FR2681348A1 - Improved installation making it possible to straighten and cut transversely textile articles, particularly fabrics - Google Patents

Abstract

Installation making it possible to cut a textile web (fabric) (2). It includes a work surface (3) onto which the cloth (2) to be cut is brought, the said work surface comprising: - a plurality of conveyor belts (4) spaced from one another and driven by parallel shafts (5, 6); - a plurality of elements for detecting the junction zone between two elementary products, associated with each conveyor belt (4) and aligned transversely with respect to the work surface; - means (7a, 7b) making it possible to provide simultaneous immobilisation of the material against the surface of the work surface, this being on either side of the parting line between two articles, and; - means making it possible to bring about the transverse displacement of a cutting member when all of the immobilising means have been actuated.

Description

IMPROVED INSTALLATION FOR STRAIGHTENING AND
CROSS-CUT CUT FABRIC TEXTILE ARTICLES
ESPECIALLY.

 The present invention relates to an improvement made to installations making it possible to carry out the transverse cutting of textile articles, in particular woven.

 In the textile industry, we very often find ourselves faced with the problem of having to cut elementary pieces, of determined length, from the basic structure (fabrics, knitwear, etc.) which is in the form of a strip of determined width, depending on the article and the trade on which the production is carried out, and whose length can reach several hundred meters. Such a problem arises in particular for the production of bedding articles (sheets, blankets, etc.), articles for household or industrial use (mops, cloths, etc.).

 In general, during the production of these artides, during the weaving (or possibly knitting) operation, each elementary product is separated from the next by a so-called "separation" zone making it possible to materialize the subsequent cutting zone. Such a separation zone can be materialized either by modifying the weave of the fabric in the junction zone, or by incorporating in this zone one or more weft threads of different color.

 At the fall of the trade, the elementary articles are therefore connected to each other and there is therefore not only the problem of making the cut between two consecutive articles, but also that of fitness given that very often, in particular for decontextured articles, the warp and weft threads are not strictly oriented perpendicular to each other.

 In general, the solution which is still the most used to date, consists in carrying out the separation manually by cutting the textile with scissors at the level of the separation zone between two articles, and by following the deformation of the fabric. If such a solution makes it possible to obtain a precise cut, it is obvious that it is long, tedious and increases the production costs. Furthermore, if the article is deformed, it is obvious that it retains this deformation and that it is therefore necessary to carry out a subsequent resumption of finishing.

 It has long been proposed to replace manual cutting by automatic cutting. The solutions proposed to date are not satisfactory, however, because they do not make it possible to straighten the fabric, which leads either to production defects if the cutting is carried out strictly transversely with respect thereto, or complicates the operation of cutting if the cutting member is made to follow a path along the deformed profile of the separation zone.

 Now we have found, and this is what is the subject of the present invention, an improved installation which makes it possible to solve all of these problems and which, more particularly, not only makes it possible to carry out the perfectly "straight wire" cutting. "between two elementary products, but also ensures automatic reorientation of the artid's threads with respect to each other, so that after cutting, the unitary product is not deformed and does not require subsequent resumption of delivery in shape.

In general, the installation according to the invention making it possible to supply and cut at a predetermined intervals a very long textile strip (fabric), is in the form of an assembly comprising essentially:
- storage means for the raw material to be cut;
- return means for bringing the strip of tape flat
material on a work surface proper, allowing
perform the transverse cutting operation;
- means of appeal allowing, on the one hand, to advance the
strip to be cut intermittently, and secondly,
to evacuate the unit article after cutting and;
- cutting means, movable transversely above
of the work plan, and it is characterized in that the work plan itself is in the form of an assembly comprising, mounted on a support frame:
- A plurality of conveyor belts, spaced regularly from each other over the width of the work surface and carried by parallel shafts, driving them permanently in order to ensure on the one hand the supply of the material to be cut flat on said work plan, and on the other hand, the evacuation of elementary products after cutting;
- A plurality of elements for detecting the junction zone between two elementary products, associated with each conveyor belt and aligned transversely with respect to the work plane;
- Means for ensuring the simultaneous blocking of the material against the surface of the work surface, and this on either side of the separation line between two articles, ;;
- Means for controlling the transverse movement of the cutting member when all of the locking means have been actuated (and that as a result, the separation zone is perfectly aligned with all of the detection means).

 Advantageously and in practice, according to a preferred embodiment in accordance with the invention, the drive of the material to be cut and its immobilization during the actual cutting operation, is ensured by pairs of rocker assemblies associated with each elementary conveyor belt, rocking elements arranged on either side of the cutting line and which comprise, on the one hand, pressure rollers coming into contact with the surface of the conveyor belts at the level of the driving shafts which drive them, and d on the other hand, actual blocking elements (straight ramps), the displacements of said assemblies being carried out by means of control jacks actuated simultaneously.

 The means for detecting the separation zone are constituted by cells sensitive to a control element, such as for example a metal wire, inserted in the article to be cut at the level of the separation zone.

The invention and the advantages which it brings will however be better understood thanks to the embodiment given below by way of indication but not limitation, and which is illustrated by the attached diagrams in which:
- Figures 1,2 and 3 schematically show, in elevation, the structure and operation of the assembly of an installation according to the invention, the supply of material to be cut and the reception of the precut elementary parts being not shown;
- Figures 4a to 4f show, top view, the manner in which the immobilization and straightening of the article to be cut is carried out on an installation according to the invention.

 If reference is made to the appended diagrams, the installation according to the invention consists essentially of an assembly, designated by the general reference (1) which makes it possible to supply and cut at predetermined intervals of a very long textile strip (fabric) (2). Such an installation is arranged downstream of storage means for the raw material (2) to be cut. In general, the textile articles being stored, at the exit of the loom, in the form of a winding, the roll of material (2) is mounted on a support shaft (not shown) which can rotate freely on a frame in bearings provided for this purpose. Return means (not shown) make it possible to bring the strip of material (2) flat on the work surface (3) proper of the installation (1) produced in accordance with the invention, and which makes it possible to produce the transverse cutting operation. Such an installation (1) also comprises call means making it possible, on the one hand, to advance the strip (2) to be cut intermittently, and on the other hand, to evacuate the unit article after cutting and cutting means movable transversely above the work surface.

 According to the invention, the actual working assembly (1) comprises, mounted on a support frame, a plurality of identical elementary modules, arranged side by side and spaced from each other, and which make it possible to ensure the bringing the material to be cut flat on the work surface, maintaining said material and the necessary straightening according to the deformation and the width of the article so that the cutting operation is carried out "straight" as well as the evacuation of said elementary products after cutting. In the embodiment illustrated by the attached diagrams, the installation according to the invention comprises, over its width, nine identical modules, one of these modules being framed in phantom lines FIG. 4a and being designated by the references (Ml), the other modules being designated by the references (M2 to M9).

 If one does not depart from the scope of the invention by making installations comprising a more or less large number of modules and that, if ultimately, one could envisage making these assemblies comprising only one module in the case for example where one would like to cut a strip of material of very small width, it is however preferable to have at least three identical modules if one wants to obtain a good reorientation of the wires constituting the article to be able to cut them in strictly following the separation zone between two elementary articles.

 Each work module (M) of an installation according to the invention, consists of a conveyor belt (4), said belts being regularly spaced from one another over the width of the work surface and being carried by the shafts parallel (5,6) driving them simultaneously and thus ensuring on the one hand the supply of the material (2) to be cut flat on the work surface, and on the other hand, the evacuation of elementary products after cutting.

Each module (M) also includes detection elements (11) (visible only in FIGS. 4a to 4f), such as cells, making it possible to detect the junction zone between two elementary products. These detection elements (11) are arranged laterally with respect to each conveyor belt (4) and are aligned transversely with respect to the work plane.

 Finally, each module includes means for ensuring the simultaneous blocking of the material against the surface of the work surface, and this on either side of the line of separation between two articles. In the illustrated embodiment, such means consist of two identical assemblies (7a, 7b) arranged on either side of the area where the cutting is to be carried out and above the work surface proper.

These means which make it possible to entrain the material to be cut and to immobilize it during the actual cutting operation, consist essentially of two rocking assemblies (8a, 8b) which comprise, on the one hand, pressure rollers ( 9a, 9b) and, on the other hand, blocking elements (10a, 10b) in the form of a ramp. The control of these rocking elements (8a, 8b) is carried out by means of jacks (lla, llb) controlled simultaneously for each module (M) and this, upon detection of the transition zone between two elementary articles, the corresponding zone to a module.

 The operation of such an installation produced in accordance with the invention is as follows. During the normal advance of the article to be cut (FIG. 1), said article (2) is driven by the conveyor belts (4) of the modules (M) thanks to the action of the pressure rollers (9a, 9b) of each tilting element (8a, 8b). When a control element inserted in the article to be cut at the separation zone (12), for example with a metal wire, arrives at a detection cell (11 ), the latter automatically controls the action of the rocking elements (8a, 8b) so that they come into the position illustrated in FIG. 2, which causes the spacing of the rollers (9a, 9b) of the fabric, and simultaneously, the actuation of the blocking elements (10a, îOb) (ramps) which come to bear on the surface of the fabric and therefore keep it immobilized on either side of the separation line between the two elementary articles , separation line designated by the reference (12) in Figures 4a to 4f. These figures illustrate a total sequence of action of the different modules (Ml) to (M9) for a material whose separation zone (12) would be deformed according to the curve illustrated in FIG. 4a. It is obvious that the action sequence of each module (M1) to (M9) will vary depending on the deformation of the junction zone. In the sequence illustrated in FIGS. 4a to 4f, the junction zone (12) arriving first at a detection cell (11), is located at the level of the module (M9) which passes from the position illustrated to the FIG. 1 to that illustrated in FIG. 2. In FIG. 4b, the separation zone corresponding to the module (Ml), is detected by the corresponding cell, this module also passing from the position shown in FIG. 1 to FIG. 2. In Figure 4c, the modules that come into action are the modules (M2) and (M9), then the modules (M3) and (M7) (Figure 4d), (M4) and (M6) (Figure 4e) and finally the module (M5) (Figure 4f). In this position illustrated in FIG. 4f, the separation zone (12) is therefore perfectly aligned and information is then sent to trigger the cutting operation proper, operation shown diagrammatically in FIG. 3. During this cutting operation, the fabric (2) is slightly raised by means of a lifting plate (13), which facilitates the transverse passage of the cutting member and the guiding and holding of the fabric during this operation. cutting operation having been carried out, all the rocking elements (8a, 8b) take up the position illustrated in FIG. 1 allowing the supply of a new length of material to be cut and the evacuation of a cut elementary product.

 Such an installation not only achieves very high productivity, but also ensures very high reliability and repeatability of the cutting operation. Furthermore, it has been observed that if at the start of cutting a piece of fabric, the first elementary article has a very deformed junction zone, that this deformation tended to fade as the cuts were made successive. Furthermore, taking into account that, in accordance with the invention, the fabric is blocked by means of two assemblies acting upstream and downstream of the cut, there is a total elimination of the folds in this area.

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

Claims (3)

 1 / Installation making it possible to supply and cut at predetermined intervals a textile strip (fabric) (2) of great length, which is in the form of an assembly essentially comprising:  - storage means for the raw material (2) to be cut;  - return means for bringing the strip of tape flat  material (2) on a work surface proper (1), allowing  to carry out the transverse cutting operation;  - means of appeal allowing, on the one hand, to advance the  strip to be cut (2) intermittently, and secondly,  to evacuate the unit article after cutting and;  - cutting means, movable transversely above  of the work plan (1), characterized in that the work plan itself (3) is in the form of an assembly comprising, mounted on a support frame:  - A plurality of conveyor belts (4), spaced regularly from one another over the width of the work surface and carried by parallel shafts (5,6), driving them continuously in order to ensure on the one hand the supply material to be cut (2) flat on said work surface, and secondly, the evacuation of elementary products after cutting;  - a plurality of elements (11) for detecting the junction zone (12) between two elementary products, associated with each conveyor belt (4) and aligned transversely with respect to the work plane  means (7a, 7b) for ensuring the simultaneous blocking of the material against the surface of the work surface, and this on either side of the separation line (12) between two articles,  - Means for controlling the transverse movement of the cutting member when all of the locking means have been actuated and that as a result, the separation zone is perfectly aligned with all of the detection means.  2 / Installation according to claim 1, characterized in that the drive of the material to be cut and its immobilization during the actual cutting operation, is provided by pairs of rocker assemblies (7a, 7b) associated with each elementary conveyor belt (4), rocking elements (7a, 7b) arranged on either side of the cutting line and which comprise, on the one hand, pressure rollers (9a, 9b) coming into contact with the surface of the conveyor belts (4), at the level of the drive shafts (5,6) which drive the said belts, and on the other hand, the actual blocking elements (lOa, lOb) (straight ramps), the displacements of the said assemblies being carried out by the 'Intermediate control cylinders (llA, llB) operated simultaneously.  3 / Installation according to one of claims 1 and 2, characterized in that the means for detecting the separation zone are constituted by cells sensitive (11) to a control element, such as for example a metal wire, inserted in the article to be cut at the separation zone.