EP0410905A1 - Method for restarting and piecing of cored yarns made from fibres, new type of piecing realized by this method and spinning machine for carrying out this method - Google Patents

Abstract

Method for the restarting and piecing of spun fibre yarns comprising a core and obtained from two fibre streams (1a, 1b) coming from a drawing system (E). This method comprises the sequence of the following operations: - extraction of a length of yarn (14) previously formed from the winding support (25); - reservation of a length of yarn thus extracted inside a storage assembly (20); - introduction in the form of a tensioned slither of part of the yarn thus reserved into the set of members (or spinning block) making it possible to produce the cored spun yarn (14); - restarting of the winding assembly (25) and engagement of the members of the treatment block, the fibres (1a, 1b) which come from the drawing system (E) being rejected; and - during the advance of the leader yarn to the spinning members: in the first stage, stopping of the rejection of the fibres (1a) intended for forming the covering of the cored spun yarn and distribution of these fibres to the moving leader yarn, and in a second stage stopping of the rejection of the fibres (1b) intended for forming the core of the cored spun yarn and distribution of these fibres to the moving leader yarn which is then cut between the exit of the reserve (20) and entry into the spinning block. <IMAGE>

Description

The present invention relates to a process making it possible to produce and re-attach yarns of fibers comprising an internal core, yarns which in the following description will be designated by the expression "core yarns"; it also relates to a new type of piecing made using such a method as well as an improved spinning machine enabling it to be implemented.

To date, numerous solutions have been envisaged for producing threads with an internal core.

The most common is to introduce a multifilament core inside a wick, during the last spinning operation, that is to say on the continuous spinning, said core being introduced upstream of the last pair of wick stretching rollers.

It has also been proposed to project elementary fibers onto a core yarn, subjected to a temporary false twist and this, upstream of the false twist spindle. This projection of the elementary fibers onto the core in the torsion rise zone can be carried out in accordance with the teachings of European patent no. 085635 (corresponding to US-A-4,489,540), by means of a movable surface on which said fibers are delivered tangentially, which makes it possible to exert a tensile force on the free ends of these fibers, the core being moved tangentially relative to said guide surface in a direction concurrent with the direction of supply of these fibers.

European patent no. 0206 956 (corresponding to patent US-A-4,757,680) describes an improvement made to such a technique and which in particular makes it possible to automate such machines and to perform in a simple, efficient and precise manner, the recovery operation after breakage of a wire or during any other intervention, or even when replacing a full spool with an empty winding support.

In the following description, the implementation of the method according to the invention will be described for an improved machine implementing the teachings of this last European patent 0206956 (or US-A-4,757,680), but it is obvious that this is not limiting and that such a process could also be implemented in any other type of installation in which a complex core yarn is produced by projection of fibers onto a fibrous core during its formation.

In general, spinning installations of the aforementioned type comprise, as illustrated in FIGS. 1, 2, 2a and 2b annexed (figures which are reproductions of FIGS. 6 to 9 of the aforementioned European patent no. 0206 956), a plurality of identical working positions arranged side by side on a support frame. Each working position essentially comprises, arranged between a source of fiber supply and a set for receiving the finished yarn (elements not shown in FIGS. 1 to 2b for simplification purposes), a treatment set proper, disposed at the outlet. a drawing system (designated by the general reference (E)), making it possible to treat two strands of fibers (1a, 1b), the fibers (1a) being intended to form the covering of the yarn while the fibers (1b ) are intended to form the soul. Downstream of the last pair of cylinders (2,3) of the stretching system (E), are arranged the members making it possible to make the associations of the core and covering fibers, these members being designated in the following description by the expression "block of spinning". Such a spinning block consists essentially of a guide surface (4) or condenser element in the form of a hollow rotary cylinder pierced over its entire periphery with orifices (5). The rotary cylinder is subjected to the action of a suction source. A false twist pin (6) is arranged downstream of this condenser guide (4). Upstream of the condenser guide (4), is arranged a second condenser element (7) of a design similar to the condenser (4) and which is associated with a movable roller (8). Thanks to such an assembly, taking into account the twist communicated by the spindle (6) which rises to the nip between the condenser (7) and the roller (8), it is formed using fibers (10 ) from the wick (1b) a core (11). The fibers (9) which come from the wick (1a) and which are delivered to the surface of the condenser (4) are deposited against the surface of the core wire (11) and, taking account of the displacement of the latter and of the twisting which goes up, are blocked around this soul forming, in a way a covering. It should be noted that in such a machine, the core (7) and cover (4) condensing elements not only ensure the transfer of the fibers from the outlet of the drawing system (E), but also a parallelization of the fibers. elementary (9,10) as well as an additional stretching function of their peripheral speed. By adjusting the peripheral speeds of said condensers (4,7), it is possible to modify the composition of the yarn obtained (modification of the proportion of the fibers constituting the core (11) relative to the covering fibers) as well as the final titer.

In such a spinning block, the covering condenser element (element 4) and the core condenser element (element 7), the false twist spindle (6) and the yarn calling system (13) ( 14) formed, are grouped on a common box designated by the general reference (15) in Figure 2 in the form of a compact assembly. Furthermore, on this box, between the outlet of the stretching system (2,3) and the surface of the condenser (4,7), are arranged separating elements (16,17,18) forming guide channels allowing channel the elementary fibers (9,10) of the wicks (1a, 1b) well, avoiding not only fiber losses, but also any disturbance between the two fibrous flows.

In order to allow the automation of such a spinning machine, the Applicant has proposed different solutions relating, on the one hand, to the stretching system (E) (FR-A-2 619 630 corresponding to US-A- 4,878,268), and on the other hand, the false twist spindle (6) that comprises the actual spinning block (FR-A-2,619,831 corresponding to US-A-4,910,953). The application of these stretching and false twist systems to a machine of the type illustrated in FIGS. 1 and 2 makes it possible to produce assemblies which can be easily automated, not only during a restart after removal of a full reel , but also when you want to carry out the recovery operations following a breakage or any other defect produced during production. However, during these recovery operations, the problem arises of making a resistant connection that does not present any defect (or a minimum of acceptable defects).

To date, conventional solutions for making such connections (for example knotting, gluing, splicing, interlacing, etc.) generally imply that the two ends to be joined are immobile, which results in either an interruption in the operating process of the machine, or the presence of wire storage elements upstream and downstream of the area where the reattachment is carried out. These conventional piecing solutions can be used for the implementation of the aforementioned machine, but the disadvantages that they present are accentuated by the fact that the wire formed is based on two constituents (1a, 1b) brought separately on the condensing elements (4,7). Furthermore, since such an installation can operate at very high production speeds (several hundred meters per minute), recovery cannot be carried out at full operating speed and, as in all textile installations operating at speeds, implies provide for either stopping or walking at slow speed, which necessarily results in variations in the characteristics of the yarn produced during this launch phase.

Now it has been found, and this is what is the subject of the present invention, that it was possible to solve these problems of recovery and piecing through a new process which, not only allows to perform piecing of very good quality, but also allows this operation to be carried out at full operating speed of the machine, both manually and completely automatically.

In general, the recovery and reattachment method according to the invention during a spinning operation on a machine making it possible to produce a yarn of core fibers, is characterized in that it comprises the succession of the following operations:
- sampling of a length of yarn previously formed from the winding support;
- setting aside a length of wire thus taken from inside a storage assembly;
- Introduction in the form of a stretched strand of part of the yarn thus set aside inside all of the members allowing the making of the core yarn;
- restarting of the winding and clutch assembly of the bodies of the processing blocks, the fibers coming from the drawing system (E) being put into waste;
- during the advance of the starter thread on the spinning members:
. firstly, the end of the disposal of the fibers intended to form the cover of the core yarn and distribution of these fibers on the moving initiation wire,
. in a second step, stopping the waste disposal of the fibers intended to form the core of the core spun, and distribution of these fibers on the moving starter wire which is then cut between the outlet of the reserve and the entry inside the spinning block.

In other words according to the invention, contrary to the logic which would lead to carrying out the recovery by following the normal process of production of the core spun, that is to say formation of the core then deposition of the covering fibers , we reverse the process during the reattachment operation by first depositing the covering fibers and then the core fibers on the recovery wire, the correct positioning of these fibers relative to each other. to others in normal operation being done automatically as soon as one arrives at the cut end of the stimulus wire.

Optionally, when making this connection, to avoid the whiplash that can occur when the leader wire is cut, a surface abrasion device allowing a refinement of the end of the launching wire is provided and is implemented when the fibrous flow intended to form the core is initiated.

Thanks to such a method, a connection is therefore obtained, the structure of which is such that, if we consider the start of the junction between the launching wire and the fibers intended to constitute the core wire:
- First of all, this launching thread is covered by the fibers intended to form the cover of the core yarn;
- Then, these covering fibers cover the fibers intended to form the core and;
- At the end of the launching wire, the elementary cover and core fibers interpenetrate so as to constitute the normal core yarn intended to be produced.

The method according to the invention can be implemented both when it is desired to make a connection following a breakage of the wire (either accidental or caused to eliminate a defect) during its production, and possibly when the we want to restart the machine by replacing a full coil with an empty support tube, in which case the latter will then include a few meters of wire previously formed and wound around it.

• a) adaptation de la structure du "bloc de filature" (condenseur (7) et galet bloqueur (8), condenseur de cou­verture (4), broche de fausse torsion (6) et délivreur d'appel (13)) pour que le fil puisse, lors du lancement être introduit par déplacement latéral à l'intérieur de ces éléments ;
• b) association à ce bloc de filature un ensemble de stockage d'une réserve de fil, disposé en dessous du plan dit "plan de filature" et qui correspond au plan passant par la surface de contact entre les courroies de la bro­che de fausse torsion (6) et qui est tangent à la surface des condenseurs (7,4) et du cylindre (13a) du délivreur d'appel de sortie (13) ; un tel "plan de filature" n'est pas à proprement parler une surface plane, étant donné qu'il suit le trajet du fil au cours de sa formation entre ces éléments et que ce trajet n'est pas obligatoi­rement rectiligne, le fil pouvant former un léger embar­rage autour du condenseur (4) ainsi qu'entre les cour­roies (6a,6b) de la broche et ;
• c) adaptation du cycle de fonctionnement de l'ins­tallation pour que, au moment de la relance, on intro­duise à l'intérieur des organes de traitement un fil de relance préalablement formé et qui a été prélevé à partir du support de renvidage pour être stocké à l'intérieur de la réserve et que la dépose des fibres soit réalisée, lors de la remise en route de l'ensemble de renvidage en distribuant tout d'abord sur le fil de relance en mouve­ment les fibres destinées à former la couverture du filé, puis, avec un léger retard, les fibres destinées à for­mer l'âme, le fil de relance en mouvement étant alors coupé entre la sortie de la réserve et l'entrée à l'in­térieur du bloc de filature.

Such a method can be implemented on an improved machine of the type produced in accordance with the teachings of EP-206 956 (or US-A-4 757 680) by the combination of the following means:

• a) adaptation of the structure of the "spinning block" (condenser (7) and blocking roller (8), cover condenser (4), false twist spindle (6) and call deliverer (13)) so that the wire can, during launching be introduced by lateral displacement inside these elements;
• b) association with this spinning block a set of storage of a thread reserve, arranged below the plane called "spinning plane" and which corresponds to the plane passing through the contact surface between the belts of the false twist spindle (6) and which is tangent to the surface of the condensers (7,4) and of the cylinder (13a) of the outgoing call provider (13); such a "spinning plane" is not strictly speaking a flat surface, given that it follows the path of the wire during its formation between these elements and that this path is not necessarily rectilinear, the wire being able to form a slight interlock around the condenser (4) as well as between the belts (6a, 6b) of the spindle and;
• c) adaptation of the operating cycle of the installation so that, at the time of the revival, a stimulus wire previously formed and which has been taken from the winding support to be stored is introduced inside the treatment members inside the reserve and that the fibers are removed, when the winding assembly is restarted by first distributing the fibers intended to form the cover of the yarn on the moving stimulus wire , then, with a slight delay, the fibers intended to form the core, the stimulus wire in motion then being cut between the outlet of the reserve and the inlet inside the spinning block.

To facilitate the introduction of the wire inside the processing members during a revival in such a machine thus improved, the rotary roller (8) and one of the call cylinders of the output deliverer (13), in the present case the call cylinder (13a), are projecting with respect to the other elements of the spinning block (core condenser, cover condenser and false twist spindle); furthermore, the core and cover condensers have a conical front face.

Finally, the storage assembly for the wire reserve is preferably in the form of a suction tube associated with a mobile element, sliding inside the tube, thus making it possible not only to bring the wire to the inside the work plan, but also facilitating the removal of the wire stored inside the reserve and its introduction into the different elements of the processing block.

In such a machine, the method according to the invention consists, during the reattachment operation (after a breakage or possibly when replacing a full coil with an empty support tube), at:
- take a length of wire previously formed from the winding support (in the case where the process would be implemented when restarting the machine by replacing a full spool with an empty support, the latter will include a few meters of thread beforehand trained);
store said thread thus taken inside the reserve arranged below the spinning plane between the first condenser and the false twist spindle, the path of the thread from the winding reel to the entry of the reserve being produced so that the portion of wire forms a loop surrounding the rotary roller associated with the core condenser, and the elongated roller of the call deliverer located downstream of the processing block; - Introduce a portion of yarn stretched between these two elongated elements, practically instantaneously inside each of the bodies of the spinning block, this introduction being carried out with the yarn running with its processing speed, starting by placing the yarn in reserve between the core condenser and its pressure roller, and by moving said wire automatically on the generator of said elongated pressure roller, which causes a helical displacement with variable pitch on this roller, allowing the instantaneous automatic introduction of the portion of the wire between the two belts of the false twist spindle and bringing it to the cover condenser as well as between the two cylinders of the output deliverer arranged downstream of the spinning block and;
- after installation inside the elements of the processing block of this reserve wire and clutching of the various members, to deliver, firstly, the covering fibers on the leader wire, then the fibers forming the core, the remaining portion of launching wire contained inside the reserve being cut substantially simultaneously with the initiation of the deposition of fibers intended to form the core during normal production.

If such a method can be carried out manually, it is possible to take the thread from the winding element by means of a suction assembly (gun) which the operator moves to surround the two elongated elements (pressure roller and roller call), and bring the wire to the entrance of the reserve, such a machine and such a process can be easily automated for example, either by providing on each position of the machine a set called "spacer" allowing to have the wire in the form of a loop around the aforementioned elements, either by providing such a spacer element on a robot, movable in front of the machine and common to all the working positions.

Furthermore, for the implementation of the method according to the invention, the channels for guiding the fibrous fluxes of core and covering arranged between the outlet of the drawing system and the surface of the condensing elements of core and covering are associated with suction means allowing the waste to be put into the fibers during the preparatory phase for launching, this aspiration being eliminated, according to a programmed sequence and determined during the launching proper, so that the covering fibers are deposited on the recovery wire prior to the deposition of the fibers intended to form the core.

When the restart is carried out, the wire placed in reserve is cut automatically.

Additional means can be provided to improve the quality of the piecing, such as for example means making it possible to refine the stimulus wire.

Such a relaunching and linking process in accordance with the invention will however be better understood thanks to the following description and to the example of embodiment given below by way of indication but not limitation, and which is illustrated by the diagrams appended in which :

• . la figure 1 étant une vue en perspective sché­matique montrant la dernière paire des cylin­dres du système d'étirage (E) et le bloc de filature proprement dit ;
• . la figure 2 étant une vue frontale d'une telle position de travail et,
• . les figures 2a et 2b étant des vues de côté montrant respectivement selon les directions B et C de la figure 2 :
  x l'étirage de la mèche de fibres d'âme, le condenseur et le galet bloqueur as­socié à ce condenseur pour former le fil d'âme (figure 2a) ;
  x l'étirage de la mèche de fibres de cou­verture et le condenseur sur lequel les fibres de cette mèche sont délivrées afin de permettre leur association avec le fil d'âme en formation (figure 2b) ;
• - la figure 3 est une vue schématique de face mon­trant les adaptations apportées à une telle position de travail pour faciliter la mise en oeuvre du procédé con­forme à l'invention ;
• - la figure 4 est une vue de dessus de cette posi­tion de travail adaptée pour la mise en oeuvre du procédé selon l'invention ;
• - les figures 5 et 6 sont des schémas, vus de face, montrant la manière dont est prélevé le fil sur la bobine réceptrice et dont il est positionné autour des éléments du bloc de filature lors de l'opération de relance ;
• - la figure 7 est une vue schématique de côté mon­trant la manière dont est prélevé le fil sur la bobine formée lorsque l'on effectue la relance ;
• - la figure 8 est une vue schématique en perspective de la courroie supérieure de la broche de fausse torsion utilisée dans la machine conforme à l'invention et mon­trant comment est réintroduit le fil à l'intérieur de cette broche lors de la relance ;
• - les figures 9a à 9n illustrent l'ensemble du pro­cessus opératoire selon l'invention pour la relance d'une position de travail sur une machine de filature adaptée pour la mise en oeuvre d'un tel processus ;
• - la figure 10 illustre, de manière schématique, la structure d'une rattache réalisée conformément à l'inven­tion ;
• - les figures 11a,11b et 11c sont des reproductions de photographies montrant les trois phases principales de réalisation d'une rattache réalisée conformément au pro­cédé selon l'invention ;
• - les figures 12 et 13 sont des reproductions de photographies de deux filés à âme pour lesquels le pro­cédé de rattache conforme à l'invention est particulière­ment adapté.

FIGS. 1 to 2a illustrate, as described above, the state of the art constituted by a working position of a spinning machine produced in accordance with the teachings of European patent 0 206 956 (US-A-4,757,680):

• . Figure 1 being a schematic perspective view showing the last pair of cylinders of the drawing system (E) and the spinning block itself;
• . FIG. 2 being a front view of such a working position and,
• . FIGS. 2a and 2b being side views showing respectively in directions B and C of FIG. 2:
  x stretching the core fiber wick, the condenser and the blocking roller associated with this condenser to form the core wire (FIG. 2a);
  x stretching the strand of covering fibers and the condenser on which the fibers of this strand are delivered in order to allow their association with the core wire being formed (FIG. 2b);
• - Figure 3 is a schematic front view showing the adaptations made to such a working position to facilitate the implementation of the method according to the invention;
• - Figure 4 is a top view of this working position suitable for the implementation of the method according to the invention;
• - Figures 5 and 6 are diagrams, seen from the front, showing the way in which the yarn is taken from the take-up reel and how it is positioned around the elements of the spinning block during the restarting operation;
• - Figure 7 is a schematic side view showing the way in which the wire is taken from the spool formed when the recovery is carried out;
• - Figure 8 is a schematic perspective view of the upper belt of the false twist spindle used in the machine according to the invention and showing how the thread is reintroduced inside this spindle during the restart;
• - Figures 9a to 9n illustrate the entire operating process according to the invention for reviving a working position on a spinning machine adapted for the implementation of such a process;
• - Figure 10 illustrates, schematically, the structure of a connection made in accordance with the invention;
• - Figures 11a, 11b and 11c are reproductions of photographs showing the three main phases of production of a connection produced in accordance with the method according to the invention;
• - Figures 12 and 13 are reproductions of photographs of two core yarns for which the joining process according to the invention is particularly suitable.

In the following description, the method according to the invention and its implementation will be described with particular reference to Figures 3 to 9n which, as said above, illustrate the adaptations made to a working position of a machine allowing making a core spun as illustrated in Figures 1 to 2b.

If reference is made to the appended diagrams, using the same references as those used to describe the state of the prior art illustrated in FIGS. 1 to 2b, a working position of a machine according to the invention comprises a drawing system E, common to the two wicks of fibers (1a, 1b) intended to form the cover and the core of the wire respectively. This stretching system is preferably arranged vertically or substantially vertically on the machine frame. Below the stretching system E, the spinning block proper is arranged, the various members of which are mounted on a support box not shown for simplification. This spinning block comprises, arranged immediately below the last pair of cylinders (2,3) of the stretching system E, a set of separating elements (16,17,18) forming guide channels (19, 20) for the fiber flows leaving the drawing system E. As the machine according to the invention operates in exactly the same way as that described in the aforementioned European patent, the elementary fiber flows (9, 10) forming the cover and core are not shown for simplicity. These separating elements (16, 17, 18) and the channels (19) which they define between them are constituted for example by a monobloc machined part which comes to wrap on a part of their periphery the condensing elements (4,7) of the fibers. of cover and soul. The entire spinning block is produced in a similar manner to the example illustrated in FIG. 5 of European patent no. 206956, if not, as will be seen in the following description, that the members that compose it are adapted to allow automation of the machine to perform the recovery operations. In general, these adaptations reside essentially, as is apparent from the top view (FIG. 4), by an increase in the length of the torsion blocking roller (8), so that it extends beyond the front with respect to the core condenser (7) and the covering condenser (4), to the spindle (6), one of the rollers of the output deliverer (13), in this case the roller (13a), also being elongated to extend forward in a manner similar to the roller (8). The false twist spindle (6) disposed downstream of the covering condenser (4) is, in turn, produced in accordance with the teachings of French patent no. 2,619,831. In such a machine, the feeding of the wicks of fibers to be treated (wicks 1a, 1b) and the extraction of the formed wire (14) at the outlet of the deliverer (13) are carried out in the opposite direction in a vertical or substantially vertical plane, while the path of the material inside the spinning block is produced either horizontally, or preferably in a plane slightly inclined in plane P known as the "spinning plane" which passes through the nip between the core condenser (7) and the roller (8), the point of tangency of the wire being formed on the surface of the condenser (4), between the two belts (6a, 6b) of the false twist spindle (6) and the point of contact of the wire with the roller (13a) of the output deliverer (13 ). As can be seen from FIGS. 3 and 5, the spinning plane is not a real flat surface, the wire coming slightly into contact with the cover condenser (4) and the surface of the belts (6).

Furthermore, in accordance with the invention, a storage assembly (20) for a reserve of wire length is arranged below the above-mentioned plane P. This storage assembly shown diagrammatically in FIG. 4 consists essentially of a suction tube (21) and is associated with a mobile assembly (22) called "launching cylinder" and which allows, as will be seen in the following description , during launching, the introduction of the yarn inside the different elements constituting the spinning block and, simultaneously, the extraction of the yarn stored inside said reserve. This mobile element (22) consists of a sliding tube inside the inlet end of the reserve (20).

In order to be able to carry out the launching operation automatically, the torsion blocking roller (8) associated with the core condenser (7) as well as the roller (13a) of the output deliverer (13) have a length such that they overflow on the front compared to the other elements of the spinning block.

Furthermore, in order to facilitate the introduction of the wire inside the various elements, the inlet faces of the condensers (7) and (4) are of conical shape and the false twist pin (6) is associated with a ramp (23) which, during the introduction of the wire, brings the latter against the upper belt (6a) of the spindle (6) in order to facilitate its positioning (see FIG. 8).

Finally, each working position comprises, and this is shown only in FIG. 3, suction means (24.25) associated with each condenser (4.7) and which allow the fibers of the wicks (1a) to be disposed of. , 1b) until the normal operating process is implemented.

Means for refining the stimulus wire can also be associated with the spinning block, these refining means being constituted by an abrasive surface (27) (see FIG. 3) disposed upstream of the nip between the condenser d 'core (7) and the roller (8), and which is constituted for example by a flexible strip. This element (27) not only makes it possible to refine the end of the recovery wire during the final phase of the process, and also prevents the free end of the recovery wire after cutting from forming a defect.

Thanks to such a machine structure, it is possible to carry out the operations for relaunching a position in a particularly simple and rapid manner, this operation being able to be carried out either manually or preferably automatically.

Such an automatic restart process is illustrated on the one hand by Figures 5,6,7,8 and, on the other hand, by Figures (9a) to (9n) which illustrate schematically the main sequences. In the following description, the invention will be described by carrying out the relaunch operation and reattaching in an automated manner, only the main functions of the robot used being described, this robotic assembly being simply shown diagrammatically by the displacements which it makes it possible to carry out. to take the yarn from the take-up reel and reintroduce it inside the spinning block as well as the functions to be performed during the stop and restart phase.

• a) première phase de séquence d'arrêt suite à la détection et la casse du fil, cette casse pouvant être soit accidentelle, soit provoquée par suite de la détec­tion d'un défaut ;
• b) deuxième phase de séquence de relance et remise en route proprement dite.

In general, the restarting operating process which the machine according to the invention allows can be summarized in two main operating phases, namely:

• a) first phase of the stop sequence following the detection and breakage of the wire, this breakage being either accidental or caused as a result of the detection of a fault;
• b) second phase of recovery sequence and restart itself.

During the stop sequence following a break, the following operations are carried out, illustrated diagrammatically in FIGS. 6 and 7:
- after detection of breakage between the output deliverer (13) and the winding system designated by the general reference (25), detection carried out using any known element, the stretching arm (E) is opened as well as the spacing of the two belts (6a, 6b) of the false twist spindle (6) and this, very quickly in order to limit the fouling of the condensers (7,4) and the deterioration of the strips of the spindles;
- After opening, the reel (25) of its drive system (26) is then raised or the drive system stops; this lifting is of the order of a few millimeters relative to the engine cylinder (26) and is carried out by means of a device making it possible to have a constant and identical spacing (e) whatever the diameter of the winding (25 ); this operation is carried out very quickly in order to avoid "burying" the end of the wire formed inside the coil (25); the reel being raised, the drawing system E disengaged, the drawing shafts, the winding cylinders and the reciprocating cam (27) can continue their movement if their control is not carried out individually by position;
the opening of the stretching arm E, of the spindle (6) and the lifting of the coil (25) being carried out, the rotation of the core condenser (7), of the covering condenser (4) is stopped, of the false twist spindle (6) and of the call provider (13).

Of course, if the winding system is individually driven for each position, the operation of lifting the reel or its drive system can possibly be eliminated since it is then sufficient to stop the position.

These operations being carried out, the vacuum can be maintained inside each of the condensers (4,7). Furthermore, the torsion blocking roller (8) remains in abutment on the core condenser (7) as well as the pressure roller (13b) of the call deliverer (13).

Optionally, if the position has been fixed for a simple reel change, we first proceed to the evacuation of the full reel and place between the forks (28) of the winding system (24), a reel previously filled a few meters of wire in order to be able to carry out the recovery operation.

Once the position has been stopped, the recovery sequence itself can be started and carried out by a robotic assembly brought in front of the position in question.

The main sequences of this recovery phase are as follows as shown in Figures 7 to 9n.

Firstly (Figures 7 and 9a), using a suction gun (30) (or any other equivalent means), the end of the wire is captured on the spool (25) to bring it to the level of the 'entry of the reserve (21) that is to say, in this case, in the extreme orifice of the launching cylinder (22) which is in the advanced position as illustrated in Figures 4,7 and 9a. The removal of the wire from the spool (25) can be facilitated by applying against the surface of the spool a motor element (31) making it possible to rotate it in the opposite direction from its normal direction of winding.

The working position is therefore then in the position illustrated in FIG. 9b. It should be noted that during these operating phases, the food wicks (1a, 1b) are stopped and simply maintained in the position they had when stopped on the cylinders of the stretching system (E).

The yarn being set aside, it can be introduced in the form of a stretched strand inside all of the bodies of the spinning block.

To do this, for example by means of spacer systems (E1, E2) (Figures 9c to 9e), a portion of wire is deflected between the end of the launching jack (22) and the coil (25) so that these spacers bring the wire in the form of a stretched strand (in position E'1, E'2 shown in Figure 6) forming a loop which surrounds the projecting ends of the cylinder (8) torsion blocker associated with the condenser (7) and the cylinder (13a) of the call provider (13). The reintroduction of the wire thus held between the cylinders (8) and (13a) is obtained thanks to the retraction of the launching cylinder (22) (FIGS. 9f to 9i) which causes a displacement of the loop of the wire at the periphery of the blocking cylinder. torsion (8), which allows a practically instantaneous introduction of this portion of thread stretched inside all the other members of the spinning block, namely on the cover condenser (4) between the two belts (6a , 6b) of the spindle (6) and between the two elements (13a, 13b) of the deliverer (13).

Taking into account the positioning of the launching cylinder (22) with respect to the different members of the spinning block, the wire begins by being introduced between the first condenser (7) and the torsion blocking cylinder (8) and there is a displacement of the portion of the wire held between the blocker (8) and the shaft (13a) in the form of a variable-pitch helix with an exponential movement of the wire which allows rapid introduction of the portion of the tensioned wire inside all the other members of the spinning block, namely on the cover condenser (4) between the two belts (6a, 6b) of the spindle (6) and between the two elements (13a, 13b) of the deliverer (13 ) (phase illustrated in Figures 9h to 9d). The wire being thus positioned, all of the elements can be rewired (figure 91) so as to produce the piecing (figures 9m and 9n).

During this operating phase, the stretching system was closed and the wicks (1a, 1b) are, during the stabilization of the fibrous flow (duration: a few seconds), sent to the waste by the suction systems (24,25) .

To make the actual connection (Figures 9m to 9n), firstly (Figure 9m), we stop the suction of the nozzle (24) putting the fibers (1a) to waste to form the cover of the core yarn. final and these fibers are distributed on the moving leader wire then, with a slight delay (a few thousandths of a second), the suction of the nozzle (25) is suppressed so that the fibers coming from the wick (1b ) which are intended to form the core of the core yarn are in turn distributed over the moving leader wire; substantially simultaneously with this depositing of the fibers (1b) by means of an appropriate thread cutter (CF), disposed between the outlet of the reserve (20) and the inlet of the thread inside the spinning block (area of pinching between the roller (8) and the condenser (7)), the launch wire is cut, the portion remaining in reserve being sent to the waste.

Preferably, a surface abrasion device (27) is disposed upstream of this entry zone inside the spinning block on the one hand, in order to peel the end of the launching yarn and on the other hand, avoid any whiplash which might produce a fault in the piecing.

The method according to the invention makes it possible to obtain a connection having the structure shown diagrammatically in FIG. 10.

If we refer to this figure 10, the arrow indicating the direction of movement of the launching wire (14), wire shown in dotted lines, during the production of the piecing, the piecing process begins at A. The thread ( 14) being introduced inside the spinning block: in the zone going from A to C, this launching thread (14) is firstly covered by the covering fibers (1a) then, from point C the distribution of the core fibers (1b) is started, the covering fibers (1a) cover the core fibers (1b) which are distributed; after cutting the launching wire (point E), the end possibly being refined in the zone EF, the core yarn (14) is obtained which must normally be produced on the machine.

As an indication, to locate the characteristics of such a fastener, when making a cotton-based core yarn, having an overall titer of 20 Tex and comprising 35% of fibers (1a) of coverage and 65% of fibers (1b) forming the core, with a production speed of approximately 500 meters / minute, a connection is obtained whose length L is between 20 and 40 millimeters and which has the following structure if we refer in Figure 10:
- in the AC zone: depositing the covering fibers (1a) over a total length L1 corresponding approximately to 30% of the length L; the title of the yarn produced in this area is around 27 Tex; the distance L2 where the flow of covering fibers is stabilized is preferably as short as possible;
- in the area from point C to the end of the piecing (point F) where the core fibers (1b) and covering fibers (1a) are deposited simultaneously, the titer of the piecing gradually increases from C to D, then stabilizes in the DE zone at twice the normal thread count to gradually decrease from E to F, point of the end of the piecing. The length L3 of the CE zone is approximately 60% of the total length L of the patch, in order to obtain good resistance. The length L4 of the zone EF corresponding to the cut and thinned end of the launching wire (14) (shown in phantom in Figure 6) is, in turn, equal to about 10% of the total length of the patch .

FIGS. 11a to 11c are photographic reproductions showing the main phases of production of a patch according to the invention as described above.

FIG. 11a corresponds to the zone of progressive introduction of the covering fibers (1a) onto the launching wire (14) (zone going from point A to point C of FIG. 10).

FIG. 11b corresponds to the zone in which the progressive introduction of the core fibers (1b) takes place under the covering fibers (1a) to go to a double count of the normal thread count (DE zone of the figure 10).

Figure 11c illustrates the end of the piecing (area EF) of Figure 10 in which the launch wire (14) is cut.

Figures 12 and 13 show by way of indication two types of core fiber yarns for which the method according to the invention can be implemented. We can clearly see in these photographs the fibers (1b) forming the core and which are surrounded by the fibers (1a) forming the cover.

Claims (14)

1 / Method for the recovery and the reattachment of fiber yarns comprising a core and obtained from two streams of fibers (1a, 1b) coming from a drawing system E, characterized in that it comprises the succession of following operations:
- sampling a length of wire (14) previously formed from the winding support (25);
- setting aside a length of wire thus taken from inside a storage assembly (20);
- introduction in the form of a stretched strand of part of the yarn thus placed in reserve inside all of the members (or spinning block) allowing the production of the core yarn (14);
- restarting of the winding assembly (25) and clutching of the bodies of the processing block, the fibers (1a, 1b) coming from the drawing system (E) being put into waste;
- and, during the advance of the starter thread on the spinning members:
. firstly, stopping the placing in the waste of the fibers (1a) intended to form the cover of the core yarn, and distribution of these fibers on the initiating thread in motion,
. in a second step, stopping the placing in the waste of the fibers (1b) intended to form the core of the core spun, and distribution of these fibers on the moving leader wire which is then cut between the exit from the reserve (20) and the entry inside the spinning block. 2 / A method according to claim 1, characterized in that when the machine is restarted by replacing a full reel (25) with an empty support tube, the latter comprises a few meters of wire previously formed and surrounded around said support. 3 / Method according to one of claims 1 and 2, characterized in that during the production of the piecing, it performs a surface abrasion of the end of the launching wire after it has been cut. 4 / Method according to one of claims 1 to 3 implemented on a spinning machine comprising a plurality of working positions arranged side by side on a common support frame, each working position comprising, arranged between a power source in fibers and a set for receiving (25) the finished yarn, a processing set essentially consisting of a drawing system (1) making it possible to process two strands of fibers (1a, 1b), the fibers (1a) being intended forming the cover of the yarn, while the fibers (1b) are intended to form the core, the association of the core and cover yarn being carried out by means of a so-called "spinning block" assembly arranged downstream of the last pair of cylinders (2,3) of the stretching system, an assembly consisting essentially of a guide surface (4) or condensing element in the form of a hollow rotary cylinder, pierced on its periphery orifices (5) subjected to the actio n of a suction source, a false twist pin (6) being arranged downstream of this condenser guide (4) and a second condenser element (7) associated with a blocking roller (8) being arranged upstream of the guide condenser (4), characterized in that it consists, either when replacing a full coil (25) with an empty support tube or after a break, in:
- take a length of previously formed wire from the winding support (25) (in the case where the machine is restarted by replacing a full spool with an empty support tube, the latter comprises a few meters of previously formed wire);
- store said thread thus taken inside a reserve (20) arranged below the spinning plane (P) between the first condenser (7) and the false twist spindle (6), the path of the thread from the winding reel (25) up to the entrance to the reserve (20) being produced so that the portion of wire forms a loop surrounding the rotary roller (8) associated with the core condenser, and the roller ( 13a) of the call provider (13) located downstream of the processing block, the rollers (8) and (13a) projecting over the front relative to the other elements of the spinning block (condensers (7) and (4) , spindle (6);
- introduce a portion of thread stretched between the two elongated rollers (8,13a) very quickly inside each of the bodies of the spinning block (condenser (7), condenser (4) and spindle (6)), this introduction being carried out with the wire running with its processing speed, starting by placing the wire in reserve between the core condenser (7) and its pressure roller (8), and by moving said wire automatically on the generator of said elongated pressure roller ( 8), which causes a helical displacement with variable pitch on this roller, allowing the instantaneous automatic introduction of the portion of the wire between the two belts (6a, 6b) of the false twist spindle (6) and bringing it on the cover condenser (4) as well as between the two cylinders of the output deliverer (13) disposed downstream of the spinning block and;
- after installation inside the elements of the processing block of this reserve wire and clutching of the various members to deliver, firstly, the covering fibers (1a) on the leader wire, then the fibers (1b) forming the core, the remaining portion of launching thread contained inside the reserve being cut simultaneously with the initiation of the deposition of the fibers (1b) intended to form the core during normal production . 5 / Method according to one of claims 3 and 4, characterized in that the fibers of the wicks (1a, 1b) are put to waste as long as the normal operating process is not implemented, this waste being obtained by means of suction elements (24,25) exerting their action against the surface of the condenser (4,7). 6 / Attachment obtained by the implementation of the method according to one of claims 1 to 5, characterized in that, if we consider the start of the junction between the launching thread and the fibers intended to constitute the yarn to soul:
- First of all, this launching thread is covered by the fibers (1a) intended to form the covering of the core yarn;
- Then, these covering fibers (1a) cover the fibers (1b) intended to form the core and;
- At the end of the launching wire, the elementary covering fibers (1a) and core (1b) interpenetrate to form the normal wire produced on the installation. 7 / spinning machine allowing the implementation of the method according to one of claims 4 to 6, characterized:
- in that the spinning block (core condenser (7) and blocking roller (8), condenser (4), false twist spindle (6), call deliverer (13) is associated with a storage assembly (20) a reserve of thread, disposed below the plane called "spinning plane" which corresponds to the plane passing through the contact surface between the belts of the false twist spindle (6) and which is tangent to the surface condensers (7,4) and the cylinder (13a) of the outgoing call provider (13), this reserve and storage element (20) comprising a suction tube (21) and a mobile assembly (22) called "launching jack" allowing the introduction of the wire inside the elements forming the spinning block and simultaneously extraction of the wire stored inside the suction tube (21);
- And in that the rotary roller (8) and one of the call cylinders (13a) of the output deliverer (13) are projecting relative to the other elements of the spinning block. 8 / Machine according to claim 7, characterized in that the condensers (7,4) have a conical front face. 9 / Machine according to one of claims 7 and 8, characterized in that the false twist spindle (6) is associated with a guide ramp (23) of the wire which, during the introduction of the wire during launching, brings the latter against the upper belt (6a) to facilitate its installation. 10 / Machine according to one of claims 7 to 9, characterized in that it comprises separating elements (16,17,18) between the outlet of the drawing system (3) and the surface of the condensers (4,7 ), these elements forming guide channels (19,20) making it possible to channel the flow of elementary fibers (9,10) of the wicks (1a, 1b), these elements being constituted by a monobloc machined part which comes to wrap on a part from their periphery the condenser elements (4,7). 11 / Machine according to one of claims 7 to 10, characterized in that suction means (24.25) are associated with each condenser (4.7) and allow the fibers of the wicks (1a, 1b) as long as the normal operating process is not implemented. 12 / Machine according to one of claims 7 to 11, characterized in that it comprises means (27) making it possible to refine the recovery wire prior to the deposition of the covering fibers (1a) and of the core fibers ( 1b) when restarting the machine. 13 / Machine according to claim 12, characterized in that said refining means consist of an abrasive surface (27) positioned upstream of the nip between the core condenser (7) and the roller (8), this abrasive surface (27) being mounted either on a robotic assembly common to a plurality of positions, or individually for each position. 14 / Machine according to one of claims 7 to 13, characterized in that it is associated with a spacer assembly (E1, E2) for arranging the wire in the form of a loop around the roller (8) and the roller (13a ) during the recovery operation.

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