EP0483024A1 - Method and device for accumulating a reserve length of yarn on a textile machine - Google Patents

Abstract

Method permitting temporary storage, in the form of a loop (4), of a moving yarn (3) inside a chamber (1) (or channel) whose opening (2) of relatively flat and rectangular cross-section is disposed vertically facing the path of the yarn during its production, the said channel being subjected to the action of a fluid stream permitting the two portions (4a, 4b) of the loop formed to be held apart, one (4a) of the portions being inserted inside the chamber (1) at a constant speed and the other portion (4b) itself being immobilised inside the chamber during the formation of the loop. It is characterised in that tractional pulses are communicated to the end (15) of the stationary portion (4b) permitting the two portions (4a, 4b) of the loop of the yarn, which may be frictionally deformed against the walls of the storage chamber, to be repositioned with respect to one another. <IMAGE>

Description

In the field of the textile industry, at the various stages of the transformation of the material since the realization of the thread until the obtaining of a finished product such as a fabric, one is very often confronted with the problem of having to temporarily store a determined length of wire.

Such a problem arises for example in the case of the different spinning machines on which one must intervene, following a breakage or to remove a defect and that one wishes to carry out such an operation without interrupting production; a similar problem arises on the weaving looms, in particular on the so-called "shuttle-free" looms in which, during the very process of inserting a weft, the length of thread necessary for the insertion of the following weft is prepared .

In both cases, it can be said that such a storage device results from the fact that upstream of a determined zone, the wire is delivered at a constant speed and, that downstream of this zone, it is transported to a different speed, or even is immobilized (or vice versa). Such a problem has been posed for a very long time as is clear from FR-A-1 404 286 which describes a solution making it possible to make a thread connection on a winder without interrupting the operation of the latter, and FR-A-1 581 247 which describes a solution which can be used more particularly on a loom and in which the thread is stored in the form of a loop, being indicated elsewhere (see page 1 lines 12 to 20) than previously to the solution described in this document, it was known to guide wires the along the mouth of a relatively flat conduit and to collect an excess quantity of a wire in this conduit in the form of a loop "by using for this purpose a current of air directed transversely compared to the course of the wire ", such a solution can be compared to that mentioned in French patent no. 1,562,147 (example illustrated in Figure 5 of this document).

Numerous other proposals have been made both in the field of "spinning" and in that of weaving after these documents, as is apparent in particular from FR-A-2 351 195, FR-A-2 162 944, FR -A-2 495 196, FR-A-2 355 932 and 2 323 783.

If in the field of weaving, the aforementioned solutions make it possible to store a sufficient length of yarn since the width of the weaving looms without shuttle rarely exceed two meters, on the other hand, in the field of spinning, they do not allow perform piecing operations (or splices) by means of systems having a slow operating cycle which therefore implies being able to store, on the spinning machine or on the robotic assembly performing the piecing operation, a large length of yarn. Thus, for example, for a machine operating at ten meters / second, and with a fastening system whose operating cycle is of the order of two seconds, it is necessary to be able to store twenty meters of wire, this which is impractical with currently known solutions.

Such an impossibility can be explained as follows by referring to Figure 1 attached.

Indeed, if we refer to this figure 1, if we wish to store inside a relatively flat conduit (1), whose inlet slot (2) is of rectangular section and has a height (L) equal for example to fifty millimeters, the thread (3) moving vertically with respect to this slot (2) (vertical displacement being the most common displacement in textile machines), if one wishes to form a long loop, in such a vertical plane, and this under the action of a speed air flow (V), the wire having a linear mass (P) and being subjected to a tension (T), the upper strand (4b) of the loop (4) will be inclined by an angle alpha of the order of 0.5 to 1 degree depending on the title of the wire and the speed of the air, the lower strand (4a) remaining, as for him, horizontal and being supported by the lower wall of the conduit (1).

Experience shows that for an initial length (L) of fifty millimeters, it is possible to form a reliable loop by having a length of the order of two to four meters (ie only four to eight meters of stored wire).

Consequently, if it is desired to obtain a length of loop compatible with a piecing system (knotter, system forming a splice, etc.), the operating cycle of which is slow and is for example of the order of two seconds, and for which it is necessary, as said previously, a length of stored wire of about twenty meters, the logically conceivable solution consists in reducing the value of the angle alpha. To reduce this angle, it is therefore necessary to increase the tension of the thread which, from a textile point of view, can be a serious drawback for the process and necessarily involves an increase in the speed (V) of the air, therefore losses of load and as a result of the energy consumed. It could also be envisaged to increase the height L of the inlet slot to store the desired length, but then, the section is increased and consequently the flow rate, therefore the energy consumed and also the space requirement becomes very large.

Another theoretically conceivable solution would consist in forming the loop in a horizontal conduit. In such a case, we are faced with the problem of the loop passing from a vertical plane to the horizontal main storage plane since, as said above, the path of a yarn on a spinning machine is carried out in such a plane. vertical. Tests carried out in this direction indeed show that the two strands of the loop tend to approach each other and to become tangled during this change of direction.

Now we have found, and this is what is the subject of the present invention, an improvement made to such devices for temporary storage of a wire, which makes it possible to solve these problems and to form a stable loop, the two strands are perfectly separated from each other and whose length can easily reach twenty meters and even more.

Furthermore, thanks to the method according to the invention, it is possible to produce a storage enclosure having a reduced bulk, the positioning of which relative to the structure of the machine is not limited by the fact that said enclosure may have a configuration other than straight and can form bends in different orientations.

In the following description, the invention will be described for a storage device used on a spinning machine in which the yarn feed rate cannot be interrupted, but it is obvious that it could also be applied to a machine in which the opposite problem would arise, that is to say, as in the case of FR-A-1 404 286, on a machine in which the reception of the wire formed cannot be interrupted.

In general, the invention therefore relates to an improved method for temporarily storing, in the form of a loop, a moving wire inside a chamber (or channel), including the section mouth relatively flat and rectangular, is arranged vertically opposite the path of the wire during its production, said channel being subjected to the action of a stream of fluid making it possible to keep the two strands of the loop formed separate, one of the strands (said "input strand") being introduced inside the chamber at a constant speed, and the other strand (said "output strand") being immobilized inside the chamber during of the formation of the loop, the method according to the invention being characterized in that one communicates at the fixed end of the output strand of the traction pulses making it possible to reposition the two strands relative to one another of the wire loop which can be deformed by friction t against the walls of the storage chamber.

Thanks to such a method, it is possible to produce a very long storage chamber, said storage chamber being able to be twisted to make it pass from a vertical entry plane to a horizontal storage plane, said storage zone being able to have a multiplicity of different orientations, but being such that if a cut is made, the two strands are arranged in the same horizontal plane (with the exception of changes in direction of the chamber), the frequency of the traction pulses communicated at the fixed end of the stationary strand being exerted at least immediately after the end of the loop formed has crossed a transition zone between two different storage planes.

Optionally, to promote the separate maintenance of the two strands of the loop, the section of the storage chamber, initially rectangular, can be profiled in order to define two separate channels for each of the strands of the loop, channels connected together by a free area. allowing the passage of the wire, and the profile of which is such that it tends to keep the mobile strand and the fixed strand of the loop separated from one another in the areas where they tend to approach one of the 'other.

The method according to the invention can be implemented on any type of textile machine, and in particular on spinning machines, the means allowing its implementation and in particular the wire storage enclosure which can be associated, either with each working position that the machine comprises, or be mounted on a mobile assembly of the "robot" type which moves in front of the machine so as to be able to intervene indifferently in any position.

• la figure 1 illustre comme vu précédemment, la manière dont se forme une boucle de fil en mouvement à l'intérieur d'un conduit de stockage soumis à l'action d'un courant de fluide ;
• la figure 2 est une vue schématique, montrant la manière dont est mis en oeuvre le procédé conforme à l'invention sur une machine de filature ;
• la figure 3 est une vue schématique de la forme de réalisation de la chambre de stockage que permet de réaliser le procédé conforme à l'invention ;
• la figure 4 illustre de manière schématique le type de chambre de stockage permettant d'accumuler une boucle de fil de très grande longueur (de l'ordre de vingt mètres ou plus) et ce, grâce au procédé conforme à l'invention ;
• les figures 5a et 5b sont des coupes transversales selon l'axe XX de la figure 3 montrant les variations de profil internes que peut avoir la chambre de stockage dans les zones rectilignes (figure 5a) et dans les zones où la chambre subit un changement de direction (figure 5b) ;
• les figures 6,7 et 8 illustrent l'application du procédé conforme à l'invention sur une machine textile où chaque position est équipée d'un dispositif de stockage (figure 6), ou sur une machine dans laquelle le dispositif de stockage est monté sur un ensemble de type robot déplaçable au regard de chaque position de la dite machine (figures 7 et 8).

The invention and the advantages which it brings will however be better understood thanks to the exemplary embodiments given below for information but not limitation, and which are illustrated by the appended diagrams in which:

• Figure 1 illustrates as seen above, the manner in which a loop of moving wire is formed inside a storage conduit subjected to the action of a stream of fluid;
• Figure 2 is a schematic view showing the manner in which the method according to the invention is implemented on a spinning machine;
• Figure 3 is a schematic view of the embodiment of the storage chamber that allows the method according to the invention to be carried out;
• FIG. 4 schematically illustrates the type of storage chamber making it possible to accumulate a loop of wire of very great length (of the order of twenty meters or more), and this, thanks to the method according to the invention;
• Figures 5a and 5b are cross sections along the axis XX of Figure 3 showing the internal profile variations that may have the storage chamber in the rectilinear areas (Figure 5a) and in the areas where the chamber undergoes a change of management (Figure 5b);
• Figures 6,7 and 8 illustrate the application of the method according to the invention on a textile machine where each position is equipped with a storage device (Figure 6), or on a machine in which the storage device is mounted on a robot-type assembly movable with respect to each position of said machine (Figures 7 and 8).

If one refers to the appended figures using the same references as those used in Figure 1, the method according to the invention can be implemented on any type of textile machine, such as for example a schematic spinning machine in Figure 2, in particular for making a connection for which the material flow (3) must not be interrupted. In such an installation, when it is desired to carry out a reattachment operation, without interrupting the flow of material (3), it is advisable to proceed in the manner illustrated diagrammatically in FIG. 2. In such an installation, the movable wire (3 ) issued by the supplier (12) is transferred from this supplier to a position (P2) by a vacuum cleaner ensuring sufficient tension in the wire so that the latter, passing in front of the inlet (2) of a temporary storage assembly (1), is not sucked in by the latter. Furthermore, the other end of the wire taken from the winding system (13) which has been stopped is, in turn, brought to a suction (P1) which provides a slight tension to this moving wire. The two ends thus positioned are then introduced into a reattachment system (14) of any known type, allowing for example to make a splice. The suction systems (P1 and P2) allow, after completion of the piecing, to evacuate the two ends of cut wire. The reattachment cycle begins with the closing of a clamp (15) which thus immobilizes the wire (3) coming from a power source (12). The wire flow being interrupted, the reattachment device (4) can therefore operate. During this actual connecting phase, the wire (3) coming from the deliverer (12) must therefore be stored, the length of stored wire being a function of the duration of the connection and the speed of flow of the wire (3) and being able to reach , as seen above, twenty meters for a machine operating at 600 meters / minute and with a fastening time of two seconds.

The solution according to the invention for obtaining such a length of wire, consists in accumulating the wire (3) coming from the power source (12) inside a chamber (1) in the form of 'a loop (4) comprising two strands (4a, 4b) obtained by the action of an air current flowing inside said chamber or enclosure (2).

During the formation of this loop, the strand (4a) moves inside the chamber while the strand (4b) (called "output strand") is, taking into account the fact that the wire is immobilized by the clamp (15), kept fixed. In order to obtain a well-separated hold of the two strands (4a) and (4b), in accordance with the method according to the invention, the stationary end of the strand (4b) is subjected to small traction pulses which make it possible to reposition the loop of wire. Such pulses can be communicated either by moving the clamp (15), or possibly by means of an additional guide (16) which intermittently moves the fixed strand at the outlet of the storage member (1).

It was found that by proceeding in this way, it was possible, not only to be able to pass the storage enclosure which is normally arranged vertically opposite the path of the wire in a horizontal plane of great length as shown schematically in the Figure 3, which eliminates the stresses due to gravity, but, also, it was possible to give this conduit a shape other than straight, allowing to adapt such a storage assembly to many different types of materials and by having a minimum size.

Thus, FIGS. 4 and 6 illustrate an embodiment in which the storage enclosure (1) passes from a vertical position to a plane transition zone but inclined relative to the horizontal, in order then to present two superimposed horizontal sections . Such an embodiment is particularly useful when it is desired to adapt a storage assembly to each working position.

FIGS. 7 and 8 illustrate two embodiments of a storage duct made possible by the method according to the invention and in which said duct is associated with a “robot” type system which can be moved in front of each position that comprises the machine. In the two illustrated embodiments, the entry area of the duct is arranged vertically opposite the path of the wire, then is twisted to form a flat duct, oriented vertically, duct which is then folded horizontally as illustrated in the embodiment (Figure 7), or vertically as illustrated in the embodiment (Figure 8). Thanks to the method according to the invention, it was possible to make loops of stored wire having a length of twenty meters using enclosures subjected to a vacuum of 50 to 250 mb and having a flow rate of the order of 10m3 / h under normal temperature and pressure conditions; and this by having an enclosure whose inlet section (2) is rectangular, the dimensions of which are: L = 50 mm and e = 4 mm.

It has also been found that it was possible to promote the well-separated maintenance of the two strands of the wire loop by adapting the internal profile of the storage duct, this profile being able to be formed from two channels separated by a raised part forming two beads. which leave a free area between the two channels sufficient to allow the passage of the wire and which, in the change of direction zones, is adapted to have the configuration as illustrated in FIG. 5b in which the two channels are asymmetrical, this which promotes the separate maintenance of the two strands (4a, 4b) of the loop.

Of course, the invention is not limited to the embodiments described above, but it covers all the variants produced in the same spirit.

Claims (5)

1 / Method for temporarily storing, in the form of a loop (4), a wire (3) in movement, inside a chamber (1) (or channel) whose mouth (2) of relatively flat and rectangular section is arranged vertically opposite the path of the wire during its production, said channel being subjected to the action of a stream of fluid making it possible to keep the two strands (4a, 4b) of the loop formed separate, one of the strands (4a) being introduced inside the chamber (1) at a constant speed, and the other strand (4b) being immobilized inside the chamber during the formation of the loop, characterized in that at the end (15) of the fixed strand (4b) there are traction pulses making it possible to reposition the two strands (4a, 4b) of the loop of wire which can be deformed by friction against the walls of the storage chamber. 2 / A method according to claim 1, characterized in that the loop (4) of wire is of great length and is stored inside a chamber (1) twisted to pass it from a vertical entry plane to a horizontal storage plane, said storage zone possibly having a multiplicity of different orientations, but being such that if a cut is made, the two strands are arranged in the same horizontal plane (with the exception of changes in direction of the chamber), the frequency of the traction pulses communicated to the fixed end (15) of the strand (4b) being exerted at least immediately after the end of the formed loop has crossed a transition zone between two planes different storage. 3 / A method according to claim 1, characterized in that the section of the initially rectangular storage chamber (1) is profiled in order to define two separate channels for each of the strands (4a, 4b) of the loop (4), the channels interconnected by a free area allowing the passage of the wire, said profile being such that it tends to keep apart the movable strand (4a) of the fixed strand (4b) of the loop in areas where they tend to get closer to each other. 4 / Device for the formation of a thread reserve on a textile machine of the type according to which the thread (3) is stored inside a chamber (1), the mouth (2) of relatively flat section and rectangular is arranged vertically with respect to the path of the wire during its production, said channel or chamber (1) being subjected to the action of a stream of fluid allowing the two strands (4a, 4b) of the loop to be kept separate (4) formed, one of the strands (4a) being introduced inside the chamber (1) at a constant speed, and the other strand (4b) being immobilized inside the chamber during the formation of the loop, characterized in that it comprises means (16) making it possible to communicate, at the fixed end (15) of the strand (4b), traction pulses. 5 / Device according to claim 4, characterized in that the storage chamber (1) is twisted to pass it from a vertical entry plane to a horizontal storage plane proper, said storage area having a multiplicity of 'different orientations and traction pulses communicated to the fixed end of the output strand acting at least immediately after the end of the loop formed has crossed a transition zone between two different storage planes.

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