FR2997389A1 - Control device for controlling dispensing of synthetic thread between two reels in rack, has detector for detecting presence of thread connecting two reels, and securing unit securing thread perpendicular to normal insertion direction - Google Patents

Abstract

The device (1) has a detector for detecting the presence of a thread (2) connecting two reels (3) that are successively emptied by the last turn of the thread and the first turn of the thread. A securing unit firmly secures the thread perpendicular to its direction of normal insertion in the control device. The securing unit includes an elastic lever forming a jaw to press the thread against an opposite surface forming another jaw. The detector includes an electrical circuit (15) presenting two contacts that are open in the event of presence of the thread. An independent claim is also included for a rack for dispensing thread from the reels.

Description

The present invention relates to the field of equipment for the treatment of yarn, in particular of synthetic yarn to be textured, woven, tufted, and more particularly to a yarn control device, as well as a rack on which Wire coils can be mounted to feed a downstream processing facility. In the equipment concerned by the invention, the treatment line generally works continuously, while the wire is fed by coils, which therefore represents a discontinuous power supply. To supply a yarn continuously from bobbins, it is then common to connect the spool that is unwound to a spare spool so that the last spire of the spool that is unwound is tied by a piecing thread to the first spool. turn of the spare coil. Thus, after the last turn of the first coil has been sent in the downstream stages of the treatment, it is the first turn of the reserve coil which is sent in turn. Then simply replace the empty coil with a full reel, and connect them again as described above. One of the problems that appears in this type of equipment is however that the number of different son to feed can be very high, and it is then necessary to intervene very regularly on the rack to install a spare coil, and this at various places. An operator must therefore spend a large part of his time verifying whether, for each wire, the power comes from the spare coil. No. 5,544,679 proposes to detect the presence or absence of the piecing wire to signal the permutation between the coils.

Indeed, as the supply is continuous, the piecing wire is, when the first coil is empty, sent to the downstream parts of the treatment, followed by the first turns of the spare coil. The absence of the piecing wire is therefore the logical sign that the permutation between the two coils has taken place, and that it is necessary to put a new spare coil. Various piecing wire detection devices have been developed. Thus, US 2005/0 278 914 proposes a piecing thread detector which has a groove in which the piecing thread can be inserted transversely, the latter being taken in a pivoting fork. When the piecing wire is sent in the downstream stages of treatment, the fork pivots and actuates, at the end of its movement, a micro switch.

FR 2 527 661 proposes a detection device having a groove in which the wire must be placed longitudinally, and so as to hold a blade against one of the walls of the groove. When the wire disappears, the blade returns to its stable position and, as it then acts directly on a micro switch, it can detect the absence of piecing wire. However, it is necessary for the operator to correctly handle both the wire, to place it in the groove, and the blade. The detection of the position of a moving part driven by the piecing thread is also used in US 2001/0 037 545 or US 5 137 059, the moving part of the latter taking a shape of L pivoting around its right angle, one of the branches being driven by the output of the wire and detected, the other being driven by the insertion of the wire. BE 905 312 proposes a detection device having a normally closed electrical circuit thanks, inter alia, to a lamella arriving at the electrical contact of a conductive plate. When the piecing wire is sent downstream of the treatment, its movement requires its passage between the lamella and the conductive plate, thereby generating a temporary opening of the circuit, the detection of which is the sign of the permutation between the coils. One of the drawbacks of this embodiment is that the reliability of the detection is based on the strict electrical closing of the circuit outside the moments when the piecing wire moves. A bad electrical contact will be misinterpreted as a permutation. In addition to the possible disadvantages related to the reliability and ergonomics of some of the embodiments mentioned above, they generally have the disadvantage of being too sensitive to the movement of the piecing wire, to the point that any movement, even not caused by permutation but for example by a current of air, manipulation close to the operator, vibrations, or others, creates a permutation signal, which can be erroneous. In addition, too great mobility of the piecing thread, in particular in the direction of its axis, can be problematic in applications where the reeling is done at high speed, as for yarns for textile applications: the unwinding speed can make radially away the wire unwound from the coil, creating a peripheral volume around it in which the presence of the piecing wire is likely to create breaks. Regardless of the detection of the piecing wire, it is therefore important to ensure that the latter does not risk at any time to interfere with the wire moving widely around the coil. The object of the present invention is to overcome at least a part and preferably all these drawbacks and thus to improve the control of the unwinding by holding the piecing thread sufficiently tightly in the presence detector, and / or by keeping the piecing thread sufficiently away from the coils. For this purpose, the invention firstly relates to a control device for piecing thread, comprising at least one means for detecting the presence of a piecing thread connecting the windings of two coils to be emptied successively, and this at the last turn for the first emptied spool and the first spire for the spool then emptied. This device is characterized in that it comprises, in addition, at least one holding means for firmly holding the piecing wire. The invention also relates to a feed rack for continuously feeding at least one wire from reels, comprising at least two reel supports for their fixing in the rack, said supports each having a front end at the level of which wire is cut and a base at the opposite end for anchoring to the rest of the rack. This rack is a rack characterized in that it comprises, in addition, at least one control device for piecing thread, comprising at least one holding means for firmly holding the piecing thread, connecting the windings of two coils to be emptied successively. at the last turn for the first emptied spool and the first turn for the spool emptied afterwards. The invention will be better understood, thanks to the following description, which refers to preferred embodiments, given by way of nonlimiting examples, and explained with reference to the appended diagrammatic drawings, in which: FIG. 1 shows a control device provided with two holding means and two detecting means; - Figure 2 shows an exploded partial view of a control device; Figure 3 shows a rack portion on which a control device is mounted; - Figure 4 shows a rack according to the invention; - Figure 5 shows a section of another control device according to the invention; - Figure 6 shows the same section, but in perspective, and - Figure 7 shows a beam provided with such a control device. The invention therefore firstly relates to a control device 1 for connecting yarn 2, comprising at least one means for detecting the presence of a piecing yarn 2 connecting the windings of two coils 3 to be emptied successively, and this at the last turn for the coil 3 emptied first and the first turn for the coil 3 emptied after.

The piecing yarn 2 is conventionally obtained by simply connecting the windings of the two coils 3, it therefore extends normally from the central core of the reel 3 unwound first to the circumference of the reel 3 then unwound. In a normal case, the piecing wire 2 leaves the reel 3 unwound first from the opposite end to that where the wire is pulled by the downstream installation, and arrives at the reel 3 unwound then at the level of the end where the wire is pulled. As will be described further below, the coils 3 are mounted on supports 13 of a rack 10, these supports 13 allowing them to be threaded thereon and being oriented toward each other in the direction of exit of the wire, that is to say towards an exit zone of the wire, the latter being thus unwound and not unrolled. To obtain a continuous supply of the wire, it is therefore sufficient to connect by piecing son 2 as many coils 3 as desired. Conventionally, the wire is provided by a coil 3, another serving as reserve. When the power has switched on the reserve coil 3, a new coil 3 is placed and so on. Naturally, the continuous supply for a wire can be done using a succession of more than two coils 3 attached to one another, the rack 10 then being designed accordingly, so that the supports 13 coils 3 of the same wire can be oriented towards the same output zone of the wire. According to the invention, the control device 1 further comprises at least one holding means for firmly holding the piecing wire 2, thus helping to ensure that only the switching between the coils 3 creates a movement detected by the at least one corresponding detection means. The piecing thread 2 is thus mechanically retained by the holding means, the latter not however completely blocking the piecing thread 2 but allowing it to leave the control device 1 during normal unwinding and the passage of a reel 3 to the other. Maintaining the piecing thread 2 firmly at the level of the control device 1 thus makes it possible to guarantee that the piecing thread 2 is not too sucked up by the movement of the thread pulled during the unwinding, also prevents the piecing thread 2 from moving for other reasons than a permutation between the coils 3, for example vibrations, which could have the effect of causing absence detection, or even placing the piecing wire 2 in the circulation zone of the unwound wire. The firm hold does not prevent the tension exerted to unwind releases the piecing thread 2 of the holding means and leads to the downstream processing steps. Thus, the control device 1 alone fulfills two functions for a piecing thread 2, namely, on the one hand, to hold it firmly so that only the permutation between two coils 3 is detected, and, on the other hand, 2. The control device is thus provided, for the or each wire to be unwound continuously, respectively, a holding means and a detection means. Possible specificities of the holding means are detailed below. Thus, according to a possible additional feature, the at least one holding means is arranged to hold the piecing wire 2 perpendicular to its normal insertion direction in the control device 1, and thus to retain it in its great length. The holding means is arranged so that the piecing wire 2 is engaged by a movement perpendicular to the direction of its great length, and maintains the piecing wire 2 to prevent movement in the direction of its great length, which means that the holding means will firmly oppose a pull on the piecing thread 2 and which is parallel to the portion of the piecing thread 2 which is gripped by the holding means. The holding means retains much less firmly the piecing thread 2 perpendicular to the portion that it grasps, which corresponds to the normal direction of insertion or output of the control device 1. The insertion piecing thread 2 is performed by an operator, the output of the piecing wire 2 being caused by the traction of the processing equipment downstream of the rack 10. To obtain a maintenance of this type, and according to an additional possible feature, the piecing wire 2 is held by gripping between two jaws 4, at least one of them being elastic and forming part of the control device 1. Various configurations are possible, among which: the holding means comprises a jaw 4 at the end of a elastic lever 17, which, once the control device 1 installed, comes against a beam 9 of a rack 10, said beam 9 forming the second jaw 4, the piecing wire 2 coming from be clamped between the two jaws 4 and away through its presence, the resilient lever 17 of the beam 9; - The holding means comprises two jaws 4, of which only one of them is elastic, the other being rigid and carried by a rigid piece fixed on a beam 9 of a rack 10, or carried by a beam 9 of the control device 1, which is mounted on the rack 10; - The holding means comprises two jaws 4, one of them, elastic, located between a beam 9 of the rack 10 and the piecing thread 2, the other being formed at a base 5 of the device 1, placed around said beam 9. In these different embodiments, the at least one holding means comprises at least one elastic lever 17, forming a first jaw 4 for pressing the piecing wire 2 against an opposite surface 25 forming a second jaw 4, possibly elastic too, belonging to the control device 1 or the rack 10. Thus, in a first embodiment, and as shown in Figure 1, the at least one elastic lever 17 is arranged to elastically press the 2. The possible base 5 of the control device 1, illustrated in FIG. 3, is in fact normally intended to be placed around a truss. the 9 or profile of a rack 10, which passes through it essentially at its center and forms a fixing of the support 5 on a rack 10. The elastic lever 17 is such that its springback exerts a force on the piecing thread 2 in the direction of fixing the support 5 of the center of the beam 9, and therefore the median plane 16 of the base 5, plane of symmetry. In other words, the elastic lever 17 acts on the piecing wire 2 in the direction of the holding zone of the support 5 to the rack 10. It is therefore easily possible to use for the second jaw 4 the beam 9 it itself, on which the support 5 is fixed, since the elastic lever 17 can press the piecing thread 2 in its direction.

According to a possible additional characteristic of the control device 1, it further comprises a piece, in the form of a beam 9, to be fixed to a rack 10, and forming one of the jaws 4, in particular the jaw 4 facing The control device 1 therefore comprises here a beam 9 which is then placed on a rack 10. The beam 9 is intended to pass through the possible base 5 of the control device 1. in the center, the base 5 being mounted on the beam 9. Once the beam 9 of the control device 1 placed on the rack 10, the base 5 of the control device 1 is placed around it, so that the absence of piecing wire, the elastic lever 17, forming one of the two jaws 4, comes into contact with the beam 9, forming the second jaw 4, and it deviates from it when a wire 2 is inserted between these two jaws. type of part that a section in the form of beam 9 can be used for fixing the control device 1.

According to another possible additional feature of the control device 1, it comprises two holding means, each for a respective piecing wire 2, arranged vis-à-vis one another. As shown in Figures 1, 2, 5 and 6, each holding means therefore comprises two jaws 4 which meet at one end and which move away from each other at their other end, to form a flared shape facilitating the introduction between them of piecing wire 2. Each of the two holding means may thus take the form of an elastic lever 17 which presses the possible piecing wire 2 against a beam 9, as shown in particular FIGS. 5 or 6. Each of the elastic levers 17 is intended for a piecing wire 2, which it presses against the beam 9 in the direction of the other elastic lever 17. In the cases where the control device 1 is provided with a base 5, the elastic lever 17 of each of the two holding means is a part mounted within this base 5, thus forming a capsule in which the various functional elements are housed. It should be noted that in the case of FIGS. 1, 5 and 6, a single piece is used to form each of the two jaws 4 against which the elastic levers 17 come to press the piecing wire 2. This piece can be the beam 9 already existing a rack 10, or a profile of the control device 1 which is then mounted in the rack 10, or a piece of another form that is placed in the rack 10. Possible specificities detection means will now be described. Thus, according to an additional feature, the at least one presence detection means comprises an electrical circuit 10 having two contacts between which it is open in the presence of the piecing wire 2 which then moves them away from each other, and closed in case of absence of piecing wire 2. If piecing wire 2 is present in the control device 1, and more precisely in the detection means, its electrical circuit is open, whereas if it is absent the contacts of the electrical circuit are touching and the circuit is closed. The insulating nature of the piecing wire 2 can therefore be used here to ensure that the piecing wire 2 itself forms the insulating substance placed between the electrical contacts. According to an additional possible feature, one of the contacts is carried by the at least one elastic lever 17. Thus, when the piecing thread 2 is present and deforms this lever, it moves one of the contacts and away from the other, and can therefore open the electrical detection circuit. As shown in FIG. 1, and according to a possible additional characteristic of the control device 1, one of the contacts takes the form of a metal insert in the at least one elastic lever 17, the latter being made of insulating material, the Another contact may be formed by a metal beam 9, in contact with which the insert can come. Thus, one of the contacts of the electrical detection circuit is carried by the at least one elastic lever 17 and is therefore preferably housed within the base itself 5. This contact, in the absence of piecing wire 2, comes into contact with 30 the beam 9 is mounted in the rack 10. This beam 9 is therefore part of the electrical detection circuit, but it is also possible, as described further below, the other contact is simply a metal piece, which passes through the beam 9 against which is the elastic lever 17 carrying the other contact. One of the advantages of using an existing beam 9 of a rack 10 is that it generally belongs to a metal structure, which is therefore conductive, which makes it possible to place a plurality of control devices 1 - 9 - whose electrical detection circuits are connected to the same electric mass. It is sufficient, for each detection device 1, to connect one of the contacts to the beam 9, the other contact coming, in the absence of the piecing wire 2, in contact with the beam 9.

In particular embodiments, the at least one detection means also comprises a power supply and a light indicator, lit when the piecing wire 2 is absent, or even a signal transmission means, with or without wire to indicate the presence and / or absence of the piecing wire 2 between the coils 3, such as a wireless signal transmitter or a plug-in terminal of a cable. The indicator light is off because the piecing wire 2 opens the detection circuit between the two contacts. Preferably, the power supply is autonomous and takes the form of a battery, rechargeable battery, possibly by a photovoltaic cell whose control device 1 is provided. In the appended figures, the control device 1 therefore has, each time for a piecing wire 2, on the one hand, a presence detection means, and, on the other hand, a means for maintaining said piecing wire 2 As will appear in the description below, the firm holding function and the detection function are provided by the same parts, namely the two jaws 4 that form, on the one hand, a metal elastic lever 17, conductive, and, on the other hand, the beam 9. Thus, each holding means is essentially formed by an elastic lever 17 placed along a surface of a beam 9 belonging to the rack 10. The piecing thread 2 is then periodically located between the beam 9 and the elastic lever 17, then deformed. The tendency of the elastic lever 17 to return to press against the surface of the beam 9 has the natural effect of pinching the piecing thread 2 against the beam 9, the latter being thus firmly maintained, but which can, however, easily be removed from the beam. this position. According to an additional possible feature, the surface of the beam 9 against which the piecing thread 2 passes during the exchange between two coils 3 is oriented towards an exit zone of the rack 10. Thus, and as shown in FIGS. 1 to 3 and 5 to 7, the beam 9 preferably has a section C, an elastic lever 17 being provided on each side of C. Thus, the traction exerted on the wire on the occasion of the permutation between the two coils 3 is only slightly slowed by the shape of the surface of the beam 9 against which it circulates on this occasion. For each of the two piecing wires 2, the detection means forms an electric circuit which the piecing wire 2, by its presence, comes to open. This opening is done by removing the elastic lever 17, which forms one of the contacts of this circuit, the end of a rounded tip screw forming another contact it must touch to close the circuit. It is advantageous that the end of this screw, for contact, has no sharp angle so as not to hinder the movement of the piecing thread 2.

Thus, as shown in FIG. 6, the elastic lever 17 is conductive and electrically connected by a screw which also fixes it to the beam 9. This screw advantageously has the particularity of having a locally square section at the anchor the elastic lever 17 and at the passage of the screw in the thickness of the beam 9. By forming in the beam 9 an opening of square section too, the screw, the elastic lever 17 and the beam 9 are therefore integral in rotation about the axis of the screw. The lever 17 therefore does not rotate, which ensures that the pinching zone of the piecing wire 2 remains the same, as well as the electrical contact area, as described below.

The screw is electrically connected to the necessary potential in the electrical detection circuit thanks to a terminal which it passes through. Of course, it is possible to imagine that the setting to the electrical potential is done directly by contact with the beam 9. Thus, as the screw passes through the beam 9 so that its head forms the contact that will come to touch the elastic lever 17, one of the contacts is carried by a piece against which the elastic lever 17 rests in the free position. More particularly, as shown in FIGS. 5 and 6, the contact, against which the elastic lever 17 carrying the other contact comes, is formed by a conductive screw, whose head reaches at the level of the surface against which the elastic lever 17 extends, thanks to an orifice of greater dimension than the section of said screw, in particular the surface of a beam 9. In the embodiment illustrated graphically, the screw allows, as has been said, to fix the elastic lever 17 but also to retain an insulating base 18, placed on the other side of the skin of the beam 9, inside. Again, at least a portion of the section of the screw where it passes through this base 18 is square, which thus secures in rotation this base 18 with both the screw that the beam 9 and the lever - 11 - Elastic 17. This solidarity in rotation is necessary since the base 18 carries the electrical contact against which the elastic lever 17 comes when the circuit is closed. This base 18 is in fact crossed by another screw, in contact with which should come the elastic lever 17 to close the electrical circuit. To ensure the correct position of the second screw, the base 18 is provided with an insert, preferably metal, duly tapped. This second screw, the end of which forms a contact of the electrical detection circuit, is electrically connected to the remainder of the circuit by means of a lug which it passes through and from which extends a wired, cable-type conductor. The end of this second screw is intended to be touched by the elastic lever 17 to close the elastic circuit when the piecing wire 2 is absent, and it therefore crosses the same wall of the beam 9, thanks to a hole large enough to that the second screw does not come into electrical contact with the beam 9. In order to avoid permanently deforming the elastic lamella, and especially in order not to impede the circulation of the piecing wire 2, it is important that the head of the the screw does not protrude too far beyond the surface of the beam 9, against which the elastic lever 17 extends. It is also important that in the absence of piecing wire 2, the lever 17 is in contact with the second screw, to ensure that the electrical circuit is closed. The use of a calibrated screw whose head has a rounded shape is thus advantageous. Figures 2, 5 and 6 show that the control device 1 has two elastic levers 17, each for a holding means and a detection means, and that the elastic levers 17 are such that the presence of the piecing thread 2 deforms them by moving them away from each other, and their elastic return tends to bring them closer to each other. Of course, in the absolute, a structure in which the elastic deformation is oriented to the opposite is possible. In this case, the presence of the piecing yarn 2 has the effect of bringing the deformable jaws 4 formed by the elastic levers 17 closer to one another. The invention also relates to a feeding rack 35 for dispensing continuously at least one wire from coils 3, comprising at least two supports 13 of coil 3 for their attachment in the rack 10, said supports 13 each having a front end 14 at which the wire is cut and a base 15, at the opposite end, for anchoring to the rest of the rack 10. The base 15 can be pivotable, which allows the operator to access the front end 14 of the support 13, and thus to The bases 15 are generally placed on the structural sections of the rack 10, which can thus have a matrix arrangement of its supports 13, in line and in column. For a wire, two coils 3 are generally provided, and therefore two supports 13, although it is possible to arrange a sequence of more than two coils 3 and thus more than two supports 13. The supports 13 for the same wire are oriented towards an exit zone of the wire, and placed next to each other, pointing towards said zone. As the supports 13 are oriented towards the wire exit zone, the coils 3 are unwound, and therefore remain fixed, the wire being pulled substantially parallel to the radial axis of symmetry of the coils. As explained above, the use of a piecing thread 2 between the two coils 3 allows the wire to be continuously fed. According to the invention, the rack 10 further comprises at least one control device 1 for piecing thread 2, comprising at least one holding means for firmly holding piecing thread 2, connecting the windings of two coils 3 to empty successively, and this at the last turn for the coil 3 emptied first and the first turn for the coil 3 emptied then. The rack 10 is therefore adapted so that a portion of the piecing wire 2 is firmly held in a holding means of a control device 1, which avoids involuntary movements of said piecing wire 2. The at least one device for control 1 that comprises the rack 10 according to the invention makes it possible to firmly hold the piecing wire 2. As has been defined above, this holding means thus ensures a firm hold of the piecing wire 2, that is to say to say a maintenance avoiding an impromptu movement of the piecing thread 2, which may distort the detection or bring it too close to the unwound wire, without however preventing the piecing wire 2 can not be sent downstream of the treatment by the tension exerted on the wire during reeling.

According to an additional possible feature, the at least one holding means is positioned between the two supports 13 and sufficiently far from their front end 14 so that the threaded wire and the piecing thread 2 can not interfere when the latter is caught in the at least one holding means. The unwound thread and the piecing thread 2 do not come into contact with each other, thanks to the position of the holding means which holds the piecing thread 2 and which is housed in the base 5.

The essential advantage of this rack 10 is thus to prevent the piecing thread 2 from catching in the unwound wire which moves radially away from the coil 3, given its speed of movement. The control device 1 can therefore be placed on a beam 9 of the rack 10 so that, once the piecing wire 2 taken in the holding means, it is outside the path that follows the wire unwound, to the circumference of the circumference of the immobile coil winding 3. As the rack 10 has two supports 13 for a wire, each support 13 alternately carries the reserve coil 3, and the piecing wire 2 can therefore start from the proximity of the base 15 of each of the two supports 13, alternatively. It is therefore relevant to place the control device 1 substantially in the middle between the two supports 13. Advantageously, the control device 1 can maintain the position of a portion of the piecing wire 2 beyond the rear end of the supports 13, opposite to the front end 14. As will be further described below, and as shown in Figure 4, when the rack 10 has at least two pairs of supports 13 superimposed, each pair serving a wire, the means of maintaining, and therefore also the detection means, can be placed substantially equidistant, on the one hand, the two coils 3 of the same pair, and, secondly, the two pairs themselves.

According to an additional possible feature, the means for detecting and holding the at least one wire control device 1 are placed behind the supports 13, opposite their front end 14, at the height of the base 15. , so that the piecing thread 2 must be inserted into the holding means of the control device 1 away from the front end 14 of the supports 13, and that, when switching between the two coils 3, it comes out towards the front end 14 of the supports 13. Advantageously, the control device 1 is thus oriented on the rack 10 so that the piecing thread 2 must be inserted by moving the piecing thread 2 away from the front end 14, in the direction of the base 15 of the supports 13. The at least one holding means of the control device 1 is such that it has a portion where the piecing thread 2 is actually maintained, and , remote from this por in the direction of exit of the wire, an open portion, through which it is inserted into said holding means. The bases 15 of the supports 13 are generally placed on a structure made of profiles or beam 9, and it is therefore proposed to place the means for holding and detecting the control device 1 on these beams 9, and therefore essentially in the same This positioning can help to ensure that the piecing wire 2 and the moving wire do not interact with each other. Of course, in cases where the control device 1 comprises a beam 9 to report on an existing rack 10, the same positioning is guaranteed: the holding means ensures a position of piecing wire 2 sufficiently far from the wire unwound to avoid any interference between the unwound wire and the piecing wire 2. According to a possible additional feature of the rack 10, it has at least two pairs of supports 13 superimposed, so as to be able to supply at least two different wires, one wire per pair, the devices holding and detection being positioned between these two pairs and comprising two holding means, one for each wire, arranged in one piece. The detection and holding means of the holding device 1, or even the base 5, are then essentially in the same plane as the bases 15 of the various supports 13, the control device 1 then having two holding means, one for the piecing wire 2 of each coil pair 3. In general, the rack 10 may comprise at least one holding device 1 which has at least one or more of the characteristics described above, in particular a control device 1 which comprises at least one holding means with its possible additional features, and / or which comprises at least one detection means, with its possible additional features, and / or in which the at least one holding means is positioned between the two supports 13 and sufficiently far from their front end 14 so that the wire and the piecing thread 2 can not interfere when the latter is pri s in the at least one holding means. In certain particular embodiments, the control device 1 has a base 5 which takes the form of a U and which is mounted on a beam 9 extending between the two pairs of support 13 and parallel to their plane. common, so that said beam 9 is between the branches of the U, the latter extending towards the front end 14 of the supports 13. The holding means for a piecing wire 2 and 5 the holding means for the other piecing thread 2 are, for one, on one side of the beam 9 fixing, and for the other on the other side. For a piecing thread 2, the detection means and the holding means are thus preferably made by two jaws 4, between which the piecing thread 2 can be taken to ensure a firm hold 10 and that the piecing thread 2 can separate by its simple presence so as to open an electrical circuit, thanks to two contacts that said jaws 4 carry or to which they are electrically connected, one of the two jaws 4 being formed by an elastic lever 17 coming into contact with the second jaw 4 in form of a beam 9 of the rack 10, for the possible fixing of the base 5 of the control device 1. In the embodiment illustrated in FIGS. 1 and 2, the control device 1 comprises two holding means, positioned in the base 5 mirrors one of the other, and the control device 1 thus ensures both the mechanical maintenance function sufficient to stabilize the piecing thread 20 2 that the detecting function of the piececut 2, and this for two piecing son 2 simultaneously. The control device 1 thus comprises a base 5, preferably made of insulating material, taking a global U shape, to be deposited around a beam 9, belonging to the rack 10 on which the control device 1 is mounted, then essentially in the form of the base 5 and its components, or belonging to the control device 1 itself. The branches of this U gradually refine, so that the internal space between them flares outwardly, which facilitates mounting on the beam 9. The elastic lever 17 forming one of the jaws 4 and carrying one of the contacts, is such that once mounted on the beam 9, it moves away from it towards its free end, which allows the operator to simply slip the piecing wire 2 in this space to bring it into the area where the two jaws 4 are almost contiguous at a junction 7, which in Figures 5 and 6, is formed by a screw. The two jaws 4 come closer to each other in the direction of insertion of the piecing wire 2, the nipping thus increasing with the introduction of the piecing wire 2. The control device 1, since the jaws 4 separate from one another from a junction 7 towards which the piecing thread 2 is directed during the insertion, is such that, on the one hand, inserting the wire further 2, in the direction of the junction 7, increases the clamping on the piecing wire 2 and further distances the electrical contacts of the detection circuit from one another, which is therefore very simple for the operator who It is not necessary to gauge the amplitude of the insertion movement required, and secondly, the piecing wire 2 is held by pinching, its extraction, in the direction opposite to its insertion, remaining however easy since the nip decreases. during extraction. The holding means is such that the normal traction exerted on the wire during unwinding for processing in the downstream equipment is sufficient to remove the piecing wire 2, but such as much lower solicitations, air currents, friction , etc., are not enough to clear it. Thanks to this nip between two jaws 4 which converge towards one another, the piecing thread 2 is also maintained in its great length, transverse to the direction of insertion of the piecing thread 2. It follows from this conception that it is not necessary to use electrical components of the micro-switch or other type, since these are two contacts of the electrical detection circuit which must deviate to receive and pinch the piecing wire 2 and thereby , open the circuit. By extension, proximity electromagnetic sensors could also be used. Since the electrical contacts of the detection means are arranged on the inside of the elastic lever 17, they are practically not visible or accessible. The fact that the electrical contacts do not appear and are not accessible also contributes to securing the operator and masking the technical functions of the outside, making the control device 1 much more discreet.

The control device 1 as described is thus mounted in a rack 10, thanks to a profile that extends between two pairs of support 13. Due to its symmetrical design, and therefore having a holding means and a detection means, for two wires, the control device 1 serves the piecing wire 2 of the upper pair of coils 3 and the lower pair of coils 3. In order to ensure that the piecing wire 2 does not interfere with the balloon formed by the wire when it is unwound, the control device 1 having at least one holding function and the at least one holding means corresponding, with or without detection means, is placed so that the base 5, and therefore also the holding means, is at the height of the bases 15 of the supports 13, in particular at the level of the plane in which the various profiles and beams 9 on which are fixed the supports 13, this plane helping to define the outer template of the rack 10. The base 5 of the control device 1 then surrounds the profile on which it is mounted, and extends, for the one of the piecing threads 2, on one side of the profile or beam 9, and, for the other piecing thread 2, on the other side. In general, and therefore even in the case where the device does not have a base 5, as in FIGS. 5 to 7, the elastic levers 17 are placed on one side of the other of the beam 9 or other fastener part. 10. One of the branches of the U whose base 5 takes the form therefore extends on one side of the beam 9, the other branch extending on the other side, the holding means, or even the detection means, being, for each piecing wire 2, at one or other of these branches. As shown in Figure 3, the base 5 also has fastening means to the rack 10, here in the form of a passage for screws, but other forms can of course be considered, such as a snap, for example. Advantageously, the base 5 of the control device 1 has a shape complementary to a part of the rack 10, at least to a beam 9 on which it can be mounted. Each of the two holding means of the control device comprises an elastic lever 17, elastically deformable piece. As has been said above, the base 5 has a global shape in U, to be installed around a support part, extending on both sides thereof. The elastic lever 17 is thus such that it tends to return elastically towards the median plane 16 of symmetry of the base 5 of the control device 1, on either side of which extend the branches of the U which it takes the form. Thus, the presence of a piecing wire 2 will have the effect of further moving the elastic lever 17 of this median plane 16, and the elasticity of said lever will return a mechanical clamping effect, so that the holding means then takes the form of a pair of jaws 4 clamping the piecing thread 2, one of the jaws 4 being formed by the elastic lever 17, the other jaw 4 may be a part of the support part vis-à- screw, in particular a beam 9 mounted or to be mounted on the rack 10, or simply another part of the control device 1 which is placed between the median plane 16 and the elastic lever 17. The direction of the springback having For the effect of pinching the piecing wire 2 may of course be the opposite to that described above, the insertion of piecing wire 2 then having the effect of bringing the elastic lever 17 of the median plane 16, said elastic lever 17, under the effect of its elastic tendency away from the median plane 16, then pressing the piecing wire 2 against an opposite surface, in particular a surface of the base 5 itself. In such a design, the elastic lever 17 is then possibly carried by a piece located between the median plane 16 and the branch of the base 5, the piecing wire 2 is then pinched between the elastic lever 17 and the base 5. The base 5 thus preferably takes the form of a half-shell open on the sides and can be traversed by a profile at a cavity extending from two lateral openings, the elastic lever 17 being arranged in a wall of this cavity, so that the piecing thread 2 can be taken between the elastic lever 17 and a piece housed in this cavity. As shown in Figures 1 and 2, the resilient lever 17 may have a slightly open L-shape, placed against the beam 9 or the like. The small branch of the L extends perpendicularly to the median plane 16, the large branch of the L extending at an angle slightly larger than a right angle, to direct the piecing wire 2 to the exit zone of the wire.

Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications are possible, in particular from the point of view of the constitution of the various elements, by different combination of all or part of the characteristics described above, by combination of the embodiments described, or by substitution of technical equivalents, without going out for as much of the field of protection of the invention.

Claims (14)

REVENDICATIONS1. Control device (1) for piecing thread (2), comprising at least one means for detecting the presence of a piecing thread (2) connecting the windings of two coils (3) to be emptied successively, and this at the level of the last turn for the initially emptied spool (3) and the first turn for the subsequently emptied spool (3), characterized in that it further comprises at least one holding means for firmly holding the thread piecing (2). 2. Control device (1) according to claim 1, characterized in that the at least one holding means is arranged to retain the piecing thread (2) perpendicular to its normal insertion direction in the control device ( 1), and thus to retain it in its great length. 3. Control device (1) according to any one of claims 1 or 2, characterized in that the at least one holding means comprises at least one elastic lever (17), forming a first jaw (4) for pressing the piecing wire (2) against an opposite surface forming a second jaw (4). 4. Control device (1) according to any one of claims 1 to 3, characterized in that it further comprises a piece, in the form of a beam (9), to be fixed to a rack (10) , and forming one of the jaws (4), in particular the jaw (4) vis-à-vis the or an elastic lever (17). 5. Control device (1) according to any one of claims 1 to 4, characterized in that it comprises two holding means, each for a piecing thread (2) respectively, arranged vis-à-vis one of the other. 6. Control device (1) according to claim 5, characterized in that the elastic levers (17) are such that the presence of piecing wire (2) distorts them away from one another, and that their springback tends to bring them closer to each other. 7. Control device (1) according to any one of claims 1 to 6, characterized in that the at least one presence detection means comprises an electrical circuit having two contacts between which it is open in case of presence of the wire of piecache (2) - 20 - which then removes them from one another, and closed in case of absence of piecing wire (2). 8. Control device (1) according to claim 7 and according to any one of claims 3 to 6, characterized in that one of the contacts is carried by the at least one elastic lever (17). 9. Control device (1) according to any one of claims 3 to 6 and according to any one of claims 7 and 8, characterized in that one of the contacts is carried by a piece against which the elastic lever rests (17) in free position. 10. Control device (1) according to claim 9, characterized in that the contact, against which comes the elastic lever (17) carrying the other contact, is formed by a conductive screw, the head reaches the level of the surface against which the elastic lever (17) extends, through an orifice of greater dimension than the section of said screw, in particular the surface of a beam (9). Feed rack (10) for continuously feeding at least one thread from bobbins (3), comprising at least two bobbin supports (13) for fixing them in the rack (10), said supports (13) each having a front end (14) at which the thread is cut and a base (15) at the opposite end for anchoring to the rest of the rack (10), rack (10) characterized it comprises, in addition, at least one control device (1) for connecting thread (2), comprising at least one holding means for firmly holding the piecing thread (2), connecting the windings of two coils ( 3) to empty successively, and this at the last turn for the coil (3) emptied first and the first turn for the coil (3) emptied then. 12. Rack (10) according to claim 11, characterized in that the at least one holding means is positioned between the two supports (13) and sufficiently distant from their front end (14) for the wire cut and the wire of piec (2) can not interfere when the latter is caught in the at least one holding means. Feed rack (10) according to one of claims 11 or 12, characterized in that the at least one control device (1) is in the form of a control device (1) according to one of any of claims 1 to 10. 14. Feed rack (10) according to claim 13, characterized in that the surface of the beam (9) against which the piecing thread (2) flows during the exchange between two coils (3) is oriented towards an outlet area of the rack (10).