bobbin. In order to ensure a uniform thread tension, it is also known that breathing and mirror disturbance take place synchronously in such a way that changes in the traversing speed caused by changes in the thread guide stroke are compensated for by the changes for the purpose of mirror disturbance.

In systematic investigations of the running behavior of bobbins, it was surprisingly found that flattening the cylindrical outer surface area of the package on the side facing away from the take-off side of the thread brings about a substantial improvement in the running properties of the thread. In contrast, bead-shaped thickening of the bobbin on the thread take-off side, in particular due to the inevitable depositing of an excessive amount of thread in the area of the reversal of stroke, had no disadvantageous consequences. This result was completely unexpected, because, based on the known experience with the running behavior of the threads of tapered bobbins, the opposite result had been expected.

It should be mentioned that the flattening of the cylindrical outer surface area of the package is not an oblique end face, as is obtained in the production of a biconical package by a uniform reduction in the thread guide stroke, but a deliberately brought about, in particular constant, reduction in diameter at least the end of the cylindrical winding area, which is opposite the thread take-off side. In the case of bobbins which have a thread reserve winding for connecting the beginning of the thread of a bobbin to the end of the thread of a following bobbin, the flattening lies on the side of the bobbin on which the thread reserve lies.

The thread take-off side of a bobbin is further defined in that the bobbin tubes have a rounded edge on their end face facing the thread take-off side.

The production of such bobbins can be accomplished primarily by the fact that the length of the breathing strokes is significantly increased, for example to approximately, in the case of cross-winding devices whose traversing devices have facilities for cyclically shortening and lengthening the thread guide stroke (breathing) in addition to the possibility of image interference to improve the edge structure 20 mm stroke reduction on one or both stroke ends with a basic stroke of the traversing thread guide of 250 mm.

Coils created in this way, however, had relatively soft faces. Depending on the type of further processing, this is undesirable since soft coils are more easily damaged than hard coils. Thus, the spools with flattened ends turned out to be unfavorable in many cases, particularly because of the transport and handling problems that arise, despite their favorable running properties.

The EP application 85 109 799.8 was able to maintain the advantages of the spools with flattened ends and at the same time avoided excessive softness of the spool ends and to produce a spool with the desired, adjustable hardness with excellent running properties. The EP application 85 109 799.8 is based on the method known from EP-PS 27 173 = US-PS 4 325 517, in which the breathing stroke is the difference between the maximum and the smallest stroke length from one breathing cycle to another in synchronism with the mirror disturbance is continuously changed (Bag. 1157). This process has brought about a substantial homogenization of the spool structure and improvement of the run-off properties.

Methods in which breathing is known from US Pat. No. 4,498,637 and from GB-A 2,157,725 follows a parabolic, wave-like time diagram. This is intended to reduce the formation of thickenings at the ends of the coil circumference (US Pat. No. 4,498,637, column 10, line 25).

According to GB-A 2 112 029, page 1, line 13 and Fig. 20, this parabola-like timing diagram is still used to achieve a specific positioning of the thickening on the coil length. Different time diagrams are used so that the thickening is evenly distributed.

Thus, according to the above-described methods, bobbins are also formed which have thickened areas in their end regions, only the thickening being kept low according to the US-PS and limited according to GB-A to a thread layer which arises during each breathing cycle and then from breathing cycle to breathing cycle be distributed.

In contrast, it is an object of the invention to completely avoid thickening by specifying a suitable timing diagram for breathing and to produce bobbins with a large diameter and a large bobbin length, which at high take-off speeds of 1000 m / min and more ensure trouble-free running of the thread overhead, which moreover have a stable cylindrical shape and are wound with a uniform thread tension that is independent of the traversing movement and the mirror disturbance.

The measures according to the invention can be applied to cylindrical cross-wound bobbins with straight end faces and those with sloping end faces in longitudinal section (biconical bobbins).

The method according to this invention is characterized in that at most two breaths of different sizes, but preferably only breaths of the same size are carried out in constant alternation. The breathing curve between the inner end points and the outer end points of the traversing stroke follows a wave course with valleys similar to parabolas, the apex of the breathing curve lying on the outer end point of the traversing stroke and the slope there being zero. The reversal of the breathing curves in the inner end points occurs essentially discontinuously, in that the parabolic branches of the breathing curve with decreasing traversing stroke and the branches of the breathing curve with increasing traversing stroke merge into one another in the respective inner end point of the traversing stroke.

• 2 x maximaler Atmungshub = (Changierhub zwischen den äußeren Endpunkten) - (Changierhub zwischen den inneren Endpunkten)
• 2 x maximaler Atmungshub = maximaler Changierhub - minimaler Changierhub und
• 2 x Atmungshub = maximaler Changierhub - aktueller Changierhub.

In the context of this application, the time law of movement of the end point of the traversing stroke with the shortening of the traversing stroke (breathing stroke) is referred to as the ordinate and the time as the abscissa under the respiration curve. The breathing stroke is the temporary shortening of the traversing stroke at one end of the coil compared to the basic traversing stroke, so that when breathing at both ends of the coil the equations apply:

• 2 x maximum breathing stroke = (traverse stroke between the outer end points) - (traverse stroke between the inner end points)
• 2 x maximum breathing stroke = maximum traversing stroke - minimum traversing stroke and
• 2 x breathing stroke = maximum traverse stroke - current traverse stroke.

The traverse stroke between the outer end points is referred to as the basic traverse stroke. To produce a biconical coil, the basic traverse stroke is also constantly reduced compared to the initial traverse stroke. The initial traverse stroke is the largest traverse stroke of the winding travel. It is moved at the beginning of the winding cycle and determines the length of the bobbin.

The respiration curve therefore has a parabolic-like course in the respiratory stroke-time diagram and this course is determined in such a way that the amount of thread deposited in the reversal area of the traversing is evenly distributed over the reversal area. A - theoretically - slightly thickened coil end is thus created at the coil ends at which breathing is carried out, which, however, is not - as before - in the form of an annular bead, but is exactly cylindrical.

The invention is explained below on the basis of exemplary embodiments. First, devices are described with which the invention can be carried out.

• Fig. 1 eine Vorrichtung zum Aufwickeln eines Fadens auf eine Spule nach dem erfindungsgemäßen Verfahren;
• Fig. 2 Vorrichtungen 20 bis 23 nach Fig. 1 zum Antrieb und zur Einstellung des Changierhubs im Detail;
• Fig. 3a das Zeit-Weg-Diagramm des Changierfadenführers nach einem ersten Ausführungsbeispiel;
• Fig. 3b das Geschwindigkeits-Zeit-Diagramm des Changierfadenführers nach dem ersten Ausführungsbeispiel;
• Fig. 4a die Abwicklung der Changierkurven für das erste Ausführungsbeispiels;
• Fig. 4b, das theoretische Diagramm der pro Zeiteinheit 4d erzeugten Fadenschichten, wobei Fig. 4d eine Vergrößerung von Fig. 4b ist;
• Fig. 4c Diagramm des Spulenaufbaus im Axialschnitt;
• Fig. 5a das Zeit-Weg-Diagramm des Changierfadenführers eines zweiten Ausführungsbeispiels;
• Fig. 5b das Geschwindigkeits-Zeit-Diagramm desselben Ausführungsbeispiels;
• Fig. 6a der Spulenaufbau des zweiten Ausfüh_- rungsbeispiels in schematischer Darstellung;
• Fig. 6b der Spulenaufbau des zweiten Ausführungsbeispiels;
• Fig. 7a entspricht Fig. 5a;
• Fig. 7b entspricht Fig. 3b;
• Fig. 7c das Diagramm der Umfangsgeschwindigkeit der Spule für ein weiteres Ausführungsbeispiel;
• Fig. 8a das Zeit-Weg-Diagramm des Changierfadenführers für ein weiteres Ausführungsbeispiel;
• Fig. 8b das Geschwindigkeits-Weg-Diagramm des Ausführungsbeispiels;
• Fig. 8c das Diagramm der Umfangsgeschwindigkeit der Spule für dieses Ausführungsbeispiel;
• Fig. 9a das theoretische und praktische Diagramm des 9b Spulenaufbaus für dieses Ausführungsbeispiel.

The individual shows:

• Figure 1 shows a device for winding a thread on a bobbin according to the inventive method.
• Fig. 2 devices 20 to 23 of Figure 1 for driving and adjusting the traversing stroke in detail.
• 3a shows the time-path diagram of the traversing thread guide according to a first embodiment;
• 3b shows the speed-time diagram of the traversing thread guide according to the first embodiment;
• 4a the development of the traversing curves for the first embodiment;
• FIG. 4b shows the theoretical diagram of the thread layers generated per unit of time 4d, FIG. 4d being an enlargement of FIG. 4b;
• Fig. 4c diagram of the coil structure in axial section;
• 5a shows the time-path diagram of the traversing thread guide of a second exemplary embodiment;
• 5b shows the speed-time diagram of the same exemplary embodiment;
• FIG. 6a, the coil assembly of the second exporting _- approximately example in a schematic representation;
• 6b shows the coil structure of the second exemplary embodiment;
• Fig. 7a corresponds to Fig. 5a;
• Fig. 7b corresponds to Fig. 3b;
• 7c shows the diagram of the peripheral speed of the coil for a further exemplary embodiment;
• 8a shows the time-path diagram of the traversing thread guide for a further exemplary embodiment;
• 8b shows the speed-distance diagram of the exemplary embodiment;
• 8c shows the diagram of the peripheral speed of the coil for this embodiment;
• Fig. 9a the theoretical and practical diagram of the 9b coil structure for this embodiment.

In the following description of the device with reference to FIGS. 1 and 2, reference is made to US Pat. No. 3,730,448, which essentially corresponds to FIG. 3 of German Patent 1,916,580. To the reference numerals in FIG. 3 of US Pat. No. 3,730,448, 100 were added to identify identical parts in FIG. 1 of this invention.

In Fig. 1, a coil 102 is formed on the coil sleeve 101. The spool is driven by friction roller 105 on shaft 106. The shaft is driven by motor 50 via a frequency converter 51. The traversing device 107 consists of a thread guide 108 with an angle lever 109, which is rotatably mounted on pins 110. The pin 110 is fastened to a slide 111 which is driven by the sliding shoe 113. The sliding block 113 moves in a helical or spiral groove 114 on the cam drum 115. The sliding block 117 is guided in the guide rail 118 and is rotatably mounted on the pin 116 at the other end of the angle lever 109. The guide rail 118 is rotatably mounted in the pivot point 120. The traversing stroke of the thread guide 108 depends on the inclined position of the guide rail 118.

Cam head 135, which is fastened to rod 126, is used to adjust the inclined position of guide rail 118. Bar 126 is a series of winding units arranged side by side. assigned and has a central drive, which is described below. The working surface 136 of the cam head 135 acts on the guide rail 118 via transmission cams 128 and transmission member 129 and thus determines the inclined position of the guide rail 118 and consequently the length of the traversing stroke. With the aid of the transmission member 129, coils 102 with biconical ends are produced by shortening the traversing stroke as a function of the growing diameter of the coil 102. In this connection, reference is made to the description of the aforementioned U.S. Patent 3,730,448. To produce spools with straight edges, the guide rail 118 is moved to the left and locked (this will be discussed later), so that the cam head 123 is operatively connected to the shoulder 138 on the guide rail 118 via its working surface 137. In this position, the transmission link 129 is out of operation due to the greater inclination of the guide rail 118.

In addition to what is shown in FIG. 3 of US Pat. No. 3,730,448, devices for driving and adjusting the rail 126 are shown in the left part of FIG. 1 of this description. These devices (shown schematically) consist of a program unit 18, a signal current converter 19, an electromagnet 20, the magnetic force of which is transmitted to a hydraulic control valve 21, a spring 22 and to the piston of the cylinder-piston unit 23. The piston rod 24 is connected to the end of the adjusting rod 126. The group consisting of magnet 20, control valve 21, spring 22 and cylinder-piston unit 23 is arranged on slide 25. This group is shown in detail as unit 26 in FIG. 2.

The unit 26 comprises the electromagnet 20, the hydraulic control valve 21, the spring 22 and the cylinder-piston unit 23. The iron core 27 of the magnet 20 acts on the piston rod 28 of the control valve 21. The piston rod 28 has three control collars 29, 30, 31 , which serve to control the connecting lines between the pump 32, tank 33 and the rear 34 of the cylinder-piston unit 23. The spring 22 acts on the other side of the piston rod 28 via a corresponding spring plate 35. The other end of the spring 22 acts on the spring plate 36 and the piston 37 of the cylinder-piston unit 23. The piston 37 is a differential piston because of its end face 38 is reduced by the area of the piston rod 24. The end face 38 of the piston 37 is permanently connected to the pump 32 via channel 39. The rear 34 of the piston 37 is connected both to the pump 32 via channel 40 and to the tank 33 via channel 41. This connection is controlled by moving the control collar 30, which connects the channel 41 to both channel 40 and channel 42.

One arm 43 of the channel 42 leads to the rear 34 of the cylinder-piston unit 23. The other arm 44 serves to compensate for the pressure that prevails on both sides of the hydraulic control valve. It should be noted that piston 37 abuts a shoulder 45 of the cylinder in its outer, left position. As a result, the outermost stroke ends of the coil are mechanically fixed.

In Fig. 2 it can also be seen that the unit 26 is mounted on a carriage 25. The slide is fastened on two parallel rods 49, which are slidably mounted in plain bearings 46. The carriage 25 is displaceable between two positions, one position being limited by a stop 47 and the other position by a stop from flange 48 to slide bearing 46.

In operation, one of the winding programs shown in the previous drawings and diagrams is stored in the program unit 18. The program unit generates an output signal which corresponds to a certain traverse stroke length in accordance with one of the traverse programs according to this invention. This output signal is converted by the converter 19 into an electrical current, which activates the magnet 20. The magnetic force is transmitted to the piston rod 28 of the control valve 21, to the spring 22 and to the piston 38 and piston rod 24.

The function of the unit 26 will be described with reference to the position of the control valve 21 shown in FIG. 2. A specific output signal is converted into a current which exerts a force on the iron core 27, which then pushes the piston rod 28 with the control collar 30 into the position shown. In this position, channel 42 is ge closed. Consequently, the end face of the cylinder-piston unit 23 is acted upon by the liquid flow coming from the pump 32. The back 34 is closed. As a result, piston 37 and piston rod 24 are locked in the position shown.

If the output signal of the program unit is changed in such a way that a stronger current acts on the electromagnet 20, a stronger force in turn acts on the iron core 27, which moves the iron core 27 to the right. Channel 42 then opens to channel 41, which leads to tank 33. A pressure drop now arises on the rear side 34 of the cylinder-piston unit 23, and the pump pressure acting on the front side 38 displaces the piston 37 and the piston rod 24 to the left. As a result, the spring 22 is compressed, and the resulting spring force causes the piston rod 28 of the control valve 21 to be displaced to the left, whereupon the control collar 30 interrupts the connection of the channel 42 to the channel 41 and thus to the tank. Thus, the force of the iron core 27 is balanced by the spring 22. Conversely, when the current is decreased, the spring 20 moves the piston rod 28 to the left, and collar 30 opens the channel 42 to the arm 40 leading to the pump. The pump pressure is now applied to both sides of the piston 37. Because the active area on the rear 34 is larger than the active area on the front 38, piston 37 is moved to the right. As a result, the spring 22 expands and the spring force acting on the piston rod 28 decreases. Due to the magnetic force acting on the iron core 27, the piston rod 28 is now moved to the right, so that collar 30 closes the connection between channel 42 and pump channel 40.

From this description it can be seen that the input current acting on the electromagnet 20 causes a certain position of the piston 37, the piston rod 24 and consequently the rod 126 and thus the inclination of the guide rail 118. The traverse stroke length of the thread guide 108 shown in FIG. 1 is thus controlled by the output signal of the program unit 18.

As already mentioned, unit 26 is mounted on slide 25. In the position shown, in which the flange 48 bears against the stop 37, the unit 26 and the rod 126 are positioned such that the inclined position of the guide rail 118 via the cam head 135 on the rod 125 is now determined. If the slide 25 and the unit 26 are in this position, biconical coils 102 are produced. If the slide is in the other position, in which the flange 48 bears against the slide bearing 46, the cam head 123 of the rod 126 is in operative connection with the shoulder 138 on the guide rail 118, as a result of which coils 102 with flattened end regions are formed.

Fig. 1 also shows that shaft 106 with friction roller 105 is driven by motor 50. Motor 50 is controlled by the output signal of frequency converter 51. The cam drum 115 is driven by motor 52. Motor 52 is controlled by the program unit 53, whereby the traversing speed is changed to prevent unwanted mirrors on the formed roll. The frequency converter 51 is controlled on the one hand by the output signal of the program unit 18, by which the breathing is influenced according to this invention, and on the other hand by the output signal of the program unit 53, by which the traversing speed is changed. As a result, changes in the tension of the thread to be wound on the bobbin 102, which are caused either by breathing and / or the change in the traversing speed, can be compensated for by slight changes in the peripheral speed of the friction roller 105 and the bobbin 102. Timer 54 coordinates the output signals of the program units 18 and 53, via which the breathing and the change in the traversing speed are controlled according to this invention and in particular according to the diagrams shown.

A first exemplary embodiment of the traversing method according to this invention is described below with reference to FIGS. 3 and 4.

3a shows the method of breathing, i.e. the change of the traversing stroke over time. Except for the exception cited above, the breathing methods that have become known so far use breathing laws with a zigzag-shaped but rectilinear course. In contrast, a breathing law with a parabolic shape is provided according to this invention, as shown in Fig. 3a. The time on the abscissa of the diagram shown there is shown on the ordinate, the end area of the traversing stroke N or the breathing stroke A. The curves shown represent the end points at which the traversing thread guide 108 (FIG. 1) indicates the course of the winding travel over time reverses a coil end. The time-distance diagram of the traversing thread guide 108 is shown in a partial time area of the diagram according to FIG. 3a, wherein. the display on the time axis can only be shown distorted in the drawing, since the traversing speed is actually faster. The course of this time-path diagram is designated by 8. It can be seen from this time-path diagram 8 that the end points E, at which the traversing thread guide reverses, continuously move a parabolic arc between the vertex Ea (outer end point) and the inner end point Ei in the course of a cycle time.

The end points E are identical to the apex of the respective traverse stroke. The parabolic arch is referred to in this application as the "breathing curve".

The distance A = Ea - Ei is referred to in this application as "maximum breathing stroke" and is 25 mm when breathing is carried out.

The cycle time of an implemented breathing law was 6 seconds. It can be seen from the diagram shown in Fig. 3a that the respiratory curve at apex Ea has zero slope and that the branches of the respiratory curve enter the inner end points Ei at a rather acute angle. This corresponds to the ideal course. The This ideal course can only be selected if the mechanics shown in FIG. 1, ie in particular the drive of the guide rail 118, can represent the required rapid reversal of movement. If this is not the case, the method is used according to the invention, which is described below with reference to FIGS. 5 to 7.

It should be noted that in the time-path diagram of the breathing stroke shown in FIG. 3a, the descending to the ascending branches of the breathing curve at the apex Ea are mirror-symmetrical. As will become apparent from the further description below, this is expedient, but also not necessary if the breathing stroke of the successive breathing cycles remains constant.

Before the exact course of the breathing curve 1 is described, reference should first be made to the synchronization between breathing curve 1 and disturbance curve 2. The interference curve 2 is shown in FIG. 3b, with the same abscissa as the time axis and with the traversing speed DH as the ordinate. The traversing speed is given as the double stroke rate DH. The double stroke number is the number per unit time of the back and forth movements of the traversing thread guide 108 (FIG. 1). The traversing thread guide 108 is operated with a certain average double stroke rate DHM. This average double stroke number is related to the surface speed given to the bobbin by the drive roller 105 and determines the angle at which the thread is deposited on the bobbin. The traversing speed is now continuously varied between an upper limit value DHO and a lower limit value DHU, e.g. according to the linear, sawtooth-shaped fault law. The breathing law 1 and the disturbance law 2 are synchronized in such a way that the lowest traversing speed DHU always coincides with the largest traversing stroke in the peak value Ea of the breathing curve and the highest traversing speed DHO with the smallest traversing stroke in the inner end point of the breathing curve. This ensures that the change in the linear traversing speed, which is caused by breathing, is compensated for by an opposite course of the perturbation and the thread tension is thereby kept constant or is very evenly leveled. It should be noted that the average traversing speed preferably remains constant in the course of the winding cycle, but can also be slightly increased or decreased during the winding cycle to influence the storage angle.

• Es ist bereits aus Fig. 1 ersichtlich, daß die Nut 114 auf der Kurventrommel 115 an den Endpunkten des Changierhubes mit einer gewissen Krümmung umkehrt. Dieser Verlauf der Nut ist als Bewegungsgesetz 3 der Changierung (Changierkurve) in Fig. 4a als Linie 4, 6 dargestellt. Linie 4, 6 in Fig. 4a stellt insofern eine Abwicklung der Kurventrommel 115 dar. Es ist aus Fig. 4a ersichtlich, daß der geradlinige Ast 4 der Changierkurve vor und hinter der Hubumkehr in einem Punkt 5 in eine gekrümmte Kurve 6 übergeht. Die axiale Strecke zwischen den Punkten 5 und dem Scheitelpunkt - äußerer Endpunkt Ea des Changierhubes - wird als äußerer Umkehrbereich Ba bezeichnet.

And now to determine the course of the breathing curve:

• It is already apparent from FIG. 1 that the groove 114 on the cam drum 115 reverses at the end points of the traversing stroke with a certain curvature. This course of the groove is shown as the law of motion 3 of the traversing (traversing curve) in FIG. 4a as line 4, 6. Line 4, 6 in FIG. 4a thus represents a development of the cam drum 115. It can be seen from FIG. 4a that the straight branch 4 of the traversing curve merges into a curved curve 6 at a point 5 before and after the stroke reversal. The axial distance between points 5 and the apex - outer end point Ea of the traverse stroke - is referred to as the outer reversal area Ba.

When determining the reversal area Ba, it must also be taken into account that the filing of the thread on the bobbin is not only based on the traversing law, which is predetermined by the shape of the cam drum 115. Rather, it must also be taken into account that the thread is under tension when it is deposited on the bobbin and therefore does not deposit according to the traversing law specified by the cam drum. The thread therefore tends to form an arc with the smallest possible curvature in the reversal area. The size of the curvature depends on the thread tension on the one hand, but on the other hand also on different thread parameters, in particular the friction of the thread on the deposited thread layers. The quality of the bobbin therefore depends not only on the traversing law of the cam drum 115, but even more on the actual placement of the thread on the bobbin. Therefore, the reversal area Ba is preferably measured on a bobbin as the axial distance between the end of the traversing stroke predetermined by the cam drum through the cam drum and the normal plane of the bobbin, in which the curved reversal area of the thread actually deposited on the bobbin merges into the area of the linearly deposited thread.

The course of this curve 6 can be parabolic. However, there are other curves, e.g. sinusoidal, conceivable. It is essential that the traversing thread guide with carriage 111 and all the parts attached to it (FIG. 1) pass through the reversing area Ba with as little deceleration and acceleration as possible and without jerks or bumps. This means that the outer end point Ea of the traversing stroke compared to the theoretical end point Eth, in which the straight branches 4 of the traversing groove would meet at an angle, is axially offset to the center of the coil by a certain amount.

4a shows that the traversing curve of the traversing thread guide 108 is moved back and forth from the end region to the center of the bobbin by pivoting the guide rail 118 (breathing). 4a shows the axially outermost traversing curve with the curve pieces 4 and 6 as well as the axially innermost traversing curve 9 (dash-two-dotted lines) and in between three arbitrarily selected traversing curves 10 (dashed lines), 11 (chain-dotted lines), 12 (dotted lines) . These curves 10, 11, 12 are traversed in arbitrarily selected fractions of the cycle time of a breathing stroke, once in both directions of breathing.

The distance between the apex Ea of the axially outermost traversing curve and its transition point 5, at which the straight curve curve 4 merges into the curved curve curve 6, is referred to in the context of this application as the reversal region Ba. It now appears from Fig. 4a that the breathing stroke A, ie the axial distance between the outer end point Ea and the inner end point Ei of the traversing stroke, essentially corresponds to the reversal area Ba and is at least the same size.

According to the invention, the breathing stroke A is preferably greater than the reversal area Ba. The reversal area B is the axial length of the bobbin, on which the thread does not lie at a constant angle of deposit. This area must be determined from case to case by measurement. The outer reversal area Ba is the reversal area that the thread has with the greatest traversing stroke. The turning range depends, as will be explained, on the one hand on the traversing law, according to which the direction of movement of the thread at the ends of the traversing stroke is reversed with finite deceleration and acceleration, but also on the thread pulling force and friction with which the thread on the Coil is deposited.

When the traversing thread guide 108 moves on the axially outermost traversing curve with the curve pieces 4, 6, an equal amount of thread is deposited on the straight pieces 6, on which there is a constant traversing speed, on each unit of the bobbin length. This creates a cylindrical layer of thread. On the curved curve pieces 6, however, the traversing speed initially decreases to zero in the outer vertex Ea of the traversing curve and then increases again to the constant value described above. Since a larger amount of thread is deposited on each unit of the bobbin length at a low traversing speed than at a high traversing speed, a very large amount of thread is deposited in the area of the outer vertex Ea. The thickness of the thread layer, which is deposited in the reversal region Ba, is therefore greatest at the apex of the traversing stroke and decreases from there to the layer thickness deposited by the rectilinear traversing curve 6.

The diagram according to Fig. 4b shows the length L of the bobbin on the abscissa, starting from the outer vertex Ea and the thickness of the thread layer on the ordinate, e.g. measured in millimeters, which is stored on the spool per unit of time. The curve 6.2 shows the course of the thread layer thickness when the traversing thread guide keeps the traversing curve after the curves 4, 6 in Fig. 4a.

With breathing, as can be seen from FIG. 4a, the traversing curves are shifted in parallel. The reversal area Ba is thus also moved axially towards the center of the coil. It follows from this that each of the instantaneous traversing curves 9, 10, 11, 12 shown in FIG. 4a results in an assigned, deposited layer thickness profile 9.2, 10.2, ₁₁ . ₂ , ₁₂ .2 leads.

These layers generated per unit of time are recorded side by side in FIG. 4b and their enlargement in FIG. 4d. The diagram according to FIG. 4c shows the summation of the layers. The essence of the invention results from this summation:

FIGS. 4a to 4c are simplified insofar as only four further individual traversing curve profiles of the traversing thread guide or the layers generated with these traversing curve profiles are shown during a breathing stroke. In reality, all traversing curves that lie between the traversing curves 4, 6 and 9 shown are traversed.

The step-by-step approach chosen, however, makes the principle of the invention clearer: on the one hand, the maximum breathing stroke essentially corresponds to the axial length of the reversal area. On the other hand, the breathing curve according to FIG. 3a is calculated so that the sum of the layer thicknesses formed is constant over the entire breathing stroke Amax and results in a cylindrical coil surface OB. 4c shows the layer 6.3 which is generated at the apex of the breathing stroke by the traversing curve 4, 6 (FIG. 4a). By specifying the time in which this traversing curve is traversed, i.e. by specifying the slope dA / dT of the breathing curve (FIG. 3a) at the apex Ea, the layer thickness of the layer 6.3 is determined such that the maximum located at the end of the coil results in the enlarged diameter D of the coil desired in the deflection area. This applies to the gradual observation. In reality, i.e. in the case of a constant breathing curve, this specification results from the curvature of the breathing curve at the apex.

The layer 10.3 which is wound onto the layer 6.3 may only be so large that its maximum with the layer 6.3 below it again reaches the desired diameter of the end region Ea. Layer 10.3 is generated by traversing curve 10. Traversing curve 10 is approached for a certain period of time while the traversing stroke is reduced (outward breathing) and for a certain period of time while the traversing stroke increases (return path of breathing). The duration of the outward and return journey of breathing can preferably be the same. In this case, the respiratory curve is mirror-symmetrical to the traversing axis at its apex. The duration of the outward and return journey of breathing can also be unequal. The result is an asymmetrical breathing curve. In any case, the total period of time which is observed for the traversing curve 10 is predetermined by the maximum diameter D of the thread layers previously wound.

As I said: These explanations apply to the simplified, step-by-step view. When driving through a steady breathing curve, this time period corresponds to a specific slope and curvature of the breathing curve to be specified at the point of the breathing stroke at which the traversing curve 10 is driven. Just like the length of time, the slope or curvature for the outward and return path of breathing can be different.

Back to the gradual examination:

In the next breathing stage, layer 11.3 is wound onto layers 6.3 and 10.3 by setting the traversing curve 11 (FIG. 4a). This traversing curve 11 in turn creates a layer with a maximum thickness. By specifying the times during which the traversing curve 11 is maintained on the outward and return path of breathing determines the maximum of the layer 11.3 in such a way that, together with the layers 6.3 and 10.3 underneath, it results in the predetermined diameter D of the layers wound one above the other in the preceding stages of the breathing stroke.

The same now applies to the traversing curve 12 and the layer 12.3 thus generated as well as the traversing curve 9 and the layer 9.3 thus generated.

The inner end of the breathing stroke is reached and the breathing movement goes backwards again. As mentioned, the traversing curves 12, 11, 10 are again run through and the outer traversing curve 4, 6 is finally reached again. This steady-state process is carried out over the entire reversal area Ba, calculated from the extreme apex of the traversing stroke.

It can be seen from FIG. 4c that when viewed step by step in the reversal area Ba, theoretically a coil surface with individual sharp rings is created. If the breathing is provided according to the invention - but takes place continuously or the breathing levels are chosen to be as small as is dictated by the digital electronic control, a smooth, cylindrical surface with the diameter D that is larger than the coil diameter d in the region of the coil length is produced with a straight line traverse curve.

The breathing curve is thus calculated and specified in such a way that the amount of thread deposited per unit length of the bobbin is distributed into a cylindrical amount. The slope and curvature of the breathing curve and the course of the slope determine the exact observance of the quantity distribution over the reversal area Ba of the coil. It is. It can be seen that the course of the guide groove 114 in the reversal area B is also included in the calculation of the breathing curve. The thread diameter and other quality parameters of the thread also come into consideration as correction factors. These factors can be determined in particular by experimentally determining the distance between the theoretical apex Eth (FIG. 4a) of the traversing law and the actually determined extreme apex of the thread deposit on the bobbin.

From Fig. 4c it follows that in the reversal area Bi, which the thread guide 108 passes through at maximum breathing stroke (see curve 9 in Fig. 4a), the enlarged cylinder circumference OB gently runs into the cylinder circumference 0, which arises in the area with constant traversing speed .

5a, 5b, 6a, 6b: As the time-path diagram of the traversing stroke according to FIG. 5a shows, breathing takes place with a variable breathing stroke A1, A2, A3 etc. and the disturbance with a variable interference amplitude C1, C2, C3 etc. In both Fig. 5a and Fig. 5b, the abscissa is the time axis. 5a, the traverse path H or the breathing stroke A is plotted on the ordinate. 5b, the traversing speed is plotted on the ordinate. The traversing speed is given as the double stroke rate DH. The double stroke number is the number per unit time of the back and forth movements of the thread guide 108 (FIG. 1). The traversing speed is continuously varied between the lower, fixed limit value DHU and an upper, variable limit value DHO, whereby - as shown - a linear, sawtooth-shaped fault law can also be used here. As before, the breathing law 1 and the disturbance law 2 are synchronized in such a way that the lowest traversing speed DHU always coincides with the largest traversing stroke in the peak value EA of the breathing curve and the highest traversing speed DHO coincides with the smallest traversing stroke in the inner end point of the breathing curve. This synchronization serves to compensate the thread tension fluctuations, which are caused on the one hand by breathing and on the other hand by the disturbance. In contrast to the embodiment according to FIGS. 5a, 5b, however, the mirror disturbance takes place here in such a way that the lower traversing speed DHU is predetermined via the winding travel. Therefore, the mean value of the traversing speed does not remain constant in the course of a series of mirror disturbance cycles with a variable upper traversing speed DHO. As a result, the deposit angle of the thread on the bobbin is also changed in its mean value. The change is, however, very small. The lower value of the traversing speed DHU preferably remains constant during the winding cycle. However, it is also possible to change the lower value during the winding cycle, e.g. let it fall off weakly or rise slightly during the first third of the winding cycle and then let it fall off slowly.

To determine the course of the breathing curve according to FIG. 5a: FIG. 5a shows three breathing cycles from a series of four breathing cycles. However, more can be added to a series, e.g. include eight breathing cycles. The series of related breathing cycles is characterized in that the breathing stroke A1 of the first breathing cycle is equal to the maximum breathing stroke and that the breathing stroke A2, A3 ... of the following breathing cycles is then continuously shortened from one breathing cycle to the next. The next immediately following series of breathing cycles begins again with the maximum breathing stroke.

It has already been pointed out that the breathing curve represents the displacement of the end point of a traversing stroke during a breathing cycle. The breathing curve typically consists of a shortening branch K and an extension branch L. The shortening branch represents the shortening of the traversing stroke between the outer vertex Ea and the inner vertex Ei of the traversing stroke H.

The extension branch shows the time course of the extension of the apex of the traversing stroke H between the inner apex Ei and the outer apex Ea.

In deviation from the preceding description, a shortening branch K and an extension branch L are assigned to a respiratory cycle.

The first breathing cycle shown in FIG. 5a now has the shortening branch K1 and the extension branch L1. The breathing curve extends over the maximum breathing stroke Amax. The basic curve of the breathing curve of the first cycle, which is shown as a solid line, is designed such that - as already described above with reference to the diagram according to FIGS. 4b, 4d, 4c and 3a - the thickness of the deposited thread layer in the entire breathing stroke A. _ma x is constant and results in a cylindrical coil surface. This layer is marked as layer 1 in FIG. 6a. However, the breathing curve is corrected as indicated by the dashed curve 13.1. The breathing curve 13.1 is designed such that an additional thread quantity 14.1 is deposited in the axial excess area D1 of the bobbin, which is the difference between the maximum breathing stroke Amax or A1 and the breathing stroke A2 of the next breathing cycle with the branches K2, L2. This thread quantity 14.1 forms a layer which is as thick as the sum of all layers which are deposited in the reversal area Ba of the bobbin during the series of breathing cycles concerned.

The resulting breathing curve after the dashed curve 13.1 now has the advantage over the ideal, drawn curve that in the inner end point Ei there is a relatively gentle reversal of the shortening branch K1 into the extension branch L1. This means in practice that only slight decelerations and accelerations are required to drive the breathing rod 126 (FIG. 1) and the cylinder-piston unit 23. It should be noted that the correction 13.1 is ideally limited to the upper range D1, that for practical, in particular dynamic reasons, possibly. however, a further correction is advisable - as shown. The effects of this further correction on the thread placement can, however, be kept low.

As FIG. 5a shows, the following breathing cycle is carried out with a shortened breathing stroke A2. The breathing cycle consists of the shortening branch K2 and the extension branch L2. The basis for the calculation of this curve again is the specification that the thread is uniform over the area of the breathing stroke A2, i.e. should be distributed to an equally thick layer 2 (Fig. 6a). However, this curve is also corrected, and the dashed curve 13.2 is practically driven. This dashed curve is designed so that in the axial excess area D2 of the coil between the inner end points Ei2 and Ei3 of the subsequent breathing cycle, an additional amount of thread 14.2 is deposited in such a way that a layer thickness is reached in the axial area D2, which is the sum of all layers of the in of the affected series corresponds to the following shortened breathing cycles

During the now following breathing cycle, the breathing stroke is again shortened, namely to the breathing stroke A3. Here too, the shortening branch K3 and the extension branch L3 are designed in their basic course so that the thread quantity is distributed over the breathing stroke A3 to form a cylindrical layer 3. In addition, however, the amount of thread 14.3 (FIG. 6a) is additionally stored in the excess area D3 of the bobbin by again making the dashed-line correction 13.3 of the breathing curve. The additional thread quantity 14.3 in turn reaches the layer thickness of the entire thread layer, which is deposited in the reverse region in the series of breathing cycles.

During the last breathing cycle 4 (not shown) of the series there is again a shortening of the breathing stroke to the breathing stroke A4. The breathing curve is designed so that a uniformly cylindrical layer is wound over the A4 breathing stroke.

This is followed by a new series of breaths, the next breath cycle beginning with the maximum breath stroke A _max as shown in FIG. 5a, and again a gradual shortening of the breath stroke from one cycle to the next.

The layer structure of the end region is shown in FIGS. 6a and 6b, four breathing cycles being carried out in a series.

It can be seen from FIG. 6a in a schematic representation that this modified method also results in a cylindrical winding over the breathing area Amax, which has a somewhat larger diameter than the winding in the central area of the coil. In the reversal area Bi, which adjoins the maximum breathing stroke Amax, there is a smooth transition between the winding with a larger diameter and the winding with a smaller diameter, as already described above with reference to FIG. 4c.

FIG. 6b shows the layer formation, which is shown schematically in FIG. 6a, in a manner which comes closer to practice. It should be noted that on the one hand the amount of thread deposited during each breathing cycle is very small, since each breathing cycle only lasts a few seconds, e.g. Lasts 6 seconds. On the other hand, it must be taken into account that due to this short duration of a breathing cycle, no sharp edges of the individual layers and thread quantities arise. The thread is a linear structure. The individual thread turns of a layer do not lie close together, but at a distance that can be a few millimeters. Because of this thread spacing of successive turns, the turns deposited in a later layer are always, i.e. in the case of a functioning mirror disturbance, are deposited between the turns of the previous layer, so that the individual layers do not necessarily have different radii from a geometric point of view. What appears in FIGS. 6a and 6b as a radially applied thread layer therefore in reality only becomes noticeable to a large extent only in an increase in the packing density of the bobbin.

It can be seen from FIG. 5a that the corrections of the breathing curves lead in all cases to that the breathing movement can be carried out with little delay and acceleration.

Fig. 5b shows that for the mirror disturbance, the traversing speed, starting from the lower double stroke rate DHU, is increased synchronously with the shortening of the traversing stroke H, the upper value of the double stroke rate (DH02, DH03 ...) being proportional to the respective one in each mirror fault cycle Shortening the breathing stroke A1, A2, A3 ... compared to the double stroke number DHO of the previous mirror disturbance cycle is also reduced.

In a preferred embodiment of the invention, DH04, i.e. the smallest upper value of the double stroke rate within a series of breathing and mirror disturbance cycles is chosen at least so large that the ratio of mirror disturbance amplitude (C = DHO - DHU) to cycle time T does not fall below a certain predetermined value. The mirror interference amplitude C3 is the difference between the smallest upper double stroke rate DH03 and the lower double stroke rate DHU. Half the cycle time T / 2 is the time for increasing the double stroke rate from DHU to DHO. The ratio C3 / T / 2 shows the smallest slope of the mirror interference curves according to FIG. 5b. This lowest pitch must be so great that two thread turns, which are placed directly next to one another by successive traversing strokes, have a distance measured perpendicular to the thread that is at least equal to the thread thickness. One can also formulate: The distance in the axial direction must be at least equal to the placement width (measured in the axial direction) with which. the multifilament thread lies on the spool. This placement width is to be determined on the spool by measurement.

Another embodiment of the invention will now be explained with reference to FIGS. 7a to 7c. The breathing law and the resulting thread deposit on the bobbin corresponds to the description and illustration according to FIGS. 5a and 6a, 6b. The execution of the mirror disturbance according to FIG. 7b corresponds to the representation and description according to FIG. 3b. That is, the mirror interference amplitude is constant.

If one assumes with a constant mirror disturbance amplitude that the upper value of the double stroke rate DHO is dimensioned such that it results in an ideal thread tension compensation at maximum breathing stroke, it follows that with the smallest breathing stroke no complete thread tension compensation takes place. For this reason, the circumferential speed of the coil - as shown in FIG. 7c - is increased in synchronism with breathing or mirror disturbance in this exemplary embodiment. During the breathing cycle with maximum breathing stroke A _max , the peripheral speed of the coil is equal to the initial value VAO. Synchronously with the beginning of a breathing cycle with a shortened breathing stroke A2, there is also a slight increase in the peripheral speed V of the coil, the difference between V2 and V1 being proportional to the difference between the breathing strokes A1 and A2. Then, as the traversing stroke is extended, the traversing speed is again reduced to its initial value VAO = V1. When the next breathing cycle is carried out, the traversing speed is increased again, to an increased value V3. The difference V3 - V1 is in turn proportional to the total shortening of the breathing stroke A _max - A3. By appropriately specifying the initial value of the circumferential speed of the bobbin V1 and the increased values V2 and V3, which can be determined by calculation and experiment, a complete thread tension compensation can be brought about, so that the thread tension to which the thread is subjected to the bobbin neither during the winding travel fluctuates during a series of breathing cycles even during one breathing cycle.

It can be seen that the method according to FIG. 7c can also be combined with a method according to FIGS. 5a, 5b. This will be done with advantage if a viable compromise cannot be found between the requirement for good mirror interference and the requirement for thread tension compensation.

Another exemplary embodiment of the invention is explained with reference to FIGS. 8a to 8c. 3b corresponds to the representation and description according to FIG. 3b. That is, the mirror interference amplitude is constant. However, it should be pointed out in advance that the method according to FIGS. 8a, 8c, which is described below, can also be combined with a mirror interference method according to FIG. 5b. The possibility of varying the mirror interference amplitude will be used in particular if this is necessary to compensate for thread tension fluctuations. In this respect, reference is made to the description of FIG. 3b.

A biconical winding is produced with the aid of the traversing diagram according to FIG. 8a. At the beginning of the winding cycle, the thread is laid with the initial traverse stroke H1. In the course of the winding cycle, the traversing stroke H is constantly reduced, on both sides of the coil. This creates a cylindrical coil with flattened, i.e. conical faces. The difference in the axial winding length between the initial winding and the final winding is denoted by D. This means that the basic traverse stroke becomes smaller and smaller during the winding cycle. Breathing now starts from this decreasing basic traverse stroke.

Breathing takes place with a variable breathing stroke A1, A2, A3 etc. Both in FIGS. 8a to 8c, the abscissa is the time axis. The traversing speed is plotted on the ordinate in FIG. 8b. The traversing speed is given as the double stroke rate DH. The double stroke number is the number. per unit time of the back and forth movements of the thread guide 108 (FIG. 1). The traversing speed is continuously varied between the lower, fixed limit value DHU and an upper, variable limit value DHO, with a linear, sawtooth shape, as shown law can be applied. As before, the breathing law 1 and the disturbance law 2 are synchronized in such a way that the lowest traversing speed DHU always coincides with the largest traversing stroke in the peak value EA of the breathing curve and the highest traversing speed DHO coincides with the smallest traversing stroke in the inner end point of the breathing curve. This synchronization serves to compensate the thread tension fluctuations, which are caused on the one hand by breathing and on the other hand by the disturbance.

8a, the traverse path H or the breathing stroke A is plotted on the ordinate. It can be seen that the basic traverse stroke changes constantly compared to the initial traverse stroke. In the illustration according to FIG. 8a, the basic traversing stroke forms a straight line rising at the angle beta. The traversing stroke now constantly returns to this basic traversing stroke in the course of a breathing cycle and the breathing strokes A1 to A4 are calculated from this basic traversing stroke.

8a: Three breathing cycles from a series of four breathing cycles are shown in FIG. 8a. However, more can be added to a series, e.g. include eight breathing cycles. The series of related breathing cycles is characterized in that the breathing stroke A1 of the first breathing cycle is equal to the maximum breathing stroke and that the breathing stroke A2, A3 ... of the following breathing cycles is then continuously shortened from one breathing cycle to the next. The next immediately following series of breathing cycles be. starts again with the maximum breathing stroke.

It has already been pointed out that the breathing curve represents the reduction of the traversing stroke compared to the basic traversing stroke during one breathing cycle. The breathing curve typically consists of a shortening branch K and an extension branch L. The shortening branch represents the shortening of the traversing stroke between the outer vertex Ea = basic traversing stroke and the inner vertex Ei of the traversing stroke H. The extension branch shows the time course of the extension of the apex of the traverse stroke H between the inner apex egg and the outer apex Ea = basic traverse stroke.

In the following, a shortening branch K and an extension branch L are assigned to a respiratory cycle.

The first breathing cycle shown in FIG. 8a now has the shortening branch K1 and the extension branch L1. The breathing curve extends over the maximum breathing stroke Amax. The basic curve of the breathing curve of the first cycle, which is shown as a solid line, is designed such that - as already described above with reference to the diagram according to FIGS. 4b, 4d, 4c and 3a - the thickness of the deposited thread layer in the entire breathing stroke A. _ma x is constant and results in a cylindrical coil surface. This layer is marked as layer 1 in FIG. 9a. However, the breathing curve is corrected as indicated by the dashed curve 13.1. The breathing curve 13.1 is designed such that an additional thread quantity 14.1 is deposited in the axial excess area D1 of the bobbin, which is the difference between the maximum breathing stroke Amax or A1 and the breathing stroke A2 of the next breathing cycle with the branches K2, L2. This thread quantity 14.1 forms a layer which is as thick as the sum of all layers which are deposited in the reversal area Ba of the bobbin during the series of breathing cycles concerned.

The resulting breathing curve after the dashed curve 13.1 now has the advantage over the ideal, drawn curve that in the inner end point Ei there is a relatively gentle reversal of the shortening branch K1 into the extension branch L1. This means in practice that only slight decelerations and accelerations are required to drive the breathing rod 126 (FIG. 1) and the cylinder-piston unit 23. It should be noted that the correction 13.1 is ideally limited to the excess area D1, that for practical, in particular dynamic reasons, possibly. however, a further correction is advisable - as shown. The effects of this further correction on the thread placement can, however, be kept low.

As FIG. 8a shows, the following breathing cycle is carried out with a shorter breathing stroke A2. The breathing cycle consists of the shortening branch K2 and the extension branch L2. The basis for the calculation of this curve again is the specification that the thread is uniform over the area of the breathing stroke A2, i.e. to be distributed to an equally thick layer 2 (Fig. 9a). However, this curve is also corrected, and the dashed curve 13.2 is practically driven. This dashed curve is designed so that in the axial excess area D2 of the coil between the inner end points Ei2 and Ei3 of the subsequent breathing cycle, an additional amount of thread 14.2 is deposited in such a way that a layer thickness is reached in the axial area D2, which is the sum of all layers of the in of the affected series corresponds to the following, shorter breathing cycles.

During the now following breathing cycle, the breathing stroke is again shortened, namely to the breathing stroke A3. Here too, the shortening branch K3 and the extension branch L3 are designed in their basic course so that the thread quantity is distributed over the breathing stroke A3 to form a cylindrical layer 3. In addition, however, the amount of thread 14.3 (FIG. 9a) is additionally stored in the excess area D3 of the bobbin, by again making the dashed-line correction 13.3 of the breathing curve. The additional thread quantity 14.3 in turn reaches the layer thickness of the entire thread layer, which is deposited in the reverse region in the series of breathing cycles.

During the last breathing cycle 4 (not shown) of the series there is again a shortening of the breathing stroke to the breathing stroke A4. The breathing curve is designed so that a uniformly cylindrical layer is wound over the A4 breathing stroke.

This is followed by a new series of breaths, the next breathing cycle beginning with the maximum breathing stroke A _max as shown in FIG. 8a, and again a gradual shortening of the breathing stroke from one cycle to the next.

The layer structure of the end region is shown in FIGS. 9a and 9b, four breathing cycles being carried out in a series.

It can be seen from Fig. 9a in a schematic representation that the shortening of the basic traversing stroke compared to the initial traversing stroke leads to the end faces of the coil being erased, i.e. is wound conically. However, it should be noted that the cone angle has been drawn oversized in FIGS. 9a, b. In reality, changing the basic traverse stroke during a breathing cycle that lasts a few seconds does not have as much of an impact.

It can be seen from FIG. 9a in a schematic representation that this modified method also results in a cylindrical winding over the breathing area A _max , which has a somewhat larger diameter than the winding in the central area of the coil. In the reversal area Bi, which adjoins the maximum breathing stroke A _max , there is a smooth transition between the winding with a larger diameter and the winding with a smaller diameter, as already described above with reference to FIG. 4c.

FIG. 9b shows the layer formation, which is shown schematically in FIG. 9a, in a manner which comes closer to practice. The slope angle of the front edge is also drawn too large in FIG. 9b. In the context of this application it must be taken into account that, on the one hand, the amount of thread deposited during each breathing cycle is very small, since each breathing cycle is only a few seconds, e.g. Lasts 6 seconds. On the other hand, it must be taken into account that due to this short duration of a breathing cycle, no sharp edges of the individual layers and thread quantities arise. The thread is a linear structure. The individual thread turns of a layer do not lie close together, but at a distance that can be a few millimeters. Because of this thread spacing of successive turns, the turns deposited in a later layer are always, i.e. in the case of a functioning mirror disturbance, are deposited between the turns of the previous layer, so that the individual layers do not necessarily have different radii from a geometric point of view. What appears in FIGS. 9a and 9b as a radially applied thread layer is therefore in reality only to a large extent noticeable only in an increase in the packing density of the bobbin. It can be seen from FIG. 8a that the corrections of the breathing curves in all cases lead to the breathing movement being able to be carried out with little delay and acceleration.

5b, the traversing speed, starting from the lower double stroke rate DHU, could be increased synchronously with the shortening of the traversing stroke H, the upper value of the double stroke rate (DH02, DH03 ...) being proportional to each mirror disturbance cycle the respective shortening of the breathing stroke A1, A2, A3 ... compared to the double stroke number DHO of the previous mirror disturbance cycle is also reduced. For further refinement, reference is made to the comments on FIG. 5b.

However, if the breathing process is operated with constant mirror disturbance - as shown in FIG. 8b - it may be advantageous to also change the peripheral speed to compensate for thread tension fluctuations, as shown in relation to FIG. 8c. First of all, the peripheral speed is increased synchronously with the decreasing basic traverse stroke compared to the initial value of the peripheral speed VAO. This continuously increasing circumferential speed is designated in the diagram according to FIG. 8c, in which the ordinate represents the circumferential speed of the coil, with "basic circumferential speed". According to the invention, there is now a further modification.

If one assumes with a constant mirror disturbance amplitude that the upper value of the double stroke rate DHO is dimensioned such that it results in an ideal thread tension compensation at maximum breathing stroke, it follows that with the smallest breathing stroke no complete thread tension compensation takes place. For this reason, the circumferential speed of the coil - as shown in FIG. 8c - is increased in synchronism with the respiration or mirror disturbance compared to the basic circumferential speed in this exemplary embodiment. during the breathing cycle with maximum breathing stroke Amax, the peripheral speed of the coil is equal to the basic peripheral speed. Synchronized with the start of a breathing cycle with a shortened breathing stroke. A2 there is also a slight increase in the peripheral speed V of the coil, the difference between V2 and V1 being proportional to the difference between the breaths A1 and A2. Then, as the traversing stroke is extended, the traversing speed is again reduced to the basic peripheral speed. When the next breathing cycle is carried out, the traversing speed is increased again, to an increased value V3. The difference V3 - V1 is in turn proportional to the total shortening of the breathing stroke A _max - A3. By appropriately specifying the initial value and basic value of the peripheral speed of the bobbin V1 and the increased values V2 and V3, which can be determined by calculation and experiment, complete thread tension compensation can be brought about, so that the thread tension to which the thread is subjected on the bobbin is neither during the winding cycle still fluctuates during a series of breathing cycles even during one breathing cycle.

Claims (10)

1. A method of winding a yarn into a cross-bobbin by laying the yam to and fro (traversing) during reversal of the motion of the yam guide in the reversing ranges of the traversing stroke with predetermined final retardation and final acceleration as well as with "breathing" of the traversing stroke, according to a wavy timing diagram with wave throughs following a course like a parabola ("breathing" curve), where the breathing curve has its peak at the outer endpoint of the traversing stroke and reverses at the innermost endpoint of the traversing stroke with heavy retardation and acceleration, characterized in that the breathing is effected in such a way that at least in the reversing range (Ba) of the longest traversing stroke the amount of yarn wound up is distributed essentially uniformly into a cylindrical winding, the cylindrical winding having a slightly larger diameter than the middle region of the bobbin, and that the breathing curve extends in the axial direction at least over the reversing range (Ba) of the longest traversing in the case of the traversing stroke.

2. A method as in Claim 1, characterized in that the breathing stroke Amax of successive breathing curves remains the same.

3. A method as in Claim 1, characterized in that in one series of successive breathing cycles the breathing stroke of one (second) breathing cycle is shortened as compared with breathing stroke of the preceding (first) breathing cycle and that the timing diagram of the first breathing cycle is laid out in such a way that (in accordance with Claim 1) in its breathing stroke (Amax = A1) the amount of yam wound up is distributed essentially uniformly into a cylindrical winding, and that in addition in the excess part (D1) of the first breathing stroke, by which the breathing stroke (A1) of the first breathing cycle exceeds the breathing stroke (A2) of the succeeding second breathing cycle (D1 = A1 - A2), an additional amount of yam becomes laid down in a thickness of layer which corresponds essentially with the thickness of layer in all the succeeding breathing cylces of shortened breathing stroke.

4. A method as in Claim 3, characterized in that in one series of breathing cycles the breathing stroke (A1, A2, A3 ...) of the successive breathing cycles is steadily shortened and at the start of the new series is lengthened again to the original value (A1 = Amax) of the breathing stroke.

5. A method as in one of the Claims 3 or 4, characterized in that the "mirror interference" is effected in synchronism with the breathing cycles with a view to equalizing the yam tension, in doing which the mirror interference amplitude (C1, C2, C3 ...) which is the difference (DHO - DHU) between the maximum and minimum speed of traverse, decreases during one series of breathing cycles in dependence upon the breathing stroke (A1, A2, A3 ...) as it becomes shorter.

6. A method as in Claim 5, characterized in that the mirror interference is effected in such a way that the minimum speed of traverse (DHU) in the course of the bobbin travel proceeds according to a law predetermined for the bobbin travel (e.g., it remains constant) and that during each series of breathing cycles the speed of traverse is increased in synchronism with the arrival of the breathing stroke at a maximum value (A1, A2, A3 ...) at the time.

7. A method as in one of the Claims 1 to 6, characterized in that the duration of one breathing cycle and of the mirror interference cycle synchronous with it as well as the smallest value of the maximum speed of traverse (DH04) within one series of breathing strokes are predetermined to be of such values that the alteration of the bobbin ratio (spindle r.p.m/speed of traverse) which during one double stroke is caused by the alteration in the speed of traverse, leads a spacing of two successive turns of yarn which is wider than the width of lay of the yarn on the bobbin.

8. A method as in one of the preceding Claims, characterized in that for compensation of yarn tension the circumferential speed of the bobbin is increased in synchronism with the breathing cycles in such a way that the longest breathing stroke is in synchronism with the highest circumferential speed of the bobbin.

9. A method as in Claim 3 or 4, characterized in that the mirror interference is effected in synchronism with the breathing cycles with a view to equalizing the yarn tension, in doing which the mirror interference amplitude (C1) which is the difference (DHO - DHU) between the maximum and minimum speeds of traverse remains constant, and that the circumferential speed of the bobbin during all the breathing cycles of reduced breathing stroke is altered in dependence upon the size of the reduction in the breathing stroke in such a way that the yarn tension remains essentially constant.

10. A method as in one of the preceding Claims, characterized in that for compensation of yarn tension the circumferential speed of the bobbin is increased in synchronism with the decreasing traversing stroke.

Images