EP0581077A1 - Tail winding drawing off device particularly for transfer tails and/or for yarn ends near the bottom ends of bobbins - Google Patents

Abstract

The object of the invention is to propose a device of this type which allows a reliable, prompt and complete removal of end turns. This object is achieved, according to the invention, in that the suction orifice (17) of the device is followed, in a suction housing (14), by a roller (15) having a non-slip surface (31). The roller is connected to a drive (16) which imparts to it a circumferential speed causing the sucked-up thread to fray. The roller (15) advantageously possesses a sawtooth-like covering (31), the tooth flanks (33a) of which are located at the front in the direction of rotation of the roller. The invention guarantees, at the same time as a high uniform pull on the thread by mechanical means, that a constant suction flow is maintained. Use is possible in spinning cops, slipped onto mandrels, when these spinning cops are rotated, or also in the direction of the cop longitudinal axis of spinning cops which are drawn off from the slip-on mandrel. <IMAGE>

Description

The invention relates to a device for removing end windings, in particular foot windings and / or thread ends in the region of the sleeve foot, with the features of the preamble of claim 1.

At the end of the cop production, it is customary on ring spinning machines to place end windings on the tip of the head or to form a back winding with the end of the thread, which runs from the tip of the head towards the base of the cop. For this purpose, the ring bench is moved relatively quickly from top to bottom, for example, when spindles are already running out. Usually, the back turn at the base of the sleeve ends in foot turns. Depending on the ring spinning machine and its setting, there may be a relatively large number of foot turns, for example twelve to twenty. This can lead to twisting between the piecing thread on the core of the tube and the winding thread. If such a cop is presented to a conventional cop preparation device which searches for the thread end by means of a suction slit on the winding surface of the cop, this thread end cannot be exposed.

For this reason, separate cop preparation units have already been proposed, initially in particular to expose the thread end located on the tube foot.

CH-PS 442 101 and DE-OS 33 08 172 describe devices in which the cop is placed directly above a suction pipe with its cop base. This thread end should be grasped by the suction flow and can be pulled off the cop base. In order to avoid that a thread end that is too long hangs from the bobbin and leads to drag threads during further transport to the next preparation station, it is provided that the thread end is cut off immediately before further transport. However, these devices are only suitable for releasing a thread end which is easily exposed and, above all, is not twisted with the piecing thread.

DE-AS 15 60 571 describes a cop preparation device in which a foot turn is first loosened by means of blowing nozzles and then it is to be detected and pulled off by a pair of rollers underneath. These rollers can achieve a significantly higher pull-off force than the purely pneumatic detection and removal of foot turns. However, the disadvantage associated with such a device is that the suction air opening located behind the nip is covered by clamping the thread by means of two rollers. It is therefore particularly important to ensure that the nip is open to detect the beginning of the thread. This can be done by the fact that, as in the cited document, the rollers have a conical approach and the cops are moved in the direction of the roller gap during the preparation. It is also possible to move at least one of the rolls transversely to its longitudinal axis and thereby open the roll gap. In any case, the nip must be closed again at a certain time for the clamping of the thread. If the thread start is not yet in the nip at this point detected, the foot turns can no longer be solved. There is also the possibility that after detecting the beginning of the thread in the nip the thread breaks and the rest of the foot turns remain on the cop as well.

So-called suction cutting drum thread looseners, such as are known for example from DE-OS 35 12 403, are based on the fact that suction openings are provided in the circumferential direction at intervals from one another in the jacket of the suction cutting drum, which are arranged one after the other with a thread end suction opening arranged in the vicinity of the thread end to be removed in the suction housing Come cover. This means that the full suction power is only available when both openings overlap. However, in order to be able to feed a detected thread end to a fixed cutting edge quickly enough, the suction cutting drum must have a corresponding speed. As a result, the time span in which each suction opening of the suction cutting drum at least largely coincides with the thread end suction opening of the suction housing and in which the thread end can be effectively sucked in is extremely short. When the cop is simultaneously rotated in the thread unwinding direction, there is a danger that the thread end will pass the suction opening of the suction housing several times without it being able to be detected. If the end of the thread has been gripped and then tears, if the unwinding speed and the pulling-off speed of the thread clamped between the suction cutting drum and the suction housing differ, the renewed grasping of the end of the thread can in turn be delayed accordingly. As a result, a very long dwell time in the cop preparation device is required in the known device, particularly if there are a large number of foot windings on the sleeve base of the spinning cop. This is difficult to reconcile with the short cycle times that are common today in automatic winding machines.

It is therefore an object of the invention to further develop such a device for removing end windings, in particular foot windings and / or thread ends in the region of the tube foot of spinning bobbins, in such a way that these end windings can be quickly detected and quickly and completely removed.

This object is achieved by the characterizing features of claim 1.

The invention takes over the knowledge that end windings, which can lie firmly on top of one another and have twists with other thread parts, cannot be removed pneumatically alone. While the known devices, which used additional mechanical aids, were associated with a significant reduction in the effectiveness of the pneumatic means, according to the present invention both means are fully effective in the entire preparation phase. In addition, the rapid rotation speed of the roller according to the present invention generates a strong additional suction flow. By defibrating the thread, a constant high tensile force is exerted on the detected thread end without, however, as with the known clamping, giving the thread a predetermined pull-off speed. As a result, the thread take-off speed is determined exclusively by the release of the thread by the bobbin. The continuously acting intensive suction flow ensures a quick and safe detection of the thread start as soon as it passes the suction opening for the first time. Even after the thread tears outside the suction opening, the continuous suction air flow catches it again very quickly and it can be drawn off further.

In order to achieve a sufficient negative pressure at the suction opening, there is only a slight negative pressure, if any, due to the tangential flow achieved by the roller necessary from outside, which may only have to ensure the removal of the separated fibers.

In particular, if a large number of foot turns, for example more than twelve, are to be unwound, the device according to the invention allows a significant increase in the speed of rotation of the cop, since the constant tensile force on the thread is strong enough to pull it off much faster than with known devices.

By means of the defibrating, thread twisting can also be solved particularly easily and effectively with the aid of the device according to the invention.

Compared to devices which cut off the thread ends by means of cutting tools, the device according to the invention has the additional advantage that the thread, which is kept under constant tension, breaks off when it passes into the steep rear windings. The thread end remaining on the cop shoots upward due to the tension present during the tearing and the steep winding direction and can be detected very quickly and easily by a suction slot arranged in a subsequent station.

The invention is advantageously further developed by the features of claims 2 to 7.

Although the device according to the invention can, as already indicated, also be operated without a vacuum source, since the roller with its non-slip surface and high circumferential speed already generates a sufficient suction flow, it is advantageous to additionally connect a vacuum source, in particular for suctioning off the detached fibers.

A particularly non-slip surface is obtained with a sawtooth-like coating on the roller, the tooth flanks having to be at the front in the direction of rotation of the roller. For this purpose, for example, a dissolving roller which is customary for dissolving a sliver of a rotor spinning machine can be used.

If the spinning head remains on a plug-on mandrel while the thread end is being sought and pulled off, a rotating device is required which rotates the spinning head in the thread unwinding direction.

In order to be independent of the thread winding direction, the suction opening is designed such that a vertical center plane of this suction opening also includes the longitudinal axis of the spinning cop to be prepared.

In particular, in the case in which fifteen or more turns of the foot are to be detached from the sleeve base of the spinning cop, it can prove to be advantageous to pull off the foot turns in the direction of the longitudinal axis of the spinning cop to avoid unwinding of each individual turn. To do this, the spinning cop must be removed from a plug-on mandrel, which can be part of a caddy for transporting the spinning bobbins, for example, and positioned over the suction opening.

In any case, it is advantageous if an air shut-off device is provided between the vacuum source and the suction housing in order to thereby limit the required air output.

Fig. 1

eine Seitenansicht der erfindungsgemäßen Vorrichtung,

Fig. 2

eine Draufsicht zur Fig. 1,

Fig. 3

eine Variante der erfindungsgemäßen Vorrichtung in Seitenansicht,

Fig. 4

eine perspektivische Darstellung der Walze zum Zerfasern des angesaugten Fadens,

Fig. 4a

eine vergrößerte Darstellung eines Teiles der Garnitur, die den Belag der Walze bildet und

Fig. 5

eine weitere Variante der Erfindung, bei der der Spinnkops zum Lösen der Endwindungen von einem Aufsteckdorn abgezogen wird, ebenfalls in Seitenansicht.

The invention will be explained in more detail below on the basis of exemplary embodiments. In the accompanying drawings:

Fig. 1

a side view of the device according to the invention,

Fig. 2

2 shows a top view of FIG. 1,

Fig. 3

a variant of the device according to the invention in side view,

Fig. 4

1 shows a perspective illustration of the roller for defibrating the sucked-in thread,

Fig. 4a

an enlarged view of part of the set that forms the covering of the roller and

Fig. 5

a further variant of the invention, in which the spinning cop is pulled off a plug-on mandrel to loosen the end windings, also in a side view.

The cop 1 according to FIGS. 1 and 2 is attached with its cop sleeve 2 or its sleeve base 2 'to the arbor 7 of a caddy 5. This caddy 5 stands on a conveyor belt 8, by means of which the caddy 5 can be transported along a transport path by means of frictional engagement.

C-shaped guide rails 9 and 10 are provided for guiding the caddy's 5. The lower horizontal parts of these guide rails 9 and 10 also serve as a support for the conveyor belt 8.

In the position shown, a drive roller 11 and two rollers 13 arranged opposite one another rest on a base plate 6 of the caddy 5. The Caddy is fixed in its position by these three roles.

The drive roller 11 is connected to a motor 12, by means of which the same is set in rotation. This drive roller 11, which is designed as a flange roller, drives the same by frictional engagement on the circumference of the base plate 6 of the caddy 5 at. The cop placed on the arbor 7 is set in rotation in this way.

A base 6 'can also be arranged between the base plate 6 and the arbor 7, which can serve either as a support for the sleeve base or as a system for stoppers which may be present in the transport system and also for management purposes.

As can be seen in particular from FIG. 2, the guide rails 9 and 10 have cutouts 9 'and 10' in order to enable the drive roller 11 and the further rollers 13 to pass through on the opposite side. In addition, it is conceivable to additionally provide a stopper that stops incoming caddy's 5 in a position in which the rotary drive between the three rollers 11 and 13 can take place. For this purpose, for example, which is also not shown here, the drive roller 11 or the drive rollers 13 can be changed in position transversely to the transport direction of the conveyor belt 8.

A suction housing 14 is fixedly arranged in the position shown, no brackets being shown. A suction opening 17 is arranged as close as possible to the surface of the cop 1, which is positioned between the rollers 11 and 13.

The arrows in FIGS. 1 and 2 show which air flow is achieved at the cop 1, through the suction opening 17 and past a roller 15 through a channel 18. By means of a relatively high rotational speed, for example 5,000 rpm, of the roller 15, an air flow can be generated solely by its non-slip surface, which is sufficient for the detection and removal of the thread. The covering of the roller 15 advantageously corresponds to the covering 31 shown in FIG essentially consists of a clothing wire 32 running spirally around the circumference of the roller 15 or 24, which in turn is shown as a detail in FIG. 4a and will be explained in more detail below.

Due to the air flow generated as described, a thread end, which may even be twisted with the so-called piecing thread, is sucked through the suction opening 17 and reaches the surface of the roller 15. The gripping surface and the high peripheral speed make the detected thread ends in Individual fibers dissolved, but a high tensile force is still exerted on the thread itself. In contrast to the prior art, this does not require the thread to be pinched, for example in a nip. This ensures that the tensile force remains constant even after the end of the thread has been mechanically gripped while maintaining the full suction flow. As a result, the new end of the thread can be gripped again very quickly even when the thread is torn off.

The pulling force on the thread end is almost independent of the unwinding speed of the thread, since the peripheral speed of the roller 15 is many times greater than the pulling-off speed of the thread. It is therefore not necessary to match the take-off speed to the take-off speed, which can fluctuate greatly with one and the same bob, depending on the respective winding diameter from which the thread is to be pulled. Since extremely jerky tensile force fluctuations in the thread are avoided in this way, the thread will only rip in rare cases as long as it is still in the area of the suction opening 17. This ensures that the end windings are unwound quickly and completely.

The device shown can be used regardless of the winding direction of the thread on the spinning cop 1. It is only necessary to ensure that the motor 12 drives the drive roller 11 in the direction that enables the spinning head 1 to rotate in the unwinding direction of the thread. The design and arrangement of the suction opening 17 ensures the same functionality regardless of the direction of rotation of the spinning cop 1 or the winding direction of the thread. By means of baffles 20 and 21 arranged on both sides of the suction opening 17, the thread drawn off the spinning cop 1 is safely guided into the suction opening 17 and from there onto the roller 15.

A suction pipe 19 is connected to the suction housing 14 and has a connection to a vacuum source with an interposed filter. An air shutoff element, not shown here, is advantageously arranged between the vacuum source and the suction housing 14. As a result, the connection of the suction housing 14 to the suction air source can be limited to the period in which a cop is processed.

An air guiding edge 22 ensures that the air flowing tangentially from the roller 15 is passed on in the duct 18 into the suction pipe 19 and that as little air as possible, including fibers detached from the coating on the roller 15, is carried along by the roller 15.

In the present case, the roller 15 is connected directly to a motor 16 which runs at a speed of 5,000 rpm. The peripheral speed of the roller 15 achieved in this way is approximately 1,000 m / min, the diameter of which is 60 mm. This is an opening roller, as shown in FIG. 4, and is used to open a fiber sliver in rotor spinning machines.

In the variant of the invention shown in FIG. 3, the roller 24 is arranged horizontally with its axis of rotation. This illustration is intended to clarify that the device according to the invention is not restricted to a specific position of this roller.

The suction housing 23 has a suction opening 25 of a similar design to the suction opening 17. The channel 27 connects directly to the direction of movement of the covering of the roller 24. This results in a relatively cheap air flow. Here, too, the channel 27 continues in a suction pipe 28, which is advantageously connected to a suction air source and can be shut off by a slide.

In addition, a trailing thread loosener 29 is indicated in FIG. 3, which can additionally be provided in this preparation station. In the direction of flow of the air, which results from the specific position of the roller 24, there is also the possibility here to first cut the rear thread 3 with the rear thread loosener 29 and then, starting with this thread end, to suck in the lower part of the rear thread 3 including the foot threads 4 . To do this, the opposite direction of rotation of cop 1 must be selected. In this example, too, an air guiding edge 26 ensures that the tangential air flows which arise on the circumference of the roller 24 are passed on in the suction tube 23.

4, the shaft 30 on which the armature of the motor 34 is seated can also be seen on the roller 24. Of course, however, it would also be possible to use a motor with a lower speed and to translate the drive accordingly onto the shaft 30 via V-belts.

The section of a clothing wire 32 shown enlarged in FIG. 4 clearly shows tooth flanks 33a and tooth back 33b. The tooth flanks are arranged at the front in order to increase the pulling force on the thread or the fibers in the direction of rotation of the roller 24. In addition, a larger amount of air is entrained in this way, thereby increasing the suction flow achieved solely by the roller. Since the clothing wire 32 is inserted helically in a bed on the roller 30, it is ensured that the thread does not enter an alley between the clothing wires 30, but is rather quickly gripped by the tooth flanks 33a.

Instead of using a set with a sawtooth coating, it is also conceivable within the scope of the invention to use a needle coating, as is known, for example, from a card drum. The decisive factor in any case is that the covering has enough grip to defibrate the thread and, if possible, also to generate an air flow which exerts a sufficient suction force on the thread to be detached from the cop.

In a further variant of the invention shown in FIG. 5, the removal of a relatively large number of foot windings 4 is to be accelerated in that they do not first have to be handled by rotating the spinning cop 1. For this purpose, a device for manipulating the cops described in more detail below is available.

The cop also stands here on the arbor 7 of a caddy 5, the base plate 6 of which is on a conveyor belt 37, the support of which is not shown separately here. Since the spinning cop 1 does not have to be rotated in the present case, no rotary drive is provided in this preparation position. Rather, only guide profiles 36 and 38 are arranged for guidance along a transport path. Covers 35 and 39 ensure that the Caddy 5 when Pulling off the spinning cop 1 is held back. In addition, a stopper 40 is shown here, which holds the caddy 5 on the base 6 'until after the spinning head 1 has been replaced on the plug-on mandrel 7, further transport can take place.

A lifting mechanism 41 has two carriers 49 arranged one behind the other in FIG. 5, the front carrier not being visible due to the sectional illustration. Both carriers can be connected to one another via a bridge 49a shown in section.

In the carrier 49 scenes 45 and 46 are arranged, in which guide bolts 43 and 44 can slide. A rope 48 is connected to a fastening 58 with a gripper 42 in order to generate the lifting movement. This rope 48 is placed around a rope pulley 47, which in turn can be driven by a motor 50.

By turning the rope pulley 47 counterclockwise, the rope 48 is wound onto the rope pulley 47 and the gripper 42 is thereby raised. In the first part, the gripper 42 executes a pure lifting movement which inevitably results from the vertical course of the links 45 and 46. If the guide pin 43 then reaches the upper end of the link 46, this guide pin 43 is at the same time the fulcrum for the gripper 42 in the subsequent movement phase. The guide pin 44 then slides in a partial circle section of the link 45 to its upper end. With this end position, the spinning cop 1 assumes the position 1 'in which it is arranged in the suction opening 52 of a suction housing 57. The suction opening 52 has an additional lateral opening 52 'for pivoting in.

The gripper 42 is not shown in further detail here, since any known gripper with an arbitrarily selectable clamping mechanism can be used.

A roller 53 is designed corresponding to the rollers 15 and 24, respectively. Likewise, the design of the suction housing 57 with channel 55 and suction pipe 56 corresponds to the design in FIGS. 1 and 2. The roller 53 is also driven here directly by a motor 54.

A control unit 51 is indicated here for coordinating the stopping of a caddy 5, the removal of a spinning cop 1 and positioning over the suction opening 52 and, if appropriate, the actuation of an air flap for closing the suction tube.

With the device shown in FIG. 5, a large number of turns of the foot can be detached from the cop with one stroke. An application will come into question in particular in cases in which the time for unwinding the foot turns is greater than the total time required for pulling off, positioning and then reattaching the cop including the suction of the foot turns as a bundle.

Even if only the loosening of the foot windings from cops was described with the exemplary embodiments, the use of the device according to the invention is also conceivable for the loosening of so-called tip windings or top windings.

Claims (8)

Device for removing end turns, in particular foot turns (4) and / or thread ends in the region of the tube foot (2 ') of spinning bobbins (1) in preparation for the unwinding process in a winder, wherein a suction opening (17; 25; 52) of the device and the spinning cop is movable relative to one another with its sleeve base and can be positioned close to one another,
characterized,
that a roller (15; 24; 53) with a non-slip surface (31) is arranged in a suction housing (14; 23; 57) in connection with the suction opening (17; 25; 52) and that the roller is equipped with a drive (16; 34; 54) is connected to it, which gives it a peripheral speed which causes the thread to be shredded. Device according to claim 1, characterized in that the peripheral speed is at least 500 m / min. Apparatus according to claim 1 or 2, characterized in that the suction housing (14; 23; 57) can be connected to a vacuum source. Device according to one of claims 1 to 3, characterized in that the roller (15; 24; 53) has a sawtooth-like coating (31), the tooth flanks (33a) of which are at the front in the direction of rotation of the roller. Apparatus according to claim 4, characterized in that the roller (15; 24; 53) is an opening roller which is customary for opening a fiber sliver of a rotor spinning machine. Device according to one of claims 1 to 5, characterized in that the device includes a rotating device (11 to 13) for the spinning cop (1) to be prepared. Apparatus according to claim 6, characterized in that the suction opening (17; 25) is designed and arranged such that its vertical center plane also includes the longitudinal axis of the spinning cop to be prepared. Device according to one of claims 1 to 5, characterized in that the device comprises a device (41) for grasping and temporarily withdrawing a spinning cop (1) from a plug-on mandrel (7) and for positioning its sleeve base (2 ') over the suction opening (52 ) has.

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