EP1163385B1 - Bias-bound fabric, method for making same and weaving machine for continuously making such a fabric - Google Patents

Abstract

A bias fabric is provided in that it is in the form of a cloth of length (L) and of finite width (l), being constructed by interlaced yarns (2, 3) extending in respective directions (D and d) that are oblique relative to the length (L), and each of which presents no knotting. The invention is applicable to engineering fabrics based on flat yarns.

Description

TECHNICAL AREA :

The present invention relates to the technical field of weaving but it aims, more particularly, the field of fabrics having a vocation of use industrial.

If such a technical field appears more preferential, it must be considered that the invention can be implemented in other areas without exclude for example upholstery or clothing.

In the preferred field, it is known that the arrangement of the fibers of a fabric has a great influence on its performance which can be of resistance, in one or more preferred directions, or to conform to surface conformations, especially when such fabrics are used as reinforcements used in the composition of a composite material while being associated with a matrix, for example resin.

Indeed, such skills are recognized and sought to obtain structural technical parts of more or less complicated forms, otherwise than by the usual machining operations, even stamping or stamping which are either delicate, time-consuming and expensive to implement, or sometimes difficult to drive when the material to be used, although resistant suitable, represents by its mass an insurmountable obstacle.

The technique of manufacturing composite parts is currently particularly adapted to the realization of technical pieces of shapes more or less complex and must present a certain lightness and a optimal resistance.

This is, for information only, the case of hulls, floats, warheads rockets, even powertrain hoods, etc.

From the moment he is tempted to meet the requirements that such manufacturing technique imposes, it is certain that the optimization of the characteristics structural requirements, it is necessary to take into account the orientation in the the good directions of the reinforcement that constitutes the fabric, so that its fibers resumed in the appropriate direction or direction the solicitations which will be imposed later on the piece obtained.

Similarly, a requirement of adaptability to the conformation of the part to be obtained which is generally represented by a mold positive or negative on or in which the composite material has to be arranged so to faithfully return to the shape of the model.

In the art, this ability to marry the model is usually qualified as toppling or draping, a quality that a technical fabric must ability to present in association with the previous requirement.

All of these reasons make it generally sought after to use a fabric whose elementary threads are not intertwined or intertwined with usual way, so that some, generally qualified chain, extend in the length of the woven width while others, generally qualified weft, extend in the cross direction, that is to say the width of said width.

In practice, it is indeed often sought to have tissue available whose elementary wires extend obliquely with respect to the two directions above, such bias, generally referred to as plus or minus 45 ° which, of course, may be subject to angular variations favoring openness angular of one of the categories of threads.

PRIOR ART:

To satisfy such a requirement from textile productions traditional methods, it has been proposed to cut in one piece of fabric produced from conventional way, elementary strips of fabric, in an orientation oblique for example at an angle of 45 °. Each band can then be qualified as bias fabric that can be oriented in such a way that some of the threads elementary elements are placed parallel to certain demands that the piece definitive will have to bear.

Such a method is certainly penalizing in different ways.

First of all, it is clear that the elementary tapes of tissues produced are of finite length, at best equal to the diagonal of the square corresponding to the width of the width when the orientation retained is the one of more or minus 45 °. This results in a significant drop rate which largely penalizes the cost price of the bias fabric, especially if the constituent fiber son is a high production cost.

Another disadvantage is that it becomes necessary to place side-by-side of such slits or strips of fabric at an angle when appropriate cover a large area and, more particularly, a long length. The question that arises then for obtaining a homogeneous structure is well obviously that of the connection between the contiguous edges, such a link to be executed in such a way as to have the same characteristics of topping, draping, but also of mechanical strength than those of the fabric. It can be considered that proposals that are made in this sense do not allow to answer this requirement when the composite material to be used as reinforcement may or only be formed by a single layer of technical fabric embedded in a matrix of resin. The only way to bind contiguous strips is to overlay locally at least several layers of tissue at an angle to form somehow a sandwich at the adjoining edges, which significantly increases the price of returns from the final piece and gives it dimensional characteristics and heterogeneous local resistance.

In an attempt to provide an answer to the problem thus posed, the technique previous has seen a number of other proposals (see for example WO 89/01405).

It can be cited the method of skewing from a fabric unidirectional consisting of elementary chain wires in relatively small quantities to the weft threads.

Such a technique involves passing the traditional fabric width between pressure rollers beyond which the fabric is taken up by a roll receiver whose axis is inclined at a given angle to the direction of the pressure rollers.

So that the expected result can be obtained durably, we conceive that it is necessary to involve, in the part between the rollers pressers and the receiving roller, fixing or connecting means, for example at the crisscrossing knots of the threads, so as to fix these in the new imposed orientation. Whatever the means implemented, such an obligation translated by a significant stiffness of the biased tissue which is no longer able to then respond equally well to the requirement of ease of topping or draping.

Moreover, the fixing process generally involves the provision of a binding product whose presence may have a detrimental effect on behavior subsequent tissue in its bond with its composite matrix.

Finally, the biasing of a traditional fabric necessarily results in a reduction in the width of the width initially produced.

In addition, such a method results in having a fabric of which only one son direction only is skewed, which does not exactly meet the goal referred.

The prior art has known another proposal consisting of realizing a fabric with traditional weft threads and warp yarns but which is produced under the form of a continuous tubular sheath. The principle is then to cut out a such sheath along a helical path, for example oriented at 45 °, so as to have, after opening and flattening, a woven web whose threads are oriented slantwise. The production of such a sheath can be provided from a trade traditional or circular craft.

Such a technique can be considered as an advance over to the previous one, but it nevertheless has a certain number of disadvantages.

Among these, it is worth mentioning the recovery operation that constitutes the helical cut that must be carried out accurately to obtain straight edges. To this end, means for cutting and maintaining the tubular sheath, but also open parts of the latter are necessarily to implement, which represents a significant industrial cost.

Another disadvantage is the means of feed retained for the son weft, whether it is a traditional craft or a circular craft.

As a general rule, the feeding of such wires is ensured from bobbins, or pre-formed bobbins with winding capacity limited liability to have to make the change periodically, with the requirement to restore the continuity of the threads by splicing, knotting, binding or other technical means. Such operations are penalizing for the production, increase the cost price and impose in the width produced the presence of means binding or knotting of yarns that can not be considered as providing the definitive fabric with homogeneous characteristics of thickness, flexibility, mechanical resistance.

However, the requirement to replace bobbins or cans comes from relatively common, since their capacity usually a continuous production without binding of the threads only for a length of width relatively weak.

In addition, the use of a traditional trade poses a problem extra, which is that resulting from the unwinding of the wire from a can is not animated by a rotation on itself. The result is, inevitably, a twist imposed on the wire. Such a technique is therefore absolutely not suitable when the fabric must be made from flat threads, whether these threads are single stranded or multi-filaments. Indeed, by such a method of weaving, such flat threads undergo a twist that destroys the homogeneous character in thickness but also in resistance and faculty of draping or topping of the resulting fabric.

The prior art has also proposed using an assimilated method for obtaining a fabric at an angle. It involves bringing in a braiding machine open which actually makes it possible to produce a band whose intertwined threads are oriented at an angle to the production direction of the band.

Conventionally, an open braider is made up of a power supply yarns from bobbins that are rotated about their axis, so that the same wire change problems are here to take into account.

Moreover, an open braider does not allow, generally and of practical way, to achieve a width of width sufficiently important for respond positively to the demands made on the account of an oblique fabric, especially in a technical application.

In all, therefore, the need is always felt to be able to have a bias fabric that can be produced continuously without being exposed to all defects and disadvantages that are to be put to the account of the technical solutions currently known.

It is precisely the object of the invention to produce such a fabric presenting in the form of a sheet homogeneous in thickness, in aesthetic appearance, in technical characteristics, so that it can be used in different areas of application where it is required a great ability to adapt by layering or draping relative to a reference model surface.

It is another object of the invention to provide the means of obtaining bias fabric that can be obtained at a relatively fast rate of production high, at an interesting manufacturing cost and which can be indifferently achieved at from monofilament or monofilament yarns or indifferently pluri-filaments, of form regular, homogeneous and / or heterogeneous, and even from strands or single-stranded threads flat or not, by nature or by previous should be preserved in the constitution of the fabric obtained bias.

SUMMARY OF THE INVENTION

To achieve the above objectives, the bias fabric according to the invention is characterized in that it is in the form of a width of width (L) and width (l) finished, consisting of interlaced son, established in respective directions oblique to the length (L) and none of which has any knotting, even for an infinite length (L) of the width.

• ourdir une nappe de fils de direction (x-x') parallèles entre eux en les faisant prendre en charge par un premier et un deuxième moyen de transfert occupant des directions parallèles (y-y') entre elles qui font un angle (α) avec la direction (x-x'),
• constituer progressivement ladite nappe en disposant successivement des fils au droit d'une bordure dite d'établissement de la nappe,
• déplacer d'un pas lesdits fils dans le sens travers oblique par les premier et deuxième moyens de tranfert depuis la bordure dite d'établissement vers une bordure opposée dite de reprise,
• faire prendre en charge supplémentairement le fil occupant la bordure de reprise par un troisième moyen de transfert situé à distance et parallèlement au premier moyen pour agir sur la partie sensiblement médiane dudit fil,
• ouvrir la nappe en deux demi-nappes pour délimiter une foule à proximité des premier et troisième moyens de transfert,
• couper, dans sa partie sensiblement médiane, le fil établi et amené au droit de la bordure de reprise,
• laisser en place la partie dudit fil maintenue par l'entrée du troisième moyen de transfert et la sortie du premier moyen de transfert pour constituer un fil de la future laize.
• prélever le segment dudit fil situé entre le troisième et le deuxième moyens de transfert et l'insérer dans la foule selon une direction perpendiculaire à la direction (x-x') depuis la bordure de reprise vers la bordure d'établissement pour constituer un fil de la future laize,
• procéder de même successivement avec chaque fil amené au droit de la bordure de reprise tout en disposant, complémentairement, un nouveau fil au droit de la bordure d'établissement et constituer progressivement un entrelac de segments de fils pris en charge par les premier et troisième moyens de transfert et qui progresse selon la direction (α) oblique par rapport à la direction (x-x').

The subject of the invention is also a process for continuously manufacturing a bias fabric of the above type, such a method being characterized in that it consists in:

• forming a ply of direction yarns (x-x ') parallel to each other by having them supported by first and second transfer means occupying parallel directions (y-y') between them which form an angle (α) with the direction (x-x '),
• progressively constituting said sheet by arranging successively threads to the right of a said edge of establishment of the sheet,
• to move said threads in the oblique traverse direction by a first step by the first and second transfer means from the so-called establishment edge to an opposite said recovery edge,
• additionally take over the wire occupying the return edge by a third transfer means located at a distance and parallel to the first means for acting on the substantially median portion of said wire,
• open the tablecloth in two half-plies to delimit a crowd near the first and third transfer means,
• cut, in its substantially median part, the thread established and brought to the right of the recovery edge,
• leaving in place the portion of said wire held by the input of the third transfer means and the output of the first transfer means to form a wire of the future width.
• taking the segment of said wire between the third and second transfer means and inserting it into the crowd in a direction perpendicular to the direction (x-x ') from the recovery border to the establishment border to form a wire of the future width,
• similarly proceed successively with each thread brought to the right of the recovery border while at the same time having a new thread at the right of the establishment border and progressively constituting an interlacing of segments of threads supported by the first and third means of transfer and which progresses in the direction (α) oblique with respect to the direction (x-x ').

• une section d'ourdissage d'une nappe de fils établis successivement, parallèlement les uns aux autres à partir d'une bordure d'établissement de la nappe,
• un premier et un deuxième moyens de prise en charge et de transfert transversal oblique desdits fils en direction d'une bordure de la nappe dite de reprise, lesdits moyens étant établis parallèlement entre eux selon une direction oblique (α) par rapport à celle des fils et cette direction oblique définissant la direction et le sens de production de la laize,
• un troisième moyen établi à distance et parallèlement au premier et entraíné dans le même sens que les deux premiers, de manière à prendre en charge la partie sensiblement médiane du fil de la nappe occupant la bordure de reprise,
• une section d'ouverture-fermeture de la nappe en deux demi-nappes pour délimiter une foule en amont des premier et troisième moyens de prise en charge selon le sens de production de la laize,
• des moyens pour, d'une part, couper le fil de la nappe occupant la bordure de reprise en amont du troisième moyen de prise en charge, d'autre part, laisser subsister entre le premier et le troisième moyen de prise en charge une partie de fil destinée à constituer un fil de la laize et, par ailleurs, prélever et insérer dans la foule ouverte le segment de fil compris entre la coupe et le deuxième moyen de prise en charge,
• et des moyens pour frapper chaque segment de fil inséré et le faire prendre en charge par les premier et troisième moyens qui assurent le guidage de la laize de tissu en biais ainsi produite.

Finally, the invention also aims, for the production of a fabric of the above type, a loom characterized in that it comprises

• a warp section of a sheet of son established successively, parallel to each other from a setting edge of the web,
• first and second oblique transverse transfer and transfer means of said yarns towards a border of the so-called recovery web, said means being established parallel to each other in an oblique direction (α) with respect to that of the yarns; and this oblique direction defining the direction and direction of production of the width,
• a third means established at a distance and parallel to the first and driven in the same direction as the first two, so as to support the substantially median portion of the wire of the sheet occupying the recovery edge,
• an opening-closing section of the web in two half-plies to delimit a crowd upstream of the first and third means of support according to the direction of production of the width,
• means for, on the one hand, cutting the thread of the sheet occupying the recovery border upstream of the third management means, on the other hand, leaving between the first and the third means of support a part of wire for forming a wire of the width and, furthermore, to take and insert into the open shed the segment of wire comprised between the cut and the second means of support,
• and means for striking each inserted segment of wire and having it supported by the first and third means which provide guidance of the slanted fabric web thus produced.

Various other features are apparent from the description below with reference to the accompanying drawings which show, by way of examples not restrictive embodiments of the subject of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS:

Fig. 1 is a schematic plan view partially showing a width of bias fabric according to the invention.

Figs. 2 to 6 are schematic views illustrating different phases of implementation of the method.

Fig. 7 is a schematic perspective illustrating the art for the implementation of the method leading to obtaining the bias fabric according to the invention.

Fig. 8 is a partial perspective highlighting some of the building blocks of the trade.

Figs. 9 to 12 are schematic views showing certain constituent parts of the craft.

Figs. 13 and 14 are perspectives illustrating some constructive details of the trade.

Fig. 15 is a schematic elevation showing other components of the craft in an alternative embodiment.

Fig. 16 is a plan view taken substantially along the line XVI-XVI of FIG. 15 .

Fig. 17 is an elevation similar to FIG. 15 but showing another functional characteristic.

Fig. 18 is a plan view taken substantially along the line XVIII-XVIII of FIG. 17 .

Figs. 19 and 20 are plan views, similar to FIGS. 16 and 18 but illustrating another example of armor.

BEST MODE OF REALIZING THE INVENTION:

The bias fabric according to the invention is illustrated schematically in FIG. 1 which shows that this fabric is in the form of a width 1 of length L and width l finished. With respect to this width, the length L must be considered infinite, that is to say likely to present a large footage having consistent constructive characteristics over the entire length.

The width is made of threads 2 and 3 which are interlaced or crisscrossed in any suitable armor, the most general being the taffeta frame. The wires 2 and 3 are established in respective directions D and d which are oblique with respect to the direction of the length L. Preferably, the directions D and d are orthogonal and symmetrical with respect to the direction L while making with respect to the latter each an angle which is generally qualified in the technique of plus or minus 45 °.

It goes without saying that while remaining orthogonal to each other, the directions D and d could have a different obliqueness with respect to the direction of the length L with, understandably, the incidence of a behavioral heterogeneity of the tissue obtained due to the existence of different angular directions and not symmetrical with respect to the direction L and complementary in value such as for example + 50 ° and - 40 °.

According to another characteristic, the son 2 and 3 are of finite length and are interrupted on at least one of the selvedges such as 1a relative to each other such that 1b.

According to a method of implementation, as will appear in what follows, the width of fabric may comprise son such as 2 which form every other time a loop 4 at one of the selvedges such as 1b.

The web 1 may also comprise selvedges 1a and 1b provided with a loop 5 formed by a ribbon or cord or else by a coating of appropriate material, reported during manufacture to imprison, or the cut ends of the son 2 and 3, either the loops 4 .

In an alternative embodiment, the width 1 comprises at least one reinforcing straight wire 6 which extends parallel to the direction L of the width. Such reinforcing wire is then trapped between the son 2 and 3 which may be of single-strand or multi-strand monofilament or multifilament nature and have a flat section of small thickness or a different cross-sectional conformation such as circular. The elementary son 2 and 3 may be of any suitable material, including carbon fiber.

On the basis of the technical means generally used, it is conceivable to make a width 1 may have a width l equivalent to that of a width produced by a traditional craft.

According to an embodiment feature of the bias fabric according to the invention, the width is produced over an infinite length L from elementary threads 2 and 3 , none of which presents an interruption compensated by any junction or knotting, as this intervenes with traditional methods of weaving, braiding and even knitting. This characteristic is essential and decisive to consider within the meaning of the invention, even for an infinite length L of the width 1.

According to another characteristic which is also essential and decisive in the sense of the invention, the width 1 can be produced over an infinite length L from elementary wires 2 and 3 of flat shape and which, in such a case, are free from torsion on their entire length, even in the case where the son 2 form an open loop 4 to the right of one of the selvedges such as 1b.

To obtain the bias fabric, as described above, one proceeds according to the invention as follows.

First, we define a warping plane such that P shown in phantom in FIG. 2, so as to have a border 10 ', said establishment and a border 10 ", said recovery and which is parallel to the establishment border 10' The plane P is, moreover, delimited transversely to the borders 10 by a first means 11 and a second 12 of support and transfer which are parallel to each other by extending over the entire width between the edges 10, while making with the x-x 'direction of the latter an angle α determined, for example equal to 45. The means 11 and 12 and occupy the same direction y-y ' which is oblique to the direction x-x'.

According to a condition of the invention, the distance between the parallel means 11 and 12 is advantageously chosen at most equal to or even slightly less than twice the width taken between the borders 10 ' and 10 ", perpendicular to the direction x-x' .

The method also involves a third handling and transfer means 13 extending in the same direction α with respect to the reference x-x ' from the recovery border 10 " that it intercepts by its input section. while being arranged parallel to the means 11.

The means 11 to 13 may be animated, in the same direction which is that of the arrow f ₁ , synchronous movements intermittent or stepwise or continuous.

According to a first step of the method shown in FIG. 3, a wire 15 is rewound from a reel 14 which is established, under relative tension, to the right of the edge 10 ' ensuring its support by the means 11 and 12 . The wire 15, once established as said above, is cut upstream of the support means 11 relative to the unwinding direction, so that it remains then on the warp plane P a wire elementary 15 ₁ .

According to another step of the method, then moves, by the means 11 and 12 driven simultaneously in the direction of the arrow f ₁ , a step in the cross direction, the wire ₁ to allow establishment, as described herein. above, a second wire 15 ₂ to the right of the establishment border 10 '.

By the intermittent operation of the handling and transfer means 11 and 12, the procedure described above is repeated as many times as is necessary to completely fill the warping plane P with a succession of wires 15 , the last of which 15 _n according to FIG. 4 is set to the right of the border 10 ' while the first ₁ is placed in the vicinity of the recovery border 10 " being always maintained by the means 11 and 12. It should be noted that in this state, the wire 15 ₁ is then also supported, in its substantially median part, by the input of the means 13 .

For this condition to be advantageously performed properly, the method involves a means 13 whose input is aligned with that of the means 11, such that this alignment occupies a direction z-z ' which is perpendicular to the direction x-x'.

In this situation, as illustrated in FIG. 5 , a crowd is opened in a zone such as 16 located below the aligned inputs of the means 11 and 13 . Such an opening is carried out by suitable means to move the web son 15 _l to 15 _n hatched on the plane P into two half-plies which are equal in number of son in the case where the selection of the weave to form is of the taffeta type. In such a case, the opening of the shed 16 may occur, for example by raising one wire out of two. A similar result would be obtained by moving down only one wire out of two or acting up for every other wire and down for every other wire. The skilled person is able to adapt this requirement of opening the crowd when choosing a different type of armor.

According to a next step, one then proceeds to a yarn cutting 15 ₁ by a member 17 located just upstream of the inlet of the conveying means 13 (Fig. 4) so as to leave between the input of this means 13 and approximately the output of the first means 11, a wire segment _1a which will be intended to subsequently constitute a wire 2 of the web 1. The second portion _1b of the wire ₁ cut ₁ is maintained between the output of the means 12 and a member 18 for gripping and insertion capable of being animated at least one displacement in the direction of the arrow f ₂ .

This segment of wire _1b is then inserted into the shed 16 by the member 18 so as to be arranged parallel to the inputs of the support means 11 and 13 in the direction z-z ' to be engaged thereafter by a striking operation which can be considered as classic in weaving.

This is done in succession with each of the wires 15 ₂ , 15 ₃ ... successively brought to the right of the recovery edge 10 " as the successive threads are made to the right of the border 10 ' so as to to always have a complete warping plan in son 15 .

In this way, each segment of wire 15 _nb , between the entrance of the transport means 13 and that of the transport means 11, is inserted in the shed 16 and supported by the transport means 11 and 13 by constituting as this is apparent from FIG. 6 an elementary wire which is interwoven with the son 2 maintained between the carriers 11 and 13 to give rise to the formation of a width which progresses in the direction of the arrow f ₃ in the y-y ' direction defining the production direction L.

On the basis of FIG. 6 that progressively establishes the width 1 composed of the son 2 and 3 which are perpendicular to each other while being oriented obliquely with respect to the direction of progression y-y'-L, according to the angle α. In this case, the width woven skew can be qualified plus or minus 45 ° for the orientation of the son 2 and 3 .

The method implemented as described above involves various auxiliary phases, one of which is the adaptation of the second means 12 to a sliding carriage or to an oscillating assembly that can be moved in the direction of the arrow f ₄ to compensate for the variation in the length of the wires 15 _n following the opening of the crowd 16 .

In the method described, each wire, _n established at the right of the edge 10 ', corresponds to a reeling from the reel 14 over an elementary length close to that of the warping plane P, then to a cut by an organ 19 located between the coil 14 and the means 11 and preceded by a retaining clip or the like 20 (Figure 2) .

It could be envisaged to ensure this establishment without cutting the wire 15, for example by means of a zig-zag framing carriage which would establish continuously the wire 15 from the coil 14 on the means 11 and 12 then provided with pins, fingers, needles or other technical means able to hold the wire unwound continuously and looped alternately. In such a case, the cutting thread 15 occupying the _n 10 "involves a border member 17 and a mating member 17 _implanted in the vicinity of the means 12 (Fig. 4).

Another variant of the process is to border the edges _1a and _1b of the web 1 with loops 5 for stopping the ends of son 2 and 3 resulting from the sequential cutting of each wire 15. Each band 5 may be formed by a ribbon, a cord or a strip of suitable material or may result from a contribution by coating, sampling or molding of a coating of material chosen from those able to have a residual flexibility that is compatible with that of the width 1 . Each band 5 can be reported permanently or temporarily.

As is apparent from the method described above, the object of the invention makes it possible to form a width 1 of width l and infinite length L by using only one wire such as 15 from the coil 14 to form the elementary son 2 and 3 which, accordingly, and regardless of the length of the width 1, are always free of junction points, knotting, binding. The width thus obtained is of a homogeneous nature in its constitution, in its presentation and in its technical characteristics, and can be manufactured over an infinite length by the simple replacement of a coil 14 of large capacity which is simply changed when it does not. is more in the state, with the only winding remaining on it, to deliver a length of elementary wire capable of being established between the inputs of the carriers 11 and 12 .

Such a characteristic makes it possible to have production rates uninterrupted industrial and thus produce a width of fabric at an angle of length infinite without the manufacturing process experiencing phases of interruption that are made necessary, as is practiced in the weaving technique usual, for the knitting of the threads interrupted during the changes of coils in particular, and by any necessary intermediate operations, such as only the rustling and packing of bobbins and cans. This results in a reduction sensitive cost of production.

Alternatively, it should be noted that the son 15 _n could be derived from more than one coil 14, with or without alternation, each corresponding to a title and / or a constituent material determined.

It goes without saying that the operation of opening the shed 16 as described above, involves a local displacement of the son concerned in elevation and / or lowering, so as to respect, as is traditional weaving, the desired weave for interlacing wires 2 and 3 . Such an opening can be achieved by the implementation of a comb system providing the lateral guiding functions of each of the son, the opening and closing of the half-plies and the striking of each segment of cut wire to from the one occupying the 10 " recovery border .

Fig. 6 shows that, according to a variant of the method, it can be provided to take advantage of the opening of the shed 16 to insert at least one reinforcing straight wire 6 trapped entered the interlaced son 2 and 3 and extending parallel to the direction y-y '.

Fig. 7 shows, schematically, an example of construction of a loom capable of implementing the method described above to obtain the bias fabric according to the invention.

According to this figure, the profession is presented in a constructive form horizontal in the broad sense of the word, but it is quite obvious that a type of construction in a vertical direction could also be considered.

The loom, designated as a whole by the reference M, comprises a warping section 21 which is intended to delimit the plane P described above. This warping section 21 is essentially constituted by the two support conveyors 11 and 12 which form the parallel means between them to support and move the cross direction different son 15 _n warped as mentioned above.

In the example shown, the conveyors 11 and 12 each consist of two endless conveyor belt pairs whose upper 22 and lower 23 facing strands are superimposed and pressed so as to maintain the end portions of each wire 15 _n ourdi. The conveyor belts 22 and 23 may be simple belts or belts with pins or needles or with a hanging or adhesive coating.

To delimit an establishment border 10 ' and a recovery border 10 ", the lower conveyor belts 23 of the means 11 and 12 have a length less than that of the belts 22 to define, as it were, entry and exit zones. Release of son 15 _n the two means 11 and 12 are, as mentioned above, set parallel to each other having a same length and each making an angle α relative to the direction of the edges 10 'and 10 " of the plane P whose length of establishment occupies the direction x-x '. In consideration of this direction, the orientation of the carriers 11 and 12 is established in the y-y 'direction which corresponds to the direction of production L of the fabric width at an angle. The means 11 and 12 are spaced from each other in the x-x 'direction, preferably by a measure equal to twice the width considered perpendicular to the x-x' direction, between the borders 10 ' and 10 ".

The loom comprises, moreover, a third support and transfer means designated by the reference 13 and which meets the constructive characteristics of the means 11 and 12, or even characteristics equivalent to the technical plan. In the case illustrated, the means 13 therefore also comprises an upper conveyor belt 22 and a lower conveyor belt 23 . The means 13 is located parallel to the medium 11 so that its inlet is able to take over the hatched thread occupying the take-up edge 10 "in the median part of the latter. To this end the input 30 of the means 12 and that 31 of the means 13 are aligned in the direction z-z ' which is orthogonal to the direction x-x'.

In the case illustrated, the angle α is close to 45 ° and the length of the third handling and transfer means 13 is calculated so that its output is substantially aligned with the output of the means 12 in a direction which is perpendicular to the direction y-y '.

The loading and transfer means are responsible for ensuring the displacement in the oblique direction y-y ' of the nap sheets 15 _n and, for this purpose, are driven by motor units not shown but conventional in the field, training in intermittently preferential synchronous displacements in a step that corresponds, in elementary manner, to the spacing that must be respected between each wire 15 _n of the layer laid. It must, of course, be considered that it is possible to cause the continuous synchronous displacement of the means 11 to 13 insofar as the establishment members of each wire 15 _n are able to ensure the removal of each elementary length wire in masked time to obtain a parallel arrangement of these son on the plane of warping P.

At a distance from the output of the handling means 11 and 13, the loom comprises a winding roll 32 of the width 1 produced. This distance is advantageously used to provide the means 33 capable of bordering the selvedges of the width 1 produced by means of a strap, a ribbon, a band, etc. ..., or to ensure the filling of a coating in any appropriate material. It should be considered that such a lining could also come from the prior removal, for example at the entrance of the means 11 and 13 of a layer of adhesive product intended to take care of the ends of the yarns, and then to be detached from the conveyor belts to form the coatings of the selvedges.

Such a method of management can also be retained for the conveyor belts of the means 12 by providing, in addition to the right of the exit zone 34, a film or a peel film, so as to strip the conveyor belts 22 and 23 as they escape from the recovery edge 10 ".

The loom comprises, moreover, a device 40 for placing each elementary wire 15 _n , at the right of the establishment border 10 ' . Such a device is, for example, consisting of a gripper 41 which is adapted to a truck or other driving member can be guided in reciprocating motor in one and / or the other direction of arrow f ₅ , so as to be able to take the wire 15, coming from a reel 14, to pass it on the input section of the conveyor 11 and then to bring it to the input section of the conveyor 12 .

The stroke along the arrow f ₅ takes into account the presence of the cutting member 19 which is located beyond the clamp 20 taking into account the direction of unwinding of the wire with respect to the coil 14 . The position of the clamp 20 can be considered to be approximately that of support by the clamp 41 during the extension-unwinding phase of the wire 15 .

The loom further comprises a section 45 of opening-closing the shed 16 by action on the lap of threads to form it into two half-plies. Such a system 45 comprises, according to FIGS. 7 to 12, a plurality of combs or the like 50 loaded, to take care of the son 15 _n to ensure lateral guidance and transfer stepwise, if necessary, maintaining their selected relative spacing. These combs 50 are advantageously each constituted by two walls 51 defining a kind of stirrup open upwards and responsible for guiding a wire 15 _n . The walls 51 are mounted at the end of a resiliently deformable blade 52 which is connected to a moving drive system 53 capable of adopting different structural shapes.

By way of example according to FIGS. 9 and 10, the system 53 is constituted by an endless belt 54 capable of being moved intermittently in the direction of the arrow f ₆ by passing over the return members 55 having the effect of establishing some of the blades 52 in the same plane under the warping plane P with said bars an orientation of the stirrups open upwards. It should be considered that a different structural form could consist in adapting the blades 52 on a carriage that can be reciprocated by being associated with an erasing system, so that each comb 50 can be moved laterally in the cross direction, at the same time as the threads 15 _n for each step of incrementation then, then, lowered to be erased below the sheet of threads, to be brought back to an initial position in which it is again raised to support another wire 15 _n .

Whatever the system used, the blades 52 are also associated with elevation pushers 56 which can be controlled in any appropriate manner and selectively depending on the armor chosen to be raised from a position of erased as shown in figs. 9 and 10 to an elevation position, as shown in FIG. 11. Each raised pusher acts on the corresponding blade to deform it upwards, so that the comb 50 raises the corresponding wire 15 _n to delimit, in relation to those held in place, the crowd 16 in which the segment 15 _nb yarn , cut from yarn 15 _n occupying the recovery margin 10 ", is inserted as described in connection with the method.

The opening-closing system 45, as described above, is advantageously mounted on a frame 57 which is carried by a bench 58 with respect to which it can be moved by a suitable drive member to be driven by a movement in the double direction of the arrow f ₇ with respect to the initial position in which it opens the crowd 16 .

Thus, after the insertion of the wire segment 15 _nb into the shed 16, as illustrated in FIG. 11, the pushers 56 are controlled in retraction, so as to return all the combs to the original position in which they are aligned parallel to the warping plane P (FIG 12) . In this state, the drive member is controlled to move the entire system on the bench 58 in the direction of alignment of the input sections 30 and 31 of the support means 11 and 13, so that the different Combs 50 assume a flap function for striking and plating the inserted thread segment 15 _nb against the previous ones in the manner of what occurs in conventional weaving, as shown in FIG. 12 .

Finally, the loom is again provided with the gripping and insertion member 18 which is intended to take over the free end after cutting of the segment 15 _nb of thread 15 _n occupying the recovery margin 10 ". for insertion into the shed 16. Such a member may be constituted by a gripper adapted at the end of a lance 61 may be introduced into the crowd, for example from the establishment border 10 '. It goes without saying that a reverse arrangement may also be envisaged In all cases, the lance is driven by an alternating rectilinear stroke which is sufficient to insert the segment of cut thread 15 _nb into the crowd 16 over the entire width of the tablecloth hatched.

It goes without saying that the lance 61 can also be replaced by two opposite half-lances provided, each end, complementary gripping means and animated rectilinear movements inversely synchronized.

It may also be envisaged to make the member 61 in the form of an actuator with rectilinear reciprocating movement, provided with lateral gripping means and which, in a waiting position, is immobilized parallel to the segment of yarn to be cut at law up edge 10 ". such a gripper would then be mounted on a vertical pivot located near the wire cutting section, so that after care, it may be rotated to bring the gripper 18 which it has in the axis of the shed, inside which the segment of thread 15 _nb cut, and taken in its entirety, would then be inserted, as illustrated in FIG. member 61 is arranged to take care of the end of the segment _nb sectioned by the cutting member 17 which is located near the inlet section 31 of the means 13 .

When the gripping member 61 is of the type illustrated schematically in FIG. 7, the loom is additionally provided with an inflection finger 70 which, in one embodiment, is constituted by a vertical cylindrical rod, implanted substantially in line with the recovery margin 10 " and at a distance from the cutting member 17. Such a finger is retractable, so that it can be controlled in elevation after crosswise movement of the wire 15 _n brought to the right of the edge 10 "

A functional sequence can then be established in the following manner.

The gripping member, such as the gripper 18, grips the wire 15 _n occupying the recovery edge 10 ", then the cutting member 17 is actuated to cut said wire and leave a first segment of wire 15 _na which is retained at the exit of the means 11 and the entrance of the means 13 to subsequently constitute a wire 2 .

The member 18 can then be controlled in displacement stroke inside the shed 16 in a direction perpendicular to the direction x-x ', so that the segment of wire 15 _nb cut is driven and caused to bypass the inflection point 70 to be arranged and properly aligned within the crowd 16 .

In a widely preferred application, the wire used and unwound from the reel 14 is of the flat type, being for example constituted by a multi-filament combination of carbon fibers which may for example be of the 3K, 6K, 12K type, even 24K, 48K, 80K. In such an example of commissioning, it is imperative to be able to insert in the crowd 16 the flat wire segment 15 _nb without causing it to undergo any torsion which could normally intervene by bypassing the point of inflection 70 . In order to meet this requirement, the point of inflection 70 can then advantageously be realized as illustrated in FIG. 13 being constituted by a finger 71 associated with a bar 72 delimiting with the finger a passage window of restricted width. The finger 71 extends above the web son hatched 15 _n, so that the last wire occupying the take-up edge 10 ", is engaged between the pin 71 and the strip 72. In addition, the provision of inflection point 70 is made such that the finger 71 extends obliquely with respect to the x-x 'direction, being oriented at 45 ° to be directed towards the crowd 16.

In this way, when the wire segment 15 _nb is taken, it is automatically brought to wind in an open half-loop on the finger 71 which ensures the inflection in a direction at 90 ° to the original direction , without induced torsion effect.

The same effect can be obtained by using dynamic rather than static organs and by replacing the finger 71 by a turntable capable of being rotated about 180 ° on its axis immediately after the actuation of the cutting member 17, so that the end portion 15 ' _nb , between the return bar and the cutting member, is automatically, after turning, oriented in the direction favorable to support by the organ of gripping, such as 18, moving parallel to the shed 16, as shown in FIG. 14.

The point of inflection 70 could also include instead of the bar 72 a pad or a clamping jaw relative to the end portion 15 ' _nb .

Finally, the loom may comprise a device for inserting at least one straight reinforcing wire, such as the wire bearing the reference 6 in FIGS. 1 and 6 . Such a device, designated as a whole by the reference 80 in FIGS. 15 and 16, comprises a wire guide bar 81 carrying at least one eyelet 82 in which is engaged the wire 6 which is unwound from a superimposed coil not shown. The wire guide bar 81 is placed in abutment against the combs 50 between the latter and the alignment of the inputs 30 and 31 of the loading and transfer means 11 and 13 . Beyond the eyelet 82, each wire 6 is inserted into the shed 16 to be trapped in a crossing zone between a wire 2 and a wire 3 constituting the width of the fabric at an angle 1.

Figs. 15 and 16 show a possibility of insertion of several right reinforcing son 6 that should, in such a case, be able to imprison so that they are established parallel to the direction of formation of the width, defined by the y-y ' axis . In such a case, the insertion device then comprises, for each reinforcing thread 6, a retractable needle 83 which ensures, in its lowering position, as illustrated in FIG. 15, the maintenance of the portion of the reinforcing thread 6 trapped in line with the last thread 3 inserted and away from the eyelets 82 .

During the striking operation, performed as previously said by the combs 50, the needles 83 are retracted, as illustrated in FIG. 17, so as to allow full insertion of the last 15 _nb segment of inserted wire. During the withdrawal phase of the combs 50, the needles 83 are moved in a reverse movement to come to hold each wire 6 in the waiting position, as shown in FIG. 18.

It should be noted that, in order to obtain the desired result, each pivoting needle 83 is offset from the eyelet 82 corresponding thereto by an elementary wire width 15 _n .

Figs. 16 and 18 show an example of weaving of the web 1 in a satin weave. Figs. 19 and 20 illustrate an example of weaving according to the invention with the adoption of a twill weave 2/1, with position of the eyelets 82 during the insertion of the segment of thread 15 _nb (FIG 19) and during the striking of said segment (Fig. 20).

INDUSTRIAL APPLICATION:

The invention finds a preferred application in tissue production so-called ± 45 ° techniques and reserved for the production of shaped parts from a matrix of synthetic material in which said fabric is embedded as an armature of reinforcement.

The invention is not limited to the examples described and represented, because various modifications can be made without departing from its scope.

Claims (41)

1. A bias fabric, characterized in that it is in the form of a cloth of length (L) and of finite width (ℓ), being constituted by interlaced yarns (2, 3) extending in respective directions (D and d) that are oblique relative to the length (L), and each of which presents no knotting, even for a cloth of indefinite length (L).
2. A fabric according to claim 1, characterized in that it includes at least one reinforcing yarn (6) held captive between the interlaced yarns and extending parallel to the length (L).
3. A fabric according to claim 1 or claim 2, characterized in that at least one of the selvages (1a, 1b) of the cloth (1) is formed by the ends of the interlaced and cut yarns.
4. A fabric according to claims 1 to 3, characterized in that one of the selvages of the cloth is formed by loops (4) interconnecting two successive yarns (2).
5. A fabric according to any one of claims 1 to 4, characterized in that at least one of the selvages of the cloth is bound.
6. A fabric according to any one of claims 1 to 5, characterized in that the yarns are interlaced with one of the following weaves: satin, taffeta, serge.
7. A fabric according to any one of claims 1 to 6, characterized in that the interlaced yarns occupy respective directions close to +45° and -45° relative to the length L.
8. A fabric according to any one of claims 1 to 7, characterized in that the interlaced yarns are monofilament yarns.
9. A fabric according to any one of claims 1 to 7, characterized in that the interlaced yarns are multifilament yarns.
10. A fabric according to any one of claims 1 to 9, characterized in that the interlaced yarns are flat and free from twisting.
11. A fabric according to any one of claims 1 to 10, characterized in that it is made in the form of a cloth (1) of indefinite length (L) and of finite width (ℓ), being made up of interlaced yarns of finite length.
12. A method of manufacturing bias fabric in the form of a cloth (1) of finite width and of indefinite length,
       the method being characterized in that it consists in:

    warping a sheet of yarns (15) parallel to a direction (x-x') by causing them to be taken in charge by first and second transfer means (11, 12) occupying mutually parallel directions (y-y') at an angle (α) with the direction (x-x');

    progressively building up said sheet by placing the yarns successively along a sheet set-up edge (10');

    moving said yarns by the first and second transfer means through one step in the oblique transverse direction from the set-up edge towards an opposite "take-up" edge (10") ;

    causing the yarn (15_n) occupying the take-up edge (10") additionally to be taken in charge by a third transfer means (13) situated at a distance from and parallel to the first transfer means in order to act substantially on the middle portion of said yarn;

    opening the sheet to form two half-sheets so as to define a shed (16) close to the first and the third transfer means;

    cutting the set-up yarn (15_n) brought substantially over the take-up edge substantially in the middle portion thereof;

    leaving in place that portion (15^na) of said yarn (15_n) that is held by the inlet of the third transfer means and by the outlet of the first transfer means to constitute a yarn (2) of the future cloth;

    taking the segment (15_nb) of said yarn that is situated between the third and the second transfer means and inserting it into the shed along a direction (z-z') perpendicular to the direction (x-x') from the take-up edge towards the set-up edge so as to constitute a yarn (3) of the future cloth; and

    proceeding in the same manner in succession with each yarn brought to the take-up edge while also placing a new yarn along the set-up edge and progressively building up an interlace of yarn segments taken in charge by the first and third transfer means and progressing along the direction (y-y') that is oblique relative to the direction (x-x').
13. A method according to claim 12, characterized by beating each segment of yarn (15_nb) inserted successively into the shed.
14. A method according to claim 12, characterized in that each yarn (15_n) of the sheet is set up by using the first and the second transfer means simultaneously to take a unit length of yarn for being taken in charge from a feed reel (14).
15. A method according to claim 12, characterized in that each yarn of the sheet is set up from the yarn (15) unwound continuously from the feed reel by means of a zigzag picking carriage co-operating with retaining needles or pins presented by the first and second transfer means, and then cutting the yarn (15) when brought to the take-up edge (10") at the outlet from the second transfer means and upstream from the third means.
16. A method according to claim 12, characterized in that each yarn (15_n) of the sheet is taken in charge throughout its transfer in the transverse direction from the set-up edge (10') to the take-up edge (10") by a set of combs (50) performing the functions of guiding the yarns laterally, of opening and closing the half-sheets in a selected weave, and of beating each yarn segment inserted into the shed (16).
17. A method according to claim 12, characterized in that the second transfer means (12) is placed on a moving support for compensating the apparent reduction in yarn length when the shed is opened.
18. A method according to claim 12, characterized in that at least one straight reinforcing yarn (6) extending parallel to the length (L) of the cloth is inserted between the yarns of the sheet and the inserted yarn segments.
19. A method according to claim 18, characterized:

    in that the reinforcing yarn (6) is inserted by a yarn-guide eyelet (82) placed substantially over the opening of the shed, between the comb system (50) and the insertion direction of each yarn segment; and

    in that said reinforcing yarn (6) is temporarily held in position between each insertion of a yarn segment, substantially in the vicinity of the most recently inserted segment, by a removable alignment needle (83).
20. A method according to claim 19, characterized in that the alignment needle is offset laterally relative to the yarn-guide eyelet by a distance equal to the width of the yarn (15_n).
21. A method according to claim 12, characterized in that when the yarns constituting the sheet are of the flat type, the method consists in implementing a mechanism (70) for turning over and bending the yarn without twisting after the yarn brought to the take-up edge has been cut.
22. A method according to claim 12, characterized in that it consists in binding at least one of the selvages of the cloth taken in charge by the first and third handling and transfer means.
23. A loom for continuously manufacturing a bias fabric, the fabric being in the form of a cloth (1) of finite width (ℓ) and of indefinite length (L), the loom being characterized in that it comprises:

    a section (21) for warping a sheet of yarns (15_n) that are set up in succession parallel to one another from a sheet set-up edge (10');

    first and second handling and transverse transfer means (11, 12) extending obliquely relative to said yarns towards a "take-up" edge (10") of the sheet, said means extending parallel to each other along a direction (α) that is oblique relative to the direction (x-x') of the yarns, said oblique direction defining the direction (y-y') in which the cloth is produced;

    third means (13) set up at a distance from and parallel to the second means and driven in the same direction as the first two means so as to take in charge the substantially middle portion of the yarn (15_n) of the sheet that occupies the take-up edge;

    a section (45) for opening and closing the sheet to form two half-sheets so as to define a shed (16) upstream from the first and second handling means in the cloth production direction;

    means (17-18) serving firstly to cut the yarn (15_n) of the sheet that occupies the take-up edge at a point upstream from the third handling means, and secondly to leave a portion (15_na) of yarn for constituting one of the yarns (2) of the cloth in place between the first and third handling means, while also taking hold of the segment of yarn (15_nb) extending between the cut and the second handling means and inserting it into the open shed; and

    means (50) for beating each inserted yarn segment (15_nb) and causing it to be taken in charge by the first and third means which guide the resulting bias fabric.
24. A bias loom according to claim 23, characterized in that the warping section comprises, in association with the set-up edge (10'), a placing device (40) for successively placing yarns (15_n) tensioned between the inlet ends of the first and second handling and transfer means.
25. A bias loom according to claim 24, characterized in that the placing device (40) is constituted by gripping means (41) suitable for unwinding a unit length of yarn from a reel (14), for setting it up between the inlet sections of the first and second handling means, and in that the device is associated with a member suitable for cutting off said unit length.
26. A bias loom according to claim 24, characterized in that the placing device (40) is constituted by a zigzag picking carriage unwinding a yarn from a reel and passing it around pins or needles presented by the first and second handling and transfer means, and in that it then comprises an additional cutting member (17_a) situated at the outlet from the second transfer means (12).
27. A bias loom according to claim 23, characterized in that the handling and transfer means are constituted by endless belts that are driven to move synchronously.
28. A bias loom according to claim 23 or claim 27, characterized in that the handling and transfer means are provided with means for temporarily securing the yarns.
29. A bias loom according to any one of claims 23, 27, and 28, characterized in that the handling and transfer means lie in a direction that is at 45° relative to the direction of the yarns of the sheet.
30. A bias loom according to any one of claims 23 and 27 to 29, characterized in that the first and/or third handling means are associated with means (33) for binding at least one of the selvages of the cloth.
31. A bias loom according to claim 23, characterized in that the opening and closing section comprises a system of combs (50) taking charge individually of the yarns (15_n) of the sheet by providing them with lateral guidance, stepwise transfer, and relative spacing selected as a function of the selected weave so as to define the insertion shed and the beating of the inserted yarn segment.
32. A bias loom according to claim 31, characterized in that the comb system (50) comprises, for each yarn of the sheet, an elastically deformable blade (52) associated with a selectively controlled pusher (56) forming a bracket (51) for guiding the yarn laterally, for transferring the yarn laterally, and for beating the inserted yarn segment.
33. A bias loom according to claim 23, characterized in that the means for cutting the yarn (15_n) occupying the take-up edge (10") and for inserting it into the shed (16) comprise a member (17) for cutting said yarn, a member (18) for taking hold of the segment of yarn (15_nb) extending between the cut and the second handling means (12) and a member (61) for inserting said segment into the shed from the take-up edge towards the set-up edge (10').
34. A bias loom according to claim 33, characterized in that the insertion member is a rod.
35. A bias loom according to claim 33, characterized in that the holding member is a rod that is pivotally mounted and capable of taking hold of the cut-off segment of yarn, parallel to its length, and for causing it to be moved in a common plane through 90° so as to face the open shed and so as to insert it into said shed.
36. A bias loom according to any one of claims 33 to 35, characterized in that the means for cutting and inserting the yarn segment are associated with a turn-over finger (70) performing an orienting function.
37. A bias loom according to claim 36, characterized in that the turn-over finger (70) comprises a cylindrical bar (71) associated with a tongue (72) with which it defines a notch for passing the yarn (15_n) that occupies the take-up edge (10"), said bar being oriented at 45° relative to the direction of said yarn.
38. A bias loom according to claim 37, characterized in that the bar is mounted so as to be capable of pivoting about its axis.
39. A bias loom according to claim 23, characterized in that it includes a device for inserting at least one straight reinforcing yarn (6) extending parallel to the length of the cloth and held captive between the yarns of the sheet and the inserted yarn segments.
40. A bias loom according to claim 39, characterized in that the insertion device comprises a yarn-guide eyelet (82) disposed substantially over the section for opening and closing the sheet.
41. A bias loom according to claim 39 or claim 40, characterized in that the insertion device comprises, on a removable alignment needle (83) disposed substantially over the last-inserted yarn segment and offset by one segment width from the eyelet.

Images