EP1319623B1 - Method and device for knotting a thread on a bobbin - Google Patents

Description

The present invention relates to the field of the textile industry, in particular winding son and in particular the knotting of an end of thread on a spool and relates to a method of knotting a thread on a spool. coil.

The invention also relates to a device for the implementation of of this process.

The packaging of products in the form of threads is carried out usually on media called coil. Such a coil is constituted by a succession of layers of the product to be wound. In end of coil, the end of the wound product should always be attached in order to avoid more or less unwinding during subsequent handling of the reel, especially during transport. This phenomenon of unwinding is even more important that the wound product is flexible, in particular in the case of textile threads.

Currently, the subjection of the free end of the wire is performed in different ways, namely by implementing a film in synthetic material encircling the coil by pinching the end of the wire in the support or bobbin, by manual or automatic knotting of the end of the wire on itself or by pinching said end in the under layers.

End tying processes known to date have been however a number of disadvantages. In the case of realization strapping, it is necessary to use a complementary product such as a film, while in the case of a pinch of the end in the support the shape of the coil must be specially adapted, so that it can not more, then, that to be used only at the unrolled.

The knotting of the end of the thread on itself induces a movement of complex knotting and risk of slipping, in the presence of slippery threads.

Finally, during a pinching of the end in the under layer, this pinching is dependent on the hardness limit of coils and brittle wires may be damaged.

It is also known from DE-C-187 936 a method and a device for forming two loops that are twisted on themselves. In such a process, it is not the end of the wire which is seized to entangle the threads and their knotting on the spool, but a thread energized on a winder and guided by a wire guide.

Furthermore, JP-A-08 319062 discloses a device, in which a twist is made on a loop obtained by inserting a bar between the wire to be wound and the coil in formation, this bar being removed before entangling the entire loop with the end of the wire. It follows that this entangling practically makes a knot on the spool, so that it becomes impossible to undo the entanglement by pulling on the end of the thread.

The present invention aims to overcome these disadvantages by proposing a method of tying a thread onto a spool and a device for the implementation of this method allowing automatic locking and universal end of a wire on a coil, regardless of the type of support, wire or hardness of the coil, while ensuring a knot Reliable and easy stripping, when used later.

For this purpose, the method of tying a thread on a reel, wherein the end of the wire is previously grasped, characterized in that essentially consists in positioning said wire under tension in the extension of the last wound coil, to make a loose loop parallel to the end of the stretched wire, then to form a twist for twisting a strand of the loose loop with the end of the wire stretched, to tighten the twist obtained on the spool, the tightening being carried out by a pull on the end of the stretched wire, and cut off the remaining end of the wire.

The invention also relates to a device for the implementation of of this method, comprising a device for gripping the end of the wire, characterized in that the gripper of the end of the wire forms also a device for positioning said wound end of wire, and in that it essentially consists of a means for producing a loose loop, by a device for forming a twist and by a means cutting the remaining end of the wire.

la figure 1 est une vue schématique en perspective d'un dispositif pour la mise en oeuvre du procédé conforme à l'invention, et

les figures 2 à 9 sont des vues partielles en perspective représentant différentes phases du nouage.

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

FIG. 1 is a schematic perspective view of a device for carrying out the method according to the invention, and

Figures 2 to 9 are partial perspective views showing different phases of the knotting.

Figures 1 to 5, 8 and 9 of the accompanying drawings show a coil of wire 1 mounted on a rotation support 2 and having a free end 3 located randomly on the periphery of the coil 1, the machine comprising this rotation support 2 being further provided with a device 4 for knotting a thread on a spool. In the embodiment shown, the coil 1 is mounted on a mandrel-shaped support. However, it is also possible to mount the coil 1 on a support different, this support being simply able to turn in both directions of rotation.

According to the invention, the device 4 for knotting a yarn implements a knotting process, which essentially involves grasping the end 3 of the wire and to position said wire under tension in the extension of the last wound coil, to make a loose loop parallel to the end 3 of the tensioned wire, then to form a twist for each twisting a strand of the loose loop with the end of the wire stretched, to tighten then the twist obtained on the reel and cut the remaining end of the thread.

According to a first embodiment of the invention represented in the accompanying drawings, the capture of the end 3 of the wire and its positioning energized in the extension of the last wound coil are performed by suction of said end 3 and rotating unwinding rotation of wire of the coil 1 by the support 2, with simultaneous realization of a predetermined length of tensioned wire, then by displacement of the strand of wire stretched transversely to the longitudinal axis of the coil 1 and by partial rewinding of the yarn to obtain an aligned right turn with the stretched wire (Figures 2 and 3). For this purpose, a predetermined length of wire, corresponding to a predetermined number of rotation turns of unwinding of the coil 1 can easily be calculated, is unwound and aspirated. During aspiration or at the end of the aspiration, it is spared a space in which the thread is stretched and in which can penetrate a means of deflection of the wire at the end of the aspiration, so that the latter can be brought under tension in a position inclined transversely to to the longitudinal axis of the coil 1 (Figure 3). When rewinding As a result, the thread thus held rolls up until a straight turn is made (Figure 3).

Making the loop loose, parallel to the end 3 stretched wire is made by forming a turn of circumference clearly greater than that of the turns of the coil 1, in the direction of rotation of winding, with keeping the free end 3 of the wire under tension. This Loose loop formation can be achieved with pull on the end free wire 3 and simultaneous rotation of the coil 1 and a support means offset with respect to the maximum diameter of the coil 1, in the direction of the winding, as shown in Figures 4 and 5 of the accompanying drawings. So, part of the suction-stretched wire is sent back to the spool 1 forming a loop or turn of diameter greater than that of the turns beforehand coiled, this loop being placed by one of its strands, after a rotation of a turn, next to the end 3 of stretched wire.

According to an alternative embodiment of the invention, not shown In the accompanying drawings, the formation of the loose loop may also be carried out by a support means offset with respect to the maximum diameter of the coil 1, moving around the coil 1 in the winding direction, the end 3 of tensioned wire being held firmly and the coil 1 being kept free rotation on the support 2, the loop looses or turns more large circumference being obtained by a corresponding partial unwinding of the coil 1, under traction. In such a case, the displacement of the means deported support relative to the maximum diameter of the coil 1 drive a pull on the wound thread causing the effect of unwinding corresponding partial part of the coil 1 during the displacement of the medium deported support and its passage on the generator of the latter. So, the Loose loop or larger diameter coil is made by pulling on a wound spire and elongation of this turn by partial unwinding corresponding.

The formation of the twisting twist is effected by a seizure simultaneous one strand of the loose loop and the end 3 of stretched wire, followed by a mechanical or pneumatic impression of a movement of rotation of the strand of the loop around the end of stretched wire 3 (FIGS. 7). This formation of the twist consists, in fact, in twisting a Loose loop strand on the end 3 of stretched wire, so that they remain intimately linked.

The tightening of the twist obtained on the spool 1 is carried out, as shown in particular in Figure 9 of the accompanying drawings, by action a pull on the end 3 of stretched wire under the effect of a rotation of the coil 1 in the winding direction and a stationary hold of said end 3 of tensioned wire or under the effect of a direct traction on said end 3 of stretched wire. Such traction has the effect of forming a light knotting the last turn of thread on the spool 1, by reducing the circumference of the loose loop and simultaneous cooperation of a strand of this last with the end 3 of stretched wire. In the case where the end 3 of wire tense is subjected to direct traction, the said end is drawn in direction opposite to the coil 1, the latter being kept motionless, of so that the reduction effect described above is also obtained.

The cut of the remaining end of the thread, after knotting, is performed according to known methods with mechanical or thermal action.

The device 4 for knotting a thread for the implementation of this essentially consists of a device for capturing and positioning of the free end 3 of the wound wire, by means 6 of making a loose loop, by a device 7 for forming a twist and by means 8 for cutting the remaining end 3 of the wire.

According to a preferred embodiment of the invention, shown in FIGS. 1 to 3 of the accompanying drawings, the gripping device 5 and for positioning the free end 3 of the wound wire is advantageously constituted by a suction nozzle 9, equipped with a wire detection cell (not shown) and movable toward and away from the coil 1 in a plane passing through the longitudinal axis of the latter and by a positioning plate 10 movable from an external position to the longitudinal dimensions of the coil 1, parallel to the axis longitudinal axis of said coil 1 and provided with a notch 10 'for indexing the wire sucked by the nozzle 9. Preferably, the suction nozzle 9 is provided internally with a permeable retainer such as a fine grid or a foam sheet, intended to retain the sucked end of the wire 3. Thus, the wire sucked by the nozzle 9 can be disposed inside the latter in avoiding being subjected to a detorsion effect due to suction. It results the end of the wire stays perfectly in shape when rewinding or of subsequent use.

The search of the free end 3 of the wire is carried out by displacement of the suction nozzle 9, in a movement C (Figure 2) towards the surface of the coil 1 which turns on itself in direction A winding the wire until the free end 3 of the wound wire is detected by the detection cell of the suction nozzle 9. This cell then triggers a reversal of the direction of rotation of the coil 1 by means of of the support 2 in the direction B, so as to perform a unwinding of the wire, which can be sucked by the nozzle 9. The latter moves away in direction D of the coil 1, while remaining in operation, when a length predetermined thread is sucked. The sucked wire is therefore under tension between the coil 1 and the nozzle 9 (Figure 2).

The positioning plate 10 is then moved parallel to the longitudinal axis of the coil 1, so as to cross the end 3 of wire stretched between said coil 1 and the suction nozzle 9, the wire automatically positioning itself in the indexing notch 10 '. This displacement of the positioning plate 10 has the consequence to bring the wire in an inclined position relative to a perpendicular to the coil 1. The latter is then rotated in winding by the support 2, which has the effect of positioning the wire perpendicularly to the coil 1 and making at least one straight turn aligned with the wire stretched (Figure 3).

The means 6 for producing a loose loop is presented advantageously in the form of a retractable abutment 11 mounted by through a pivoting linkage 12 actuated by a non-jack shown, on a rotary sleeve 13 coaxial with the coil 1 and driven in rotation, disengageable manner. The rotational drive of the sleeve 13 can advantageously be achieved by means of an engine independent, not shown, or by means of a device clutch (not shown) co-operating with the rotational drive of the spool 1. To allow a complete clearance of the stop retractable 11 in the rest position, the rotary sleeve 13 is advantageously slidably mounted coaxially to the coil 1 and is actuated in sliding displacement via a cylinder not shown. Moreover, to ensure a perfect release of the retractable abutment 11 after the completion of the loose buckle, the linkage 12 advantageously in the form of a parallelogram, the large opposite side to the corresponding end of the coil is slightly longer than that articulated with the small side bearing the retractable stop 11.

According to a first embodiment of the invention, the stop retractable 11 is advantageously mounted coaxially on a mandrel 14 receiving and rotational drive of the coil 1 (Figures 1 to 5).

So, for the formation of the loose loop in the form of a Spire of circumference clearly greater than that of the turns of the spool 1, after stopping the winding of at least one straight turn in extension of the free end 3 of the wire, the retractable stop 11 is moved in front of said wire stretched by suction of the nozzle. For this purpose, the linkage 12 carrying the stop 11 is first moved by coaxial sliding towards the coil 1, then it is actuated by the corresponding jack in the direction of a pivoting of the abutment 11 in front of the stretched wire, at the right of the notch indexing 10 '(Figure 4).

As shown in FIG. 5 of the accompanying drawings, the loop loose is then formed by a simultaneous rotation of the coil 1 and the retractable abutment 11 around the longitudinal axis of the coil 1. It As a result, part of the suction-stretched wire is sent to the spool 1 by forming a loop or turn of diameter greater than that of the turns previously wound, this loop being placed by one of its strands, after a rotation of one turn, next to the end 3 of stretched wire. This Loop loop is made by pulling on the wire stretched by aspiration.

According to an alternative embodiment of the invention, not shown in the accompanying drawings, the means 6 for producing a loose loop can also be in the form of a retractable abutment independent of the drive of the coil 1 and whose axis of rotation is coaxial with that of the coil 1, said retractable stop being guided along a path elliptical. Such an embodiment may, in particular, be adapted to a application of the device on a winder, the retractable stop being then driven by a specific means and guided laterally to the post of winding. Thus, it is sufficient, at the end of winding, to make several turns straight by stopping the movement of the winder's fly and pinching at the level of said fly at the stop of the winding cylinder, the setting in place of the retractable stop in front of the stretched wire and the displacement consecutive of said abutment along its elliptical trajectory having the effect of allow the realization of the loose loop with traction on the wire maintained under tension by clamping. As a result, the formation of the loop is carried out with a light unwinding of the thread previously wound on the turns straight, the drive of the coil 1 being then disengaged.

The device 7 for forming a twist may be constituted, according to a first embodiment of the invention shown in FIG. of the accompanying drawings, by an open channel air nozzle 15 'having a receiving chamber of a portion of stretched wire 3 and a portion corresponding parallel strand of the loose loop.

Figure 7 of the accompanying drawings shows a variant of embodiment of the device 7 for forming a twist, in which this device is constituted by a mechanical friction assembly comprising two strips 16 moving against the direction and pressing each other of the assembly formed by the stretched wire end 3 and by the strand corresponding to the loose loop.

In the case of using an air nozzle 15 according to FIG. 6, an injection of pressurized air into said nozzle for a period of predetermined, allows to create an entanglement of the two portions of son parallel, by torsion. The use of a mechanical friction assembly (Figure 7) allows to achieve the same result. It follows that the free end 3 of stretched wire is closely related to a corresponding portion of the loop loose.

Tightening the obtained twist or tying the end of the thread on the coil 1 is simply performed by pulling on said end thread held by a thread clamp 17 in the notch 10 'of the plate 10, said traction being generated by a rotation of the coil 1 in the direction of a rewind. It is also possible to pull on the wire by Braking the coil 1 on its drive means the wire end 3 being then subjected to a displacement in the opposite direction to the winding direction, for example by printing a withdrawal movement on a threaded wire in a winder. This pull on the wire on the stretched end of wire has for effect of making a knot of said yarn around the spool 1, knot of sufficient consistency to prevent inadvertent unwinding of wires during transportation or handling operations.

The means 8 for cutting the remaining end 3 of the wire can be constituted by any existing devices, mechanical or thermal wire cutting and is not described in more detail.

Thanks to the invention, it is possible to perform a hooking Automatically from a free end of a coil wire on a coil, what regardless of the type of wire support or coil hardness, while guaranteeing optimum reliability or strength with regard to the point of attachment and maintaining an opportunity to easily undo the knot obtained during the use of the wound product, by simply pulling on the free end.

Of course, the invention is not limited to the mode of embodiment described and shown in the accompanying drawings. Modifications remain possible, particularly from the point of view of the constitution of the various elements or by substituting technical equivalents, without going out for as much of the field of protection of the invention.

Claims (20)

1. Method of tying a yarn to a bobbin, in which the end (3) of the yarn is taken up beforehand, characterised in that it consists essentially of positioning said yarn under tension in the extension of the last wound turn, of making a slack loop parallel to the end (3) of the taut yarn, then making a twist by twisting a strand of the slack loop together with the end (3) of the taut yarn, of then tightening the obtained twist onto the bobbin (1), the tightening being effected by traction on the end (3) of the taut yarn, and of cutting off the remaining end of the yarn.
2. Method according to claim 1, characterised in that the end (3) of the yarn is taken up and positioned under tension in the extension of the last wound turn by aspiration of said end (3) and unwinding of the yarn from the bobbin (1) by means of a support (2) with simultaneous production of a predetermined length of the taut yarn, then by moving a strand of the taut yarn transversely to the longitudinal axis of the bobbin (1) and by partially rewinding the yarn with a view to obtaining a straight turn aligned with the taut yarn.
3. Method according to any one of claims 1 and 2, characterised in that during aspiration or at the end of aspiration, a space is created in which the yarn is tensioned and into which yarn diverting means may penetrate at the end of aspiration, so that the yarn may be brought under tension into a transversely inclined position relative to the longitudinal axis of the bobbin (1).
4. Method according to any one of claims 1 to 3, characterised in that when the yarn is rewound after completion of aspiration, the supported yarn winds into a straight turn.
5. Method according to claim 1, characterised in that the slack loop, parallel to the end (3) of the taut yarn, is produced by formation of a turn having a much greater circumference than the circumference of the turns of the bobbin (1), in the rotational direction of winding, the free end (3) of the yarn being kept under tension.
6. Method according to claim 5, characterised in that the slack loop is formed by traction on the free end (3) of the yarn and by simultaneous rotation of the bobbin (1) and a support means, which is off-centre in comparison with the maximum diameter of the bobbin (1), in the winding direction.
7. Method according to claim 1, characterised in that the slack loop is formed by a support unit, which is off-centre in comparison with the maximum diameter of the bobbin (1), moving around the bobbin (1) in the winding direction, the end (3) of the taut yarn being firmly held and the bobbin (1) being kept in free rotation on the support (2), the slack loop or the turn having a greater circumference being obtained by corresponding partial unwinding of the bobbin (1) under traction.
8. Method according to claim 1, characterised in that the twist, which is formed by twisting, is made by simultaneous take-up of a strand of the slack loop and the end (3) of the taut yarn, followed by mechanical or pneumatic impression of a rotational movement of the strand of the loop around the end (3) of the taut yarn.
9. Method according to claim 1, characterised in that the twist obtained on the bobbin (1) is tightened by traction on the end (3) of the taut yarn by the effect of rotation of the bobbin (1) in the winding direction and holding of said end (3) of the taut yarn in a stationary manner, or by the effect of traction on said end (3) of the taut yarn.
10. Device for carrying out the method according to any one of claims 1 to 9, comprising a take-up device (5) for the end (3) of the yarn, characterised in that the take-up device (5) for the end (3) of the yarn also forms a positioning device for said end of the wound yarn, and in that the take-up device consists essentially of means (6) for producing a slack loop, a device (7) for producing a twist and cutting means (8) for the remaining end (3) of the yarn.
11. Device according to claim 10, characterised in that the take-up and positioning device (5) for the free end (3) of the wound yarn consists of a suction nozzle (9) for the yarn, the suction nozzle being provided with a yarn detection cell and being movable in the plane of the longitudinal axis of the bobbin (1) as it moves closer to or away from the bobbin (1), and of a positioning plate (10) which is movable from a position at the exterior of the longitudinal dimension of the bobbin (1) parallel to the longitudinal axis of said bobbin (1) and which is provided with an index notch (10') for the yarn aspirated by the nozzle (9).
12. Device according to claim 11, characterised in that the suction nozzle (9) is provided with an internal permeable retaining element in the form of a fine grille or foam sheet for holding the aspirated yarn end (3).
13. Device according to claim 10, characterised in that the means (6) for producing a slack loop are in the form of a retractable stop (11), which is mounted by means of a cylinder-operated pivotal rod linkage (12) on a rotating sleeve (13) which is coaxial to the bobbin (1) and set into rotation in a disengaging manner.
14. Device according to claim 13, characterised in that the sleeve (13) is rotated by means of an independent motor or a clutch device cooperating with the rotation of the bobbin (1).
15. Device according to claim 13, characterised in that the rotatable sleeve (13) is mounted in a sliding manner coaxially to the bobbin (1) and is made to slide by means of a cylinder.
16. Device according to any one of claims 13 and 14, characterised in that the rod linkage (12) is in the form of a parallelogram, of which the large side opposite to the corresponding end of the bobbin is slightly longer than the side which is hinged to the small side carrying the retractable stop (11).
17. Device according to claim 13, characterised in that the retractable stop (11) is coaxially mounted on a mandrel (14) for receiving the bobbin (1) or setting it into rotation.
18. Device according to claim 10, characterised in that the means (6) for producing a slack loop are in the form of a retractable stop independent of the drive of the bobbin (1) and of which the axis of rotation is coaxial to that of the bobbin (1), said retractable stop being guided along an elliptical path.
19. Device according to claim 10, characterised in that the device (7) for forming a slack loop consists of an air nozzle (15) having an open channel (15') exhibiting a chamber for receiving a portion of the taut yarn (3) and a corresponding parallel portion of strand of the slack loop.
20. Device according to claim 10, characterised in that the device (7) for forming a twist consists of a mechanical friction unit comprising two bands (16), which move in opposite directions and are placed against either side of the unit formed by the end of the taut yarn (3) and by the corresponding strand of the slack loop.

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