EP0412344B1 - Device for withdrawing the thread-end from the surface of cops - Google Patents

Description

The invention relates to a device for releasing the rear winding thread from the surface of cops according to the preamble of the first claim.

At the end of the cop production, it is customary, for example on ring spinning machines, to form a rear winding with the end of the yarn, which runs from the tip of the head towards the cop base. For this purpose, the ring bench is moved relatively quickly from top to bottom, for example, when spindles are already running out. The back winding can end in a reserve winding at the base of the sleeve. However, this reserve winding is no longer present in the case of fully automatic doffing processes on the ring spinning machines.

When preparing such cops for the unwinding process in a winding machine, it is important to expose the end of the yarn so as to avoid damage to the surface of the winding so that it can be detected in the unwinding position and presented to the corresponding units of the winding unit.

Devices which search for the beginning of the thread on the surface of cops and then prepare them for the unwinding process at a defined point are already known. In most of these devices, the cops are in a circular path on several passed different treatment stations, which results in a step-by-step preparation process.

For example, according to DE-A 36 02 002, the reserve and / or backwinding thread is first loosened by a suction tube cutter, then the beginning of the thread is wound on the surface of the bobbin and then searched for on the entire bobbin surface by means of a suction slot arranged in a suction tube Slit led to the next station, cut there and placed in the head sleeve. Such devices are very expensive. In particular, due to the high air consumption, there is a considerable energy requirement.

The US-PS 26 75 971 also describes a preparation device for cops that are fed to the winding units of a winding machine. Before searching for the beginning of the thread, the rear winding is loosened by means of a suction slot arranged along a suction tube by means of a hook formed from a bent wire. This hook is mounted in a hinge and is also displaced parallel to the longitudinal axis of the cops by the thread pull of the detected thread, thereby preventing the hook from penetrating into the thread layers. The hook is in engagement with the cop surface until the cop has moved a certain amount along the transport route. If the hook grasps the rear winding thread immediately after it has come into contact with the surface of the cop, it pulls the thread part running in the direction of the tip of the head tightly onto the surface of the winding of the cop. It is also to be expected that the detected thread will break relatively late due to the downward movement of the hook, as a result of which additional relatively flat, very firm turns will be applied to the surface of the cop. The detection of the thread by subsequent devices is thus made considerably more difficult.

From the generic DE-OS 15 60 427 a cop preparation device is known in which one or more thread looseners are present in a station of this device, which can be applied to a cop positioned on the transport route. Means for rotating the cop in the thread winding direction are also present in order to bring the thread loosener in the form of a finder knife under the rear winding. Also with this device, there is the possibility already described in connection with US Pat. No. 2,675,971 that additional, relatively flat and very strong turns which are no longer detectable in a subsequent device are applied to the cop surface after the winding thread is detected when the cop is rotated further are. The treatment time on this device must be set so high that the rear winding is released with as many cops as possible. This results in an unnecessary time delay in the event that the rear winding is detected early by the respective finder knife.

The object of the invention is to propose a device for loosening the thread on the surface of cops, which has a high efficiency.

This object is achieved by the features of claim 1.

The invention is advantageously developed by the features of claims 2 to 13.

The arrangement of a sensor, which detects when the detected winding thread slides onto the thread loosener designed as a finder knife, makes it possible to initiate further steps directly via command signals. By lifting the finder knife immediately after the thread is recognized, it is loosened or torn. As a result, it is not possible for the thread to be fixed in tight turns on the surface of the cop above the finder knife. It is also avoided that the thread already loosened at the level of the finder knife is ironed into the cop surface by the finder knife. The shape of the finder knife ensures a gentler treatment of the cop surface compared to the known hook consisting of a bent wire.

By loosely placing the thread start on the bobbin surface in connection with monitoring the success of the thread search and the dependent control of the bobbin on its further transport path, it is possible, depending on the thread material, to dispense with further preparation stations, especially if the thread is in the winding station is released from the surface of the cop by an upward air flow surrounding the cop and is fed to a feeder device. The likelihood of success of such a simplified preparation corresponds to the familiar one Preparation facilities that have several preparation stations.

Since after the thread start has been detected and released, a further rotary movement of the cop is normally not necessary, this drive can also be deactivated by a command signal generated by the sensor.

In addition to the design of the thread remover as a finder knife, the arrangement of a finder guide in the area of the finder knife also has an advantageous effect on the protection of the cop surface, since the finder knife is positioned exactly and is prevented from penetrating into the thread turns.

The sensors are advantageously formed by light barriers, which consist of different arrangements of light sources and photocells. The thread sliding onto the finder knife breaks through the respective light barrier at one or more points.

The success rate of cop preparation can be further increased if several finder knives that come into operation one after the other are arranged one above the other. After the sensor arranged at the lowest finder knife has recognized the thread, this finder knife is lifted from the surface of the cop and the finder knife arranged above it is pivoted to the surface of the cop. This prevents the thread from first tearing through the upper finder knife when the rear winding thread is detected, and the lower part of the rear winding remains on the outer surface of the cop, which can subsequently lead to considerable difficulties during the winding process. Through the upper finder knife, after loosening the lower part of the rear winding, the beginning of the thread is placed loosely on the upper part of the bobbin surface, which makes it very easy to loosen the beginning of the thread in the area of the winding point, for example, if the thread from the winding point The bobbin surface is released by an upward air flow surrounding the bobbin and fed to a feeder device.

If reserve windings are formed on the bobbin foot on the ring spinning machine following the rear winding, the additional arrangement of a suction nozzle in the region of the bobbin foot of the preparation device according to the invention may be necessary. In this case, however, the switching off of the drive for the bobbin rotation would have to be delayed after the sensor recognizes the winding thread. If several finder knives are arranged one above the other, it may be sufficient if the cop is rotated until the upper finder knife has also grasped the remaining part of the rear winding.

Fig. 1

eine perspektivische Gesamtansicht einer erfindungsgemäßen Vorbereitungseinrichtung,

Fig. 2

eine stark vergrößerte Darstellung der Einzelheit X aus Fig. 1,

Fig. 3

eine stark vergrößerte Darstellung einer Variante der Gestaltung des Suchermessers und

Fig. 4

eine weitere stark vergrößerte Darstellung einer Variante der Ausgestaltung von Suchermesser und Sucherführung.

The invention will be explained in more detail below using exemplary embodiments. The drawings show:

Fig. 1

an overall perspective view of a preparation device according to the invention,

Fig. 2

2 shows a greatly enlarged illustration of the detail X from FIG. 1,

Fig. 3

a greatly enlarged representation of a variant of the design of the finder knife and

Fig. 4

another greatly enlarged illustration of a variant of the design of the finder knife and finder guidance.

A cop 3 is fed upright on the arbor of a pallet 1 on the conveyor belt 5 of a conveyor track 2 of a preparation device according to the invention and positioned there. The pallet 1 is guided along the transport path 2 by guide plates 6 and 6 '. The Arrival of a pallet 1 is reported by a sensor 28 via a control line 28 'to a central control unit 60 which actuates a rotary solenoid 27 via a control line 27'. Correspondingly delayed, a pivot rod 14 is rotated counterclockwise by the rotary solenoid 27. A roller holder 13 with pressure roller 12 is also pivoted in such a way that the pressure roller 12 bears against the base plate 1 'of the pallet 1. For this purpose, the guide plate 6 has a recess 7. By designing the pressure roller 12 as a flanged roller, the pallet 1 can also be tilted slightly, as a result of which the base plate 1 'no longer lies with the entire surface of its underside on the conveyor belt 5.

The pressure roller 12 presses the base plate 1 'of the pallet 1 against two pulleys 11 on the opposite side of the transport path 2, of which only one can be seen in FIG. 1. For these pulleys 11 with the flat belt 10, a recess 7 'is provided in the opposite guide plate 6'. The flat belt 10 is driven by a motor 9 via a drive roller 8. The motor 9 receives its control command signals from the central control unit 60 via a control line 9 ′.

Since the pulleys 11 penetrate the transport path for driving the pallet 1, the plate 61 on which both pulleys 11 and the drive roller 8 are mounted can also be pivoted. It is pivoted in synchronism with the swivel rod 14 and thus with the roll holder 13 for positioning the pallet.

A bracket 41 is also attached to the pivot rod 14 by means of a bracket 42 by means of a fastening screw 43. After swiveling the bracket presses so against the sleeve tip 3 'of the cop 3 that it is tilted slightly against the tilting direction of the pallet 1, whereby the frictional force on the Pallet 1 mandrel increased. As a result, the rotational movement from the driven pallet 1 is also transmitted to the cop 3 in the direction of the arrow 4 when it is not seated tightly on the arbor. By means of an adjusting screw 44, it is possible to adjust the height of the bracket 41 to different cop lengths. In addition, the angular position of the bracket 41 can be changed either by means of the fastening screw 43 or the adjusting screw 44.

1 already shows a variant of the invention in which two finder knives 16, 18 are arranged one above the other. Sensor carriers 45 and 46 are also arranged on both finder guides 15 and 17. However, it would be conceivable within the scope of the invention to provide only one finder knife 16 with a corresponding sensor. The lower finder guide 15 is rotatably mounted in a holder 23 by means of a pivot pin 21. The bracket 23 is fastened to the swivel rod 14 by means of a fastening screw 25. The finder knife 16 is attached to the finder guide 15 with fastening screws 19. In this case, 15 elongated holes can be provided in the finder guide, in which the fastening screws 19 can be displaced, as a result of which the finder knife 16 can be adjusted according to the scope diameter.

On the viewfinder guide 15 opposite side of the pivot pin 21, a pivot lever 29 is attached. This pivot lever 29 is connected to the piston 31 of a pneumatic cylinder 33 via a swivel joint 29 '. This cylinder 33 is fastened to the swivel lever 14 via a holder 39. Air lines 35 and 36 open at the two ends of the pneumatic cylinder 33. These air lines 35 and 36 are connected to a compressed air source, not shown. They can be pressurized with compressed air alternately via valves, also not shown. The valves are controlled via the central control unit 60.

For example, if the valve that connects the compressed air source to the air line 35 is opened, the piston 31 is shifted to the left. The viewfinder guide 15 is pivoted clockwise by the transmission via the pivot joint 29 ', pivot lever 29 and pivot pin 21. As a result, the finder knife 16 lifts off the surface of the cop. This process is initiated after the rear winding thread 47, which is picked up by the finder knife 16 and pushed onto its back, has interrupted the light barrier formed by a light source 48 and a photodiode 49. The photodiode 49 has a connection 49 'to the central control unit 60, which then opens the valve leading to the air line 35. In this way, it is ensured that the finder knife 16 lifts off the surface of the cop immediately after capturing the rear winding thread 47, as a result of which the rear winding thread 47 is detached from the head of the cop or also torn. This prevents the rear thread 47 from being ironed into the cop surface at the level of the finder guide 15.

As shown in FIG. 1, a further viewfinder guide 17 with viewfinder knife 18 is attached to the pivot rod 14. The structure corresponds to that of the lower arrangement of the finder guide 15. The finder knife 18 with fastening screws 20 is fastened to the finder guide 17 analogously to the finder knife 16. At the end of the finder guide 17 there is also a pivot pin 22 which is connected on the opposite side to a pivot lever 30 which in turn has a pivot joint 30 '. The swivel joint 30 'is connected to a piston 32 which is guided in a pneumatic cylinder 34. The pneumatic cylinder 34 is fastened to the swivel lever 14 by means of a holder 40. Air lines 37 and 38 are arranged at the two ends of the pneumatic cylinder 34 and are also connected to a compressed air source via valves, not shown. The pivot pin 22 is mounted in a holder 24 which is secured by a fastening screw 26 is attached to the pivot rod 14. The valves leading to the air lines 37 and 38 are also controlled by the central control unit 60.

In the illustration according to FIG. 1, the winding thread 47 has just been recognized by the sensor formed by the light source 48 and the photodiode 49, which is why the central control unit, which has received the success signal from the sensor, opens the valve to the air line 35, thereby guiding the viewfinder 15 with the finder knife 16 off the surface of the cop. At the same time, the valve which leads to the air line 38 is opened via the central control unit 60. As a result, the piston 32 is displaced to the right in the pneumatic cylinder 34, as a result of which the finder guide 17 with the finder knife 18 is pivoted to the surface of the cop. This ensures that the thread search on the upper part of the head jacket only begins when the rear winding thread 47 has been detached from the lower finder knife 16.

Since in the present case the upper viewfinder guide 17 is also equipped with a sensor, the success of the thread search is also recorded there. Depending on this, the viewfinder guide 17 is then lifted off via the central control unit by a valve which leads to the air line 37.

In the event that an additional reserve thread has been applied to the cops foot 3 ″ on the ring spinning machine, a swiveling suction nozzle 50 is additionally arranged. This suction nozzle 50 has a suction air connection 51. In deviation from the illustration in FIG. 1, this suction nozzle 50 could also be attached directly to the swivel arm 14. It would be sufficient if the suction nozzle 50 is only pivoted to the bobbin foot when the lower finder knife 16 has gripped the winding thread 47. Because with a longer reserve winding on the cops foot in most cases If the winding thread 47 is torn, the suction nozzle 50 can grasp the lower end of the torn thread and, while maintaining the cop rotation, unwind and suck in the reserve thread.

After the upper viewfinder guide 17 has been pivoted away from the surface of the cop, the central control unit 60 deactivates the motor 9, as a result of which the rotational movement of the cop 3 is stopped. The central unit 60 then controls the rotary solenoid 27, which pivots the pivot rod 14 with all the devices attached to it in a clockwise direction, as a result of which all these devices are removed from the transport path 2. The plate 61 is also pivoted. As a result, the pallet 1 with cops 3 of the conveyor belt 5 is moved further in the direction of the arrow.

In a variant, the motor 9 can also be put out of operation directly by the pivoting mechanism for the finder guides 15 and 17 after reaching the end position via a switch (not shown).

In particular, if no further preparation station is arranged on the feed path of the cops 3 to the winding points of the winding machine (not shown), it is important to control the cop 3 with pallet 1 as a function of the success of the search for the winding thread 47. It is thus possible, for example by means of a switch, to guide a cop 3, in which the search of the winding thread 47 was unsuccessful, into a branch path which does not lead directly into the winding positions of the winding machine. If necessary, another preparation device can then be arranged on this branch path, which, for example, searches for the beginning of the thread on the upper head cone. It is also possible to arrange a storage section in which the cops are prepared by hand.

Alternatively, another preparation device can also be arranged on the same transport route following the device according to the invention, which, for example, searches for the thread on the entire surface of the cop by means of suction air. This device would only be active if the search for the tail thread 47 on the device according to the invention was unsuccessful.

In the central unit 60 there is a timer in which a maximum search time is stored. This ensures that even in exceptional cases, in which the finder knife 16 cannot catch the winding thread 47 quickly enough, no jam is caused on the transport path 2 by the cop positioned at the treatment station. After the maximum search time has elapsed, even if no successful thread search was indicated by the sensor, all actuating units and the components of the positioning and drive device are pivoted away from the cop 3 so that it is released again. This is necessary in order to continuously supply the bobbin with fresh cops for unwinding.

Instead of the pneumatic cylinders 33 and 34, other actuating devices can also be used, with the aid of which the finder guides 15 and 17 can be pivoted. For example, rotary solenoids are conceivable, which are fastened to the brackets 23 and 24 and which rotate the rotary bolts 21 and 22 by a certain amount about their longitudinal axis on the basis of control commands from the central control unit 60.

Depending on the arrangement and possible pivot path of the finder guides 15 and 17, it is also possible within the scope of the invention to replace the torsion bar 14 by a fixed bar. The search guides 15 and 17 are then exclusive pivoted by means of the pivot pins 21 and 22. The roll holder 13 then also requires a separate pivoting device.

The rounded shape of the bracket 41 also allows it to be arranged stationary. The sleeve tip 3 'of the cop 3 then slides over the bracket 41 when the cop enters the preparation station, whereby the cop is also tilted in such a way that the frictional force on the mandrel of the pallet 1 increases sufficiently to prevent the pallet from rotating on the cop transferred to.

2 to 4 show variants of the design of the finder guides with finder knives and sensors.

Fig. 2 contains the variant shown in Fig. 1 in an enlarged form. The viewfinder guide 15 or 17 has a window 15 'or 17'. A viewfinder knife 16, 18 protrudes through this window. The wedge-shaped shape of the viewfinder knife is clearly recognizable. The front edge of the finder knife 16, 18 projects beyond the side of the finder guide 15, 17 facing the cop surface. As a result, the winding thread 47, which lies diagonally on the surface of the cop due to its large pitch, can be easily grasped by the finder knife 16, 18. The finder guide 15, 17 prevents the finder knife from penetrating into the thread layers of the cop 3. As can clearly be seen in FIG. 2, the trailing thread 47 slides on the back of the finder knife 16, 18. It is arched so that it the light barrier formed by the light source 48 and the photodiode 49 breaks through when it slides on and thus triggers a signal. This signal is then used via the central control unit 60 as a command signal for further processing steps. While a sensor carrier 45, 46 is required in this example, in the variant according to FIG. 3 the finder knife 53 is curved so that it has a light barrier, which is formed by the light source 54 and the photodiode 55, releases within the window 52 'of the viewfinder guide 52. The photodiode 55 has a line 55 'which leads to the central control unit 60. In this variant, if the thread search is successful, the light barrier is interrupted by thread triangles formed between the back of the finder knife 53 and the finder guide 52.

In the variant according to FIG. 4, a light source 58 is attached to the finder knife 57 itself, which, together with the photodiode 59 attached to the finder guide 56, represents the light barrier forming the sensor. Here too, the winding thread 47 interrupts the light barrier when the search is successful while it is sliding open. The photodiode 59 has a line 59 ', via which the success of the thread search is transmitted to the central control unit 60.

Claims (13)

1. Device for releasing the back-winding yarn from the surface of cops which is arranged on a conveying track (2) leading to the winding stations of a winding machine, with a yarn releaser which may be applied to a cop (3) positioned on the conveying track, and with means for rotating the cop in the yarn winding direction in order to bring the yarn releaser beneath the back-winding, the yarn releaser being designed as a hunting blade (16, 18; 53; 57), characterised in that the hunting blade is allocated an electronic sensor (48, 49; 54, 55; 58, 59) for monitoring the detection of the yarn (47), in that a timer is provided in which a maximum hunting time is stored, in that command signals may be generated directly by the sensor if the yarn has been detected within the maximum hunting time, in that at least the front part of the hunting blade is wedge-shaped in design and in that the rear of the hunting blade has a form by means of which the detected yarn sliding thereon is lifted sufficiently far from the cop surface to be detectable by the sensor.
2. Device according to Claim 1, characterised in that the hunting blade (16, 18; 53, 57) is allocated a hunting guide (15, 17; 52, 56) and in that the tip of the hunting blade projects beyond the side, facing the cop, of the hunting guide surface.
3. Device according to Claim 1 or 2, characterised in that the hunting blade is connected to an actuator (29 to 38) which is set into operation by a command signal generated by the sensor on detection of a yarn and which lifts the hunting blade from the cop surface.
4. Device according to one of Claims 1 to 3, characterised in that treatment, conveying or guiding means arranged successively on the conveying track (2) may be controlled by a command signal generated by the sensor on detection of a yarn.
5. Device according to one of Claims 1 to 4, characterised in that a rotary drive (9 to 11) for the cop may be put out of operation by a command signal generated by the sensor on detection of a yarn.
6. Device according to Claim 3, characterised in that the actuator has a circuit which puts the rotary drive for the cop out of operation after the lifting of the hunting arrangement.
7. Device according to one of Claims 1 to 6, characterised in that the hunting guide is arranged pivotally.
8. Device according to one of Claims 1 to 7, characterised in that the sensor is formed by a light barrier between hunting blade (57) and hunting guide (56) consisting of a light source (58) and photocell (59).
9. Device according to one of Claims 1 to 7, characterised in that the side of the hunting blade (53) facing the cop is designed such that it releases a sensor-forming light barrier between light source (54) and photocell (55) arranged on opposing arms of the hunting guide (52).
10. Device according to one of Claims 1 to 9, characterised in that several separately movable hunting blades are superimposed, at least the lowest hunting blade (16) being allocated a sensor (48, 49).
11. Device according to Claim 10, characterised in that the upper hunting blades (18) are controlled such that they are pivoted over the cop surface only when the sensor (48, 49) of the lower hunting blade (16) has detected the yarn (47).
12. Device according to one of Claims 1 to 11, characterised in that the device additionally has a suction nozzle (50) which is arranged in the region of the cop foot of the positioned cop (3) and has a suction slot (50') for the aspiration of a reserve winding provided on the cop foot.
13. Device according to one of Claims 1 to 12, characterised in that it is arranged on the supply path to a winding machine provided, at its winding stations, with arrangements by means of which the yarn may be released from the cop surface by an upwardly directed airstream surrounding it and may be supplied to a feed arrangement.

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