EP2260133A1

EP2260133A1 - Weaving method and loom for implementing this method

Info

Publication number: EP2260133A1
Application number: EP09705577A
Authority: EP
Inventors: Georges-Paul Deschamps
Original assignee: Deschamps SARL
Current assignee: Deschamps SARL
Priority date: 2008-01-29
Filing date: 2009-01-28
Publication date: 2010-12-15
Anticipated expiration: 2029-01-28
Also published as: FR2926822A1; US20110036446A1; JP2011511174A; WO2009095415A1; JP5592272B2; US20140014222A1; FR2926822B1; EP2260133B1; US8627855B2; US8950440B2

Abstract

The invention relates to an improved weaving method and to a loom for implementing this method. This loom comprises: a weaving zone (18) into which weft yarns in at least an upper channel and a lower channel are inserted, each of these weft yarns being inserted between at least two warp yarns by at least one weft insertion element; first means for dealing with one of these channels and determining the position of the warp yarns relative to said weft yarn; and second means for inserting at least one binding yarn (16) above, between and below these channels. According to the invention, the loom includes at least one element for gripping said at least one binding yarn (16) and means for moving said at least one gripping element out of and into the weaving zone (18) so as to place said at least one gripping element in contact with said at least one binding yarn (16) and to draw said at least one binding yarn (16).

Description

Weaving process and loom for implementing this method

The present invention relates to a weaving process and a loom for the implementation of this method. It relates more particularly to a method of weaving a flexible container.

Aircraft lift airbags are known to facilitate the desmiling and recovery of commercial and military aircraft accidentally exited the runway.

These cushions allow airport rescue teams facing a runway excursion of an aircraft, lift the aircraft and then tow it quickly and safely, avoiding secondary damage.

Figure 1 is a sectional view of an aircraft lifting cushion of the prior art. This cushion typically comprises two walls 1, 2 woven coated for sealing and vulcanized hot. These woven walls 1, 2 are connected on their periphery by a thickening 3 of rubber. These walls 1, 2 are also interconnected by polyamide threads 4 which when they are tensioned by inflation of the cushion are parallel and regularly spaced from each other.

These son 4 are of identical length so as to maintain the walls 1, 2 parallel. This ensures the application of a uniform lifting pressure on the structure of the aircraft under which the cushion is placed.

This last point is particularly critical, for example, when lifting fragile elements such as an aircraft wing, to avoid the appearance of structural damage (Fig. 2).

However, one can observe air losses of these lifting cushions resulting from a manufacturing defect or appearing in time at the level of breaking points 6 of the structure of the lifting cushion. By way of illustration, the manufacturing defects may result from poor vulcanization or from slipping of the excess thickness of rubber 3 before vulcanization. Such defects result in uneven application of the lifting force on the aircraft structure and possibly are responsible for secondary damage.

There is therefore a pressing need for an inflation cushion which is made in one piece in order to have an increased resistance to forces.

More generally, many woven articles having a complex shape such as poufs filled with polystyrene beads, chair covers, etc., result from the assembly of initially separate textile pieces which are then joined, for example, by sewing to confer its definitive form to the article.

However, these articles by definition have a certain structural weakness in these assembly areas.

Premature wear of the article at these areas may result for example in the loss of the filling material of the article. Finally, the assembly time of these items having a complex shape can be relatively long and require qualified operators, which makes the item expensive.

The object of the present invention is therefore to provide a weaving method and a weaving machine for implementing this simple method in their design and their procedure for manufacturing a woven piece in one piece thus conferring on them mechanical properties superior to known articles of the prior art obtained by assembling elements initially separated by sewing, gluing, ... or by a combination of these methods of assembly. Another object of the invention is a method of weaving an integral woven structure having a complex shape such as a conical or cylindrical shape for the production of composite parts such as radomes, fuselage sections, aircraft, ship hulls or indoor or outdoor furniture. To this end, the invention relates to a method of weaving at least two sheets interconnected by at least one binding yarn. According to the invention, a) the weaving of these plies is initiated by inserting into the basic weave of a first ply at least one additional warp or suture, the latter constituting said binding yarn, b) before introducing said at least one binding yarn into the basic weave of the second ply, suspending the weaving of the plies, c) drawing said at least one binding yarn from the side of the second ply by placing at least a portion of the ply length drawn outside the assembly formed by these plies thus connected, d) then, taking up the weaving of said plies by introducing said at least one binding yarn into the basic weave of the second ply,

before each new introduction of said at least one binding yarn into the basic weave of one of these plies, the following cycle is repeated: e) the weaving of said plies is stopped, f) said at least one binding thread is pulled by placing at least a portion of the length drawn outside the assembly formed by these sheets thus connected, g) then, we resume the weaving of the webs by introducing said at least one binding yarn into the basic armor of said web.

The method of the invention makes it possible to manufacture woven structures comprising at least two woven walls connected to one another by at least one non-attached binding thread. This woven structure can be closed or at least partially open. This opening may be placed at any point of the woven structure, that is to say at least at one of its ends, the corresponding edges of these walls not then being interconnected or resulting from the presence of an orifice on at least one of the walls. The section of this woven structure may advantageously have any shape such as a circular, square, rectangular, rhombus, T, U, L, H, I, ... shape after possible cutting. unnecessary warp threads.

"Unwired binding thread" is understood to mean that this thread is not brought back after weaving each of these walls for the assembly of these but on the contrary, it is inserted into the weft of these woven walls as and when they are manufactured. The binding yarn is therefore an integral part of the weave of the two walls on portions thereof.

The woven structure thus obtained is in one piece which gives it an increased mechanical resistance to stress.

This woven structure can either be in one piece or on the contrary be made of different materials.

The expression "the woven structure is in one piece" means that this structure is monobloc and made from a single material. The warp or weft threads used may, however, be of a different shape, that is to say be monofilament yarn, multi-filament yarn, flat yarn, twisted yarn, yarn single or rotor, for example, and have different thicknesses or diameters.

These yarns may, for example, be cotton yarns, polyester yarns, polyamide yarns, polypropylene yarns, polyethylene yarns, biodegradable starch-based plastic materials, oxodegradable plastics materials, yarns made of carbon, graphite, glass, silica, aramid, ...

The walls may furthermore have different dimensions and / or different shapes depending on the application envisaged for the woven structure.

The binding threads may advantageously be made of different materials in the weft direction of the woven structure so that this structure has different areas of mechanical strength. In various particular embodiments of this weaving method, each having its particular advantages and susceptible to many possible technical combinations:

after weaving these plies, these are separated from each other to retract said at least one part of length drawn between these plies and to give its final shape to the assembly formed by the plies thus bonded,

in steps c) and f), the binding yarns are pulled so that these binding yarns are tensioned, at least a majority of the lengths between two consecutive leashes of these binding yarns are rectilinear and regularly spaced apart or not , in steps c) and f), at least one gripping element is introduced into this weaving zone in order to pull only said at least one binding yarn and before the corresponding steps d) and g), this gripping element is removed from the weaving zone, - this gripping element being a temple, it has a different shape between at least two cycles e), f) and g) successive to give a complex shape to the assembly formed by the sheets thus bonded,

The term "temple", a rod that can pass under the son of binding so as to ensure the draw thereof. At least the edge of the temple intended to receive the said at least one binding yarn may have a shape serving as impression of the relief to confer on one of these sheets in line with the said at least one binding yarn. This form is particularly advantageous when it is necessary to draw the binding son of a different length in the warp or weft direction to give a complex shape to one of the webs relative to another. Of course, it may be necessary to change the temple between the consecutive cycles of weaving and pulling son binding to build as weaving of the assembly formed by said at least two sheets and linked together by less a bonding wire, the final shape of this sheet.

each binder yarn is drawn with a needle having at its end a hook for receiving said binder yarn and moving this needle in translation,

the lengths drawn on at least a part of this assembly formed by the sheets thus bonded in the direction of the weft and / or of the warp are varied in a continuous manner or not,

"Continuous variation" is understood to mean that this variation is uniform and does not show jumps or levels. Conversely, this variation may have levels. the lengths drawn are constant over at least part of this assembly formed by the plies thus bonded in the direction of the weft and / or the warp,

the following steps are carried out: a) the simultaneous weaving of an upper wall, an intermediate wall and a lower wall is initiated by introducing into the armor of one of the upper and intermediate webs and one of the lower and intermediate webs at least one additional warp or yarn, this or these and / or this or these latter constituting the binding yarn of the upper and intermediate webs and lower and intermediate plies, b) before introduction of said at least one binding yarn in the other ply respectively of the upper and intermediate plies and the lower and intermediate plies, the weaving of these plies is interrupted; a binding yarn of the upper and intermediate plies and the lower and intermediate plies of a given length by placing at least a portion of these lengths drawn outside the assembly formed by the walls thus bonded, d) taking up the weaving the plies by introducing said at least one binding yarn of the upper and intermediate plies and the lower and intermediate plies into the basic weave mentality of this other tablecloth,

before each new introduction of said at least one binding yarn into the basic weave respectively of one of said upper and intermediate plies and said lower and intermediate plies, e) the weaving of these plies is suspended, f) at least one binding yarn of the upper and intermediate plies and the lower and intermediate plies of a given length by placing at least a portion of the lengths drawn outside the assembly formed by the walls thus bonded, g) then, we take the weaving said plies by introducing said at least one binding yarn of upper and intermediate plies and lower and intermediate plies into the basic weave of said other ply.

Preferably, said at least one binder yarn is pulled from the upper and intermediate walls with a first gripping member by placing at least a portion of the length pulled above the upper sheet and pulling said at least one binder yarn from the lower and intermediate walls with a second gripping member by placing at least a portion of the drawn length below the lower ply.

Advantageously, said at least one binding yarn and the constituent yarns of these plies are pre-impregnated prior to the beginning of the weaving operations. For example, these yarns may be pre-impregnated with a thermosetting or thermoplastic resin, and in particular a thermostable thermoplastic resin such as that of the families of polyetherimides (PEI), polyetheretherketones (PEEK) or polyamides (PA).

The invention also relates to a loom comprising a weaving zone in which are introduced into at least one upper track and one lower track of the weft son, each of these weft son being introduced between at least two warp son by least one weft insertion element, first means for carrying on one of these channels and determining the position of the warp yarns with respect to the weft yarn and second means for introducing at least one binding yarn above , between and below these pathways.

According to the invention, this loom comprises at least one gripping element of said at least one binding yarn and means for moving said at least one gripping element out of and into the weaving zone to place said at least one element gripping means in contact with said at least one binding yarn and allowing drawing of said at least one binding yarn.

Said at least one gripping element can be a temple. Advantageously, the edge of this temple intended to receive said at least one binding yarn comprises means for retaining these binding yarns to prevent the yarns from slipping when they are pulled.

Preferably, at least the edge of the temple intended to receive said at least one binding yarn has a shape serving as impression of the relief to give to one of these sheets in line with said at least one binding yarn.

Said at least one gripping element may also be a needle having at its end a hook for receiving a binding thread. The loom therefore has as much needle as tying wire to pull. The means for moving each needle comprise, for example, a electromagnet or a hydraulic or pneumatic piston. The movement of these needles is controlled by control means.

Advantageously, these control means are individual control means of each needle so as to vary the length drawn from one binding thread to another. Each needle is then mobile in translation. Preferably, this loom is a dry loom, such as a jet loom, a loom (s) or a projectile loom (s).

The invention also relates to the use of at least one woven structure obtained by the method or the loom as described above for producing composite parts, in which said at least one woven structure is placed in a mold, and closed. said mold, a matrix material is introduced into said mold and then the assembly thus obtained is hardened.

The invention also relates to a composite part comprising a preform obtained by the method or by means of a loom as described above, this preform being embedded in a matrix material.

These composite parts are, for example, structural panels for example for vehicles such as aircraft or automobiles. It can still be furniture. The matrix material used is, for example, a thermosetting or thermoplastic resin, and in particular a heat-stable thermoplastic resin such as that of the families of polyetherimides (PEI), polyetheretherketones (PEEK) or polyamides (PA). Polymerization operations are well known processes of the state of the art that will not be described again here. The resin transfer molding process (RTM) or the liquid resin infusion molding (LRI) process is merely illustrative.

The invention will be described in more detail with reference to the accompanying drawings in which:

- Figure 1 is a sectional view of a lifting cushion of the prior art;

- Figure 2 shows a stack of lifting cushions of Figure 1 placed under a wing of an aircraft out of the airstrip for its lifting; - Figure 3 shows a top view of a lifting tank according to a preferred embodiment of the invention;

FIG. 4 is a partial schematic view showing the lengths drawn from the binding yarns placed outside the assembly formed by the plies bound together by binding yarns; FIG. 5 shows the armor of the flexible reservoir of FIG. 3; FIG. 6 schematically shows the armor of FIG. 5 reduced to weft yarns and warp yarns 1 to 8, the warp yarns 5 and 6 being binding yarns;

FIG. 7 is a partial view of the simplified loom, that is to say without the healds and without the shuttle in one embodiment of the invention;

FIG. 8 shows the packing followed by the bladder;

Figure 3 is a top view of a bladder according to a preferred embodiment of the invention. This flexible reservoir consists of a woven structure comprising two woven walls 10, 11 which are connected to one another by unreported tying son. These walls have been woven in a circular fashion, which gives the container increased mechanical strength since the yarns at each end of the woven structure have not been cut.

These two walls 10, 11 are continuous and have several parts going from an edge of the tank towards its center.

On the entire periphery of the tank, firstly observed first part 12 woven flat. This first part 12 forms the edge of the tank. This edge corresponds to the assembly of the two woven walls and delimits the edge of the tank. This edge 12 can receive accessories such as eyelets, ... and stretch the flexible container. For illustrative purposes, the width of this first portion is about 15 cm.

Then there is a second portion 13 called rounded to give a rounded shape on the contour of the flexible container after filling thereof with a gaseous fluid such as air or with particles such as sand, polystyrene beads, ...

When this container is sealed, this second part 13 makes it possible to size the inflation height of the flexible reservoir. The container is sealed after weaving the woven structure giving the shape of the reservoir by a step of coating this structure with a sealing material such as a material based on polyvinyl chloride (PVC) or polyurethane and further better a material based on flame retarded plasticized PVC.

It is from this level that the plies 11, 12 are separated by being connected to one another by the binding yarns introduced in such a way that alternative in the basic armor of the upper and lower plies. These two walls 11, 12 have a lining 1 to 1 with a number of warp son greater than 10 son / cm and a number of weft son greater than 6 son / cm so as to ensure good sealing of the woven structure . Of course, these armor may not be identical. One could thus have a honeycomb armor base of the upper wall so that it has female indentations intended to receive male indentations placed on the lower sheet (honeycomb armor) of another tank superimposed on this flexible tank. This zone where the plies 10, 11 are connected to one another by the unreported binding yarns constitutes the central portion 14 of the bladder. In the latter are placed handles 15 to separate the two plies 10, 11 to return the lengths drawn from the binding son in the assembly formed by these two sheets interconnected. As a purely illustrative example, the warp threads of this woven structure are 2354 Dtex multi-filament polyester yarns for the envelope, that is to say the selvedge 12 and second part 13 and the central part 14 and the handles 15. For the binder yarns 16 which are here additional warp yarns, 2 x 235 Dtex multi filament polyester yarns are used with 215 S turns. The binder yarn density is typically between one yarn / 10 cm ² and several hundred threads / cm ² . Finally, the weft yarns are 2354 Dtex multi-filament polyester yarns.

More generally, the binding yarns are chosen from the group comprising monofilament yarns, multi-filament yarns, single or rotor yarn, yarns comprising agglomerated fibers, flat yarns, flexible metal yarns, sheathed yarns, that is to say each comprising a core wire and a sheath made of thermoplastic material, and combinations of these elements.

The term "flat wire" means an extruded product through a die, drawn or otherwise whose solid and substantially constant cross section over its entire length is in the shape of an oval, a square, a rectangle, a flattened circle and square or modified rectangle, that is to say having two opposite sides having a convex arc shape, the other two being rectilinear, equal and parallel. These flat wires may still be hollow and have, for illustrative purposes, a flattened tubular section.

The warp, weft and binding yarns may, for example, be cotton yarns, polyester yarns, polyamide yarns, polypropylene yarns, polyethylene yarns, biodegradable starch-based plastic materials, plastics materials. oxodegradable, yarns formed of carbon fibers, graphite, glass, silica, aramid, ...

The woven structure giving the shape of the reservoir was obtained according to the manufacturing method described hereinafter (FIG. 4). We start to weave the walls simultaneously by weaving an upper layer 10 and a lower layer 11 according to the basic weave of each of these walls, the binding threads 16 being only connected to the basic weave of the upper layer 10. At the moment to connect these two walls 10, 11 by the binding yarns, that is to say before binding the binding yarns in the lower ply 11, the weaving is interrupted and a temple rod is introduced into the weaving zone; , to come and pull only these binding son 16. The rod being of constant section, the length of the binding son thus drawn is identical. This pulled length is placed above the upper ply 10 forming a loop 17. This length thus drawn from the binding yarns as well as the distance separating the upper and lower plies 11 corresponds to the distance separating the walls of the final reservoir, that is to say its thickness in service.

Once the binding threads pulled to the correct length, the temple is removed from the weaving zone and the manufacture of the woven walls 10, 11 is normally resumed until the next binding of the walls by these binding threads 16.

These binding yarns 16 are thus pulled on the top of the two plies forming the upper and lower walls of the woven structure and the lengths thus drawn are thus placed partly outside the woven structure by forming loops 17. Alternatively, the temple can move below the assembly formed by these webs linked together so that these loops 17 are placed partly below this set.

These binding son 16 are then returned to the woven structure by separating the sheets from one another using the handles 15.

Finally, the woven structure is coated with a sealing material to form the lifting tank. Figure 5 shows the weave of this woven structure having a reservoir shape for the manufacture and binding of upper and lower walls 11. This conventionally represented weave comprises ten warp threads, numbered 1 to 10, facing ten columns. vertical and 20 weft threads, numbered 1 to 20 and an actuation of the temple in the weaving area numbered 21, next to 21 rows in an evolution of the armor.

The warp threads numbered 1 and 3 correspond to the warp threads of the lower ply 11 and the warp threads numbered 2 and 4 correspond to the warp threads of the upper ply 10. The warp threads numbered 5 and 6 correspond to the warp threads. binding and the son numbered 7 and 8 correspond to the warp son of the handles 15. The warp numbered 9 corresponds to the binding yarn of the selvedge 12 and the warp numbered 10 corresponds to the nightingale. At the intersections of the rows and columns are shown in the known manner, in black, the warp threads taken and white, the warp threads left in the remaining intersections.

Thus, for example, considering FIGS. 5 and 6, it can be seen that the numbered warp thread 4 passes successively (is taken) on the first two weft threads (No. 1 and 2), then goes under (is left) the weft thread No. 3 passes over the three weft threads Nos. 4 to 6, then under the weft thread No. 7, then again onto the three weft threads Nos. 8 to 10, and then under the thread weft n ° 11, then on the weft threads Nos. 12 to 14, then under the weft thread No. 15, then again passes on the three weft threads Nos. 16 to 18 and then passes again on the thread of frame No. 19, then under the weft thread No. 20 and leaves above the first two weft threads No. 22 and 23 to the next evolution of the armor.

It is also noted that the row 21 of the armor corresponds schematically to the replacement of a pick, that is to say to a weaving phase, by the introduction into the weaving area of the temple to pull the threads of the weave. binding numbered 5 and 6 and the removal of this temple from the weaving area. This corresponds to the level of the loom at the non-propulsion of the shuttle.

The weaving of the upper and lower plies 11 with the introduction of the binding yarns into the weave of the lower ply 11 then resumes normally (row 22 and following). Figure 7 shows the loom for carrying out the method described above according to one embodiment. This loom comprises a weaving zone 18 in which are introduced into at least one upper track and one lower track of the weft son, each of these weft son being introduced between at least two warp son by at least one element d Weft introduction such as a shuttle or jet of air or water jet. The loom also includes first means for carrying on one of said lanes and determining the position of said warp yarns with respect to said weft yarn. These first means may comprise for example a first smooth warp, these first smooth being controlled by a weave mechanism also called dobby. The loom further comprises second means for introducing at least one binding yarn above, between and below said lanes. These second means comprise for example a second smooth binding wire, these second smooth being controlled by this same armor mechanics.

The loom also includes a temple 19 for pulling the binding yarns and means for moving this temple out of and into the weaving zone 18 to place the temple 19 in contact with the binding threads and to allow the drawing of those -this. Preferably, the edge 20 of this temple for receiving the binding son comprises means for retaining these son to maintain their spacing in a direction perpendicular to the direction of propagation of weaving of the woven structure. The rod 19 has for example on this edge a rough surface or an array of vertical grooves (not shown) intended to each receive one or more binding son.

The operation of the beam 21 carrying the binding son is as follows. The operator supplies a motor 22 operating continuously until the operator decides to stop it or a first sensor 23 is activated, for example because the unrolled length of the binding wire is too large. The motor 22 makes it possible to unwind the tying son of the beam. Of course, this beam 21 must be replaced by a creel when the shape to be achieved is complex, that is to say, as soon as the walls 10, 11 are not flat.

The loom comprises on either side of the weaving zone 18 receiving elements such as boxes 24, 25 allowing the reception temporary shuttle (not shown) so as to move the latter in height to prevent it is launched on the loom for example by a thruster-type device cleat or air jet.

The second sensor 26 makes it possible to detect that these boxes 24, 25 are placed in height so that the shuttle can not leave. It is then possible to pull the binding son with the temple 19. The third sensor 27 can detect instead that the flush 28 is open for the passage of the shuttle.

The displacement means of the temple 19 comprise firstly two actuators 29, 30 of the jack or telescopic arm type for advancing or retreating the temple in the weaving zone 18. These actuators 29, 30 are synchronized so that they work together. They are placed laterally to the weaving zone 18 and their range of motion makes it possible to determine the length of the binding threads drawn by the temple 19.

These displacement means also comprise a third actuator 31 for laterally moving the temple, that is to say, to enter or leave the temple 19 in the weaving zone 18. When the temple 19 is placed in the zone weaving 18, its end is received in a housing 32 provided for this purpose at the end of the first actuator 29. A fourth sensor such as a stop detector 33 can detect that the end of the temple is in position in its housing 32 and stops the actuator 31. This actuator may be a roller placed on a motor shaft which converts a rotary movement into a translational movement. A fifth sensor 34 makes it possible to detect that the temple has left the weaving zone entirely 18.

The temple 19 is thus movable in translation along the X and Y axes in the plane of the weaving zone 18.

A fourth actuator 35 of the jack type makes it possible to engage and disengage the loom.

The initial cumulative conditions to allow the start of the operating cycle of the temple 19 are: one of the two boxes must be in the up position: second sensor 26 active, the loom must be flush 28 open: third sensor 27 active, the temple 19 must be in abutment: fourth sensor 33 and fifth sensor 34 active, - the first, second and fourth actuators are in a rest position, that is, ie the rods of the cylinders are for example returned.

The method of the invention is applicable to the production of composite parts of sheet metal as well as structural parts used in the production of aircraft, for example fuselages or fuselage parts such as the wings of an aircraft or the radome. It is also possible to make propeller tanks or tank skirts.

Maritime applications are conceivable, for illustrative purposes, the realization of hulls of boats, containers, floats, ...

Claims

1. A method of weaving at least two plies bonded together by at least one binding yarn, characterized in that a) initiating the weaving of said plies (10, 11) by inserting in the basic armor a first at least one additional warp or yarn, the latter constituting said binding yarn (16), b) before introducing said at least one binding yarn (16) into the basic weave of said second ply, suspending the weaving of said plies (10, 11), c) drawing said at least one binding yarn (16) from the side of the second ply by placing at least a portion of the length drawn outside the formed assembly by these plies (10, 11) thus connected, d) then, the weaving of said plies (10, 11) is introduced by introducing said at least one binding yarn (16) into the basic weave of the second ply,

before each new introduction of said at least one binder yarn (16) into the basic weave of one of these plies, the following cycle is repeated: e) the weaving of said plies (10, 11) is stopped; pulling said at least one binding yarn (16) by placing at least a portion of the length drawn outside the assembly formed by these plies (10, 11) thus connected, g) then, the weaving is repeated. webs (10, 11) by introducing said at least one binding yarn (16) into the basic weave of said web.

2. Method according to claim 1, characterized in that after weaving said plies (10, 11), said plies (10, 11) are separated from each other to enter said at least a portion of length drawn between said plies and give its final shape to the assembly formed by said plies thus bonded.

3. Method according to claim 1 or 2, characterized in that in steps c) and f) is introduced into the weaving area (18) at least one gripping element to pull only said at least one binding yarn ( 16) and before the corresponding steps d) and g), said gripping element is pulled out of said weaving zone (18).

4. Method according to claim 3, characterized in that said gripping element is a temple (19).

5. Method according to claim 4, characterized in that the temple (19) has a different shape between at least two cycles e), f) and g) successive to give a complex shape to said assembly formed by said plies (10, 11 ) so linked.

6. Method according to claim 3, characterized in that one draws each binding yarn (16) with a needle having at its end a hook and moving said needle in translation.

7. Process according to any one of Claims 1 to 6, characterized in that the lengths drawn on at least a part of the said assembly formed by the said plies (10, 11) thus bonded are continuously varied or not. meaning of the frame and / or the chain.

8. Method according to any one of claims 1 to 7, characterized in that the drawn lengths are constant over at least a portion of said assembly formed by said plies (10, 11) thus bonded in the direction of the frame and / or chain.

9. A method according to claim 1, characterized in that the following steps are carried out: a) the simultaneous weaving of an upper wall, an intermediate wall and a lower wall, introducing into the basic armor one or more of the upper and intermediate plies and one of the lower and intermediate plies comprise at least one additional warp or yarn, this or these and / or these latter constituting said binding yarn (16) of the upper and lower plies; intermediate and lower and intermediate layers, b) before introduction of said at least one binding yarn (16) into the other ply respectively of said upper and intermediate plies and said lower and intermediate plies, the weaving of said plies is interrupted, c) draws said at least one binding yarn (16) from the upper and intermediate plies and the lower and intermediate plies of a given length by placing at least a portion of said lengths drawn outside the assembly formed by said walls thus bonded, d) taking up the weaving of said plies by introducing said at least one binding yarn (16) of the upper and intermediate plies and the lower and intermediate plies into the basic weave of said other ply, - before each new introduction of said at least one binding yarn (16) in the basic weave respectively of one of said upper and intermediate plies and said lower and intermediate plies, e) suspending the weaving of said plies, f) pulling at least one binding yarn (16) of upper and intermediate plies and lower and intermediate plies of a given length by placing at least a portion of said lengths drawn outside the assembly formed by said walls thus bonded, g) then, the weaving of said plies is repeated. introducing said at least one binding yarn (16) of upper and intermediate plies and lower and intermediate plies into the basic weave of said other ply.

10. The method of claim 9, characterized in that said pulling said at least one binding yarn (16) of said upper and intermediate walls with a first gripping member placing at least a portion of said length drawn above the tablecloth upper and in that said at least one binder yarn (16) is pulled from said lower and intermediate walls with a second gripping member placing at least a portion of said drawn length below said bottom ply.

11. Method according to any one of claims 1 to 10, characterized in that said at least one binding yarn and the constituent yarns of said plies are pre-impregnated prior to the beginning of the weaving operations.

12. Loom comprising a weaving zone (18) in which are introduced into at least one upper track and one lower track of the weft son, each of said weft son being introduced between at least two warp son by at least one weft insertion member, first means for carrying on one of said channels and determining the position of said warp yarns with respect to said weft yarn and second means for introducing at least one tying yarn (16) above , between and below said channels, characterized in that it comprises at least one element of gripping said at least one binding yarn (16) and means for moving said at least one gripping member out of and into the weaving area (18) to place said at least one gripping member (19) in contact with said at least one binding thread (16) and allowing drawing of said at least one binding thread (16).

13. Loom according to claim 12, characterized in that said at least one gripping element is a temple (19).

14. Loom according to claim 13, characterized in that the edge (20) of said temple for receiving said at least one binding yarn (16) comprises means for retaining said binding yarns to prevent said yarns (16 ) slip during the draw of these.

15. A weaving machine according to claim 13 or 14, characterized in that at least the edge of said temple for receiving said at least one binding thread (16) has a shape serving as impression of the relief to be given to one of said webs at the right of said at least one binding yarn (16).

16. Loom according to claim 12, characterized in that said at least one gripping element is a needle having at its end a hook.

17. Loom according to claim 16, characterized in that it comprises individual control means of each of said needles so as to vary the length drawn from one binding thread (16) to another.

18. Loom according to any one of claims 12 to 17, characterized in that it is a dry loom, such as a jet loom, a loom ( s) or a projectile loom (s).

19. A composite part comprising a preform obtained by the method or by means of a loom according to any one of the preceding claims, embedded in a matrix material.