EP1163385A1

EP1163385A1 - Bias-bound fabric, method for making same and weaving machine for continuously making such a fabric

Info

Publication number: EP1163385A1
Application number: EP00911023A
Authority: EP
Inventors: Alain Bruyere; Christian Debaille; Franck Perret
Original assignee: Hexcel Fabrics SA
Current assignee: Hexcel Fabrics SA
Priority date: 1999-03-22
Filing date: 2000-03-22
Publication date: 2001-12-19
Anticipated expiration: 2020-03-22
Also published as: FR2791365A1; FR2791365B1; CA2366296A1; JP4567205B2; EP1163385B1; DE60010676D1; WO2000056965A1; US6494235B1; ATE266753T1; CA2366296C; JP2002540306A; DE60010676T2

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

BIASED FABRIC, MANUFACTURING METHOD AND WEAVING MATERIAL FOR CONTINUOUSLY MANUFACTURING SUCH A FABRIC

TECHNICAL AREA :

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

If such a technical field appears more preferable, it should be considered that the invention can be implemented in other fields without excluding, for example, furnishing or clothing fabrics.

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

Indeed, such aptitudes are recognized and sought after in order to obtain structural technical parts of more or less complicated shapes, other than by the usual machining operations, or even stamping or stamping which are either delicate, long and expensive to to implement, or sometimes as difficult to drive when the material to be used, although of adequate strength, represents by its mass an insurmountable obstacle.

The technique of manufacturing parts made of composite materials is currently particularly suited to the production of technical parts of more or less complex shapes and having to present a certain lightness as well as optimal resistance.

This is, for information only, the case of hulls, floats, rocket warheads, even hoods of powertrains, etc. From the moment it is tempted to meet the requirements that such a manufacturing technique imposes, it is certain that the optimization of the structural characteristics necessarily involves taking into account the orientation in the or the correct directions of the reinforcement that the fabric constitutes, so that its fibers can resume in the direction or the appropriate direction the stresses which will be imposed later on the part obtained.

Likewise, it is necessary to be able to meet a requirement of adaptability to the conformation of the part to be obtained which is generally represented by a positive or negative mold on or in which the composite material must be placed so as to faithfully resume the shape of the model.

In the technique, this ability to marry the model is generally qualified as topping or draping, a quality that a fabric with a technical vocation must be able to present in association with the previous requirement.

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

In practice, it is indeed often sought to be able to have fabrics whose elementary threads extend at an angle relative to the two fundamental directions above, such a bias, generally qualified by more or less 45 ° being able, of course, know angular variations favoring the angular opening of one of the categories of wires.

PRIOR ART:

To meet such a requirement from traditional textile productions, it has been proposed to cut, from a width of fabric produced in a conventional manner, elementary strips of fabric, in an oblique orientation, for example at an angle of 45 °. Each strip can then be described as a bias fabric capable of being oriented in such a way that some of the elementary threads are placed parallel to certain stresses that the final piece will have to bear.

Such a method is certainly penalizing for different reasons. First of all, it is clear that the elementary strips of bias fabric thus produced are of finite length, at best equal to the diagonal of the square corresponding to the width of the width when the orientation adopted is that of plus or minus 45 °. This results in a significant drop rate which largely penalizes the cost price of the bias fabric, in particular if the fiber constituting the threads is of high production cost.

Another drawback stems from the fact that it then becomes necessary to place such cut-outs or strips of fabric side by side when it is necessary to cover a large surface and, more particularly, a great length. The question which then arises for obtaining a homogeneous structure is obviously that of the connection between the contiguous edges, such a connection having to be carried out so as to have the same characteristics of layering, layering, but also of resistance. mechanical than those of fabric. It can be considered that the proposals which are made in this sense do not make it possible to meet this requirement when the composite material to be used as a reinforcement can or must be formed only by a single layer of technical fabric embedded in a resin matrix. The only possibility for binding the adjoining strips is then to locally superimpose at least several layers of oblique tissue to form a sort of sandwich at the adjoining edges, which very significantly increases the cost price of the final piece and gives it heterogeneous dimensional and local strength characteristics.

In an attempt to provide an answer to the problem thus posed, the prior art has given rise to a number of other proposals.

Mention may be made of the method of biasing from a unidirectional fabric consisting of elementary warp threads in small quantities relative to the weft threads.

One such technique consists in passing the width of traditional fabric between pressure rollers beyond which the fabric is taken up by a receiving roller whose axis is inclined at a given angle relative to the direction of the pressure rollers.

So that the expected result can be obtained durably, it is understood that it is necessary to involve, in the part between the rollers pressers and the take-up roller, fixing or connecting means, for example to the interlacing nodes of the wires, so as to fix the latter in the new imposed orientation. Whatever the means used, such an obligation results in a significant stiffness of the biased fabric which is no longer able to meet the requirement of ease of topping or draping.

Furthermore, the fixing process generally involves the supply of a binding product, the presence of which can have a detrimental effect on the subsequent behavior of the tissue in its binding 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 direction of yarn is biased, which does not exactly meet the intended objective.

The prior art has known another proposal consisting in producing a fabric with traditional weft and warp threads, but which is produced in the form of a continuous tubular sheath. The principle then consists in cutting such a sheath along a helical trajectory, for example oriented at 45 °, so as to have, after opening and flattening, a woven sheet whose threads are oriented at an angle. The production of such a sheath can be ensured from a traditional loom or a circular loom.

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

Among these, mention should be made of the recovery operation constituted by helical cutting which must be carried out precisely in order to obtain straight edges. To this end, means for cutting and holding the tubular sheath, but also open parts of the latter are necessarily to be implemented, which represents a significant industrial cost.

Another drawback is due to the supply means used for the weft threads, whether it is a traditional loom or a circular loom. As a general rule, the feeding of such threads is ensured from either bobbins or pre-formed cans which have a limited winding capacity implying having to ensure the change thereof periodically, with the requirement to restore the continuity of the threads by joining, knotting, tying or other technical means. Such operations are penalizing for production, increase the cost price and impose in the width produced the presence of means of binding or knotting of threads which cannot be considered to provide the final fabric with homogeneous characteristics of thickness, flexibility, mechanical resistance.

However, the requirement to replace bobbins or cans occurs relatively frequently, given that their capacity generally allows continuous production without binding of the threads only for a relatively short width.

In addition, the use of a traditional loom poses an additional problem which is that arising from the unwinding of the thread from a bobbin which is not driven by a rotation on itself. This inevitably results in a twist imposed on the wire. Such a technique is therefore absolutely not suitable when the fabric has to be made from flat threads, whether these threads are single-strand or multi-filament. Indeed, by such a weaving method, such flat yarns undergo a twist which comes to destroy the homogeneous character in thickness but also in resistance and in draping or covering ability of the fabric obtained.

The prior art has also proposed using an assimilated process for obtaining a bias fabric. This involves using an open braiding machine which effectively makes it possible to produce a strip whose interlaced threads are oriented at an angle relative to the direction of production of the strip.

Conventionally, an open braider consists of a supply of yarn from bobbins which are subjected to rotation on their axis, so that the same problems of yarn change are here to be taken into account.

In addition, an open braider does not generally and practically make it possible to achieve a width of width which is large enough to respond positively to the requirements charged for a bias fabric, in particular in a technical application. In total therefore, the need is still felt to be able to have a bias fabric that can be produced continuously by being free of all faults and drawbacks which are to be taken into account currently known technical solutions.

It is precisely the object of the invention to produce such a fabric having the appearance of a homogeneous sheet in thickness, in aesthetic appearance, in technical characteristics, so as to be able to be used in the various fields of 'application where it is required a great adaptability by coating or draping relative to a reference model surface.

It is also an object of the invention to provide the means for obtaining a bias fabric capable of being obtained at a relatively high production rate, at an advantageous manufacturing cost and which can be produced equally from of single-strand or monofilament or indifferently pluri-filament yarns, of regular, homogeneous and / or heterogeneous shape, and even from locks or single-strand yarns or strands, flat in nature or by previous conformation, a character which should be preserved in the constitution of the bias fabric obtained.

PRESENTATION 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 finished length (L) and width (1) width, made up of interlaced threads, established in respective directions oblique to the length (L) and none of which has knotting, even for an infinite length (L) of the width.

The subject of the invention is also a process for the continuous production of a bias fabric of the above type, such a process being characterized in that it consists in: • warping a ply of direction threads (x-x ') parallel to each other by having them taken care of by a first and a second transfer means occupying parallel directions (y-y') between them which form an angle (α) with the direction (x-x '),

• gradually build up said tablecloth by successively arranging the wires in line with a border known as the establishment of the tablecloth, Move said wires one step in the oblique transverse direction by the first and second transfer means from the so-called establishment border to an opposite so-called recovery border,

To have the wire occupying the recovery edge taken in addition by a third transfer means located at a distance and parallel to the first means for acting on the substantially middle part of said wire,

• open the sheet in two half-sheets to define a crowd near the first and third transfer means, • cut, in its substantially middle part, the wire established and brought to the right of the recovery edge,

• leave in place the part of said thread held by the inlet of the third transfer means and the outlet of the first transfer means to constitute a thread of the future width. • take the segment of said wire located between the third and second transfer means and insert it into the shed in a direction perpendicular to the direction (x-x ') from the recovery edge towards the establishment edge to constitute a thread of the future width, • do the same successively with each thread brought to the right of the recovery edge while also having, as a complement, a new thread at the right of the establishment edge and gradually build up an interlacing of segments of threads taken load by the first and third transfer means and which progresses in the direction (α) oblique to the direction (x-x ').

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

A warping section of a sheet of threads established successively, parallel to each other from a border for establishing the sheet,

• first and second means for taking over and oblique transverse transfer of said wires towards an edge of the so-called recovery ply, said means being established parallel to each other in an oblique direction (α) relative to that of the threads and this oblique direction defining the direction and the production direction 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 middle part of the ply yarn occupying the recovery edge,

An opening-closing section of the sheet into two half-sheets to define a crowd upstream of the first and third support means according to the production direction of the width,

• means for, on the one hand, cutting the thread of the sheet occupying the recovery edge upstream of the third support means, on the other hand, allowing a subsistence between the first and the third support means part of the wire intended to constitute a web of width and, moreover, to take and insert into the open crowd the segment of wire between the cut and the second support means,

• and means for striking each segment of inserted wire and having it taken care of by the first and third means which guide the width of bias fabric thus produced. Various other characteristics will emerge from the description given below with reference to the appended drawings which show, by way of nonlimiting examples, 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 trade for the implementation of the process leading to the production of the bias fabric according to the invention.

Fig. 8 is a partial perspective highlighting some of the constituent elements of the trade. Figs. 9 to 12 are schematic views showing certain constituent bodies of the trade.

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

Fig. 15 is a schematic elevation showing other constituent elements of the trade in an alternative embodiment.

Fig. 16 is a plan view taken substantially along 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 line XVIII-

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

BEST WAY TO IMPLEMENT THE INVENTION:

The bias fabric according to the invention is illustrated diagrammatically in FIG. 1 which shows that this fabric is in the form of a width 1 of length L and width 1 finished. In relation to this width, the length L must be considered to be infinite, that is to say capable of presenting a large footage while having homogeneous constructive characteristics over the entire length.

The width is made up of threads 2 and 3 which are intertwined or intertwined according to all appropriate weaves, 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 making with respect to this last 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 obliquity 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 wires 2 and 3 are of finite lengths and are interrupted on at least one of the selvedges such as la relative to the other such as lb.

According to an implementation process, as will appear in the following, the fabric width may include threads such as 2 which form a loop 4 every two times at one of the selvedges such as lb. The width 1 may also include selvedges 1a and 1b furnished with a loop 5 formed by a ribbon or cord or by a coating of suitable material, added during manufacture to trap, either the cut ends of the wires 2 and 3, either the loops 4.

In an alternative embodiment, the width 1 comprises at least one straight reinforcing thread 6 which extends parallel to the direction L of the width. Such a reinforcing wire is then trapped between the wires 2 and 3 which can 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 wires 2 and 3 can be of any suitable material, and in particular of carbon fibers.

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

According to an embodiment characteristic of the bias fabric in accordance with the invention, the width is produced over an infinite length L from elementary threads

2 and 3, none of which has an interruption compensated for by any junction or knotting, as occurs with traditional methods of weaving, braiding, even knitting. This characteristic is essential and determining 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 within the meaning of the invention, the width 1 can be produced over an infinite length L from elementary yarns 2 and 3 of flat shape and which, in such a case, are free from twisting on their entire length, even in the case where the wires 2 form an open loop 4 in line with one of the selvedges such as lb.

To obtain the bias fabric, as described above, the procedure according to the invention is as follows. First of all, a warping plane such as P shown in phantom in FIG. 2, so as to have a border 10 ′, called establishment and a border 10 ″, called 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 support and transfer means 12 which are parallel to each other extending over the entire width between the borders 10, while making with the direction xx 'of these latter a determined angle α, for example equal to 45 °. The means 11 and 12 thus 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, or even slightly less than twice the width taken between the edges 10 'and 10 ", perpendicular to the direction x-x' .

The method also involves a third take-over and transfer means 13 extending in the same direction α relative to the reference xx 'from the return edge 10 "which it intercepts by its input section while being arranged parallel to the means 11.

The means 11 to 13 can be driven, in the same direction as that of the arrow fi, by intermittent synchronous movements or step by step or even continuous. According to a first step of the process shown in FIG. 3, a wire 15 is unwound from a reel 14 which is established, under relative tension, in line with the border

10 'by ensuring its assumption of responsibility by means 11 and 12. The wire 15, once established as said above, is sectioned upstream of the support means 11 relative to the direction of unwinding, so that there then remains on the warping plane P an elementary wire 15ι.

According to another step of the process, the means 15 and 12 are then moved simultaneously by the means 11 and 12 driven simultaneously in the direction of the arrow fi, in the transverse direction to allow establishment, as described above. , a second wire 15 ₂ to the right of the establishment border 10 '.

By the intermittent operation of the take-over and transfer means 11 and 12, the procedure is as described above as many times as necessary to completely fill the warping plane P with a succession of wires 15, the last of which 15 „according to fig. 4 is established at the edge of the border 10 'while the first 15ι is placed in the vicinity of the recovery edge 10 "while still being maintained by the means 11 and 12. It should be noted that in this state, the wire 15j is then also supported, in its substantially middle part, by the input of the means 13.

In order for this condition to be advantageously fulfilled properly, the method involves a means 13, the inlet of which is aligned with that of the means 11, so that this alignment occupies a direction zz 'which is perpendicular to the direction x-x'. In this situation, as illustrated in fig. 5, a crowd is opened in an area such as 16 located below the aligned inlets of the means 11 and 13. Such an opening is carried out by suitable means for moving the sheet of wires 15 | at 15 „warped on plane P in two half-plies which are equal in number of threads in the case where the choice of weave to be made is of the taffeta type. In such a case, the opening of the crowd 16 can occur, for example by raising one thread in two. A similar result would be obtained by moving only one wire out of two downwards or by acting upwards for one wire out of two and downwards for one wire out of two also. Those skilled in the art are able to adapt this requirement for crowd opening when it is necessary to choose a different type of armor. According to a following step, the wire 15ι is then cut by a member 17 located just upstream from the entrance to the means of transport 13 (fig. 4), so as to leave between the entry of this means 13 and approximately the output of the first means 11, a 15ι wire _segment that will be designed to constitute subsequently a wire 2 of the strip 1. The second part 15i _b 15ι cut wire is maintained between the output of means 12 and means 18 for gripping and insertion capable of being driven at least by a movement in the direction of the arrow h.

This segment of wire 15i _b 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 zz 'to be engaged thereafter by a striking operation can be considered classic in weaving. One proceeds thus on with each of the wires 15 ₂ , 15 ₃ ... successively brought to the right of the recovery edge 10 "as one establishes the successive wires to the right of the edge 10 'so always have a complete warping plan 15.

In this way, each segment of wire 15 „ _b , lying between the inlet of the means of transport 13 and that of the means of transport 11, is inserted into the shed 16 and taken care of by the means of transport 11 and 13 by constituting as shown in fig. 6 an elementary thread which is crossed with the threads 2 held between the conveyors 11 and 13 to give rise to the formation of a width which progresses in the direction of the arrow f ₃ in the direction yy 'defining the direction L of production. We see on the basis of fig. 6 that gradually establishes the width 1 composed of 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 the present case, the width woven at an angle can be qualified by plus or minus 45 ° for the orientation of the threads 2 and 3. The process implemented as described above involves various additional phases, one of which d 'they is the adaptation of the second means 12 on a sliding carriage or on an oscillating assembly capable of being moved in the direction of the arrow f to compensate for the variation in length of the wires 15 „following the opening of the crowd 16 In the process described, each wire, 15 _n established in line with the border 10 ', corresponds to a unwinding from the coil 14 over an elementary length. close to that of the warping plane P, then to a cut by a member 19 located between the coil 14 and the means 11 and preceded by a retaining clamp or the like 20 (fig. 2). It could be envisaged to ensure this establishment without cutting the wire 15, for example by means of a zig-zag weft carriage which would continuously establish the wire 15 coming from the coil 14 on the means 11 and 12 then provided with pins, fingers, needles or other technical means capable of retaining the thread unwound continuously and looped alternately. In such a case, cutting of the wire 15 "occupying the 10 edge" implies a body 17 and a counterpart member 17 _implanted in the vicinity of the means 12 (Fig. 4). A further process variant consists flanging the edges the _a and l _b of the width 1 with the loops 5 making it possible to stop the ends of the wires 2 and 3 resulting from the successive cutting of each wire 15. Each loop 5 can be formed by a ribbon, a cord or a strip of material appropriate or may result from an addition by coating, removal or molding of a coating of material chosen from those capable of possessing a residual flexibility which is compatible with that of the width 1. Each loop 5 can be definitively added or temporary.

As is apparent from the process described above, the object of the invention makes it possible to constitute a width 1 of finite width I and of infinite length L by using only one thread such as 15 from the spool 14 to constitute the elementary threads 2 and 3 which, consequently, and whatever the length of the width 1, are always free from points of junction, 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 reel 14 of large capacity which is simply changed when it is is no longer 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 rates of uninterrupted industrial production and thus to produce a width of bias fabric of infinite length without the manufacturing process experiencing phases of interruption which are made necessary, as is practiced in the technique of usual weaving, for knotting interrupted threads when changing bobbins in particular, as well as by any necessary intermediate operations, such as warping and filling of bobbins and cans. This results in a significant reduction in the cost of production.

As a variant, it should be noted that the wires 15 _n could come from more than one coil 14, with or without alternation, each corresponding to a title and / or to a given constituent material.

It goes without saying that the opening operation of the crowd 16 as described above, involves a local displacement of the son concerned in raising and / or lowering, so as to respect, as is traditional in weaving, the weave desired for the interlacing of the wires 2 and 3. Such an opening can be carried out by the implementation of a system of combs ensuring the functions of lateral guidance of each of the wires, of opening and closing of the half - tablecloths and striking each segment of wire cut from that occupying the recovery edge 10 ". Fig. 6 shows that, according to a variant of the process, it can be expected to take advantage of the opening of the crowd 16 to insert at least one straight reinforcing thread 6 trapped between the interlaced threads 2 and 3 and extending parallel to the direction y-y'-

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

According to this figure, the trade is presented in a horizontal constructive form in the general sense of the term, but it is quite obvious that a type of construction in a vertical direction could also be envisaged. The weaving loom, generally designated 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 means parallel to each other for taking over and moving direction across the different wires 15 "warped as said above.

In the example illustrated, the conveyors 11 and 12 each consist of two duos of endless conveyor belts, the upper strands 22 and lower 23 facing each other are superimposed and pressed so as to maintain the end portions of each wire 15 „warped. The conveyor belts 22 and 23 can be simple belts or belts with pins or needles or with hooking or adhesive coating. To define a 10 'establishment border 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, in a way, zones of entry and exit of the wires 15" The two means 11 and 12 are, as said previously, established parallel to each other having the same length and each making an angle α with respect to the direction of the borders 10 ′ and 10 ″ of the plane P whose establishment length occupies the direction x- x '. In consideration of this direction, the orientation of the conveyors 11 and 12 is established in the direction y-y 'which corresponds to the production direction L of the width of bias fabric. The means 11 and 12 are distant from each other in the direction x-x ', preferably by a measurement equal to twice the width considered perpendicular to the direction x-x', between the borders 10 'and 10 ".

The weaving loom furthermore comprises a third means of handling and transfer designated by the reference 13 and which responds to the constructive characteristics of the means 11 and 12, or even to characteristics equivalent on the technical level. In the illustrated case, 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 means 11, so that its entry is able to take care of the warped wire occupying the recovery edge 10 "in the middle part of the latter. To this end, the entry 30 of the means 12 and that 31 of the means 13 are aligned in the direction zz 'which is orthogonal to the direction x-x'.

In the illustrated case, the angle α is close to 45 ° and the length of the third support and transfer means 13 is calculated so that its outlet is substantially aligned with the outlet of the means 12 in a direction which is perpendicular to direction y-y '. The take-over and transfer means are responsible for ensuring the displacement in the oblique direction yy 'of the ply yarns warped 15 _n and, to this end, are driven, by drive members not shown but conventional in the matter, for driving preferably intermittent synchronous displacements according to a pitch which corresponds, elementarily, to the spacing to be respected between each wire 15 _n of the warped ply. 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 „are able to ensure the removal of each elementary length of time masked wire to obtain a parallel arrangement of these wires on the warping plane P.

At a distance from the outlet of the support means 11 and 13, the loom comprises a cylinder 32 for winding the width 1 produced. This distance is advantageously taken advantage of to have means 33 capable of bordering the edges of the width 1 produced by means of a strap, a ribbon, a band, etc. ..., or to ensure the filling of a coating of any suitable material. It should be considered that such a lining could also come from the prior deposition, for example at the entrance of the means 11 and 13, of a layer of adhesive product intended to support the ends of the wires and then, to be detached from the conveyor belts to form the edge coatings.

Such a method of handling can also be adopted with regard to the conveyor belts of the means 12 by providing, in addition to the exit zone 34, a film or a peeling film, so as to strip the conveyor belts 22 and 23 as they escape from the 10 "recovery edge.

The weaving loom also comprises a device 40 for placing each elementary yarn 15 _n , in line with the establishment border 10 '. Such a device is, for example, constituted by a gripper 41 which is adapted to a carriage or other motor member capable of being guided in motorized reciprocating movement in one and / or the other direction of the arrow fs, so as to be able to take the wire 15 from a spool 14, to pass it over the inlet section of the conveyor 11 and then bring it to the inlet section of the conveyor 12. The stroke according to the arrow fs takes into account the presence of the cutting member 19 which is located beyond the clamp 20 taking into account the direction of wire unwinding relative to the spool 14. The position of the clamp 20 can be considered to be approximately that of taking over by the clamp 41 during the extension-unwinding phase of the wire 15.

The weaving loom further comprises an opening-closing section 45 of the shed 16 by acting on the ply of warped 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 charge of the wires 15 _n to ensure lateral guidance and step-by-step transfer, if necessary, maintaining their selected relative spacing. These combs 50 are advantageously each constituted by two walls 51 delimiting a kind of stirrup open upwards and responsible for guiding a wire 15 _n . The walls 51 are mounted at the end of an elastically deformable blade 52 which is linked to a displacement drive system 53 capable of adopting different structural forms.

By way of example according to FIGS. 9 and 10, the system 53 is constituted by an endless belt 54 capable of being driven by an intermittent movement in the direction of the arrow f _& passing over return members 55 having the effect of establishing some of the blades 52 in the same plane under the warping plane P with for 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 which can be driven in reciprocating movement 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 wires 15 „for each incrementation step then, then lowered to be erased below the sheet of warped wires, so as to be brought back to an initial position in which it is raised again to support another 15 „wire.

Whatever system is used, the blades 52 are also associated with lifters 56 which can be controlled in any suitable manner and selectively according to the armor chosen to be raised from a position of erasure, as illustrated in figs. 9 and 10 to an elevation position, as illustrated 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 shed 16 in which the segment of wire 15 „ _b , cut from the wire 15 _n occupying the recovery edge 10", is inserted, as described in connection with the process.

The opening-closing system 45, as described above, is advantageously mounted on a chassis 57 which is carried by a bench 58 relative to which it can be moved by a suitable drive member to be driven by a displacement in the double direction of the arrow f ₇ relative 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 bring all the combs back 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 inlet sections 30 and 31 of the support means 11 and 13, so that the different combs 50 assume a flapping function for striking and pressing the inserted segment of thread 15 „ _b against the previous ones in the manner of what occurs in conventional weaving, as shown in FIG. 12.

The weaving loom is finally provided, again, with the gripping and insertion member 18 which is intended to take charge of the free end after cutting the segment 15 " _b of thread 15" occupying the recovery edge 10 " , to insert it into the crowd 16. Such a member can be constituted by a gripping pliers adapted at the end of a lance 61 capable of being introduced into the crowd, for example from the establishment border 10 ' It goes without saying that a reverse arrangement can also be envisaged. In all cases, the lance is driven by an alternative rectilinear stroke which is sufficient to insert the segment of cut wire 15 _nb into the crowd 16 over the entire width. of the hatched tablecloth.

It goes without saying that the lance 61 can also be replaced by two opposite half-lances provided, each at the end, with complementary gripping means and driven by rectilinear displacements inversely synchronized. It is also possible to provide the member 61 in the form of an actuator with reciprocating rectilinear displacement, provided with lateral gripping means. and which would be, in a waiting position, immobilized parallel to the segment of wire to be cut in line with the recovery edge lb ". Such a gripping member would then be mounted on a vertical pivot located near the cutting section of the wire, so that after taking over, it can be subjected to a rotation in order to bring the gripper 18 which it comprises in the axis of the shed, inside which the segment of wire 15 _n b cut, and taken in its entirety, would then be inserted As illustrated in Fig. 8, the member 61 is arranged to support the end of the segment 15 „ _b cut 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 a embodiment, consists of a vertical cylindrical rod , located substantially in line with the recovery edge 10 "and at a distance from the cutting member 17. Such a finger is retractable, so that it can be controlled in elevation after displacement across the wire 15 _n brought to the right of the border 10 "A functional sequence can then be established in the following manner. The gripping member, such as the clamp 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 remains is retained to the right of the outlet of the means 11 and the inlet of the means 13 to subsequently constitute a wire 2.

The member 18 can then be controlled in displacement movement inside the shed 16 in a direction perpendicular to the direction x-x ', so that the segment of wire 15 „ _b cut is driven and caused to bypass the inflection point 70 to be disposed and suitably aligned inside the shed 16. In a widely preferred application, the wire used and unwound from the spool 14 is of the flat type, being for example constituted by a association of ultra-filaments of carbon fibers which may, for example, be of the 3K, 6K, 12K, or even 24K, 48K, 80K type. In such an example of putting into service, it is imperative to be able to insert into the shed 16 the segment of flat wire 15 „ _b without subjecting it to any twist which could normally occur by circumvention of the point of inflection 70. In order to respect this requirement, the inflection point 70 can then, advantageously, be produced as illustrated in FIG. 13 by 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 ply of warped thread 15 ", so that the last thread occupying the recovery edge 10" is engaged between the finger 71 and the strip 72. In addition, the arrangement of the inflection point 70 is made so that the finger 71 extends obliquely to the direction x-x ', being oriented at 45 ° to be directed towards the crowd 16.

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

The same effect can be obtained by using dynamic rather than static components and by replacing finger 71 with a turning bar capable of possibly being rotated on its axis by 180 ° immediately after actuation of the cutting member 17, so that the end portion 15 ′ _nb , comprised between the turning bar and the cutting member, is automatically, after turning, oriented in the direction favorable to being taken over by the cutting member gripping, such as 18, moving parallel to the crowd 16, as illustrated in FIG. 14. The inflection point 70 could also include instead of the bar

72 a shoe or relative clamping jaw of the terminal part 15 '„ _b .

Finally, the loom may include 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 disposed in abutment against the combs 50 between the latter and the alignment of the inputs 30 and 31 of the handling and transfer means 11 and 13. Beyond the eyelet 82, each wire 6 is inserted into the shed 16 to be trapped in a crossover zone between a thread 2 and a thread 3 making up the width of bias fabric 1. Figs. 15 and 16 show a possibility of insertion of several straight reinforcing threads 6 which it is advisable, in such a case, to be able to imprison so that they are established parallel to the direction of formation of the width, defined by the axis y-y '. 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, maintaining the part of the reinforcing wire 6 trapped in line with the last wire 3 inserted and at a distance from the eyelets 82.

During the striking operation, executed as said above by the combs 50, the needles 83 are retracted, as illustrated in FIG. 17, so as to allow insertion at the bottom of the last segment 15 „ _b of inserted wire. During the phase of withdrawal of the combs 50, the needles 83 are moved in a reverse movement in order to keep each thread 6 in the waiting position, as illustrated 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 to it by a width of elementary wire 15 ".

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

INDUSTRIAL APPLICATION:

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

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

Claims

CLAIMS:

I - Bias fabric, characterized in that it is in the form of a width of length (L) and width (1) finished, consisting of son (2, 3) intertwined, established in respective directions ( D and d) oblique to the length (L) and none of which has knotting, even for an infinite length (L) of the width.

2 - Fabric according to claim 1, characterized in that it comprises at least one reinforcing thread (6) trapped between the interlaced threads and extending parallel to the length (L).

3 - Fabric according to claim 1 or 2; characterized in that at least one of the selvages (l _a, lb) of the web (1) is formed by the ends of the interlaced and cut son.

4 - Fabric according to claims 1 to 3, characterized in that one of the edges of the width is formed by loops (4) connecting two son (2) successive.

5 - Fabric according to one of claims 1 to 4, characterized in that at least one of the edges of the width is bordered.

6 - Fabric according to one of claims 1 to 5, characterized in that the interlaced threads are according to one of the following reinforcements: satin, taffeta, twill.

7 - Fabric according to one of claims 1 to 6, characterized in that the interlaced threads occupy respective directions close to + and - 45 ° relative to the length L.

8 - Fabric according to one of claims 1 to 7, characterized in that the interlaced son are monofilament.

9 - Fabric according to one of claims 1 to 7, characterized in that the interlaced son are multifilament. 10 - Fabric according to one of claims 1 to 9, characterized in that the interlaced son are flat and free from twisting.

II - Fabric according to one of claims 1 to 10, characterized in that it is produced in the form of a width (1) of infinite length (L) and of width (1) finished by being made up of interlaced threads of finished length. 12 - Method for manufacturing a bias fabric in the form of a width (1) of finite width and infinite length, characterized in that it consists of:

• warp a sheet of wires (15) of direction (x-x ') parallel to each other by making them take charge by a first (11) and a second transfer means (12) occupying parallel directions (y-y' ) between them which make an angle (α) with the direction (x-x '),

• gradually build up said tablecloth by successively placing the wires in line with a border (10 ′) called the establishment of the tablecloth,

• move said wires in one step. the oblique cross direction by the first and second transfer means from the so-called establishment border to an opposite border (10 ") called recovery,

• have the wire (15 _n ) occupying the recovery edge (10 ") additionally taken care of by a third transfer means (13) located at a distance and parallel to the first means for acting on the substantially middle part of said wire,

• open the sheet in two half-sheets to define a crowd (16) near the first and third transfer means, • cut, in its substantially middle part, the wire (15 „) established and brought to the right of the edge of reprise,

• leave in place the part (15 _na ) of said wire (15 „) held by the inlet of the third transfer means and. the output of the first transfer means to constitute a thread (2) of the future width. • take the segment of said wire (15 „ _b ) located between the third and second transfer means and insert it into the shed in a direction (z-z ') perpendicular to the direction (x-x') from the edge of recovery towards the border of establishment to constitute a thread (3) of the future width, • proceed in the same way successively with each thread brought to the right of the border of recovery, while having, in addition, a new wire to the right of the establishment border and gradually constitute an interlacing of wire segments supported by the first and third transfer means and which progresses in the oblique direction (y-y ') relative to the direction (x -x '). 13 - Method according to claim 12, characterized in that each segment of wire is struck (15 „ _b ) inserted successively into the crowd.

14 - Method according to claim 12, characterized in that each wire (15 ") of the sheet is established by taking, from a supplying coil (14), an elementary length of wire chosen to be taken care of, both by the first and second transfer means.

15 - Method according to claim 12, characterized in that each wire of the web is established from the wire (15) continuously unwound from the supply reel by a zigzag weft carriage cooperating with pins or retaining needles presented by the first and second transfer means, then in that the wire (15) is cut brought in line with the recovery edge (10 ") at the outlet of the second transfer means and upstream of the third means.

16 - Process according to claim 12, characterized in that each wire (15 „) of the sheet is taken care of throughout its transfer direction cross direction from the edge of the establishment (10 ') to the edge recovery (10 ") by a system of combs (50) ensuring the functions of lateral guidance of the wires, opening and closing of the half-plies according to the chosen armor and striking of each segment of wire inserted in the crowd ( 16).

17 - Method according to claim 12, characterized in that there is the second transfer means (12) on a movable support, compensating for the apparent reduction in length of the son as a result of the opening of the crowd.

18 - The method of claim 12, characterized in that traps, between the son of the web and the inserted son segments, at least one straight reinforcing wire (6) extending parallel to the length (L) of the width.

19 - A method according to claim 18, characterized: • in that one introduces the reinforcing wire (6) by a thread guide eyelet (82) disposed substantially in line with the opening of the crowd, between the comb system (50) and the direction of insertion of each segment of wire,

• and in that said reinforcing wire (6) is temporarily retained in position between each insertion of a segment of wire, substantially in line with the last segment already inserted, by a removable alignment needle (83). 20 - Method according to claim 19, characterized in that the alignment needle is offset laterally with respect to the thread guide eyelet by a measure equal to the width of the thread (15 "). 21 - Method according to claim 12, characterized in that it consists, when the son constituting the sheet are flat type, to implement, after cutting the wire brought to the right of the recovery edge, a turning mechanism and torsional inflection (70).

22 - Method according to claim 12, characterized in that it consists in tucking at least one of the edges of the width supported by the first and third means of support and transfer.

23 - Loom for the continuous manufacture of a bias fabric, in the form of a width (1) of finished width (I) and of infinite length (L), characterized in that it comprises : • a warping section (21) of a sheet of wires (15 _n ) established successively, parallel to each other from a border (10 ′) for establishing the sheet,

• a first (11) and a second means (12) for taking charge and oblique transverse transfer of said wires in the direction of an edge (10 ") of the so-called recovery ply, said means being established parallel to each other in a oblique direction (α) relative to that (x-x ') of the threads and this oblique direction defining the direction and the production direction (y-y') of the width,

A third means (13) established at a distance and parallel to the second and driven in the same direction as the first two, so as to take over the substantially middle part of the wire (15 ") of the sheet occupying the recovery edge, • an opening-closing section (45) of the sheet into two half-sheets to delimit a crowd (16) upstream of the first and third support means according to the production direction of the width, • means ( 17-18) for, on the one hand, cutting the thread (15 „) of the sheet occupying the recovery edge, upstream of the third support means, on the other hand, leaving subsist between the first and the third means for taking over a part (15 _na ) of wire intended to constitute a wire (2) of the width and, moreover, to take and insert into the open shed the segment of wire (15 „ _b ) between the cut and the second way of taking charge,

• and means (50) for striking each segment of thread (15 „ _b ) inserted and having it taken over by the first and third means which guide the width of bias fabric thus produced. 24 - Bias weaving machine according to claim 23, characterized in that the warping section comprises, in association with the establishment edge (10 '), a device (40) for successively placing a thread (15 „) stretched between the inlet ends of the first and second support and transfer means.

25 - Bias weaving machine according to claim 24, characterized in that the positioning device (40) is constituted by a gripping means (41) capable of unwinding an elementary length of yarn from a spool ( 14), to establish it between the inlet sections of the first and second support means and in that the device is associated with a member capable of cutting this elementary length.

26 - Bias weaving machine according to claim 24, characterized in that the positioning device (40) consists of a zigzag weft carriage unrolling a thread from a spool and passing it around pins or needles presented by the first and second support and transfer means and in that it then comprises an additional cutting member (17 _a ) located at the outlet of the second transfer means (12). 27 - Bias weaving machine according to claim 23, characterized in that the take-over and transfer means are constituted by endless bands driven by synchronous movements.

28 - Bias weaving machine according to claim 23 or 27, characterized in that the support and transfer means are provided with systems for temporarily hanging the threads.

29 - Bias weaving machine according to one of claims 23, 27 or 28, characterized in that the means of handling and transfer occupy a direction at 45 ° relative to that of the son of the web. 30 - Bias weaving machine according to one of claims 23 and 27 to 29, characterized in that the first and / or the third support means are associated with means (33) to border at least one edges of the width.

31 - Bias weaving machine according to claim 23, characterized in that the opening-closing section comprises a system of combs (50) taking care, individually, of the threads (15 ") of the sheet while ensuring their guidance lateral, their transfer step by step, and their relative spacing selected according to the armor chosen to delimit the insertion shed and the striking of the inserted wire segment.

32 - Bias weaving machine according to claim 31, characterized in that the comb system (50) comprises, for each thread of the ply, a blade (52) elastically deformable, associated with a pusher (56) with selective control and forming a stirrup (51) for lateral guide of the wire, lateral transfer of the latter and striking of the segment of inserted wire.

33 - Bias weaving machine according to claim 23, characterized in that the means for cutting the thread (15 "), occupying the recovery edge (10") and for inserting it into the shed (16), comprise a member (17) for cutting said wire, a member (18) for gripping the segment of wire (15 „ _b ) between the cut and the second support means (12) and a member (61) for inserting said wire segment in the crowd from the recovery border towards the establishment border (10 ').

34 - Bias weaving machine according to claim 33, characterized in that the insertion member is a lance.

35 - Bias weaving machine according to claim 33, characterized in that the gripping member is a pivotally mounted lance capable of grasping the segment of cut wire, parallel to its length, to make it undergo, in the same plane, a displacement of 90 ° to bring it facing the open crowd and to ensure its insertion in said crowd.

36 - Bias weaving machine according to one of claims 33 to 35, characterized in that the means for cutting and inserting the segment of thread are associated with a turning finger (70) assuming an orientation function.

37 - Bias weaving machine according to claim 36, characterized in that the turning finger (70) comprises a cylindrical bar (71) associated with a bar (72) with which it delimits a window for the passage of the wire (15 „) occupying the recovery edge (10 "), said bar, being oriented at 45 ° relative to the direction of said wire.

38 - Bias weaving machine according to claim 37, characterized in that the bar is mounted orientable on its axis.

39 - Bias weaving machine according to claim 23, characterized in that it comprises a device for inserting at least one straight reinforcing thread (6) established parallel to the length of the width and trapped between the threads of the cable and the segments of threads inserted.

40 - Bias weaving machine according to claim 39, characterized in that the insertion device comprises a thread guide eyelet (82) disposed substantially in line with the opening-closing section of the web.

41 - Bias weaving machine according to claim 39 or 40, characterized in that the insertion device comprises, on a needle (83) removable alignment disposed substantially perpendicular to the last segment of thread inserted and offset d 'a wire width in relation to the eyelet.