EP1736585A1 - Process for working a pile in a pre-needling apparatus and apparatus for doing so - Google Patents

Abstract

The method involves executing an elliptic type combined movement in a pre-needling apparatus (3), where the combined movement includes back-and-forth movement and a forward movement of pre-needling needles (47). The forward movement of the needles is utilized for providing a movement to a stack of the apparatus (3) for allowing the introduction of the stack in a consolidation apparatus (2). The stack is directly passed from the apparatus (3) to the apparatus (2), where the apparatuses (2, 3) are combined in a common case (11) for forming a single machine. An independent claim is also included for an installation for working a stack in a pre-needling apparatus.

Description

The present invention relates to a method for opening a sheet in a pre-needling apparatus and then in a consolidation apparatus.

The present invention also relates to an installation for carrying out the method.

An unbound sheet of fibers is generally composed of superimposed layers of fibers exiting for example a spreader-lapper. In each layer, the fibers are parallel to each other. However, the direction of the fibers in a layer is different from the direction of the fibers in the immediately underlying layer and in the layer immediately superimposed.

An unconsolidated web must be worked in a consolidation machine whose function is to bind the fibers together, in particular from one layer to another, and jointly to compact the web. Once consolidated, the sheet has an appreciable mechanical strength. It is therefore relatively easy to extract the web of the consolidation machine, for example by passing the web between two extractor rollers.

Upstream of the consolidation machine, the mechanical strength of the web is on the contrary, almost non-existent, whether in longitudinal compression or in longitudinal tension. Therefore, the introduction of the web into the consolidation apparatus is a delicate problem of the nonwoven lines. In case of excessive stress at the time of its introduction into the consolidation machine, the sheet deforms irregularly and is then consolidated with irreversible irregularities in its surface weight. The product obtained is of poor quality.

A well-known apparatus for the consolidation operation is the needling machine. In such a machine, multiple needles oriented transversely to the plane of the web are driven by a fast back and forth to pass periodically through the web and thus interlace the fibers of the different layers. If extractor rollers are placed at the exit of a needling machine, traction on the consolidated sheet is not transmitted at the entry of the needling machine only when the needles are in their withdrawal phase, that is to say freed from the sheet. And anyway, given the low resistance of the web upstream of the needling, this traction transmitted through the needling is likely to affect the homogeneity of the web.

To remedy this difficulty, it has been proposed needling movement "elliptical". This term means that in profile a point of the needles describes an oval or ovoid trajectory resembling an ellipse, without necessarily being exactly an ellipse in the mathematical sense of the term. In such needling machines, the needles are given a combined movement comprising said reciprocating movement of penetration as a first component, and in superimposition a second component parallel to the direction of advancement of the web through the needling machine. . This second movement is in the same direction as the advancement of the web when the needles are in the penetration phase, and in the return direction when the needles are in the withdrawal phase or release.

The documents DE-A-1,803,342 , FR-A-2 180 928 , US-A-5,732,453 , and EP-A-892,102 describe such "elliptical" needling needles.

As the needles follow the advancing movement of the web while they are in the penetration phase, there is no longer the problem of a stretching of the web between the extractor rollers and the needles when the needles are in phase. penetration. At the same time, the needles in the penetration phase, by their movement in the direction of advancement of the web, help it to penetrate inside the needling machine.

However, these needling machines have the disadvantage of being expensive, mechanically complex, and have a large number of moving parts, some of which are heavy and bulky. This results on the one hand from vibrations, on the other hand from air movements. These are very disadvantageous for the unconsolidated sheet as it happens in the needling. The air movements tend to disperse the unbound fibers together and consequently to create inhomogeneities and irregularities in the width of the web.

Pre-needling cylinders are also known in which pre-needling needles are linearly reciprocated transversely to the plane of the sheet emerging for example from a crosslapper. Before entering the web, the needles pass through orifices of a cylinder which is rotated in the direction of advancement of the web and whose outer peripheral wall is in contact with the web. This cylinder thus plays the role of a movable stripper whose outer surface, in contact with the web, accompanies the movement of the web. The rate of striking of the needles and the circumferential displacement of the cylinder correspond to one or more circumferential steps of succession of the orifices. Thus the needles coincide each time with respective holes of the cylinder.

At the exit of such a pre-needling, the sheet is pre-consolidated, thus capable of transmitting a certain traction force, and its passage through the following needling is thus facilitated. In addition, the pre-consolidated web already has a certain cohesion for example to store it and consolidate it definitively only later, and / or in a remote location. However, cylinder pre-needling machines have certain limitations and disadvantages. As the needle holder is inside the cylinder it can only be supported at its ends located on either side of the width of the sheet. The problem of the bending of the needle holder makes it necessary to limit the operating rate and the number of needles, especially with wide webs. On the other hand, the orifices of the cylinder are substantially fixed with respect to the sheet, so that the pre-needling work, instead of being uniformly distributed over the surface of the sheet, is concentrated at the points of the sheet which have come to coincide with the orifices of the cylinder. This results in a marking that the subsequent process of consolidation does not always succeed in making disappear.

The object of the invention is thus to provide a method and an installation which makes it possible to consolidate a sheet of fibers at a relatively high rate with a deformation of the sheet which is particularly reduced.

According to the invention, the method for forming a sheet in a pre-needling apparatus and then in a consolidation apparatus, in which a combined movement comprising a transverse reciprocation is made to pre-needling needles. at the plane of the sheet and an advancement movement in the direction of advancement of the sheet when the needles are in the penetration phase in the sheet, is characterized in that the advancing movement of the pre-needling needles is used to impart to the sheet a movement favoring the introduction into the consolidation apparatus.

According to the invention, the combined movement, of "elliptical" type, concerns only a pre-needling, which can be performed with a relatively small number of needles, as well as a volume and a mass of relatively moving parts. reduced, and even, according to a possible feature of the invention, with a reduced rate compared to that of the consolidation apparatus. Thus, it limits the air movements, vibrations and additional mechanical stresses imposed on the installation by the horizontal component of the movement, while applying this horizontal component where it is really necessary, ie to the entry into the consolidation process itself.

Preferably, according to the invention, the sheet of the pre-needling apparatus is passed directly to the consolidation apparatus, preferably by pre-needling and consolidation in the same machine. This minimizes congestion while optimizing the propulsion effect of the web to the consolidation apparatus, an effect that results from the advancing movement of the pre-needling needles. If the consolidation consists of needling with a linear movement of the needles, an advantageous version of the method according to the invention consists in actuating the needling and needling needles at the same rate and in synchronizing the cycles of pre-needling. needling and needling so that the needling needles are in the penetration phase during the withdrawal phases of the needling needles, and needling needles are in the withdrawal phase when the pre-needling needles are in the penetration phase.

Thus, when the pre-needling needles are in the penetration phase and make their advancing movement with the web, the needling needles in the withdrawal phase advance the sheet which can be jointly pulled by extractor rollers at the exit needling. On the contrary, when the pre-needling needles are in the withdrawal phase and therefore no longer propel the sheet, needling needles penetrate optimal conditions through a sheet which is stopped or at a reduced speed, the extractor rollers at the exit of the needling machine being able to be stopped or respectively slowed down.

Actuation of needling needles and needling needles at the same rate or at two different rates but in a fixed ratio simplifies the drive means of the pre-needling apparatus and the consolidation apparatus . One can for example provide a single motorization, and fixed ratio transmission means connecting this motor and the two devices.

In a more sophisticated version, it is possible to provide a separate motorization for the pre-needling and the needling by means of respective servomotors subject to a common command which prescribes at each moment a position instruction, which defines the speed ratio between the two apparatuses and, when the ratio is an integer or a fraction whose numerator and denominator are integers, their cycle timing.

According to a second aspect of the invention, the plant for working a fiber web, for the implementation of a method according to the first aspect, comprising, along a path for the fiber web, an apparatus for needling followed by a consolidation apparatus, the pre-needling apparatus comprising means for imparting to a pre-needling needle a combined movement comprising a reciprocating transverse to the plane of the sheet and a movement of and -extremely parallel to the advancement movement of the web, is characterized in that the output of the pre-needling apparatus and the entry of the consolidation apparatus are in relation of conservation of the movement of advancement of the tablecloth.

It is advantageous to practice needling starting with needles penetrating into the sheet by its opposite side to that from which we just made the pre-needling.

Thus, the pre-needling equipment can be placed closer to the needling equipment, which improves the propulsion effect of the sheet by the pre-needling equipment into the needling equipment. At the same time the overall size is reduced and the textile result is improved.

• la sortie de l'appareillage de pré-aiguilletage et l'entrée de l'appareillage de consolidation sont directement reliées ;
• l'appareillage de pré-aiguilletage et l'appareillage de consolidation sont installés dans une même machine ;
• l'appareillage de pré-aiguilletage comprend, entre le trajet de la nappe et un support pour les aiguilles, un débourreur comportant des orifices traversés par les aiguilles, ces orifices ayant parallèlement à la direction d'avance de la nappe une dimension suffisante pour permettre le mouvement de va-et-vient longitudinal des aiguilles ; le débourreur étant de préférence prolongé d'un seul tenant, par une table d'aiguilletage de l'appareillage de consolidation.

Preferably, separately or in combination:

• the output of the pre-needling equipment and the input of the consolidation equipment are directly connected;
• the pre-needling apparatus and the consolidation apparatus are installed in the same machine;
• the pre-needling apparatus comprises, between the path of the web and a holder for the needles, a stripper having orifices through which the needles pass, these orifices having, in parallel with the direction of advance of the sheet, a dimension sufficient to allow the longitudinal movement of the needles; the stripper is preferably extended in one piece by a needling table of the consolidation apparatus.

According to one aspect of the invention relating to the present pre-needling and more generally to the elliptical switch, it is preferably provided on the opposite side to the pre-needling needles a movable support means with the sheet which defines the path of the tablecloth. Preferably the support means is a rotary cylinder having recesses for the needle tips; these recesses preferably being gaps between annular lamellae.

• des lamelles d'appui dans des plans parallèles à la direction d'avancement de la nappe ; et
• entre les lamelles, des évidements pour recevoir les pointes d'aiguilles.

According to another aspect of the elliptical pre-needling according to the invention, and of the elliptical needling in general, the apparatus comprises for delimiting the path of the ply on the opposite side to the needles having an elliptical movement:

• support slats in planes parallel to the direction of advancement of the sheet; and
• between the slats, recesses to receive the needle tips.

In either of the two aspects just described, the bottoms of the recesses are preferably formed by fingers which extend beyond the slats in the direction of the next apparatus, so in particular the consolidation equipment.

Another important aspect of the invention relates to a mechanism capable of giving needles an advantageous elliptical motion.

This mechanism comprises, in particular in the pre-needling apparatus according to the invention, a mobile unit with a support for the needles and attached to two connecting rod-crank systems by two axes of parallel positioning, and eccentric radii of the two crank-crank systems are capable of mutual angular stall such that dead points of the respective races of the two positioning axes are offset in time with respect to each other .

The angular setting is preferably adjustable, which has the effect of adjusting the amplitude of the component of the movement of the needles parallel to the direction of advancement of the sheet.

• l'équipage mobile est guidé coulissant dans une glissière oscillant autour d'un axe parallèle aux axes de positionnement et chaque système bielle-manivelle comprend une bielle dont un pied est articulé à l'équipage en l'un des axes de positionnement ;
• la glissière est placée sensiblement entre deux moyens à excentrique tournant en sens inverse l'un de l'autre et appartenant chacun à l'un respectif des deux systèmes bielle-manivelle.

Preferably in this mechanism, separately or in combination:

• the moving equipment is guided sliding in a slide oscillating about an axis parallel to the positioning axes and each connecting rod-crank system comprises a rod whose foot is articulated to the crew in one of the positioning axes;
• the slide is placed substantially between two eccentric means rotating in opposite directions from each other and each belonging to a respective one of the two connecting rod-crank systems.

Preferably, the two connecting rods are oriented with their ends forming a connecting rod pointing in the direction generally opposite to the plane of the web.

Thus, the process of inversion of the direction of the vertical component of the movement of the needles in the vicinity of the maximum penetration position takes place very slowly, with a quasi-stop time during which part of the movement of the needles in the direction of advancement of the sheet is effected efficiently and in good conditions. In addition, thus arranged, the mechanism is particularly compact.

Other features and advantages of the invention will emerge from the description below, relating to non-limiting examples.

• la figure 1 est une vue schématique en élévation, avec coupe partielle, d'un premier mode de réalisation de l'installation selon l'invention ;
• les figures 2 et 3 sont des vues partielles en coupe suivant II-II et respectivement III-III de la figure 1 ;
• la figure 4 est une vue analogue à la figure 1 mais simplifiée et montrant un autre stade de fonctionnement ;
• la figure 5 est une vue à échelle agrandie d'une partie de l'installation des figures 1 à 4 en élévation latérale avec coupe partielle, et à un troisième stade de fonctionnement ; et
• les figures 6, 7 et 8, sont des vues généralement analogues à la figure 1 mais concernant trois autres modes de réalisation de l'installation selon l'invention.

In the accompanying drawings:

• Figure 1 is a schematic elevational view, partly in section, of a first embodiment of the installation according to the invention;
• Figures 2 and 3 are partial views in section along II-II and III-III respectively of Figure 1;
• Figure 4 is a view similar to Figure 1 but simplified and showing another stage of operation;
• Figure 5 is an enlarged view of a part of the installation of Figures 1 to 4 in side elevation partially cut, and at a third stage of operation; and
• Figures 6, 7 and 8 are views generally similar to Figure 1 but relating to three other embodiments of the installation according to the invention.

In the example represented in FIG. 1, the installation comprises, along a path 1 for a layer of fibers (not shown in FIG. 1), a consolidation apparatus 2 directly preceded according to the invention by an apparatus 3. There is further provided an introducer apparatus 4 upstream of the pre-needling apparatus 3 relative to the direction of advance 6 of the web, and an extractor apparatus 7 located downstream of the apparatus of needling 2 and constituted by two rotary cylinders 8 defining between them a nip 9 for the web following the path 1 which is substantially plane.

In the following, "distal" and "proximal" will mean "relatively distant" and respectively "relatively close" to the path plan 1.

The pre-needling apparatus 3 and the needling apparatus 2 are united in a common box 11 and thus belong to one and the same machine. The casing 11 comprises an inlet window 12 in which the introducer apparatus 4 is installed and an outlet window 13 in which the extractor apparatus 7 is installed.

The needling apparatus 2 is in itself conventional. A crew 14 is linearly reciprocable in a sliding direction 16 fixed perpendicular to the plane of the path 1 of the web. A sliding rod 17 belonging to the crew 14 is slidably mounted in a sliding guide 18 fixed to a frame 19 of the machine, to which the box 11 is also fixed. The crew 14 further comprises a support 21 fixed to the proximal end of the rod 17 and a needle board 22 interchangeably fixed on the support 21. needling needles 23, only two of which are shown and the others are shown schematically by the mixed line 23a, are oriented perpendicular to the plane of the 1 and distributed on the surface of the board 22. In the region of the needles 23, the path of the ply is defined by a needling table 24 adjacent to the face of the ply opposite to the needle board 22, and by a stripper 26 adjacent to the face of the web facing the needle board 22. The table 24 and the stripper 26 have orifices which are traversed by the needles 23 when they are in the maximum penetration position shown in FIG. 1 .

For the generation of the movement back and forth, the needling apparatus 2 comprises a connecting rod 27 whose head 28 is articulated to an eccentric pin 29 of an eccentric shaft 31, and whose foot 32 is hinged to the distal end of the sliding rod 17. The shaft 31, rotatably supported in a bearing 33 integral with the frame 19, is rotated by a motor speed adjustable not shown.

The pre-needling apparatus 3 comprises a moving assembly 36 (see FIG. 5) comprising in turn at least one rod 38, and in practice several rods 38 which are aligned in the direction of the width of the web, and of which by therefore only one is visible in Figure 5.

In the following, to simplify the description, it is generally considered that there is only one rod 38, and thus a single set of guiding and actuating means for this rod.

At its proximal end, the rod 38 is fixed rigidly to a support 44. A needle board 46 is attached interchangeably to the support 44, on the face of the support 44 opposite the rod 38. The board 46 carries the needles of pre needling 47 which extend towards the ply 41 parallel to the longitudinal axis 42 of the rod 38.

The sliding rod 38 is mounted to slide along its longitudinal axis 42 in a guide 39 itself pivotally supported in the frame 19 along an axis of oscillation 37 which is parallel to the width of the fiber web. The axis 37 intersects the longitudinal axis 42 of the sliding rod 38. The intersection of the axes 37 and 42 is in the middle of the axial length of the bore of the guide 39 in which the rod 38 slides. By means of actuation that will be described later, the longitudinal axis 42 oscillates around the axis of oscillation 37 on either side of a general axis 43 passing through the intersection of the axes 37 and 42, and perpendicular at the plane of the path 1, to give the moving element 36 both a back and forth movement in a direction of penetration transverse to the plane of the path 1 of the ply 41, and a movement oscillating about the axis oscillation 37 secured to the frame 19. The oscillation movement is intended to give the needles 47 a component of movement, called "advancement", essentially parallel to the direction 6 of advancement of the web. Thus, there is between the needles 47 and the frame 19 of the machine, a kinematic chain comprising a sliding which is mechanically in series with a hinge. In this example, starting with the needles 47, the sliding of the rod 38 in the guide 39 first, then the rotation of the guide 39 in the frame 19.

The kinematic chain in question means that there is between the needles and the frame of the machine a mechanical part, in this case the guide 39, which is guided in rotation with respect to one of the two elements, here the frame and guided in sliding relative to the other element, here the needles. Moreover, this kinematic chain has no actuation function.

In addition, in this embodiment, the guide sliding surface of the guide 39 is located inside its cylindrical surface 40 of articulation on the frame. Thus, the two guides are extremely close to each other, and the cumulative games are as small as possible, the guidance of the moving element 36 relative to the frame being almost as accurate and robust as a simple and unique articulation.

The pre-needling installation 3 further comprises an actuating mechanism comprising in turn two eccentric shafts 48a, 48b rotatably supported by the frame 19 about axes 49a, 49b parallel to the axis of oscillation 37 and located symmetrically on either side of the general axis 43. The actuating mechanism further comprises two connecting rods 51a, 51b whose head 52a, 52b is articulated to a respective eccentric journal 53a, 53b of the eccentric shafts 48a , 48b. The foot 54a, 54b of each connecting rod 51a, 51b is articulated to the tilt-and-slide rod 38 along a respective positioning axis 56a, 56b. The positioning axes 56a, 56b are adjacent to the distal end of the rod 38. Along the axis 42 and the rod 38, the guide 39 is located between the support 44 on the one hand and the positioning pins 56a, 56b on the other hand.

The arrangement is such that the two connecting rod legs 54a, 54b are directed obliquely towards each other away from the path 1 of the web. The two positioning axes 56a, 56b are arranged symmetrically with respect to the axis 42 of the tilt-and-slide rod 38. In addition, the positioning axes 56a and 56b are relatively very close to one another. This reduces the stresses on the rod 38, and thus allows to lighten it. The eccentric radii 61a, 61b of the big-end axles have the same length, and the length of the connecting rods 51a, 51b between the big-end axle and the connecting rod foot axis is the same.

The two eccentric shafts 48a, 48b are driven in opposite direction of rotation and at equal rotation speed, as indicated by arrows 57a, 57b, for example by means of mutually meshing gears 58a, 58b (FIG. 1), each rotating jointly with the respective one of the shafts 48a, 48b. In the example shown, the arrangement and the directions of rotation 57a, 57b are such that when the eccentric journals 53a, 53b perform the part of their stroke directed towards the plane of the path 1 of the web, the rods 51a, 51b work in traction and are substantially perpendicular to the plane of the web. They thus very effectively transmit their force for the penetration of the pre-needling needles 47 in the ply 41. During the ascent phase, illustrated in FIG. 5, the connecting rods 51a, 51b are much more oblique, they work in compression and in a less favorable orientation, but the effort to be provided is less. In total, the distribution of the forces on a cycle is optimized, which makes it possible to lighten the mechanism, therefore the forces of inertia and the vibrations, which further increases the possible lightening.

• un embrayage entre la roue dentée 58b et l'arbre à excentrique 48b ;
• un codeur angulaire sur l'arbre à excentrique 48a et aussi de préférence un autre codeur angulaire sur l'arbre 48b ; et
• un frein sur l'arbre à excentrique 48b.

The mechanism comprises means for phase shifting the shaft 48b with respect to the shaft 48a. These means are shown schematically in Figure 5 by an adjustment 59 of the angular position of the shaft 48b with respect to the gear 58b which drives it in rotation about its axis 49b. In practice, in a preferred embodiment, the setting 59 represented by

• a clutch between the gear 58b and the eccentric shaft 48b;
• an angular encoder on the eccentric shaft 48a and also preferably another angular encoder on the shaft 48b; and
• a brake on the eccentric shaft 48b.

During operation, the clutch is coupled and the brake is released.

To effect a phase shift adjustment, the brake is tightened, the clutch is uncoupled and the shaft 48a is rotated for example by means of the drive motor until the desired phase shift is obtained. controlled by means of the angular encoder (s). Then we re-couple the clutch and release the brake.

Preferably the clutch discs have on their contact face teeth which are mutually engaged when the clutch is in the coupled state. The angular pitch of these teeth is typically of the order of degree.

Adjusting the phase shift angle between the rays 61a and 61b makes it possible to adjust the length of the longitudinal component (parallel to the direction of travel of the ply 41) of the movement of the needles 47.

• grâce à l'inversion des bielles 51a, 51b, c'est-à-dire avec les pieds de bielle 56a, 56b en position distale, celui des deux points morts (point d'inversion du sens de mouvement de la tige 38) pour lequel la valeur absolue de l'accélération est la plus faible est celui correspondant à la position de pénétration maximale des aiguilles 47 dans la nappe 41, position représentée à la figure 4 ;
• grâce à l'utilisation de deux bielles et deux excentriques, cet effet de douceur du changement de sens au point de pénétration maximale est encore accru.

If the phase shift 59 is adjusted so that the two eccentric radii 61a, 61b are arranged symmetrically with respect to the general pre-needling axis 43, the pre-needling is carried out strictly along the axis 43, c that is, the axes 42 and 43 coincide for all the angular positions of the eccentric shafts 48a, 48b. Indeed, in any angular position of the shafts 48a and 48b, the polygon defined by the axes 37, 49a, 53a, 56a, 56b, 53b and 49b has a mirror symmetry with respect to the axis 43. The movement obtained for the needles 47 is a movement similar to that of a single rod and crank system such as that written for the consolidation apparatus 2, but with two exceptions:

• thanks to the inversion of the rods 51a, 51b, that is to say with the connecting rod legs 56a, 56b in the distal position, that of the two dead spots (point of reversal of the direction of movement of the rod 38) for which the absolute value of the acceleration is the lowest is that corresponding to the position of maximum penetration of the needles 47 in the ply 41, position shown in Figure 4;
• thanks to the use of two connecting rods and two eccentrics, this smooth effect of the change of direction at the point of maximum penetration is further increased.

In practice, as shown more precisely in FIG. 5, the adjustment device 59 is adjusted so that the eccentric shaft 48b located behind relative to the direction of advance 6 of the web is late compared to the tree 48a located in front.

• Lorsque la tige 38 s'éloigne de la nappe 41, la bielle 51a située en avant est en même temps plus distale que l'autre bielle 51b, ce qui positionne vers l'arrière l'extrémité distale de la tige 38 ; par conséquent l'extrémité proximale de la tige 38 est décalée vers l'avant, et l'ensemble d'aiguilles 47 est lui même décalé dans le sens 6 par rapport à l'axe 43, comme représenté à la figure 5 ;.
• Pendant la phase descendante, c'est l'inverse, la bielle 51a en avance sur l'autre est plus proximale et maintient l'extrémité proximale de la tige 38 en position basculée vers l'arrière;
• Une partie significative du mouvement des aiguilles 47 vers l'avant se produit au voisinage de la position de pénétration maximale dans la nappe, où l'inversion du sens de la composante verticale de mouvement se produit avec des accélérations encore réduites du fait de la non coïncidence des points morts des deux systèmes bielle manivelle, et une partie significative du basculement de l'avant vers l'arrière se produit au voisinage de la position de retrait maximal des aiguilles 47.

This has three consequences:

• When the rod 38 moves away from the ply 41, the rod 51a located forward is at the same time more distal than the other rod 51b, which positions the distal end of the stem 38 towards the rear; therefore the proximal end of the shaft 38 is shifted forward, and the needle assembly 47 is itself offset in the direction 6 relative to the axis 43, as shown in Figure 5;
• During the downward phase, it is the opposite, the rod 51a in advance of the other is more proximal and maintains the proximal end of the rod 38 in the tilted position rearward;
• A significant portion of the movement of the forward needles 47 occurs in the vicinity of the maximum penetration position in the web, where the reversal of the direction of the vertical component of motion occurs with further accelerations due to the lack of movement. coincidence of the dead points of the two crank connecting rod systems, and a significant part of the tilting from front to rear occurs in the vicinity of the maximum needle withdrawal position 47.

The guiding and actuating means described make it possible to give the needles 47 as an "elliptical" trajectory an ovoid trajectory tapered towards the sheet. In other words, the movement of the needles has an advancement component that accompanies the movement of advancement of the web on a proximal part of the penetration stroke which is greater than half of the total penetration stroke. This fraction of the penetration stroke constitutes the useful stroke along which the needles can be engaged in the web while accompanying its movement of advancement.

The pre-needling apparatus 3 further comprises a support means 62 for the ply 41 on the side opposite the needles 47, and a stripper 63 which defines the path of the ply 41 on the needle side 47.

The stripper 63 (see also FIG. 2) comprises a core 64 of generally flat shape and parallel to the plane of the path 1 (plane of the ply 41), and longitudinal lamellae 66 extending from the core 64 towards the path 1 of so that the free longitudinal edges of the slats 66 define the position of the face of the ply 41 facing the needles 47. The core 64 has between the slats 66 longitudinal slots 67 through which the needles 47 to perforate the ply 41 In the example shown in FIG. 2, there are three slots 67 between two lamellae 66 neighbors. The needles 47 are in the example shown arranged in rows parallel to the longitudinal direction of the web (Figure 5). Each row occupies a slot 67. The length of each slot 67 is sufficient for the needles 47 to perform the longitudinal component (parallel to the direction of advance 6 of the web 1) of their movement.

The support means 62 comprises a rotary cylinder 68 having an axis 69 parallel to the width of the ply 41. The cylinder 69 comprises a core 71 and annular lamellae 72 which protrude outwardly from the core 71. Annular lamellae 72 extend in planes parallel to the direction of advancement of the ply 41 and support the ply 41 facing the needles 47 and the side of the ply 41 opposite the needles 47. Preferably, as shown in FIG. 2, the slats 72 are facing slats 66 of the stripper 63. The cylinder 68 is rotated in a manner to be specified later so that the free peripheral edges of the slats 72 contribute to the driving of the sheet 41 by frictional contact with the latter.

The slats 72 form between them recesses 73 (FIG. 2) which receive the tips of the needles 47 when they are in the position of maximum penetration through the ply 41. The bottoms of the recesses 73 are formed by fingers 74 which, like the FIGS. 1, 4 and 5 extend beyond the lamellae 72 in the direction of the consolidation apparatus, until quasi-contact with the needling table 24, to define the corresponding side of the path of the sheet. between the zone of action of the needling needles 47 and the consolidation device by needling 2. The core 71 of the cylinder 68 rotates inside a circular lumen 76 of each of the fingers 74. Upstream of the zone of action of the pre-needling needles 47 (FIG. 5), each finger 74 forms a boss 77 supporting the ply 41 substantially in the same plane as the most proximal point of the lamellae 72. Downstream of this boss 77, the fingers 74 are dug in 78 for m encircle the recesses 73 (FIG. 2) allowing the needles 47 to be deflected.

On the side of the ply 41 facing the needles 47, the stripper 63 is extended on the one hand downstream to the stripper 26 of the needling apparatus 2, and on the other hand upstream by a part of engagement guide 79 (FIG. 5) profiled in the form of an engagement ramp.

An arrow 80 symbolizes that the stripper 63 is adjustable in height relative to the frame 19. Similarly, the arrows 81 symbolize a possibility of height adjustment of the support means comprising the cylinder 68 and the fingers 74. It can thus be adjusted firstly the distance between the stripper 63 and the support means 62, and secondly the depth of penetration of the needles 47 through the ply 41.

The introducer apparatus 4 comprises, just upstream of the pre-needling apparatus 3, two cylinders 82 situated on either side of the plane of the path 1, defining between them a niping slot for the ply 41 and controlled to turn into position. opposite direction of one another so as to cause the web in the direction of advance 6, by motor means not shown in Figure 1. As shown in Figure 3, each cylinder 82 comprises a core 83 and a peripheral coating 84, for example rubber, which defines peripheral grooves 86 in which are housed non-rotating fingers 87 which extend towards the support means 62 and respectively the stripper 63. The two sets of fingers 87 delimit between them the the path of the web between the rolls 82 and the pre-needling apparatus 3. The pinch line formed between the rolls 82 receives the web from a converging belt conveyor system 88 upstream, sometimes called "booster compressor".

In the example shown in FIGS. 1 and 5, the consolidation apparatus 2 and the pre-needling apparatus 3 have the same punch rate. This cadence identity is imposed by a toothed belt or chain 89 connecting the eccentric shaft 31 of the consolidation apparatus 2 with one of the eccentric shafts 48a of the pre-needling apparatus 3. In FIG. 4, two solutions are presented for the belt, among which the lower half-view of the belt, designated 89, corresponds to the solution of Figure 1, that is to say, rate identity. In addition, the angular setting of the eccentric shaft 31 of the consolidation apparatus 2 relative to that of the eccentric shafts 48a and 48b is such that when the needles 23 of the consolidation apparatus 2 are in the penetrating position maximum (FIG. 1), needles 47 for pre-needling are in the maximum retracted position, and conversely, as shown in Figure 4, when the needles 23 of the consolidation apparatus 2 are in the maximum withdrawal phase, the needles 47 of pre-needling are in the maximum penetration position. In this position, as we have seen, and as indicated by an arrow 91a in FIG. 4, the needles 47 also have a component of movement in the direction of advance of the ply and the withdrawal of the needles from consolidation 23 allows the sheet 41 to follow this movement. At the same time, the cylinders 8 of the extractor apparatus 7 and the cylinders 82 of the introducer apparatus 4 are controlled to rotate in the direction in which they convey the web in the advancing direction 6. On the contrary, in the situation shown in Figure 1, the penetration of the needles 23 tends to block the advancement movement of the web. To avoid unnecessarily soliciting the web, the cylinders 8 and 82 can be stopped or slowed down. At the same time, the pre-needling needles 47 in the retracted position perform their movement component towards the rear of the web as indicated by the arrow 91b.

It can be ensured that the displacement measured at the periphery of the rolls 82 and 8 at each pre-needling cycle is equal to the amplitude of the movement component of the pre-needling needles 47 parallel to the path 1 of the ply. But different settings are also possible, depending on preliminary tests for each particular manufacturing mission.

Therefore, in the situation shown in FIG. 4, the pre-needling needles 47 in the maximum penetration phase engage with the core of the fiber sheet and effectively propel the sheet directly into the consolidation apparatus 2 all by giving the web a start of cohesion which has the effect that the traction exerted by the extractor cylinders 8 is effectively transmitted to the entire part of the web situated between the pre-needling needles 47 and said cylinders 8.

In the situation shown in FIG. 5, the crew 36 performs its withdrawal movement, the axis 42 is inclined around the oscillation axis 37, relative to the general axis 43, so that the needles 47 are deported downstream.

In the variant illustrated by the belt 89a in FIG. 4, the striking rate of the pre-needling apparatus 3 is equal to half that of the needling apparatus 2.

In this case, it is no longer possible to carry out strictly the condition according to which the needles 23 and 47 are engaged in turn in the sheet 41. However, it is nevertheless possible to search for a particular cycle timing of the two movements, one for each report to the other. For example, it is arranged that there is a forward movement 91a of the pre-needling needles 47 engaged in the web when the consolidation needles 23 are in the maximum withdrawal phase. The extractor rollers 7 can also be controlled to drive the consolidated web when the consolidation needles 23 are removed from the web, and to command the insertion rolls 82 to rotate when the pre-needling needles 47 are engaged in the tablecloth.

The example of Figure 6 will be described only for its differences from that of Figures 1 to 5.

In the mobile assembly 136 of the pre-needling mechanism, the tilt-and-slide rod 38 of FIG. 5 is replaced by a bent lever 138, a proximal end of which is fixed to the support 44, and whose bent part is articulated in a d-axis. oscillation 137 to an intermediate piece 92 secured to the sliding rod 17 of the consolidation apparatus 2.

Thus in this example, starting from the needles 47, there is a kinematic chain comprising firstly a rotation about the axis of oscillation 137, followed by a sliding movement, namely the sliding of the rod 17 in a solidarity guide. of the frame. In other words, there is between the needles 47 and the frame a piece, the rod 17, which is connected to the needles 47 by means of rotation and which is connected to the frame by a sliding means.

The distal end of the lever 138 is articulated to a positioning pin 156 at the foot 93 of a connecting rod 94 whose head 96 is articulated to the eccentric trunnion 97 of an eccentric shaft 98 mounted in rotation relative to the frame 19 and driven to the same speed of rotation as the eccentric shaft 31 of the apparatus 2. The eccentric radius 161b of the eccentric shaft 98 is delayed with respect to the eccentric radius 161a of the eccentric shaft 31, which actuates the axis of oscillation 137 via the connecting rod 127 and the rod 17. Thus, when the needles of 23 are in the maximum penetration position, the eccentric shaft 98 will execute a portion of its stroke in which it will push down the small end 93 and thus rotate the elbow lever 138 in the anti-direction 6. This results in the movement component according to the arrow 91a when the pre-needling needles 47 are in substantially maximum penetration position.

This solution reduces the distance between the pre-needling needles 47 and the entrance of the sheet between the table 24 and the stripper 26 of the needling apparatus 2. On the other hand, it does not make it possible to alternate the penetration phases. needles 23 with those of pre-needling needles 47, nor to give pre-needling needles 47 a striking rate different from that of consolidation needles 23.

The example of Figure 7 will be described only for its differences from that of Figures 1 to 5.

In the example of Figures 1 to 5, the pre-needling apparatus 3 and the consolidation apparatus 2 are located on the same side of the path 1 of the web. In the example of Figure 7, the needling apparatus 2 is located on one side of the path 1, in the example the upper side, and the pre-needling apparatus 3 is located on the other side of the path 1, in the example the lower side. In a manner that is not shown, this makes it possible, as in the example of FIG. 6, to bring the pre-needling needles 47 closer to the entry into the consolidation apparatus 2. With the solution of FIG. this advantage while being able to choose the solution in which the penetration phases of the consolidation needles 23 alternate with those of the pre-needling needles 47 with an identical typing rate, or else the solution of different strike rates.

In the more particular example of FIG. 7, a programmable control 201 and bidirectional links 202, 203, 204 and 207 are schematised between this control 201 on the one hand, and a servomotor (not represented the eccentric shaft 31 of the needling apparatus 2, a servomotor (not shown) for driving one of the eccentric shafts 48a of the pre-needling apparatus 3, a servomotor (not shown) driving the cylinders 82 of the introducer apparatus 4, and a servomotor (not shown) for driving the cylinders 8 of the extractor apparatus 7. The cylinder 68 can be driven by a servomotor connected by another bidirectional line to the programmable control 201, or be actuated via a transmission device from the servomotor actuating the cylinders 82 of the introducer apparatus 4. From In a manner known per se, such a structure is capable of managing at any moment the angular position of all the motor shafts which it thus controls as well as their respective speeds during each incremental period. See about it US-A-5,636,420 in the name of the plaintiff.

The control can be programmed by the user to define, before each particular production, the striking rates of the two apparatuses 2, 3, their mutual registration if the ratio of the rates is a rational number (resulting from the division of two whole numbers one by the other), the speed law of the introducer apparatus and that of the extractor apparatus.

The control 201 can also be programmed and then operate to perform other functions such as the settings 79 and 81 of Figure 5, using respective servomotors. Finally, the command 201 can be part of a control unit managing other elements of the production line, or even the entire line, from the card at the beginning of the line until the winding at the end of the line.

The example of FIG. 8 will only be described for its differences with respect to that of FIG. 7. The table 124 and the stripper 126 of the needling apparatus 2 are extended upstream to constitute the stripper and the pre-needling table of the pre-needling apparatus 3. The stripper 63 and the support means 62 of the pre-needling apparatus 3 of the preceding figures are deleted. The introducer apparatus 4 opens directly between the two plates 123 and 126 which have, for the pre-needling needles 47, slits 167, 173 elongated parallel to the direction of advance 6 of the ply (not shown), to enable the needles 47 to execute the component of their movement which is parallel to the direction of advancement of the web.

In this solution, the working zone of the pre-needling needles is brought closer to the maximum extent of the consolidation zone. In addition, the means which guide the web between the pre-needling apparatus 3 and the consolidation apparatus 2 are perfectly continuous. The drive of the pre-needling mechanism 3 can be connected by a mechanical transmission to the eccentric shaft 31 of the consolidation apparatus 2, so that the striking rates are in a given ratio; alternatively the two devices can be controlled by servomotors and a programmable control unit as described with reference to Figure 7.

In yet another variant, not shown, the pre-needling mechanism of FIG. 8 could be replaced by a structure similar to that of FIG. 6. From the needling apparatus 2 and in particular from the rod 17, the intermediate piece 92 would be extended on either side of the webs to contribute to driving the positioning axis such as 156a (Figure 6), this time located on the other side of the tablecloth. An advantage over the embodiment of FIG. 6 would then be that the penetration phases of the pre-needling needles 47 correspond to the withdrawal phases of the needling needles 23, and vice versa.

Of course, the invention is not limited to the examples described and shown. For example, the solution of the programmable control 201 (FIG. 7) can be used in an architecture such as that of FIGS. 1 to 5 in which the belt 89 would then be suppressed or maintained.

The needling apparatus may comprise several modules, in particular at least one module on each side of the sheet, to needle the sheet from each of its two faces.

The support means for the ply on the opposite side to the pre-needling needles could be fixed instead of accompanying the advance movement of the ply. It could in particular comprise longitudinal strips that are fixed instead of rotating.

The invention is applicable when the consolidation is of a different type of mechanical needling. It may be, for example, needling with water jet, sewing, impregnation, heat or chemical treatment, etc.

In the pre-needling mechanism of FIG. 5, the two positioning axes 56a and 56b could be merged.

Claims (44)

Process for forming a web in a pre-needling apparatus (3) and then in a consolidation apparatus (2), in which pre-needling needles (47) are subjected to a combined movement comprising a va-and -vient transverse to the plane (1) of the ply (41) and a forward movement in the direction (6) of the advance of the ply (41) when the needles (47) are in the penetration phase in the ply (41), characterized in that the advancing movement of the pre-needling needles (47) is used to impart to the web (41) a movement promoting the introduction into the consolidation apparatus (2). Process according to Claim 1, characterized in that the web (41) of the pre-needling apparatus (3) is passed directly to the consolidation apparatus (2). Process according to Claim 1 or 2, characterized in that pre-needling and consolidation are carried out in the same machine. Method according to one of claims 1 to 3, characterized in that during said combined movement, the reciprocating movement of penetration in the vicinity of a position of maximum penetration of the pre-needling needles is slowed down ( 47) and during this deceleration a substantial part of the advancement movement in the direction (6) of the advancement of the ply (41) is executed. Process according to one of Claims 1 to 4, characterized in that the consolidation is carried out in the form of needling by giving to needling needles (23) a substantially linear reciprocating movement. Process according to Claim 5, characterized in that pre-needling is practiced only from a first face of the ply (41), and needling is practiced starting with needles (23) penetrating into the ply (41) by its opposite side to the first face. Method according to one of Claims 1 to 6, characterized in that the amplitude of the forward movement of the pre-needling needles (47) is set. Method according to claim 7, characterized in that the amplitude of the forward motion is adjusted so that needles (47) during the penetration phase corresponds substantially to the advancement of the web (41) during said phase. Process according to one of Claims 5 to 8, characterized in that between the pre-needling cycle and the needling cycle a cycle setting is defined such that needling needles (23) are in the penetration phase. when the pre-needling needles (47) are in the withdrawal phase, and the needling needles (23) are in the withdrawal phase when the pre-needling needles (47) are in the penetration phase. Process according to one of Claims 5 to 8, characterized in that pre-needling is carried out at a slower punch rate than that of needling. Method according to one of Claims 5 to 10, characterized in that the web (41) is driven with a speed which is smaller when the pre-needling needles (47) are in the withdrawal phase and which is larger. when the pre-needling needles (47) are in the penetration phase. An apparatus for forming a fiber web for carrying out a process according to claim 1 comprising along a path (1) for the fiber web (41) a pre-needling apparatus (3) followed a consolidation apparatus (2), the pre-needling apparatus (3) comprising means for imparting to a pre-needling needle (47) a combined movement comprising a reciprocating transverse to the plane of the path (1) of the web, and a reciprocating movement substantially parallel to the direction (6) of the advancing movement of the web (41), characterized in that the output of the pre-needling equipment ( 3) and the entry of the consolidation apparatus (2) are in relation of conservation of the advancing movement of the ply (41). Installation according to claim 12, characterized in that the output of the pre-needling equipment (3) and the input of the consolidation equipment (2) are directly connected. Installation according to Claim 12 or 13, characterized in that the pre-needling apparatus (3) is installed between an upstream-mounted introducer (4), propelling the ply (41) by friction, and the consolidation apparatus (2). Installation according to one of claims 12 to 14, characterized in that the pre-needling apparatus (3) and the consolidation apparatus (2) are installed in the same machine. Installation according to one of claims 12 to 15, characterized in that the consolidation apparatus (2) comprises actuating means for giving to the consolidation needles (23) a substantially linear back and forth motion and transverse to the plane of the path (1) of the ply (41). Plant according to Claim 16, characterized in that it comprises common drive means for the pre-needling needles (47) and the consolidation needles (23). Installation according to claim 16, characterized in that it comprises means (89; 92) for giving the pre-needling needles (47) and the consolidation needles (23) the same striking rate. Installation according to one of claims 16 to 18, characterized in that it comprises means for defining a cycle setting between the movement of the pre-needling needles (47) and the movement of the consolidation needles (23). Installation according to claim 19, characterized in that the means for defining a cycle setting are adjustable. Plant according to Claim 19 or 20, characterized in that the cycle setting is such that the pre-needling needles (47) are in a withdrawal phase when the consolidation needles (23) are in a penetration phase, and the pre-needling needles (47) are in a penetration phase when the consolidation needles (23) are in a withdrawal phase. Installation according to claim 16, characterized in that it comprises means (89a; 201) for giving to the pre-needling needles (47) a striking rate different from that of the consolidation needles (23). Installation according to claim 16, characterized in that it comprises means (201) for adjusting the striking rate of the pre-needling needles (47) relative to that of the consolidation needles (23). Installation according to one of claims 12 to 23, characterized in that it comprises means of propulsion (4, 7) of the ply (41) by friction which are actuated at a higher speed when the needling needles (47) are in the penetration phase only when the pre-needling needles (47) are in the withdrawal phase. Installation according to one of claims 12 to 24, characterized in that the pre-needling apparatus (3) comprises, between the path (1) of the ply (41) and a support (44) for the needles, a stripper (63; 126) having orifices (67; 167) traversed by the needles (47), these orifices having, parallel to the direction of advance of the ply (41), a dimension sufficient to allow the movement component of the movement needles (47). Installation according to claim 25, characterized in that the stripper is extended in one piece by a needling table (124) of the consolidation apparatus (2). Installation according to one of claims 12 to 25, characterized in that the pre-needling apparatus (3) comprises a support means (68) movable with the sheet, which delimits the path (1) of the sheet ( 41) on the opposite side to the needles (47) of pre-needling. Installation according to claim 27, characterized in that the support means is a rotary cylinder (68) having recesses (73) for the needle tips (47). Installation according to claim 28, characterized in that the recesses (73) are gaps between annular lamellae (72). Installation according to one of claims 12 to 25, characterized in that the pre-needling apparatus (3) comprises for delimiting the path (1) of the ply (41) on the opposite side to the needles (47) for pre-needling. needling: - support slats (72) in planes parallel to the direction of advance of the web (41); and - Between the slats (72), recesses (73) for receiving the needle tips (47). Plant according to claim 29 or 30, characterized in that the bottoms of the recesses (72) are formed by fingers (74) which extend beyond the slats (72) towards the consolidation apparatus (2). Installation according to one of Claims 12 to 31, characterized in that the pre-needling apparatus (3) is mounted so that the pre-needling needles (47) penetrate the ply through a first face of the ply (41). ) and the consolidation apparatus (2) comprises consolidation needles (23) which penetrate through a second face opposite to the first face of the ply (41) as pre-needling. Installation according to one of claims 12 to 32, characterized in that the pre-needling apparatus comprises a movable element (36, 136) for carrying needles (47), and an actuating mechanism for imparting to the needles (47) an elliptical-like motion having a penetration component and an advancement component, and in that one of the components, preferably the advancement component, is at least largely generated by angular oscillation of the mobile equipment. Installation according to claim 33, characterized in that the moving element (36, 136) is guided relative to a frame of the machine by a functional chain comprising sliding in series with a hinge about an axis of oscillation ( 37, 137) parallel to the width of the fiber web. Installation according to claim 34, characterized in that the sliding and the articulation are carried out by means located one inside the other. Installation according to claim 34 or 35, characterized in that the movable element (36) is slidably guided in a guide (39) oscillating in said articulation. Installation according to one of claims 34 to 36, characterized in that the actuating mechanism comprises two crank-crank systems, each system comprising a connecting rod (51a, 51b) of which one foot (54a, 54b) is articulated to said moving element (36) in a so-called positioning axis (56a, 56b) parallel to said oscillation axis (37). Installation according to claim 37, characterized in that the two crank-crank systems are similar and capable of phase shift, one being located in front and the other behind the positioning axis (56a, 56b) relative to the direction (6) of advance of the web. Installation according to claim 37 or 38, characterized in that there is a respective positioning axis (56a 56b) for each of the two crank-crank systems. Installation according to claim 39, characterized in that the two positioning axes (56a, 56b) are very close together. Installation according to one of claims 37 to 40, characterized in that the two connecting rods (51a, 51b) are oriented with their small end (54a, 54b) pointing in a direction generally opposite to the plane (1) of the ply (41a, 51b). ). Installation according to one of claims 37 to 40, characterized in that the axis of oscillation (37) is placed substantially between two eccentric means (48a, 48b) rotating in opposite directions and belonging to each other. each to a respective one of the two crank-crank systems. Installation according to claim 34, characterized in that the movable element (136) is articulated by said articulation to a slide (17) actuated by a first reciprocating motion generator, in particular a crank-rod system (31, 127) generating one of the components, preferably the penetration component, and the moving element (136) is further articulated about a positioning axis (156) to a second crank-rod system (94, 98) generating said oscillation angular of the moving element (136) around said articulation of the slide (17). Installation according to one of claims 12 to 43, characterized in that it comprises: means (79) for adjusting the penetration depth of the pre-needling needles in the path of the web (41); means (57) for adjusting the amplitude of the advancement component of the movement of the pre-needling needles (47); means (201) for setting a step in advance of the sheet for each operating cycle of the pre-needling points.

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