EP0396902A1 - Unreeling method and dispenser for yarn as application for this method - Google Patents

Abstract

There are described an unwinding device and a yarn delivery method for yarns, especially yarns of the banded type, for example also lurex yarns, the yarn being drawn off from a flanged bobbin (1) and being fed to the loom via a yarn brake (28). Along the yarn guide path, a brake (16) and a prewinding device (22) can be arranged additionally after the flanged bobbin. The basic object here is, in an overhead draw-off of the yarn from the flanged bobbin (1), to prevent reliably the twisting of the yarn and loops associated with this. To achieve the object, the flanged bobbin is driven (9), and the direction of rotation of this rotary drive is opposite to the winding direction. In this case, the rotary drive (9) driving the flanged bobbin (1) has the same rotational speed as that at which the yarn is unwound from the flanged bobbin. <IMAGE>

Description

The invention relates to a thread delivery method and a unwinding device for yarns for carrying out the method, in particular for yarns with a tape character, the yarn being drawn off from a disk bobbin and fed to the weaving machine via a thread brake, according to the preamble of patent claim 1.

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.

The field of application of the present invention, however, is generally a unwinding device for any yarn, even with a round cross-section, and also for high-twisted yarns, but also for yarns that have zero turns in the weft.

The processing of such yarns on defenseless weaving machines presents considerable difficulties in practice, which result in greatly reduced numbers of turns, increased yarn breaks and a reduction in quality.

Particular difficulties arise in the processing of unreinforced Lurex yarns because such Lurex yarns are drawn off from the head of the spool, ie over the flange. Conventionally, the disk spool is here and the yarn is drawn off over the flange of the disk spool in such a way that increasing withdrawal of this yarn results in a twist in the yarn, which leads to a loop formation when the yarn is unloaded and not under tension.

These twists or twists then build up as the take-off increases until an inevitable loop is formed even when the yarn 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 thread and thus leads to a fabric defect, or the loop in the thread brake leads to thread breakage, 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 percentage, 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 part of the choice (less goods) is particularly high for Lurex fabrics with a high percentage of weft 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 elasticity, any slight deflection that occurs with the cylindrical disc spools causes stretching especially when the thread 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. Because the lurex thread is a ribbon, the bobbin is withdrawn overhead Yarn twists that accumulate at the first point of contact of the break-in brake and thus trigger curl, ie the smaller the bobbin becomes, the more layers are drawn off and the more twists are applied to the weft yarn.

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 of the fact that the twist points become visible in the fabric. 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 rolling basis 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 yarns of the generic type perpendicular to the longitudinal axis of the bobbin. However, there are synchronization problems between the drive for the bobbin and the take-off, as well as for the compensation compensation, which carries out a fine control of the drawn-off yarn.

The present invention is therefore based on the object of developing a thread delivery method and a unwinding device of the type mentioned in such a way that twists and loops associated therewith are reliably avoided when the yarn is pulled off an overhead bobbin.

To achieve the object, the invention provides the features of the characterizing part of patent claim 1.

A significant advantage is achieved with the given technical teaching, because the twisting of the yarn drawn off from the bobbin above the head, 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 bobbin drives the disk bobbin at essentially the same speed as the winding of the thread is unwound on this disk bobbin.

Ideally, the thread with zero turns is always from a constant location on the disc spool, e.g. the vertically uppermost point or any other point, without this point moving around the disc coil.

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

In order to achieve such synchronicity between the speed of the winding 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 bobbin, the increasing rotational speed is always tracked when the thread is pulled off the disc bobbin due to the decreasing diameter of the winding.

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

For this purpose, it is provided according to the invention that a first brake is arranged in the thread direction behind the disk bobbin, which is rotated in synchronism with the prewinder, namely in the direction of rotation, which counteracts the twist direction of the yarn.

In particular when using disc spools with a relatively large weight or with disc spools with a certain imbalance that do not allow high speeds, it is provided to make a speed change of the spool in such a 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 further provided that a brake is arranged on the inlet side of the prewinding device, which is driven in rotation in the direction of rotation which counteracts the twist direction of the yarn.

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

It is also important to take additional measures that achieve a cheap thread loosening on the winding of the disc spool. These thread-dissolving measures also achieve a favorable pull-off of the thread from the disc spool without 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 thread 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 with an enlarged diameter, the thread is drawn at an enlarged angle of e.g. Subtracted from 40 to 60 ° in the direction of the longitudinal axis from the winding of the disc coil, as a result of which the mutually adjacent windings are released from one another when they are removed.

Due to this larger pull-off angle of the thread from the winding, a centrifugal force on the thread also arises when the disk bobbin rotates, which pushes and pulls the thread radially away from the winding, and this also results in a thread-releasing effect.

The thread can therefore be easily pulled off the winding without the windings becoming attached to one another, which leads to thread breaks or stretching of the thread.

It remains open whether the enlarged diameter disc, which is arranged on one flange side of the disc coil, is designed to be rotating or fixed. There are both options from the present invention.

Further advantageous refinements emerge from the subclaims.

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

Further features and advantages of the invention emerge from the description and the drawing.

• Figur 1: schematisiert in Seitenansicht eine erste Ausführungsform der Erfindung mit zusätzlichen, nicht-obligatorischen Merkmalen Meßstelle), während
• Figur 2: schematisiert das Abziehen des Fadens 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: shows schematically the pulling of the thread from the disc bobbin;
• Figure 3: a schematic representation of the scanning of a rotatingly driven supply spool with a scanner on a probe lever;
• Figure 4: shows a schematic representation of the arrangement of a frontal scanner with non-contact scanning in connection with a readjustment of the motor;
• Figure 5: the scanning by means of two probe arms, which detect the rotational movement of the supply spool;
• Figure 5a: the tracking of the probe arms according to Figure 5 in detail;
• FIG. 6: the scanning 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 spool 1 is wound with a thread 2, which forms a winding 4 on the sink body 36 of the disc spool.

The disc coil 1 is laterally edged by flanges 3.

According to the invention, the disc coil 1 is rotatably driven by a motor 9, which is arranged on a machine base 8, which in turn is mounted on a support 7 in the direction of the arrows 20, 21.

The motor 9 is provided with a control 33, which interacts 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 thread 2 is now, for example, drawn off the disk bobbin 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 thread 2 are avoided with certainty, because every turn due to the drawn-off winding is compensated for by an equal, opposite rotation of the disc bobbin 1.

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

It was already mentioned earlier 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 was achieved, which means that the partially interlocking windings lead to catches of the thread to be drawn off and thread catches and weft breaks can occur as a result.

According to the invention, the take-off angle 38 is now substantially increased by the washer 37, so that the thread 2 is drawn 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 drawn-off thread, so that the thread-dissolving effect described is also thereby increased.

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

The thread 2 is now drawn off in the direction of the longitudinal axis 34 at an oblique angle to this, as shown in FIG.

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 instead only one further single brake 28 is used.

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 thread 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 spool 40 from which a thread 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 optically, electrically or electronically.

The scanner is connected to a probe arm 48, which is mounted on an axle under spring preload, the scanner 46 recording 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 controller 43 when the thread 47 is drawn 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 spool comes to a standstill.

The scanner 46, which detects the speed of rotation of the supply spool 40, supplies a signal to the signal generator 45, the output signal of which is fed into the controller 43, whereby the speed of rotation of the motor which rotates the supply spool 40 is slowed down or accelerated, so that overall is achieved that the take-off point 4 stands still when pulling the thread 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 becoming effective 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 thread 47 is drawn off, the point P moves in the direction of the arrow, this movement being detected by the sensing region 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 thread 47 is pulled out 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 thread 47 is drawn off, the scanning arms 55, 56 are displaced 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 covering 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 take-off speed of the thread 47 or the like is detected in order to thereby generate the signal generated by 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 thread 47 is pulled off the thread spool is rotated in the opposite direction to the unwinding process of the thread, so that the take-off point 44 according to FIG. 3 comes to a standstill on the circumference of the supply spool 40.

DRAWING LEGEND

• 1 disc spool
• 2 threads
• 3 flange
• 4 winding
• 5 direction of arrow
• 6 direction of arrow
• 7 support
• 8 machine base
• 9 engine
• 10 control
• 11 control
• 12 line
• 13 line
• 14 line
• 15 line
• 16 brake
• 17 brake disc
• 18 Centrifugal control
• 19 inlet eyelet
• 20 arrow direction
• 21 "
• 22 pre-winding device
• 23 runners
• 24 cylinders
• 25 machine base
• 26 deduction
• 27 eyelet
• 28 brake
• 29 arrow direction
• 30 measuring point
• 31 samplers
• 32 measuring head
• 33 control
• 34 longitudinal direction
• 35 direction of arrow
• 36 bobbins
• 37 disc
• 38 trigger angle
• 39 arrow direction
• 40 supply spool
• 41 axis of rotation
• 42 engine
• 43 Control
• 44 acceptance point
• 45 signal generators
• 46 scanners
• 47 threads
• 48 probe arm inside
• 49 probe arm outside
• 50 scanners frontally
• 51 sensing area
• 52 signal
• 53 scanners
• 54 axis
• 55 probe arm A
• 56 probe arm B
• 57 scanner A
• 58 scanner B

Claims (21)

1. Thread delivery method in the form of pulling a thread from a wound supply by a consumer, in which the thread is taken from the supply at a take-off point around the supply, characterized in that the take-off point (44) of the thread is taken from one of the supplies Forcibly applied unwinding-external rotary movement about a center of rotation of the stock is moved approximately synchronously with the consumption speed in such a way that it remains approximately stationary relative to the center of rotation (in space) or at least that a moving movement of the take-off point (44) remains limited to an acceptable minimum . 2. Thread delivery method according to claim 1, characterized in that the external rotary movement is synchronized with the linear thread consumption speed. 3. Thread delivery method according to claims 1 and 2, wherein the unwound thread is cached before delivery to the consumer by winding in adjacent turns, characterized in that the external rotary movement of the supply is derived from the winding speed of the thread during intermediate storage. 4. Thread delivery method, the thread being unwound from a wound supply, wound onto a temporary store and deducted from this as required, characterized in that the supply is rotated synchronously with the winding speed at the intermediate store and in the unwinding direction in such a way that the thread from the supply at one relative to the center of rotation (in space) stationary point (44) is processed, or that at least a moving movement of the take-off point remains limited to an acceptable minimum. 5. Thread delivery method according to claim 4, wherein a relative rotary movement is generated between a storage area of the intermediate store and a winding element adjacent to it in order to maintain an intermediate store in a need-dependent minimum size, characterized in that drive signals from the rotational speed control signals for the relative rotary movement in the intermediate store derived for the rotational movement of the supply, and that the drive signals with at least one state variable, for example the average diameter of the supply relative to the diameter of the intermediate storage supply, the thread length in the supply, a direction of travel or the extent of a moving movement of the point of thread take-off from the supply, or the like , representing synchronizing signals are linked in such a way that the point of thread take-off is dependent on changes in the winding speed and the state variable relative to the center of rotation (in space) is held. 6. Thread delivery method, with a bobbin, with a drive for the bobbin and with a thread intermediate storage device which has its own drive for a winding member, further with drive signals generating control devices for at least the drive of the intermediate storage device, characterized in that between the bobbin drive and the intermediate storage device a signal transmission connection for the drive signals for driving the intermediate storage device is provided, with the directly or in modulated form, for. B. by (drive-dependent) amplitude and / or frequency increase or decrease, the drive signals to the drive of the coil (40) or can be transmitted directly to a control device of the coil drive and modulated by this to the drive of the coil (40). 7. Unwinding device for delivering a thread from a wound supply spool, characterized in that a scanning device for the take-off point P of the thread from the supply is provided, which is in signal-transmitting connection with a rotary drive (42) for the supply, such that the drive (42) when a determined movement of the take-off point (44) is controlled as a function of the direction of travel and the extent of the move- ment such that the travel of the take-off point (44) remains limited to a minimum, ideally zero. 8. Unwinding device according to claim 7, characterized in that the take-off point (44) of the thread is sought and its movement in or against the unwinding direction is monitored, and that such an external rotary movement is applied to the supply that the take-off point (44) in essentially (in space) is kept still, or at least that a moving movement of the take-off point (44) remains limited to an acceptable minimum. 9. Unwinding device with a holder for a supply spool and with a thread storage and delivery device arranged approximately coaxially with the supply spool, in which a take-up drive motor is controlled by a control unit with demand-dependent drive signals, characterized in that the holder of the supply spool is rotatable and with a rotary drive motor (42) is in drive connection, that the rotary drive motor (42) is connected to a controller which gives it unwinding drive signals, and that the controller with the control unit of the thread storage and -Delivery device for transmitting the take-up drive signals is in a signal-transmitting connection and generates the take-off drive signals as a function of the take-up drive signals. 10. Unwinding device according to claim 9, characterized in that the control contains a circuit or a microprocessor, and that the circuit or the microprocessor additionally synchronizing signals from a signal generator (45) for at least one state variable of the supply, for example the average diameter of the supply relative to Diameter of the thread storage and delivery device can be transmitted in order to generate the unwind drive signals depending on the wind-up drive signals and the synchronizing signals so that the point (44) of the thread take-off remains stationary, or at least that relative to the center of rotation (in space) a moving movement of the take-off point of the thread on the supply remains limited to an acceptable minimum. 11. Unwinding device according to claims 9 and 10, characterized in that the synchronization signals can be generated with a sensing device for the instantaneous or an average diameter of the supply or the length of the thread in the supply or the current direction of travel or the amount of movement of the point (44) of the thread take-off . 12. Unwinding device according to claims 9 to 11, characterized in that the holder of the supply spool with its drive motor (42) are basic components of a thread, storage and delivery device with control unit, drive motor and shaft driven by this for applying the supply spool. 13. Unwinding device for yarns, in particular yarns with tape character, the yarn being drawn off from a disk spool and fed to the weaving machine via a thread brake, characterized in that the disk spool (1) is driven in rotation and that the direction of rotation of this rotary drive is provided in the opposite direction to the winding direction. 14. Unwinding device according to claim 13, characterized in that a first brake (16) is provided in the thread direction behind the disc bobbin (1), behind which a prewinder (22) is arranged. 15. Unwinding device according to claim 14, characterized in that the first brake (16) is rotatably driven synchronously with the prewinder (22) with a direction of rotation against the twist direction of the yarn (2). 16. Unwinding device according to claim 14, characterized in that the brake (16) is designed as a centrifugal brake with brake plates (17) which cooperate with a centrifugal force control (18). 17. Unwinding device according to claim 14, characterized in that the brake (16) in the manner of a slowly occurring braking action has rotating brush pads or plates or is designed as a ball brake or as an air injector brake. 18. Unwinding device according to claim 13, characterized in that the flange lying on the take-off side of the disc reel (1) is enlarged as a disc (37) is trained. 19. Unwinding device according to claim 18, characterized in that the disc (37) is self-rotating or fixed to the disc reel (1). 20. Unwinding device according to claim 13, characterized in that the disc coils (1) with a motor (9) are arranged on a machine base (8) which is horizontally and vertically displaceably mounted on a support (7). 21. Unwinding device according to claim 13, characterized in that after the disc spool (19) an additional measuring point (30) is provided, through which the thread (2) is passed, where in the manner of optoelectronic detection with a laser, light beam or video Image or the like, twisting and twisting of the thread can be determined without contact and the measuring point (30) is connected to the control (10) via a line (13).

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