EP0305305B1 - Device for imparting a false-twist by friction to at least one advancing yarn - Google Patents

Description

The present invention relates to an improved device for communicating a false torsion by friction to at least one moving wire.

The technique of communicating a false twist by friction to a wire has been known for a very long time. This technique consists, in general, of putting the moving wire in contact with a mobile surface, moving transversely with respect to said wire, so that it is twisted upstream and regains its initial twist in downstream.

This technique for which many applications have been envisaged is mainly used to date for texturing chemical threads, that is to say for imparting bulk and elasticity to them by means of a heat treatment followed by cooling. of the wire upstream of the false twist member.

Various other applications of false twist have also been envisaged, in particular for producing fancy yarns, yarns having alternating twist along their length, self-twisted yarns, yarns of simple or complex fibers, for example comprising an internal core.

As a mobile surface allowing a friction twist to be communicated to a wire, numerous solutions have been proposed. Those which, to date, are used in the field of texturing, use either bushings against the surface of which the wire is in contact (false twist by internal friction), either to discs, mounted on parallel axes, overlapping each other, the moving wire coming into contact with the external surface of said discs (false torsion by external friction).

It has been proposed for a very long time in particular in French patents n ° 1,191,361, 1,255,922, and in American patent n ° 2,908,133, to use as organ for communicating the false twist one or more endless belts against the surface of which the wire rubs.

It has also been envisaged, as described in US-A-2 262 589 and FR-A-1 076 599 to communicate a false twist by passing the thread, whether it is based on continuous filaments or of staple fibers, between two movable belts, these belts being arranged obliquely with respect to each other, so that the thread is given an impulse in the direction of its movement during its passage between the belts . The invention relates to an improvement made to the latter type of false twist device.

In the following description, such a belt device will be designated by the expression "spindle with crossed belts".

Among the problems which arise for such crossed belt spindles and which are a function of the material treated, the speed of production, the rate of twist which it is desired to communicate, one can cite that of the inclination of a belt relative to the other, from the pressure of said belts against each other, from the tension of each of the belts.

Furthermore, such spindles must be able to allow easy positioning of the wire during start-up, offer the possibility of adjusting the running speed of the belts and allow easy change of said belts when they are worn.

Taken separately, each of these problems can be solved without difficulty by those skilled in the art.

However, to date, no solution has been proposed to resolve them simultaneously.

In addition, in all the devices proposed to date, the problem arises of maintaining the belts in position around their support rollers, given that, in normal operation, said belts under the action of the stresses exerted by the passage of the wire tend to move transversely, which disrupts proper functioning. Currently, in the textile field, to ensure the maintenance of belts around the drive rollers, for example in the spindles or even in the wire deliverers, the solutions proposed have consisted either of providing rollers whose width is less to the width of the belts, or to use curved rollers.

Finally, to date, in such crossed belts it is necessary to have rollers having a relatively large diameter, rollers which are always of equal diameters, which has the consequence of increasing the size of such pins and especially d 'remove the torsion member of the means which deliver the material (wire or fiber) to be treated.

Now we have found, and this is what is the subject of the present invention, an improvement to such types of spindles with crossed belts, an improvement in design which is particularly simple, easy to use and to maintain, of small size, which not only makes it possible to easily obtain the aforementioned adjustments (inclination of the belts, pressure between them, etc.), but also eliminates any risk of slipping of the belts relative to the support rollers.

• des moyens permettant de modifier l'inclinaison de deux courroies l'une par rapport à l'autre;
• des moyens permettant de régler la pression (ou l'écartement) des courroies l'une contre l'autre;
• des moyens permettant d'entraîner en rotation les galets supports des courroies ainsi que de les embrayer et de les débrayer, caractérisé en ce que les galets supports supportant les deux courroies sont montés sur le boitier par l'intermédiaire de deux paires de bras supports:
• l'un des bras supports de chaque paire étant soumis à l'action de moyens de pression permettant d'assurer la tension de chaque courroie;
• au moins l'un des deux autres bras supports étant monté sur le boitier de manière à pouvoir pivoter autour d'un axe afin de régler la pression des deux courroies l'une contre l'autre, le parallélisme entre les axes desdits galets pouvant n'être pas respecté;
• les extrémités du bras support sur lesquels sont montés les galets supports sont inclinées afin d'obtenir l'angle souhaité entre les deux courroies.

In general, the invention therefore relates to a device making it possible to communicate a false torsion by friction to a fibrous material of the type comprising a housing on which are mounted two endless belts, inclined with respect to each other, mounted on two pairs of rollers, having two strands in mutual contact, the fibrous material passing between these belts in the zone where they are in contact, so that, on the one hand, they impart a false twist to it and other apart, they tend to deliver the wire formed, and which comprises in combination:

• means for changing the inclination of two belts relative to each other;
• means for adjusting the pressure (or spacing) of the belts against each other;
• means making it possible to rotate the support rollers of the belts as well as to engage and disengage them, characterized in that the support rollers supporting the two belts are mounted on the housing by means of two pairs of support arms:
• one of the support arms of each pair being subjected to the action of pressure means making it possible to ensure the tension of each belt;
• at least one of the other two support arms being mounted on the housing so as to be able to pivot around an axis in order to adjust the pressure of the two belts against each other, the parallelism between the axes of said rollers being able to n 'not be respected;
• the ends of the support arm on which the support rollers are mounted are inclined in order to obtain the desired angle between the two belts.

• les deux galets supports de chaque courroie ont des diamètres différents, celui situé le plus en avant par rapport au boitier étant nettement inférieur à l'autre galet, les surfaces desdits galets et des courroies qui le supportent comportant, l'une au moins un rainurage continu, l'autre au moins une partie en relief complémentaire permettant ainsi d'assurer un positionnement rigoureux des courroies dans l'espace malgré le défaut de parallélisme qui peut exister entre les axes et ce, quelque soit l'angle des courroies;
• l'entraînement des galets moteurs de chaque paire de galets est obtenu au moyen d'une courroie sans fin commune aux deux galets.

Preferably, in accordance with the invention:

• the two support rollers of each belt have different diameters, the one located furthest forward relative to the housing being significantly smaller than the other roller, the surfaces of said rollers and the belts which support it comprising, at least one grooving continuous, the other at least one part in complementary relief thus ensuring a rigorous positioning of the belts in space despite the lack of parallelism which may exist between the axes and this, whatever the angle of the belts;
• the drive rollers of each pair of rollers are driven by an endless belt common to the two rollers.

In known manner, the device according to the invention is associated on the one hand with means making it possible to deliver at least one fibrous material between the two belts as well as means making it possible to draw up and return the wire thus treated.

• soit de traiter le fil thermiquement en amont et/ou en aval du dispositif, par exemple lorsque l'on désire réaliser un fil texturé, un fil rétracté..;
• soit de faire varier le débit du fil et/ou la longueur de remontée de torsion en amont dudit dispositif lorsque l'on désire obtenir un fil présentant une tension alternée;
• soit permettre de délivrer une ou plusieurs mèches de fibres parallélisées auxquelles on désire communiquer de la cohésion.

Furthermore, it can be combined with any known means allowing:

• either heat treating the wire upstream and / or downstream of the device, for example when it is desired to make a textured wire, a retracted wire, etc .;
• either to vary the flow rate of the wire and / or the length of the twist rise upstream of said device when it is desired to obtain a wire having alternating tension;
• or allow the delivery of one or more strands of parallelized fibers to which one wishes to communicate cohesion.

In other words, such a device can be used both to treat yarns with continuous filaments as yarns of fibers, or even wicks alone or in combination with other textile elements.

• la figure 1 est une vue schématique en perspective montrant l'ensemble d'une broche à courroies croisées conforme à l'invention;
• les figures 2 et 3 ainsi que les figures 4 et 5 montrent schématiquement, vues de dessus, dans le cas d'une broche dans laquelle le défilement du fil se fait horizontalement comme illustré à la figure 1, la manière dont sont montés sur le boitier, d'une part les galets supports de la courroie inférieure (figures 2 et 3) et, d'autre part, les galets supports de la courroie supérieure (figures 4 et 5);
• les figures 6 et 7 sont des coupes montrant la structure des galets supports d'une courroie.

The manner in which the device according to the invention is produced will however emerge more clearly from the embodiment given below by way of indication but not limitation and which is illustrated by the attached diagrams in which:

• Figure 1 is a schematic perspective view showing the assembly of a spindle with crossed belts according to the invention;
• Figures 2 and 3 as well as Figures 4 and 5 show schematically, views from above, in the case of a spindle in which the wire runs horizontally as illustrated in Figure 1, the manner in which are mounted on the housing , on the one hand the support rollers of the lower belt (Figures 2 and 3) and, on the other hand, the support rollers of the upper belt (Figures 4 and 5);
• Figures 6 and 7 are sections showing the structure of the support rollers of a belt.

In the following description, the invention will be described for a spindle in which the textile material (designated by the expression "thread" but which could consist of fibers), runs horizontally but it is obvious that this is not limiting and that such a material could scroll vertically or at any other angle. In view of this provision, the terms "lower" and "upper" will be used to differentiate the different elements of such a pin.

Referring to Figure 1, the spindle with crossed belts according to the invention is of the type comprising two endless belts (1, 2), mounted on two pairs of rollers (3, 4, 5, 6) , arranged face to face and inclined with respect to each other so that, in normal operation, when the fibrous material (7) (wicks, continuous filaments, combination of such elements, etc.) passes between these belts in the area where they are in contact and they give it a false twist and tend to deliver it.

According to the invention, the belts (1, 2) are mounted on a housing (8) fixed to the housing of the machine in the following manner.

First, each roller (3, 4, 5, 6) is individually mounted at the end of a support arm respectively (9, 10, 11, 12), the support arm (12) of the roller (6) not being visible in Figure 1. These arms are designed in one piece and are mounted on the housing (1) so that they can optionally be changed. As shown in Figures 2 to 5, the ends of the arms on which the support rollers are mounted are inclined in order to obtain the desired angle between the two belts. It is therefore sufficient, in order to modify this inclination, to provide support arms comprising ends which are inclined in a different manner.

For each belt (1, 2), one of the arms, in this case the arm (12) for the lower belt and the arm (10) for the upper belt is subjected to the action of means making it possible to modify the tension of each of the belts. This is obtained in the illustrated embodiment, by mounting each arm (10, 12) pivoting about an axis (14), the body of the arm itself being directly subjected to the action of springs (15, 16) (only the spring (15) being illustrated in Figure 1). In this way, a simple articulation is produced. Admittedly, in such a design, the parallelism between the axes of the rollers supporting the belts may not be respected, but it is however possible to obtain perfect positioning and maintenance of the belts on said rollers thanks to the preferred embodiment in accordance with the invention which will be seen in the following description and in which the surface of said rollers and that of the belts comprises raised portions and complementary corresponding grooves.

Furthermore, in order to be able to adjust the pressure of the two belts against each other, the lower arm (11) is, for its part, mounted on the housing (8) so as to be able to pivot angularly about an axis (17). This pivoting can be controlled by a pneumatic cylinder (19) and therefore makes it possible, not only to secure the locking of the lower belt (2) against the upper belt (1) in normal operation, but also to achieve an automatic separation of the of them belts, for example when stopping the machine, thus avoiding any sticking between them. The interlocking between the belts (1) and (2) can be adjusted by means of a stop, fixed and adjustable (not shown in the attached diagrams) and which is interposed between the surface of the arm (11) and the surface of the body. (8) inside which this arm is mounted.

Such an embodiment therefore allows a disengagement of the belts (1, 2) upon opening and a clutch after start-up, which avoids prolonged contact between the belts, the temperature of which is generally relatively high after a long operation which can cause them to stick and, consequently, high torques during start-up and deterioration of the surface condition of the belts. This therefore also allows adjustment of the intersection of the belts (1, 2) by simple displacement of only one of the belt support rollers.

According to the illustrated embodiment, the upper arm (8, 9) which supports the roller (3) is, in turn fixed.

Furthermore, in accordance with the invention, in order to ensure perfect retention of the belts (1, 2) on the surface of the rollers, the latter include raised parts (20, 21), three in number in this case (see fig. 6 and 7), while the inner surface of each of the belts has corresponding grooves. Such grooving of the strips makes it possible to rigorously freeze their position in space despite the lack of parallelism between the axes which may result from the simplicity of such an articulation and this, whatever the angle between the strips and therefore the force exerted on them and which tends to move rollers.

Finally, in the illustrated embodiment, it is possible to obtain a very compact spindle by producing the rollers located furthest forward relative to the housing (8) in a diameter much smaller than the motor rollers themselves (3, 5 ), the latter being driven by a single continuous drive belt (22) which surrounds each roller (3, 5) passing inside a groove (23, 24), the control of this drive belt (22) being obtained by a pulley (25) itself driven by a suitable motor (26). These control elements are simply shown in dashed lines in FIG. 1.

Thanks to such a spindle design, it is possible to obtain a perfectly compact assembly, ensuring very regular operation from position to position, easy to maintain and to adjust.

Of course, the invention is not limited to the embodiment described above, but it covers all the variants produced in the same spirit. Thus, it is obvious that it is not departing from the scope of the invention by producing support rollers for each of the belts having equal diameters.

Claims (3)

1. Device for communicating a false twist by friction to a fibrous material, of the type comprising a box (8) on which two endless aprons (1, 2) are mounted, inclined with respect to each other, mounted on two pairs of rollers (3, 4, 5, 6), having two sides in mutual contact, the fibrous material (7) passing between these aprons int he zone where they are in contact, with the result that, on the one hand, they communicate a false twist thereto and, on the other hand, they tend to deliver the yarn formed, and comprising in combination:

- means for modifying the inclination of the two aprons (1, 2) with respect to each other;

- means for adjusting the pressure (or spaced apart relationship) of the aprons against each other;

- means for rotating the support rollers of the aprons (1, 2) as well as for connecting and disconnecting them,
characterized in that the support rollers (3, 4, 5, 6) supporting the two aprons (1, 2) are mounted on the box (8) via two pairs of support arms (9, 10, 11, 12):

- one of the support arms (10, 12) of each pair being subjected to the action of pressure means ensuring tension of each apron (1, 2);

- at least one of the two other support arms (9, 11) being mounted on the box (8) in order to pivot about a pivot pin to adjust the pressure of the two aprons one against the other, the parallelism between the axes of said rollers not being able to be respected;

- the ends of the support arm (9, 10, 11, 12) on which are mounted the support rollers (3, 4, 5, 6) are inclined in order to obtain the desired angle between the two aprons.

2. Device according to the claim 1, characterized by the fact that the two support rollers (3, 4) or (5, 6) of each apron (1, 2) have different diameters, that (4, 6) located foremost with respect to the spindle box (8) being clearly smaller than the other roller, the surfaces of said rollers and the aprons that they support comprising, one, at least one continuous groove, the other, at least one complementary part in relief, thus ensuring strict positioning of the aprons (1, 2) in space despite the lack of parallelism which may exist between the axes, and this whatever the angle of the straps (1, 2).

3. Device according to the claim 2, characterized in that the driving rollers (3, 5) of each pair of rollers are driven by means of an endless belt (22) common to the two rollers.

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