GB1569160A

GB1569160A - Method and apparatus for winding a flexible filament or a thread or yarn onto a bobbin

Info

Publication number: GB1569160A
Application number: GB5085676A
Authority: GB
Original assignee: Institute Po Obleklo I Textil
Current assignee: Institute Po Obleklo I Textil
Priority date: 1975-12-05
Filing date: 1976-12-06
Publication date: 1980-06-11
Also published as: DE2654944A1; BG23472A1; FR2333741B1; BE849026A; DD127749A1; JPS5277241A; CH619423A5; IT1073585B; CS200322B1; FR2333741A1

Abstract

In the process, the thread guide (6) moving to and fro in a basic linear movement is additionally given a linear reciprocal fine movement with an amplitude of 3 to 30 mm and a frequency of 60 sec.<-1>. For this purpose, a thread guide (6) is provided in the apparatus which has an eccentric (2) and a spindle (3) with small slides (5). The thread guide (6) is fastened to the small slide (5) via a device which imparts the second linear to-and-fro movement to the thread guide (6). In the end position of the small slide (5), the thread guide (6) continues the linear fine movement, so that the thread is wound on the surface of the yarn body so as to be distributed over a length equal to the basic linear movement. <IMAGE>

Description

(54) METHOD AND APPARATUS FOR WINDING A FLEXIBLE FILAMENT OR A THREAD OR YARN ONTO A BOBBIN (71) We, INsrlTuTE Po OBLEKLO I TBXTIL, of 48, Voyvodina Mogila Street, Sofia, Bulgaria, a State Research Institute organised under the Laws of Bulgaria, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a method and an apparatus for winding a flexible filament or a thread or yarn onto a bobbin, and to the windings thus obtained.

A method for winding thread over cylindrical and conical bobbins is known, in which the bobbins or yarn bodies are driven at a high linear velocity of the order of 600 to 1200 mlmin., and which avoids the piling up of threads in one and the same spiral or trajectory on the surface of the yarn body, i.e. avoids the so-called bunch windings, and there is achieved a sufficient density of the yarn winding with a good smooth surface of the individual layers, each one of them being disposed parallel to the generatrix of the bobbin. This is achieved by superimposing a slow, wavelike characteristic upon the velocity of the reciprocating motion of the thread conductor, and this oscillation of the velocity around a preset magnitude does not decrease to zero. This results in the extent of the winding layers shifting along the bobbin and back again during winding.

This wave-like character of the velocity of the thread conductor is obtained by varying the reciprocation frequency as a function of the duration of an electric pulse, as the sum of a basic oscillation and a reduced oscillation, which is effected by an electric motor for reciprocating motion. The limits in which the periods for reduced and basic oscillation vary are from 05 to 50 seconds and from 0 25 to 2 00 minutes, respectively.

When the linear velocity of winding is increased, it is necessary, in order still to avoid the formation of bundle windings, to reduce the periods of oscillation required by this method. This reduction is limited by the inertia of the moving masses, and results in a progressive reduction of the desired effect, i.e. the avoidance of bunch windings, as the linear velocity of winding increases.

It is further known that when winding threads over conical bobbins, in which the individual winding layers are disposed totally one over the other and inclined with respect to the axis of rotation of the bobbin, usually piled-up windings occur at both ends of the conical surface. In these end positions the velocity of the thread conductor element, being set in motion by an eccentric member, must pass from a positive to a negative magnitude, which values are equal one to another in absolute value.

This change cannot take place without the velocity momentarily passing to zero, i.e.

through the dead point of the thread conductor. These dead points in the motion of the thread conductor lead to a piling-up of the thread in the end portions of the cone, thus creating a danger of disintegration and entanglement of the individual windings.

When the velocity of winding is inceased, there is also an increase in the velocity of the eccentric mechanism. This means that this defect will be more strongly expressed because of the increased amount of thread involved as the velocity changes from a positive to a negative value at the end positions of the thread conductor, and hence a relatively greater time interval for this change.

The increase of the velocity of winding by the known methods is also limited from a design aspect, since there are produced considerable inertia forces in the individual links of the eccentric mechanism for producing reciprocating motion of the thread conductor.

As a result of the use of the hitherto known methods there is obtained a yarn package in which each winding layer is dis posed totally over the preceding layer. In such a yarn pack, the windings of the last layer are not fixed over the full length of the bobbin. This creates conditions suitable for their dislocation and for uncovering the windings of lower layers. At high velocities of unwinding such yarn packages, there is observed a chaotic pulling down of the yarn material.

It is therefore a general object of the present invention to provide a stable yarn package at high velocities of winding, regardless of the disposition of the individual winding layers with respect to the generatrix of the bobbin.

According to one aspect of the present invention there is provided a method of winding a flexible filament or a thread or yarn onto a bobbin, in which the bobbin is rotated about an axis while the filament is fed to the bobbin transversely of the axis from a device which moves along a line parallel to the axis, wherein the device is subjected to three superimposed motions, (i) a translational motion from one end of the bobbin towards the other, (ii) a primary reciprocating motion parallel to the axis and having an amplitude less than the length of the bobbin, and (iii) a secondary reciprocating motion parallel to the axis, the frequency of the secondary reciprocating motion being higher than that of the primary reciprocating motion and the amplitude of the secondary reciprocating motion being less than that of the primary reciprocating motion.

According to a second aspect of the invention there is provided an apparatus for winding a flexible filament or a thread or yarn onto a bobbin, which apparatus comprises: a means for supporting a bobbin for rotation about an axis; a shaft; means for imparting a primary reciprocating motion to the shaft, the primary reciprocating motion being parallel to the axis and having an amplitude less than the length of the bobbin: a support mounted on the shaft; means for imparting a translational motion to the support for moving the support along the shaft from one end of the bobbin towards the other; a thread conductor mounted on the su port for feeding the filament to the- bobbin transversely of the axis; and means for imparting a secondary reciprocating motion to the thread conductor, the secondary reciprocating motion being parallel to the axis, having a frequency higher than that of the primary reciprocating motion, and having an amplitude less than that of the primary reciprocating motion.

Advantageously, the frequency of the secondary reciprocating motion is from 4 to 50, and preferably from 15 to 40 times that of the primary reciprocating motion.

The amplitude of the primary reciprocating motion is advantageously from 2 to 10 times, preferably 3 to 8 times, that of the secondary reciprocating motion. The frequency and the amplitude ratios between the primary and secondary reciprocating motions need not be whole numbers.

The translational motion may be a continuous or intermittent motion. This results in the primary reciprocating motion gradually shifting along the axis of the bobbin as winding is taking place.

The amplitude of the secondary reciprocating motion advantageously is from 3 to 30 mm, depending on the yarn packages and the velocity at which they are to be unwound. The frequency of the secondary reciprocating motion may be up to 60 sec.~l The apparatus of the present invention may comprise an eccentric device for achieving the primary reciprocating motion, and an endless crew with the support or carriage mounted thereon.

The yarn packages obtained by the application of this method and apparatus comprise periodically repeating basic layers, in which each basic layer is built up of overlapping microlayers. One advantage of the method of the present invention lies in that at the end, dead positions of the support, the thread holder continues to perform its secondary linear micro-reciprocating motion, thus distributing the thread over the surface of the bobbin at a length equal to the range of the motion. With a winding the basic layers of which are composed of overlapping microlayers, the length of the unfixed windings is equal to the lengths of the windings of the last portion of the microlayer.

Because of the increase of the velocity of the transverse motion of the thread as the sum of the primary and secondary linear reciprocating motions, there is achieved a considerable increase in the linear velocity of winding. The linear velocity of winding is the vector sum of the velocity of the transverse motion of the thread conductor and the linear peripheral velocity of the bobbin.

Yarn packages produced by the method of this invention have a stable structure permitting a regular performance of the succeeding technological operations.

For a better understanding of the invention and to shown how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which there is illu strated a preferred embodiment of the in invention. In the drawings: Fig. 1 is a diagrammatic illustration of the method in accordance with the inven tion; Fig. 2 shows the resulting linear recipro cating motion of the thread with respect to the rotating bobbin; Fig. 3 shows the position of the basic layers of the winding on a conical bobbin, which c,orrespend to a full cycle of the linear translational motion of the thread; Fig. 4 and Fig. 5 show the disposition of the microlayers forming each of the basic layers, respectively at different ratios be t've:en the frequencies of the primary and the secondary reciprocating motions; Fig. 6 and Fig. 7 show a microlayer cor responding to one full cycle of secondary micro-reciprocating motion of the thread conductor, in accordance with Figures 4 and 5 respectively, when the thread sup port is moving forward (from left to right); and Fig. 8 and Fig. 9 show a microlayer cor responding to one full cycle of the secon dary reciprocating motion of the thread conductor, in accordance with Figures 4 and 5 respectively, when the thread support is moving backwards (from right to left).

Referring to the drawings, the apparatus illustrated comprises a main shaft 3 having a screw threaded portion 4 on which is mounted a carriage 5. The carriage 5 co moderates with the thread on the shaft. The sfiaft 3 is supported close to one end there- of remote from the threaded portion 4 by anti-friction bearings 1. The main shaft is reciprocable along its axis, the drive there for consisting of a cam mechanism indica ted generally at 2. Means (not shown) are also provided for rotating the shaft 3 about its axis in either direction. The carriage 5 is mounted in a manner so as to prevent its rotation about the axis of the shaft; hence rotation of the shaft causes axial movement of the carriage along the threaded portion 4 of the shaft.

A support 19 is mounted on the carriage 5 and in turn a device 20 is mounted for secondary reciprocating motion parallel to the axis of the shaft 3. Means (not shown), for example an electric motor with a suit able drive mechanism, is provided so that, in use the device 20 can be made to recip rotate and thus to displace a thread con doctor 6 with relatively high frequency parallel to the axis of the shaft 3.

In Figure 1, the limits of reciprocating movement of the carriage 5 with the shaft 3 and of the thread conductor 6 mounted on the device 20 on the support 19, respec lively, are indicated by the positions A and B on the one hand, and C and D on the other. The positions A, and B1 indicate the limits of primary reciprocating movement of the carriage 5 along the shaft 3 after rotation of the shaft about its axis, thus causing the carriage to shift to the right, as shown.

A conical shuttle 21 is mounted so as to be rotatable about an axis 22 which is parallel to the shaft 3. A flexible filament or thread 7, e.g. yarn, is fed to the shuttle 21 via a compensating conductor 8 and the thread conductor 6.

In operation, the end of a filament of yarn is passed through the compensating conductor 8 and the thread conductor 6 to one end of the shuttle 21 (the left-hand end as shown in Figure 1) and engages therein. At this stage, the carriage 5 is situated at its leftwards limiting position A as shown in Figure 1, and the device 20 is likewise situated with the thread conductor 6 at the Ieftwards limit of its movement (position C). The winding operation then commences, a rotation of the shuttle 21 about its axis 22 being initiated synchronously with reciprocation of the shaft 3 and of the thread conductor 6 on the device 20.

The shaft 3 is also rotated slowly, so as to cause gradual movement to the right of the carriage 5; this rotation, however, need not be continuous, nor is it essential (although it is preferred) that it should commence synchronously with rotation of the shuttle.

The relationships between rates of reciprocation of the carriage 5 and the thread conductor 6 on the device 20 and rates of rotation of the shuttle 21 and the shaft 3 affect the type of winding which is obtained and are chosen according to the type of material being wound and the rate of winding.

The frequency of reciprocation of the thread conductor 6 on the device 20 is always greater than that of the carriage 5 on the shaft 3. Further, the amplitude of reciprocation of the carriage 5 on the shaft 3 is always greater than that of the thread conductor 6 on the device 20. When the two reciprocating motions and the translational motion are all at their extreme right-hand positions, i.e. the thread is being supplied to the extreme right-hand end of the shuttle, the winding is stopped. The carriage 5 may then be returned to its initial position by reversing the direction of rotation of the shaft 3.

The characteristic feature of the method of the invention, i.e. the application of a secondary, relatively high frequency, low amplitude reciprocation to the primary reciprocating movement to which the filament or thread is subject, results in a zigzag arrangement of material on the surface of the shuttle. This can be seen from Figure 2, wherein the position at which the filament or thread contacts the surface of the shuttle is plotted along the y-axis against time along the x-axis. The position of the thread is shown in solid line; this is superimposed on a dashed line which represents the position that the thread would occupy in the absence of the secondary reciprocating motion. The rotation of the shaft 3 gives rise to the tertiary translational motion in the system, evident from Figure 2 by the progressive movement of the plot away from the origin to higher values on the y-axis. The primary reciprocating motion can be considered to give rise to the dashed line A-B-Al-Bl and the tertiary translational motion can be considered as the cause of the gradual shift along the y-axis of the points A-A1, B-Bl etc. The secondary reciprocating motion results in the actual path of the filament or thread following the solid lines C--D1, D,-CI etc.

The preferred relationship between the various frequencies and amplitude is such that the resulting layers of material wound onto the shuttle overlap the layers below.

When the carriage 5 is moving forward from point A to point B and then back towards A, corresponding to one basic layer, the thread conductor 6 performs repeated displacements along paths Cud1, D,C, and D'C', C'D,', respectively (see Figure 2).

When the direction of the secondarv reciprocating motion with amplitude CD coincides in direction with the primary linear reciprocating motion with amplitude AB or BA, respectively, then the thread 7 is displaced along paths such that CDt > CD or D'C > CD, respectively. When both motions do not coincide in direction, then the thread is displaced along paths such that DlC, < CD or C'D'l < CD, respectively (compare Figures 1 and 2).

An essential conditoin is that the frequency of the secondary micro-reciprocating motion should be always higher than that of the primary one; this makes it possible to obtain the overlapping of the individual microlayers corresponding to one full microcycle CD, C1 or D'C'D'1, respectively. The frequency of this secondary motion in this embodiment is substantially 60 sex.~' The secondary reciprocating motion gives rise to a travel C-D in the range of from 3 to 30 mm, being always smaller than the amplitude of the primary reciprocating motion.

The yarn winding is built-up of basic layers 10 (see Figure 3), formed as the result of a full cycle of the primary reciprocating motion of shaft 3, which are periodically displaced forward towards the end of the end of the bobbin by means of rotating screw 3 at a determined degree, thus determining the shape of the windings themselves.

When carriage 5 and shaft 3 are moving forward, there is formed portion 11 of the basic layer 10, designated also by AA'BB'.

When carriage 5 and shaft 3 are moving backwards, there is formed the portion 12 of layer 10, designated by B'B"AlA'l.

Each basic layer 10 is built-up by microlayers 13 and 16. Microlayers 13 of portion 11 of the basic layer 10 comprises portion 14, designated by CD1, when the directions of the primary and the secondary reciprocating motions coincide; and portion 15, designated by DlCl, when they do not coincide (see Figures 2, 4, 5, 6 and 7).

Microlayer 16 of portion 12 of the basic layer 10 comprises portion 17, designated by D'C', when the directions of the primary and secondary reciprocating motions coincide; and portion 18, designated by C'D'1 when they do not coincide (see Figures 2, 8 and 9).

Figure 4 and 5 are radial sections through windings on a cylindrical shuttle, and illustrate two different winding geometries resulting from different ratios of frequency between the primary and secondary recipe rocating motions. In Figure 4, the ratio is about 1:17, while in Figure 5 it is about 1:37. In this case, the winding is not stopped when the thread is being supplied to the extreme right-hand end of the shuttle because the winding is not necessarily complete.

WHAT WE CLAIM IS:- 1. A method of winding a flexible filament or a thread or yarn onto a bobbin, in which the bobbin is rotated about an axis while the filament is fed to the bobbin transversely of the axis from a device which moves along a line parallel to the axis, wherein the device is subjected to three superimposed motions, (i) a translational motion from one end of the bobbin towards the other, (ii) a primary reciprocating motion parallel to the axis and having an amplitude less than the length of the bobbin, and (iii) a secondary reciprocating motion parallel to the axis, the frequency of the secondary reciprocating motion being higher than that of the primary reciprocating motion and the amplitude of the secondary reciprocating motion being less than that of the primary reciprocating motion.

2. A method according to claim 1, wherein the frequency of the secondary reciprocating motion is from 4 to 50 times that of the primary reciprocating motion.

3. A method according to claim 1 or 2, wherein the ratio of the amplitude of the primary reciprocating motion to that of the secondary reciprocating motion is from 2: 1 to 10:1.

4. A method according to claim 1, 2 or 3, wherein the frequency of the secondary reciprocating motion is up to 60sec.

5. A method according to any preceding

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. time along the x-axis. The position of the thread is shown in solid line; this is superimposed on a dashed line which represents the position that the thread would occupy in the absence of the secondary reciprocating motion. The rotation of the shaft 3 gives rise to the tertiary translational motion in the system, evident from Figure 2 by the progressive movement of the plot away from the origin to higher values on the y-axis. The primary reciprocating motion can be considered to give rise to the dashed line A-B-Al-Bl and the tertiary translational motion can be considered as the cause of the gradual shift along the y-axis of the points A-A1, B-Bl etc. The secondary reciprocating motion results in the actual path of the filament or thread following the solid lines C--D1, D,-CI etc. The preferred relationship between the various frequencies and amplitude is such that the resulting layers of material wound onto the shuttle overlap the layers below. When the carriage 5 is moving forward from point A to point B and then back towards A, corresponding to one basic layer, the thread conductor 6 performs repeated displacements along paths Cud1, D,C, and D'C', C'D,', respectively (see Figure 2). When the direction of the secondarv reciprocating motion with amplitude CD coincides in direction with the primary linear reciprocating motion with amplitude AB or BA, respectively, then the thread 7 is displaced along paths such that CDt > CD or D'C > CD, respectively. When both motions do not coincide in direction, then the thread is displaced along paths such that DlC, < CD or C'D'l < CD, respectively (compare Figures 1 and 2). An essential conditoin is that the frequency of the secondary micro-reciprocating motion should be always higher than that of the primary one; this makes it possible to obtain the overlapping of the individual microlayers corresponding to one full microcycle CD, C1 or D'C'D'1, respectively. The frequency of this secondary motion in this embodiment is substantially 60 sex.~' The secondary reciprocating motion gives rise to a travel C-D in the range of from 3 to 30 mm, being always smaller than the amplitude of the primary reciprocating motion. The yarn winding is built-up of basic layers 10 (see Figure 3), formed as the result of a full cycle of the primary reciprocating motion of shaft 3, which are periodically displaced forward towards the end of the end of the bobbin by means of rotating screw 3 at a determined degree, thus determining the shape of the windings themselves. When carriage 5 and shaft 3 are moving forward, there is formed portion 11 of the basic layer 10, designated also by AA'BB'. When carriage 5 and shaft 3 are moving backwards, there is formed the portion 12 of layer 10, designated by B'B"AlA'l. Each basic layer 10 is built-up by microlayers 13 and 16. Microlayers 13 of portion 11 of the basic layer 10 comprises portion 14, designated by CD1, when the directions of the primary and the secondary reciprocating motions coincide; and portion 15, designated by DlCl, when they do not coincide (see Figures 2, 4, 5, 6 and 7). Microlayer 16 of portion 12 of the basic layer 10 comprises portion 17, designated by D'C', when the directions of the primary and secondary reciprocating motions coincide; and portion 18, designated by C'D'1 when they do not coincide (see Figures 2, 8 and 9). Figure 4 and 5 are radial sections through windings on a cylindrical shuttle, and illustrate two different winding geometries resulting from different ratios of frequency between the primary and secondary recipe rocating motions. In Figure 4, the ratio is about 1:17, while in Figure 5 it is about 1:37. In this case, the winding is not stopped when the thread is being supplied to the extreme right-hand end of the shuttle because the winding is not necessarily complete. WHAT WE CLAIM IS:-

1. A method of winding a flexible filament or a thread or yarn onto a bobbin, in which the bobbin is rotated about an axis while the filament is fed to the bobbin transversely of the axis from a device which moves along a line parallel to the axis, wherein the device is subjected to three superimposed motions, (i) a translational motion from one end of the bobbin towards the other, (ii) a primary reciprocating motion parallel to the axis and having an amplitude less than the length of the bobbin, and (iii) a secondary reciprocating motion parallel to the axis, the frequency of the secondary reciprocating motion being higher than that of the primary reciprocating motion and the amplitude of the secondary reciprocating motion being less than that of the primary reciprocating motion.

5. A method according to any preceding

claim, wherein the amplitude of the secondary reciprocating motion is from 3 to 30 mm.

6. A method according to any preceding claim, wherein the translational motion of the device is not continuous.

7. A method of winding a flexible filament or a thread or yarn onto a bobbin substantially as hereinbefore described with reference to the accompanying drawings.

8. An apparatus for winding a flexible filament or a thread or yarn onto a bobbin which apparatus comprises: a means for supporting a bobbin for rotation about an axis; a shaft; means for imparting a primary reciprocating motion to the shaft, the primary reciprocating motion being parallel to the axis and having an amplitude less than the length of the bobbin; a support mounted on the shaft; means for imparting a translational motion to the support for moving the support along the shaft from one end of the bobbin towards the other; a thread conductor mounted on the support for feeding the filament to the bobbin transversely of the axis; and means for imparting a secondary reciprocating motion to the thread conductor, the secondary reciprocating motion being parallel to the axis, having a frequency higher than that of the primary reciprocating motion, and having an amplitude less than that of the primary reciprocating motion.

9. An apparatus as claimed in claim 8, wherein the shaft is provided with a screw thread which co-operates with the support.

10. An apparatus substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

11. A bobbin having a flexible filament or a thread or yarn wound thereon by a method or in an apparatus as claimed in any preceding claim.