EP0396902B1 - Unreeling method and dispenser for yarn as application for this method - Google Patents

Description

The invention relates to a method and a device according to the preamble of claims 1 and 6.

The invention relates to yarns with a tape character, the yarn being drawn off from a disc bobbin and fed to the weaving machine via a thread brake.

Such ribbon-like yarns are e.g. known in the form of unreinforced lurex yarns, these lurex yarns having approximately foil tape character, i.e. in cross section a rectangular profile.

Such ribbon-like yarns are referred to below as foil strips.

The processing of such foil tapes on defenseless weaving machines presents considerable difficulties in practice, which result in greatly reduced numbers of turns, increased thread breaks and have a quality-reducing effect.

Particular difficulties arise in the processing of unreinforced Lurex yarns because such Lurex yarns are drawn off overhead, ie over the flange, of disc spools.
Conventionally, the disc spool is here and the film strip is pulled off over the flange of the disc spool in such a way that with increasing removal of this film strip there is a twist in the film strip, which leads to a loop formation when the film strip is unloaded and not under tension.

These twists or twists then build up as the take-off increases until a loop is inevitably formed even when the film strip is under tension, which is then caught behind the disc spool in the first thread brake and either triggers stretching, which leads to a permanent change in the cross-sectional profile of the film strip leads to a fabric defect, or the loop in the thread brake leads to the film strip breaking, which is connected with a standstill of the downstream weaving machine.

This results in increased downtimes of the weaving machine, and these downtimes lead to fabric defects in fabrics with a high or only Lurex weft component, which are apparent in the form of locations in the fabric and thus have a high impact on the quality of the goods lost. The second choice share (less goods) is particularly high for Lurex fabrics with a high weft share and can only be achieved by a better running of the weaving machine, i.e. fewer downtimes to be dealt with.

Due to the fact that Lurex yarns have a high degree of elasticity, any slight curl that occurs with the cylindrical disc spools causes stretching especially when the film strip layers run directly on the disc. This stretching can be seen in the fabric in the form of a thin spot or in a color difference of the lurex yarn.

However, the above-mentioned stretching also occurs when a loop is temporarily caught in the brake. Due to the fact that the lurex thread is a ribbon, when the bobbin is pulled off the head, there are rotations that accumulate at the first point of contact of the infeed brake and thus trigger curl, i.e. the smaller the supply of foil tape on the bobbin, the more layers are pulled off and the more the film strip is twisted.

The formation of loops and the mentioned hangings on the bobbin and the risk of weft breakage therefore increase when the bobbin runs off and have a direct effect on the production and the quality of the goods.

For fabrics with a high lurex content it is also the case that twists of the weft yarn which result from the overhead take-off of the disc spool give a poorer product appearance, because the twist points in the fabric become visible. It is therefore the wish of all users that Lurex yarns should be entered with as little twist as possible.

Devices that pull the Lurex bobbin on a roll are not well received on the market and cannot be used for high-speed weaving machines, since the acceleration and braking of the bobbin and the synchronization with the pre-winding device cannot be mastered.

It was previously known to pull foil tapes of the generic type perpendicular to the longitudinal axis of the spool. However, there are synchronization problems between the drive for the spool and the take-off, as well as for the compensation compensation, which carries out a fine regulation of the drawn-off film strip.

US-A-2,673,576 discloses a method of the type mentioned at the outset, in which so-called kinks in a textile yarn are to be avoided when being pulled off a cone bobbin. It was recognized there that the formation of kinks is caused by uneven tensile stresses when starting and braking the take-off spool, and therefore the tension on the yarn when pulling off the cone spool should be made as uniform as possible. For this purpose, it is proposed to form a balloon between the cone bobbin and a thread guide, in order to avoid loop formation in the yarn under tension. However, there is no provision for the thread take-off point to be approximately stationary in space relative to the center of rotation remains to avoid loop formation in the yarn and the resulting stretching.

With US-A-3,806,054 a further device has become known in which a rectangular tape for packaging packages and the like is to be pulled off a stock as free of twists as possible.
The resulting twists should only be reduced, but not eliminated. For this purpose, it is provided that a spiral loop is formed between the take-off point of the band moving around the supply and a sensor lying outside and above the supply. The rectangular profiled packaging tape must have such a stiffness that the tape can be passed through a guide opening adapted to the tape profile and that the twists in the tape twist the guide opening in connection with a disc in such a way that, depending on this rotation, the motor drive supplies the supply regulates a reduction or an increase in speed. A prerequisite for this known method is that the belt is very stiff in order to be able to transmit torsional forces resulting from twisting to the sensor disk as rotary movements. A further prerequisite is that a spiral loop is formed between the sensor and the unwinding spool, which requires a thread take-off point shifting on the circumference of the supply.

With such a device, not highly flexible film tapes, in particular with a rectangular cross-section, can be processed in the manner of lurex yarns because, on the one hand, the formation of loops in the area between the winding spool and the sensor would damage the sensitive tape material and, on the other hand, the restoring forces generated by twisting in the fine strip material would not be sufficient to forcibly twist a sensor disk.

With DE-A-34 32 097 a further device has become known with which torsional stresses in wires are to be avoided when withdrawing overhead from a corresponding supply spool. Such a device is also not suitable for processing highly sensitive film strips, in particular lurex yarn, because it is not sufficient to eliminate torsional stresses with such a film strip. In addition, there must be no stretching in the material that leads to visible markings in the fabric of lurex yarns. However, the device according to DE-A-34 32 097 is not aimed at avoiding such stretching because only round-profiled metal wire is to be drawn off.

The present invention is therefore based on the object of developing a thread delivery method and an unwinding device of the type mentioned in such a way that any twisting and associated loops and stretching are reliably avoided when the film strip is pulled off an overhead spool.

To achieve the object, the invention provides the features of the characterizing part of patent claims 1 and 6.

A significant advantage is achieved with the given technical teaching, because the twisting of the film strip which was previously perceived as disturbing is now avoided with certainty according to the present technical teaching.

The prerequisite for this is that the rotary drive for the disk spool drives the disk spool essentially at the same speed as the winding of the film strip is unwound on this disk spool.

Ideally, the film strip with zero rotations is always from a constant location on the disc spool, for example the vertically uppermost point or any other point, without this point moving around the disc coil.

If, for example, the film strip is unwound from the disk spool in a clockwise direction, then it is provided according to the invention that the disk spool is driven in the counterclockwise direction by the associated rotary drive.

In order to achieve such a synchronicity between the speed of the unwinding and the speed of the oppositely driven disc coil, there are several different embodiments:
A first embodiment is characterized in that the disc coil itself and the winding mounted thereon are scanned without contact.

This scanning is communicated to the rotary drive via a microprocessor control, so that it is ensured that the speed of the rotary drive for the disc spool always follows the increasing speed when the film strip is pulled off the disc spool due to the decreasing diameter of the winding.

Another problem which is solved by the invention is that the film tape is not only pulled off the disk spool without twist but also that additional stretching of the film tape is avoided when it is pulled off the disk spool.

For this purpose, it is provided according to the invention that a first brake is arranged in the tape direction behind the disc reel, which is rotatably driven in synchronism with the prewinding device, specifically in the direction of rotation which counteracts the twist direction of the film strip.

In particular when using disk spools with a relatively large weight or with disk spools with a certain imbalance that do not allow high speeds, it is provided to change the speed of the disk spool in this way via a signal directed to the electrical control, depending on the speed of the thread brake that the speed of the disc coil can be reduced by the amount of the brake speed.

It is also provided that a brake is arranged on the inlet side of the pre-winding device, which is driven in rotation, specifically in the direction of rotation which counteracts the twist direction of the film strip.

It is therefore essential that this brake is driven in the opposite direction - but synchronously - with the rotating part of the pre-winding device in order to compensate for the swirl that occurs in the pre-winding device.

It is also important to take additional measures that achieve a favorable release of the foil tape on the winding of the disc spool. These measures, which release the film strip, also achieve a favorable removal of the film strip from the disc reel without causing stretching.

For this purpose, it is provided according to the invention that the flange lying on the takeoff side of the disk coil is made enlarged.

This ensures that the film strip is not pulled off at an acute angle (e.g. 2 - 5 °) in the direction of the longitudinal axis of the entire arrangement, but by arranging a disk of enlarged diameter, the film strip is pulled at an enlarged angle of e.g. Subtracted 40 to 60 ° in the direction of the longitudinal axis from the winding of the disk coil, as a result of which the mutually adjacent windings are released from one another when they are pulled off.

Because of this larger withdrawal angle of the film bandess from the Winding also creates a centrifugal force on the film strip when the disc reel rotates, which forces and pulls the film strip radially away from the winding, and this also has the effect of releasing the film strip.

The film strip can therefore be easily removed from the winding without the windings becoming attached to one another, which leads to breaks or stretching of the film strip.

It remains open whether the enlarged diameter disk, which is arranged on one flange side of the disk coil, is designed to be rotating or stationary. Both possibilities are covered by the present invention.

Further advantageous refinements emerge from the subclaims.

The invention will now be described in more detail using exemplary embodiments.

Figur 1:

schematisiert in Seitenansicht eine erste Ausführungsform der Erfindung mit zusätzlichen, nicht-obligatorischen Merkmalen Meßstelle), während

Figur 2:

schematisiert das Abziehen des Folienbandes von der Scheibenspule darstellt;

Figur 3:

in schematischer Darstellung die Abtastung einer drehend angetriebenen Vorratsspule mit einem Abtaster an einem Tasthebel;

Figur 4:

in schematischer Darstellung die Anordnung eines frontalen Abtasters bei berührungsloser Abtastung in Verbindung mit einer Nachsteuerung des Motors;

Figur 5:

die Abtastung mittels zweiter Tastarme, welche die Drehbewegung der Vorratsspule erfassen;

Figur 5a:

die Nachführung der Tastarme nach Figur 5 im Detail;

Figur 6:

die Abtastung der Drehrichtung einer Vorratsspule mittels Tasthebeln, die in Verbindung mit einer Lagerung nach Art eines zweiarmigen Hebels auf Abtaster A und B einwirken.

Show it:

Figure 1:

schematically in side view a first embodiment of the invention with additional, non-mandatory features measuring point), while

Figure 2:

schematically represents the removal of the film strip from the disc reel;

Figure 3:

in a schematic representation, the scanning of a rotatingly driven supply spool with a scanner on a probe lever;

Figure 4:

a schematic representation of the arrangement of a frontal scanner with non-contact scanning in connection with readjustment of the motor;

Figure 5:

scanning by means of two probe arms, which detect the rotary movement of the supply spool;

Figure 5a:

the tracking of the probe arms according to Figure 5 in detail;

Figure 6:

the sensing of the direction of rotation of a supply spool by means of feeler levers which act on scanner A and B in connection with a bearing in the manner of a two-armed lever.

In FIG. 1, a disc reel 1 is wound with a foil strip 2, which forms a winding 4 on the bobbin 36 of the disc reel.

The disc coil 1 is laterally surrounded by flanges 3.

According to the invention, the disc coil 1 is driven in rotation by a motor 9, which is arranged on a machine base 8, which in turn is mounted on a support 7 such that it can be displaced in the direction of the arrows 20, 21.

The motor 9 is provided with a control 33, which cooperates with a scanner 31, which has a measuring head 32 at its front, lower end, which scans the winding 4 of the disk coil 1 without contact.

According to FIG. 2, the film strip 2 is now pulled off the disc reel 1 in the winding direction (arrow direction 6). According to the invention, the disc coil 1 is therefore driven in the opposite direction to the arrow direction 6 shown, namely in the arrow direction 5.

As a result, twists and twists of the drawn-off film strip 2 are avoided with certainty, since every turn due to the pulled-off winding is compensated for by an equal, opposite rotation of the disc reel 1.

In order to improve the film strip detaching effect and to avoid stretching of the film strip 2 when pulling off, according to the invention, a disk 37 of enlarged diameter is connected to the disk spool 1 on one flange side, namely on the take-off side.

It was already mentioned before that the disc 37 can also be rotatably mounted on the axis of the disc coil 1.

From the illustration in Figure 1 it is clear that previously - without using a washer 37 - a relatively flat take-off angle had been achieved, which leads to the partially interlocking windings leading to catches of the film band to be pulled off and thread occlusions and weft breaks thereby occurring.

According to the invention, the pull-off angle 38 is now substantially increased by the disk 37, so that the film strip 2 is pulled off the winding 4 at a steeper angle in comparison to the longitudinal direction 34, and the advantageous effect described above occurs as a result.

The disc 37 also achieves an increase in the centrifugal force on the removed film strip, so that the described film strip dissolving effect is thereby further enhanced.

In particular, the disk 37 prevents the film strip 2 from jamming in the vicinity of the two flanges 3.

The film strip 2 is now pulled off in the direction of the longitudinal axis 34 at an oblique angle to this in accordance with FIG. 1 and passes through an inlet eyelet 19 into a rotatably driven brake 16, which is arranged upstream of a pre-winding device 22.

The brake 16 is only necessary and provided according to the invention if a pre-winding device 22 is used.

Some applications do not require a prewinder 22; Therefore, the brake 16 can then be omitted and only one further brake 28 is used instead.

In the illustrated embodiment, the brakes 16 and 28 are used together, the brake 16 ensuring the winding tension for the prewinder 22, while the brake 28 ensures the tension for the weft insertion of the downstream loom.

In a manner known per se, the pre-winding device 22 consists of a machine body which is mounted on the support 7 via a machine foot 25.

A rotor 23, which interacts with a cylinder 24, is rotatably arranged on the machine body. The film strip is wound onto the cylinder 24.

When working without a pre-winding device, the bobbin motor 9 can also be controlled by the microprocessor of the weaving machine.

FIG. 3 shows a supply reel 40, from which a film strip 47 is unwound in connection with a rotation from a take-off point 44. The supply spool 40 is rotatably driven by a motor 42 which has a control 43 which is connected to a signal generator 45. The speed of rotation of the supply reel 40 is detected by a scanner 46, which can be optical, electrical or electronic.

The scanner is connected to a probe arm 48, which is mounted on an axle under spring preload, the scanner 46 absorbing the rotational speed of the supply reel 40.

It can be seen that, with the scanning according to FIG. 3, the scanning point 44 is tracked via the control 43 when the film strip 47 is pulled off in connection with the rotation by the motor 42 in such a way that the removal point 44 on the outside of the supply reel comes to a standstill in the circumferential direction .

The scanner 46 here, which detects the rotational speed of the supply reel 40, supplies a signal to the signal generator 45, whose output signal is fed into the controller 43, whereby the rotational speed of the motor which rotates the supply reel 40 is slowed down or accelerated, so that overall is achieved that the take-off point 4 stands still when pulling off the film strip 47.

Instead of a probe arm 48 arranged on the inside according to FIG. 3, a probe arm 49 can alternatively also be arranged on the outside, which in the same way detects the rotational speed or the change in diameter of the supply spool 40 and forwards its signal to the controller 43 of the motor 42.

FIG. 4 shows a frontal scanning of the supply spool 40 with a contactless scanner 50, the scanner operating in a sensing area 51 and thereby detecting the change in the diameter of the supply spool 40. It can be seen that when the film strip 47 is removed, the point P moves in the direction of the arrow, this movement being detected by the sensing area 51 of the scanner 50 and the signal 52 being fed to a controller 43 as a result of a faster or slower signal. This control 43 acts on the motor 42, which when the film strip 47 is removed Feeding coil 40 tracks in such a way that point P in sensing area 51 of the scanner comes to a standstill.

In FIG. 5, two scanning arms 55, 56, which are in connection with scanners 53, are used to scan the supply coil 40. As soon as the film strip 47 is pulled off, the scanning arms 55, 56 are moved with the scanners 53 - as is also explained according to FIG. 5a - or the scanning arms move relative to a specific scanning arm area on the scanner 53, so that a faster or slower one Signal for the tracking of the motor is generated.

In Figure 6 is shown in the same schematic representation that there are two probe arms 55, 56, which are designed in the manner of a two-armed lever, these probe arms 55, 56 sweeping over a scanning range of the scanners 57, 58, so that such a positive or negative signal is generated around the motor 42 via the controller 43, for. B. according to Figure 3.

In all cases of scanning, it is only important that the rotational speed of the supply spool or the change in diameter of the supply spool 40 or also the pull-off speed of the film strip 47 or the like is detected in order to thereby generate the signal generated via a signal generator, for example the signal generator 45 according to FIG 3 to readjust the controller 43, whereby the motor 42 is tracked. The tracking via the motor 42 takes place in such a way that when the film strip 47 is pulled off, the spool is rotated in the opposite direction to the unwinding process of the film strip, so that the removal point 44 according to FIG. 3 comes to a standstill on the circumference of the supply spool 40. DRAWING LEGEND 1 Disc spool 31 Scanner 2nd Foil tape 32 Measuring head 3rd flange 33 control 4th Winding 34 Longitudinal direction 5 Arrow direction 35 Arrow direction 6 Arrow direction 36 Bobbin 7 Support 37 disc 8th Machine foot 38 Trigger angle 9 engine 39 Arrow direction 10th control 40 Supply spool 11 control 41 Axis of rotation 12th management 42 engine 13 management 43 control 14 management 44 Acceptance point 15 management 45 Signal generator 16 brake 46 Scanner 17th Brake disc 47 Foil tape 18th Centrifugal control 48 Probe arm inside 19th Inlet eyelet 49 Probe arm outside 20th Arrow direction 50 Frontal scanner 21 Arrow direction 51 Sensing area 22 Fast forward device 52 signal 23 runner 53 Scanner 24th cylinder 54 axis 25th Machine foot 55 Probe arm A 26 Deduction 56 Probe arm B 27 eyelet 57 Scanner A 28 brake 58 Scanner B 29 Arrow direction 30th Measuring point

Claims (14)

1. A method for the delivery of thread-shaped material to looms, in which the thread-shaped material is taken from the spool (1), preferably a flanged spool, at a removal point (44) on the circumference of the spool, and a separate unwinding rotational movement is forcibly imparted to the spool,
      characterised in that as thread-shaped material a highly elastic film strip (2) is used, and that the separate unwinding rotational movement is approximately in synchronism with the consumption speed of the film strip, so that the removal point remains approximately stationary in space relative to the centre of rotation or at least a travelling movement of the removal point is restricted to an acceptable minimum.
2. A method according to Claim 1, characterised in that the separate rotational movement is synchronised with the linear consumption speed of the film strip.
3. A method according to Claim 1 or 2, in which the unwound film strip, before delivery to the consumer, is stored in the interim by winding up in adjacent coils, characterised in that the separate rotational movement of the stock is derived from the unwinding speed of the film strip on intermediate storage.
4. A method according to Claim 3, in which between a storage surface of the intermediate store and a winding element adjacent thereto, to maintain an intermediate storage stock in a minimum quantity dependent on requirements, a relative rotational movement is produced, characterised in that drive signals for the rotational movement of the stock are derived from the rotational speed control signals for the relative rotational movement on intermediate storage, and that the drive signals are linked with at least one state value, e.g. the average diameter of the stock relative to the diameter of the intermediate storage stock, synchronising signals representing the film strip length in the stock, a travelling direction or the extent of a travelling movement of the point of film strip removal from the stock, or the like, such that the point of film strip removal is held still dependent upon changes to the winding speed and the state value relative to the centre of rotation (in space).
5. A method according to Claim 4, characterised in that between the spool drive and the intermediate storage device a signal transmission connection is provided for the drive signals to drive the intermediate storage device, with which directly or in modulated form, e.g. through increase or reduction in amplitude and/or frequency (dependent on drive), the drive signals are able to be transmitted to the drive of the spool (40) or directly to a control device of the spool drive and, modulated thereby, to the drive of the spool (1,40).
6. A device for the delivery of thread-shaped material to looms, with a wound, rotationally driven storage spool (1) with a removal point (44) situated on the spool circumference, characterised in that the thread-shaped material is a highly elastic film strip (2), and that a scanning device is provided for the removal point (44) of the film strip (2) from the stock, which is in signal-transmitting connection with the rotational drive (42) for the stock, such that the drive (42), with an established travelling movement of the removal point (44) as a function of the travelling direction and the extent of the travelling movement, is controlled such that the travelling movement of the removal point (44) remains restricted to a minimum, ideally zero.
7. A device according to Claim 6, characterised in that the removal point (44) of the film strip (2) is sought and is monitored with regard to its movement in or against the unwinding direction, and that a separate rotational movement is applied from time to time onto the stock such that the removal point (44) is held substantially still (in space), or at least a travelling movement of the removal point (44) remains restricted to an acceptable minimum.
8. A device according to Claim 6 or 7, characterised in that the rotational drive motor (9,42) of the storage spool (1,40) is connected to a control arrangement which gives it unwinding drive signals, and that the control arrangement is in signal-transmitting connection with the control unit of the thread storage and delivery device to transmit the winding drive signals, and produces the unwinding drive signals as a function of the winding drive signals.
9. A device according to Claim 8, characterised in that the control arrangement contains a switching circuit or a microprocessor, and that in addition synchronising signals of a signal emitter (45) are able to be transmitted to the switching circuit or to the microprocessor for at least one state value of the stock, e.g. the average diameter of the stock relative to the diameter of the film strip storage and delivery device, in order to produce the unwinding drive signals as a function of the winding drive signals and the synchronising signals such that the thread removal point (44) remains at a standstill relative to the centre of rotation (in space) or at least that a travelling movement of the thread removal point (44) on the stock remains restricted to an acceptable minimum.
10. A device according to Claims 8 or 9, characterised in that the synchronising signals are able to be produced with a sensing device for the instantaneous or an average diameter of the stock or of the film strip length on the stock or the instantaneous travelling direction or the extent of travelling movement of the thread removal point (44).
11. A device according to one of Claims 8 to 10, characterised in that the mounting (8) of the spool (1,40) with its drive motor (9,42) are basic components of an intermediate thread storage device with control unit and the mounting (8) is mounted so as to be horizontally and vertically displaceable on a support (7).
12. A device according to one of Claims 6 to 8, characterised in that the flange lying on the withdrawal side of the spool (1,40) is constructed on an enlarged scale as disc (37).
13. A device according to Claim 12, characterised in that the disc (37) is constructed so as to be self-rotating or fixed on the spool (1,40).
14. A device according to one of Claims 6 or 8, characterised in that after the spool (1,40) an additional measurement site (30) is provided, through which the film strip (2) is passed, where in the manner of an optoelectronic detection with a laser, light beam or video image or the like, a torsion and a twist of the film strip are established without contact and the measurement site (30) is in connection via a line (13) with the control arrangement (10).

Images