EP1380528B1 - Method for automatic doffing of bobbins - Google Patents

Description

The present invention relates to the field of the textile industry, in particular wire winding machines and relates to a method automatic reel lift.

Currently, when the reels are full, the different winding, fly and pre-feed motors are cut synchronously and each full coil is released from the winding machine by an automatic lifting device. Such automatic lifting device picks up the full reel via gripping arm, after release of the holding caps of said coil, and causes said full coil to perform a pivoting movement during which a traction is carried out on the wire inducing a tension important in the latter.

This tension on the wire can have the consequence either directly lead to its rupture, or more generally to risk a tearing of the wire from its fixing between a tightening cap of the bobbin and the corresponding end of the bobbin, after cutting the finishing end wire from the full spool. Indeed, especially in the case of use of used bobbins or new bobbins with notch, it may happen that the clamping pressure of the empty bobbin between the holding caps is not sufficient to maintain a very tight wire between such an end and the corresponding cap, mainly due to irregularities in surface of said end, so that the wire is only in partial contact with surfaces pressed together and can escape from these surfaces.

As a result, restarting the machine is enough quickly interrupted, due to the detection of an incident of operation by voltage or wire presence sensors correspondents. It follows that manual interventions become necessary, which leads to a decrease in the efficiency of the winding.

To overcome these drawbacks, the operators responsible for monitoring of winding machines often carry out preventive manual interventions consisting of pulling on the wire ribbon power, when the different drive motors for the winding are cut, to make some slack on the front wires and / or during the lifting of the full reels. Such manual action is however relatively random and cannot be overcome with certainty the problems posed by the lifting of the coils and the overvoltage of son and requires, in addition, the presence of an operator during the cycle of lifted. Document FR-A-2 259 776 describes a device having the features of the preamble of claim 1.

The object of the present invention is to overcome these drawbacks by proposing an automatic reel lifting process allowing to carry out a full spool lift and automatic placement of a new empty bobbin ensuring a substantially controlled tension of the thread during the positioning of said bobbin, without risking breakage of the thread or its accidental stall before restarting the winding or when restart.

To this end, the method according to the invention consists essentially to achieve, during each lifting cycle, a relaxation of the tension of the supply wire, then to restart a new cycle of winding after completion of the lifting cycle, according to specifications of claim 1.

la figure 1 est une vue en perspective d'un poste de bobinage d'une machine de bobinage de fil en fin de bobinage d'une bobine ;

les figures 2 à 10 représentent schématiquement le procédé de levée de bobine conforme à l'invention, et

la figure 11 est une vue analogue à celle de la figure 1 au redémarrage du bobinage.

The invention will be better understood from the following description, which relates to a preferred embodiment, given by way of nonlimiting example, and explained with reference to the appended schematic drawings, in which:

Figure 1 is a perspective view of a winding station of a wire winding machine at the end of winding a coil;

FIGS. 2 to 10 schematically represent the method of lifting the spool according to the invention, and

Figure 11 is a view similar to that of Figure 1 when restarting the winding.

Figures 1 and 11 of the accompanying drawings show, by way of example, a winding station of a wire winding machine comprising a means 1 for holding and releasing a full coil 2, a winding fly 3 guiding the wire to be wound during winding, a bar 7 for clearing the winding fly 3, a coach for coil 4, caps 5 for tightening and holding the coil 6 and a device 8 for supplying the station with coils 6. In a known manner, at the end of winding of a reel 2, the reel drive 4 and the drive of the winding fly 3 are stopped, as is the lead feed, not shown in the accompanying drawings. The result that the wire has, between the filled coil 2 and the pre-supply a thread tension close to that, or even higher than that winding.

When lifting coil 2 this voltage is currently increased, due to the elongation due to the distance of the coil 2 from the station winding, as explained above. However, the invention is also applicable to different winding machines.

According to the invention and as shown more particularly Figures 2 to 10 of the accompanying drawings, the new process of automatic reel lifting essentially consists in carrying out, during each lifting cycle, a slackening of the tension of the supply wire (Figures 3 to 6), then restart a new winding cycle after the completion of the lifting cycle (Figures 7 to 11). So lifting the spool full 2 and the clearance of the winding fly 3 (Figure 4), can be carried out with a controlled tension on the wire between the full coil 2 and the frontloading device, so that the establishment of the new bobbin 6 (figure 9), its tightening between the tightening caps 5 and the pinching of the wire between a cap 5 and one end of the bobbin 6 can be carried out without tensioning the wire. It follows that, when cutting the end of the wire from the full spool, the wire tight against the end of the new bobbin 6 is held with certainty at this end and when starting the coil drive 4 (Figure 11) said wire is perfectly wound without risk of winding incident.

The slack in the tension of the power wire can be performed during winding stop, i.e. during the deceleration phase of the coil or when the coil comes to a complete stop, or even after the total stop of the reel, before or during the release of the full reel or just after the release.

In accordance with another characteristic of the invention, the loosening of the tension of the power wire can also be achieved (Figure 3), by driving the coil 2 in the opposite direction of its rotation winding, by means of the coil drive 4, which is actuated in direction reverse, for a short time, using an inverter mechanical, electrical, electronic or other. Such an inverter is known from skilled in the art and is not described in more detail. A reverse rotation of the coil, as specified above, for a relatively long time short, i.e. one or two seconds for example, allows, after stopping all the drive motors, namely the reel 4, the fly-fly trainer 3 and the front feed, to loosen or slack on the wire of a length sufficient to lift the full reel 2, release the winding fly 3 (Figures 4 and 5), the introduction of the new winding 6 and the tightening of the wire between one end of this bobbin 6 and a cap 5 of tightening of the latter (Figures 8 and 9). The full spool wire can then be cut and a new winding phase can be started (figures 10 and 11), ensuring that the wire is not subjected to any tension during all the above operations.

According to another characteristic of the invention, the relaxation of the tension of the supply wire can be realized, when the winding stops, after the complete reel stop, during the release of the full reel 2 by loosening the thread tension upstream of the winding station.

Thus, according to a characteristic of the invention, not shown in the accompanying drawings, the loosening of the tension of the supply wire can be obtained by action on the wire path upstream of the winding fly 3, all of the drive motors for the winding, for the fly winding and for frontloading being stopped. Such a relaxation can be carried out both before the release of the full coil 2 and during this release.

To this end, this loosening or slack is obtained by a relative displacement of the different detour cylinders forming the frontloading in the direction of a shortening of the wire path during of the judgment. It is also possible to act on the length of the wire path by forecast of one or more detour cylinders in said path, these detour cylinders being movable out of a straight path. In such also, the detour cylinders may, in the winding position, find out of a straight path of the wire, so that the latter performs a longer journey and, at the stop of the various drive motors, these cylinders pass to a position substantially corresponding to a path straight wire, so that said wire is automatically slack. In the cases where an action is carried out on the path of the wire upstream of the winding, the various means allowing relaxation or slack to be obtained by displacement relative to their position when winding return automatically to their initial position during the restart phase of the winding.

The different reverse commands of the coil drive 4 or for moving different detour cylinders can advantageously be carried out automatically by through the usual programmable controller assigned to the control and monitoring the operation of the winding machine. Indeed, the commands necessary to implement a process in accordance with present invention can be perfectly integrated into the processes of current orders and therefore complete the order and order programs existing surveillance.

Figures 2 to 10 show, schematically, the essential phases of a spool lift according to the invention. The Figure 2 shows the winding cycle stop and Figures 3 and 4 show a phase of relaxation of the threads followed by the release of the fly from winding 3 by means of the release bar 7. The reel holder is then lowered (Figure 5) and the reel loader is lowered (Figure 6). Then, the reel holder is mounted (Figure 7), this rise being followed a reel of the reel charger or station supply device in bobbins 6 (figure 8), itself followed by a descent of the bobbin holder (figure 9). The winding fly 3 release bar 7 is then clear (Figure 10). Figure 11 shows in perspective the start of the new winding cycle.

Thanks to the invention, it is possible, automatic, a spool lift ensuring with certainty that the thread does not undergoes no additional tension during the whole lifting operation the full reel and setting up a new reel, so that everything risk of the thread escaping on the new bobbin during start-up or wire breakage due to overvoltage is avoided.

In addition, the fact that the wire is protected against excess voltage, operating incidents such as wire breakage or wire exhaust can be avoided, so the performance of the machine can be significantly improved.

Of course, the invention is not limited to the modes of embodiment described and shown in the accompanying drawings. Modifications remain possible, especially from the point of view of the constitution of the various elements or by substitution of technical equivalents, without leaving for as much of the scope of protection of the invention as defined by the claims.

Claims (13)

1. Method for automatic doffing of bobbins on a take-up station of a yarn-take-up machine comprising a means (1) for holding and releasing a bobbin package (2), a take-up piece (3) guiding the yarn to be wound during the take-up, a bar (7) for releasing the take-up piece (3), a bobbin drive (4), caps (5) for gripping and holding a tube (6), and a device (8) for feeding tubes (6) to the station, characterised in that it substantially consists in reducing the tension of the feeder yarn during each doffing cycle, while stopping the yarn from unwinding, then in starting a new take-up cycle again after the completion of the doffing cycle.
2. Method according to claim 1, characterised in that the tension of the feeder yarn is reduced while take-up is being stopped, during the deceleration phase of the bobbin.
3. Method according to claim 1, characterised in that the tension of the feeder yarn is reduced as the bobbin is stopped completely.
4. Method according to claim 1, characterised in that the tension of the feeder yarn is reduced after the bobbin has stopped completely.
5. Method according to claim 1, characterised in that the tension of the feeder yarn is reduced while the bobbin is being stopped, before the bobbin package is released.
6. Method according to claim 1, characterised in that the tension of the feeder yarn is reduced while the bobbin is being stopped, as the bobbin package is released.
7. Method according to claim 1, characterised in that the tension of the feeder yarn is reduced while the bobbin is being stopped, just after the bobbin package has been released.
8. Method according to any one of claims 3, 4, 6 and 7, characterised in that the tension of the feeder yarn is reduced upstream of the take-up station.
9. Method according to any one of claims 3 to 8, characterised in that the tension of the feeder yarn is reduced, by driving the bobbin (2) in the opposite direction to its take-up rotation, using the bobbin drive (4), which is driven in the opposite direction, for a short period of time, using a mechanical, electrical, electronic or other type of inverter.
10. Method according to any one of claims 2 to 8, characterised in that the tension of the feeder yarn is reduced by influencing the path of the yarn upstream of the take-up piece (3), all of the driving motors for the take-up, for the take-up piece and for pre-feeding being stopped.
11. Method according to claim 10, characterised in that the reduction is achieved by influencing the length of the yarn path, by providing one or more diversion cylinders in said path, these diversion cylinders being displaceable outside a rectilinear path.
12. Method according to claim 10, characterised in that the reduction is achieved by relative displacement of the various diversion cylinders forming the pre-feed, so as to shorten the travel of the yarn during a stopping process.
13. Method according to claim 9 or claim 12, characterised in that the various commands for reversing the course of the bobbin drive (4) or for displacing the various diversion cylinders are given automatically.

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