EP1036227B1 - Method and devices for producing a textile lap - Google Patents

Abstract

A carding machine or other web production device [(1)] supplies a crosslapper [(2)] with two elementary webs [(15a, 15b)] constituting a lappable web [(16)] which is deposited in a reciprocating manner on a transverse output belt [(26)].In the device [(1) means of] adjustment of the speed of rotation of doffers [(13a, 13b)], of condensers [(17, 18)], of detachers [(19a, 19b)], of the drum [(4)] and/or of the feeder [(7)], and/or [means of] adjustment of the drum-doffer spacing affect the weight per unit area of the elementary web produced taking account of the weight per unit area desired at each point in the width of the fleece [(67)] to be formed on the output belt [(26)]. There is determined the delay length exhibited by each elementary web cross-section undergoing the adjustment of weight with respect to the section of lappable web in the process of being deposited. From this there is derived the position at which each web cross-section will be deposited when it is undergoing the adjustment of thickness and consequently the weight adjustment to be applied to it.[Utilization] The present invention is useful for producing fleeces of highly varied profiles with great industrial flexibility.

Description

The present invention relates to a method for producing a textile tablecloth by means of a spreader-lapper.

The present invention also relates to various devices allowing the implementation of this process.

It is known to produce a covering veil in a card or in another device such as for example a pneumatic lapper. The covering veil thus obtained feeds a spreader-lapper in which the veil is folded alternately in one direction and in the other on a carpet of exit. The tablecloth is thus composed of veil segments, tilted alternately in one direction and in the other, which is overlap. The folds between successive segments are aligned along the side edges of the produced web.

The sheet of fibers obtained is generally intended for a further consolidation processing for example by needling, coating, and / or etc ...

FR-A-2 234 395 teaches speed relationships that must be respected in the spreader-lapper to control the thickness of the sheet at all points of its width.

According to EP-A-0 315 930, the sheet may have, in section transverse, a non-uniform thickness profile. For it, we vary the speed of the lapper carriage which deposits the covering veil at a variable point the width of the carpet output, in relation to the speed of the belts which feed the sail on the exit mat through this carriage. If in one given position of the width of the tablecloth, the carriage moves at a speed higher than that at which it unwinds the veil, the veil is stretched and this reduces the thickness of the tablecloth at this location. If on the contrary the speed of carriage is lower than the feed speed, the web is deposited in a compressed form which increases the thickness of the tablecloth at this location.

This mode of profiling the tablecloth presents certain limitations. With certain types of fibers or certain types veils, particularly those in which the fibers are strictly longitudinal, the tensile or compression imposed on the veil tend to be absorbed by elasticity after deposition of the covering veil on the mat exit, and / or to be transmitted to the neighboring regions of the veil. In addition, the traction or compression imposed on the veil does not may not safely exceed certain limits, which vary depending on the nature of the veil and the fibers.

EP-B-0 371 948 describes a process intended for pre-compensate for faults occurring during consolidation subsequent, including needling, by varying locally the thickness of the covering veil introduced into the web-laying machine. This is achieved by adjusting so automatic speed of a card doffer relative at the speed of the card drum. The more the painter turns faster compared to the drum and more the veil formed by the painter has a reduced surface weight.

• inerties mises en jeu pour faire varier le poids surfacique du voile entrant dans l'étaleur;
• précision dans la détermination de la section d'un voile élémentaire où un poids surfacique déterminé doit être réalisé pour que cette section prenne une position déterminée dans la largeur de la nappe produite par l'étaleur;
• compatibilité entre les vitesses variables du peigneur et les vitesses, également variables, du chariot-nappeur de l'étaleur-nappeur;
• extension des applications possibles du procédé;
• définition de nouvelles structures pour le voile de nappage.

The aim of the present invention is to improve this known process with regard to at least one of the following aspects:

• inertias used to vary the surface weight of the web entering the spreader;
• precision in determining the section of an elementary web where a specific surface weight must be achieved so that this section takes a determined position in the width of the web produced by the spreader;
• compatibility between the variable speeds of the doffer and the speeds, also variable, of the carriage-lapper of the spreader-lapper;
• extension of possible applications of the process;
• definition of new structures for the covering veil.

According to the first aspect of the invention, the method to produce a textile tablecloth in which we produce at minus an elementary veil, then by means of a spreader-lapper folding a covering veil incorporating said veil elementary, alternately in one direction and in the other on a transverse exit conveyor of the spreader-lapper, is characterized in that by modifying appreciably according to a law periodic at least one adjustment upstream of the spreader-lapper we give the covering veil introduced in the spreader-lapper a surface weight which varies according to the direction longitudinal of the covering veil so that the covering obtained at the outlet of the spreader-lapper present on its width a distribution of surface weight substantially predetermined.

It may be advantageous if the setting that is changed to upstream of the spreader-lapper includes an adjustment affecting the card in an area downstream of a card drum, relative to the direction of transit of the fibers in the card, and regardless of the speed of rotation of a doffer taking fibers from the carding drum for constitute the elementary veil.

The rotational movement of the painter brings into play strong inertias, which limits the speed of reaction during changes to the speed setting.

By adjusting otherwise than by varying the speed of rotation of the comber, we can perform faster variations therefore better localized. He is in particular possible to vary the spacing between the periphery of the drum and the periphery of the painter. More this spacing is large the more the layer of fibers taken by the comb on the drum is thin. We also have the advantage that this setting mode does not change the speed of production of the veil and therefore poses no problem particular when entering the spreader-lapper.

It is also envisaged, according to the invention, to make Vary the speed of organs placed upstream of the comber. We can for example vary the speed of the organs called card "food" supplies, at least indirectly, the card drum with fibers in upstream of said drum. You can also vary the speed of the card drum relative to the doffer. All these solutions also have the advantage of not affecting the speed of production of the veil which can therefore remain at all moment equal to a constant speed of entry into the spreader-lapper. To reduce the inertia of the drum, it can be made of carbon.

When the painter is followed by at least one roller condenser, we can vary the speed by at least one condenser roller with respect to the comber so as to more or less condense the elementary veil taken from the drum by the painter.

The last element at the exit of the card is in general constituted by an organ called detacher which detaches the veil of the last condenser roll, or of the painter in the absence of a condenser roller. It is also proposed according to the invention to adjust the surface weight of the veil in varying the action of the detacher. In particular, when this detacher is a rotary roller fitted with a seal device, we can vary the rotation speed of the detacher with respect to the rotary member, for example comb or condenser, located immediately upstream.

According to an important aspect of the invention, when the adjustment made has the effect of varying the speed which the veil produced is supplied to the spreader, which is particularly the case when operating by variation of the speed of a comber, a condenser roller or a detacher, the input speed is fluctuated in the spreader-lapper so that it corresponds substantially, at all times, at the speed at which the veil reaches the spreader-lapper, and the length is adjusted at all times of a web accumulation path in the spreader-lapper to compensate for differences between instantaneous speed of entry into the spreader-lapper and the instantaneous speed at which the spreader-lapper unwinds the covering veil on the exit mat.

Known spreaders define a path accumulation of haze. FR-A-2 234 395 teaches to do vary the length of this path so that the speed at which the lapper carriage unwinds the veil on the carpet exit varies and in particular is canceled when the the speed of the lapper carriage is itself zero at its points reverse motion. According to this aspect of the invention, the length of the sail is also varied accumulated in the spreader-lapper, but to compensate for fluctuations in the speed at which the topping veil enters the spreader-lapper due to the weight setting surface operated upstream. It also falls within the framework of this aspect of the invention to vary the length of veil accumulated in the spreader to account for both variations in the speed of entry of the web into the spreader and variations in the speed at which the lapper carriage unwinds the veil on the exit mat.

For example, you can directly control the speed of an incoming section of a conveyor belt of the spreader-lapper to make this speed consistent with that at which the carding or other production device provides the sail. We then control the speed of an accumulator cart the spreader-lapper on which this conveyor belt passes, so that this same carpet takes in the lapping carriage, on which it also passes, and taking into account the speed of movement of the lapping carriage, a speed of unwinding of the sail corresponding to the desired speed.

Conversely, it is also possible to order directly the speed of a section of the conveyor belt adjacent to the lapper carriage so that the wire feed speed of the lapper carriage corresponds to the desired speed. We then controls the speed of the accumulator carriage so the incoming section of the conveyor belt has a speed consistent with that at which the card produces the veil.

We will call a "sail section" a section transverse of the veil at a determined point the length of the sail.

We will call "length of delay" the length of sail, between on the one hand a first sail section, in being deposited on the tablecloth being formed in the spreader-lapper, and on the other hand a second section of veil located at the point of the path of the fibers where said adjustment influences the surface weight of the elementary veil upstream of the spreader-lapper.

According to another important aspect of the invention, it is determines the delay length, and based on this determines the point of the width of the tablecloth where will be deposited the second section. We then adjust the surface weight of the second section according to the surface weight programmed for said point of the width of the sheet. If the spreader-lapper, by construction or by programming, unwinds the veil of topping on the exit conveyor at a speed which is always equal to the speed of movement of the lapper carriage, and if there is no stretching of the web upstream of the lapping carriage, the topping veil to be produced is the same as that would obtain by unfolding the tablecloth obtained to re-obtain the sail.

If a stretch with a constant factor greater than 1 (true stretching) or less than 1 (compression) occurs in the course of the veil between the two sections, it is a corrected delay length that must be taken into account for the part located upstream of the area where the the draw. If for example a stretch factor equal to 1.1 occurs at a point in the path, the part of the length of delay upstream of this point must be multiplied by 1.1 (increased by 10%) to find out the delay length corrected to take into account. The veil to be produced is then different from what you would get by unfolding the tablecloth obtained.

There may also be a variable stretch in the path of the veil until it is deposited on the exit mat, and especially between the topping carriage and the mat exit. In known manner, this typically results from a variable difference between the speed of movement of the topping carriage and the speed at which the carriage topping unwinds the covering veil on the exit belt. We can then provide in the central processing software integral calculation to obtain the delay length corrected by summing the elementary displacements of the carriage lapper necessary to deposit the elementary lengths the actual delay length on the output belt, in as a function of the stretch value provided at each point in the back and forth stroke of the lapper carriage. We can still do this calculation outside the machine and enter a machine memory a table of delay lengths corrected for each position of the lapper carriage. In operating a central unit of the production system can then very quickly, for each position of the carriage lapper, referring to the table, know the position that will take in the width of the tablecloth the section of veil which is currently undergoing weight adjustment surface. We can also foresee that after a step of programming before the start of the water table production, the central unit calculates the above table, and puts it into memory so you can then, during production, refer to each position of the lapper carriage. One more another method will be explained in the body of the description.

The method according to the invention can be implemented at by means of a programmable control allowing the user to enter the weight distribution in a memory area desired for the covering veil arriving in a spreader-lapper carriage at each point of a lapper carriage stroke. Programming can relate to a single run consisting of a return trip between the two race reversal points, or on a outward and back to allow the user to adjust differently the surface weight of the veil on the outward and return journey lapper carriage at at least one determined point of the width of the tablecloth. In a simple version where we do not adjust the weight surface only for a single race and where one does not plan no stretching at the exit of the lapper carriage (therefore no difference between the speed of movement of the lapper carriage and the speed at which the lapper carriage unwinds the web it is equivalent to programming the desired surface weight for the web at each point of the simple stroke of the lapper carriage and program the weight area desired for the tablecloth at each point of its width.

In more sophisticated versions, however, combine, as mentioned above, a variation of the areal weight of the web arriving in the lapping carriage and a variation in the stretch produced by difference between the speed of movement of the lapper carriage and speed of unwinding of the web through the lapping carriage. In this case, it is advantageous that the two parameters can be programmed separately for each point of the race (simple or back and forth) of the lapper carriage. The data of this program will be used by the programmable controller to determine, as said above, the point of the width of the tablecloth where a section will be deposited undergo the area weight adjustment, and therefore the areal weight to be obtained at this instant by means of said setting.

In some simple build spreaders, the variable draws at the exit of the lapper carriage are a inevitable disadvantage consisting of compressions to ends of the lapping carriage stroke. The setting of areal weight of the covering veil according to the invention allows to compensate for this defect. For this, the sail sections covering intended to form the edges of the covering have a reduced surface weight.

It is possible to produce the covering veil in superimposing at least two elementary sails. Many cards have at least two combers producing each an elementary veil, so as to increase the production possible from a single card drum. he is then possible to structure the covering veil in giving the two elementary sails contextures different. For example, one of the food sails can be condensed to give the fibers a curvy orientation on either side of the longitudinal direction, the other being less condensed or not condensed at all so that a certain dose of longitudinal fibers gives the veil of topping dimensional stability in the direction of length, particularly with regard to tensile forces.

We may then have an interest in reinforcing the effect of structuring by adjusting the weights differently respective surface areas of the two elementary sails for lead to the desired covering veil.

On the one hand, the delay lengths can be different for the two elementary sails. So we have to provide a corresponding phase difference between the two settings performed at all times.

On the other hand, we may wish that the sections of overlapping elementary veils have weights areas similarly affected by the setting, or otherwise differently affected. We can for example plan that only one of the two elementary veils undergoes a variation in basis weight.

If the area weight variations are obtained in a way inducing a variation in the speed of production of the veil, it is preferable that the lengths of delays are about the same for all sails elementary and that the speed variations undergone by the elementary sails are essentially the same, so that the elementary sails have substantially the same gears at the stacking station for elementary sails. Depending on the geometry of the card, we can in some cases even the delay lengths using different adjustment means, for example by adjusting the areal weight of an elementary veil by means of the comber and the surface weight of the other elementary sail using of the condenser.

One can foresee that one of the elementary veils undergoes relatively slow basis weight variations, operated by varying the speed of rotation of the drum with respect to the speed of rotation of the doffer, and that the other elementary veil undergoes the variations more abrupt, intended for example to produce a change thickness between two zones of the final consolidated product, by example by means of a variation of the spacing between the draftsman and card drum.

It should however be noted that such treatment differentiated from slow and abrupt variations surface weight is also possible on one and same elementary veil, in particular but not limited to when the covering veil is obtained from a veil unique elementary. We can then, for example, operate the slow variations by variation of the speed of the painter or of the drum and abrupt variations by another means, by example by varying the speed of rotation by one or several condensing rollers in relation to the comber or still of a detaching roller with respect to the rotary member, comb or condenser, located immediately upstream.

It still falls within the scope of the invention, to make a covering veil using two sails elementary, each of which has its adjusted surface weight only by varying the speed of rotation of the doffer relative to the drum, or only one of the sails elementary sees its surface weight adjusted by variation the speed of rotation of the comber relative to the drum.

The fact that the speed of rotation of the comber is used as the variable for adjusting the basis weight of the associated elementary veil does not mean that the others rotational speeds remain constant along the path of this elementary veil: when you change the speed of an organ rotating downstream of the drum to vary the weight surface area of the veil produced, the drive speeds of all drive elements located even further downstream should be changed substantially in proportion if one wants to transmit the longitudinal profile without modifications area weights generated by the setting. When we settle the speed of fiber transfer from an organ located upstream of the painter, it may be appropriate to modify so matching the transfer speed of the organ fibers located even further upstream.

• un moyen de réglage d'un écartement entre un peigneur et un tambour de la carde,
• un moyen de réglage de la vitesse de rotation d'un condenseur relativement à la vitesse de rotation du peigneur de la carde,
• un moyen de réglage de la vitesse de rotation d'un détacheur relativement à la vitesse de rotation d'un organe de transfert de fibres, tel que peigneur ou condenseur, situé immédiatement en amont;
• un moyen de réglage de la vitesse d'un organe de transfert de fibres situé en amont du peigneur.

According to another aspect of the invention, the device for implementing a method according to the first aspect, comprising a card integrating at least one means of adjustment in operation, under the action at least indirect of a programmable control , of the thickness of at least one elementary veil produced in a veil production path, is characterized in that this adjustment means is chosen from:

• means for adjusting a spacing between a doffer and a card drum,
• means for adjusting the speed of rotation of a condenser relative to the speed of rotation of the carding doffer,
• means for adjusting the speed of rotation of a detacher relative to the speed of rotation of a fiber transfer member, such as a doffer or condenser, located immediately upstream;
• means for adjusting the speed of a fiber transfer member located upstream of the doffer.

According to another version of the device for implementing the method according to the first aspect, it comprises a sail production apparatus having at least two paths for producing a respective elementary sail, the two paths then joining at a overlapping post of the two sails,
and is characterized in that it further comprises at least one means for adjusting, in operation, under the action of a programmable control, the thickness of at least one of the elementary webs, so that the web covering obtained by superposition of the elementary webs has a thickness which varies according to its longitudinal direction.

• un appareil de production d'au moins un voile élémentaire, et incluant un moyen de réglage du poids surfacique d'au moins un voile élémentaire produit,
• un étaleur-nappeur recevant un voile de nappage incorporant ledit au moins un voile élémentaire et conduisant le voile de nappage selon un trajet à géométrie variable jusqu'à un chariot nappeur mobile en va et vient transversal au-dessus d'un tapis de sortie, et
• une commande programmable capable d'envoyer au moins indirectement audit moyen de réglage un signal de commande du poids surfacique à donner au voile élémentaire à chaque instant en fonction de la position du chariot nappeur,

   est caractérisé en ce que la commande programmable comprend des moyens pour prendre en compte la longueur de voile entre une première section de voile en train d'être déposée sur le tapis de sortie de l'étaleur-nappeur et une seconde section de voile subissant le réglage, et une distance totale que devra parcourir le chariot nappeur pour déposer cette longueur, pour déterminer le point de la largeur de la nappe où sera déposée la deuxième section de voile, et pour former ledit signal de commande en fonction du poids surfacique voulu pour le voile de nappage au point de la largeur de la nappe où sera déposée cette deuxième section du voile.According to another aspect of the invention, the device for implementing the method, comprising:

• an apparatus for producing at least one elementary veil, and including means for adjusting the surface weight of at least one elementary veil produced,
• a spreader-lapper receiving a lapping veil incorporating said at least one elementary veil and leading the lapping veil along a path with variable geometry to a lapper carriage movable back and forth transversely above an output belt, and
• a programmable command capable of sending at least indirectly to said adjustment means a signal for controlling the surface weight to be given to the elementary web at each instant as a function of the position of the lapping carriage,

is characterized in that the programmable control comprises means for taking into account the length of the sail between a first section of sail being deposited on the exit belt of the spreader-lapper and a second section of sail undergoing the adjustment, and a total distance that the lapping carriage will have to travel to deposit this length, to determine the point of the width of the lap where the second section of sail will be deposited, and to form said control signal as a function of the surface weight desired for the covering web at the point of the width of the web where this second section of the web will be deposited.

• un étaleur-nappeur incluant un chariot nappeur mobile en va et vient transversal au-dessus d'un tapis de sortie, et un moyen d'accumulation pour régler la longueur d'un voile de nappage accumulée dans l'étaleur-nappeur; et
• un appareil de production d'au moins un voile élémentaire pour composer le voile de nappage envoyé au poste d'entrée dans l'étaleur-nappeur,

   est caractérisé en ce que l'appareil de production inclut pour régler le poids surfacique du voile élémentaire un moyen de réglage produisant une fluctuation de la vitesse du voile de nappage autour de la vitesse moyenne à laquelle le chariot nappeur dévide le voile de nappage, et en ce que le moyen d'accumulation est commandé pour faire varier la longueur de voile accumulée dans l'étaleur en fonction de la différence entre la vitesse d'entrée du voile de nappage dans l'étaleur-nappeur et la vitesse à laquelle le chariot nappeur dévide le voile sur le tapis de sortie.According to yet another aspect of the invention, the device for implementing the method, comprising:

• a spreader-lapper including a movable lapper carriage back and forth transversely above an output belt, and an accumulation means for adjusting the length of a lapping veil accumulated in the lapper-lapper; and
• an apparatus for producing at least one elementary veil to compose the covering veil sent to the entry station in the spreader-lapper,

is characterized in that the production apparatus includes, for adjusting the surface weight of the elementary veil, an adjustment means producing a fluctuation in the speed of the covering veil around the average speed at which the lapping carriage unwinds the covering veil, and in that the accumulation means is controlled to vary the length of veil accumulated in the spreader as a function of the difference between the speed of entry of the covering veil into the spreader-lapper and the speed at which the carriage lapper unwinds the veil on the exit mat.

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

• la figure 1 est une vue schématique en élévation latérale d'un dispositif selon l'invention;
• la figure 2 est une vue de dessus de la nappe produite sur le tapis de sortie;
• la figure 3 est une vue analogue à une partie de la figure 1 mais relative à un autre mode de réalisation;
• la figure 4 est une vue explicative de l'étaleur-nappeur de la figure 1; et
• les figures 5 et 6 sont deux vues explicatives de certains aspects du procédé et des dispositifs selon l'invention.

In the accompanying drawings:

• Figure 1 is a schematic side elevational view of a device according to the invention;
• Figure 2 is a top view of the web produced on the output belt;
• Figure 3 is a view similar to a part of Figure 1 but relating to another embodiment;
• Figure 4 is an explanatory view of the spreader-lapper of Figure 1; and
• Figures 5 and 6 are two explanatory views of certain aspects of the method and devices according to the invention.

It is specified here that the figures are purely illustrative and do not purport to show nor the details of neither the actual proportions of a card and a crosslapper.

In the example shown in Figure 1, the device includes a card 1 and a spreader-lapper 2.

Card 1 includes a frame 3 supporting in rotation a carding drum 4 rotated by a motor 6. The frame 3 also supports at least one "food" 7 essentially comprising a conveyor belt driven in rotation by a motor 8. Food 7 causes fibers textiles 9 coming from a reserve and disposing of them, in general through at least one cylinder 10, on the periphery of the drum 4. Thus, the food 7 renews regularly a layer of fibers 11 at the periphery of the drum 4. There are around the periphery of the drum 4 cylinders of known type, such as 12, (of which only one pair is shown for clarity) which serve to work the fibers and in particular to orient them circumferentially at the periphery of the drum 4.

Fibers from food 7 reach the drum 4 in the beginning of the rising zone of the periphery drum 4.

There is in the descending zone of the periphery of the drum 4 at least one comber 13a, 13b consisting of a cylinder rotating around its axis parallel to that of drum 4 by means of a specific motor 14a, 14b. There is between each comb 13a, 13b and the periphery of the drum 4 a spacing chosen so that each painter 13a, 13b, thanks to an appropriate lining of its cylindrical periphery, takes part of the fibers 11 driven in rotation by the drum 4 to form with these fibers an elementary veil 15a, 15b. In the example shown, the elementary veil 15a, after performing a fraction of a turn at the periphery of the painter 13a, is taken up by a cylinder detacher 19a to be placed on an intermediate conveyor 21 driven by a specific motor 22.

The elementary veil 15b, after having carried out a fraction of a turn on the periphery of the painter 13b, is taken over by a succession of two condenser cylinders 17, 18 then, from there, by a detaching cylinder 19b.

The condenser cylinders 17, 18 and the two cylinders detachers 19a, 19b have axes parallel to the combers 13a, 13b and have much larger outside diameters weaker than the cylinders of the combers. In general, detaching cylinders 19a, 19b are themselves smaller diameter than the condenser cylinders 17, 18. The first condensing cylinder 17 is substantially tangent to the periphery of the painter cylinder 13b, with however a gap between them. The same goes for the second condenser cylinder 18 relative to the first condenser cylinder 17, and detaching cylinder 19a relative to the painter cylinder 13a and the detaching cylinder 19b relative to the second condenser cylinder 18.

The condenser cylinder 17 has a peripheral speed lower than that of the painter 13b located just upstream of so as to cause an increase in the surface weight of the veil, accompanied by a sinuous orientation of the fibers in the veil. In general, the condensing cylinder 18 rotates at a lower speed than the cylinder condenser 17.

Figure 1 illustrates with arrows that, so classic, wherever cylinders are noticeably tangents by their periphery, the speeds at the periphery are oriented in the same direction, except for the detachers 19a, 19b which therefore cause a reversal of the meaning displacement of the fibers in the vicinity of the point of tangency with the rotary element 13a and respectively 18 above.

The detacher 19b deposits the second elementary veil 15b directly on a conveyor belt before 24 of the spreader lapper 2 and more particularly on a section 23 by which this mat enters the lapper spreader 2. The conveyor intermediate 21 deposits the first elementary veil 15a on the section 23 above the elementary web 15b deposited in upstream so as to compose a covering veil 16 with the superposition of elementary webs 15a and 15b.

The function of the spreader-lapper 2 is to deposit the veil 16 in a zig-zag on an exit mat 26 moving perpendicular to the direction of entry of the veil of topping 16 in the spreader-lapper. The management of displacement of the output belt 26 is therefore roughly perpendicular to the plane of Figure 1. To deposit the veil, the spreader-lapper comprises a lapper carriage 27 which moves back and forth over the exit mat 26 parallel to the width of it. The table topper 27 has a slot 28 above the output belt 26 which the covering veil 16 is unwound at a point variable width of the exit belt 26.

The spreader-lapper also includes a carriage accumulator 29 movable back and forth above the carriage lapper 27 and parallel thereto.

After the entry section 23 defined by rollers fixed rotary 31, 32, the front belt 24 makes a turn to 180 ° on two rollers 33 carried by the accumulator carriage 29 then defines one of the sides of the unwinding slot 28 bypassing a roller 34 carried by the lapping carriage 27. Then, the front belt 24 follows a return path on different fixed rollers 36, passing through a loop 180 ° on a roller 37 carried by a compensating carriage 38 which moves at all times at equal speed and in direction opposite of the accumulator carriage 29. The length of the path followed by the mat 24 is always the same because all variation in the length of the loop formed by the belt 24 on the accumulator carriage 29 is compensated by a contrary variation in the length of the loop formed by the belt 24 on the compensating carriage 38.

The covering veil 16 moves substantially along of the outer face of the front belt 24 from the section inlet 23 to the feed slot 28. The web of topping 16 therefore forms a length accumulation loop variable around the rollers 33 of the accumulator carriage 29 in depending on the position of this carriage along its travel back and forth. In certain known spreaders, the accumulator trolley 29 is moved so as to vary the length of the accumulation loop to accumulate sail when the constant input speed is greater than the instantaneous speed at which the lapper carriage unwinds the veil on the exit mat, and to restore a part from this loop to the lapper carriage in the case opposite. We also know less spreaders sophisticated where the lapping carriage unrolls the veil with a constant speed equal to the constant input speed: the accumulator trolley only serves to keep a constant sail length in the spreader-lapper whatever either the position of the lapper carriage along its travel back and forth.

In the part of its path between the carriage accumulator 29 and the lapping carriage 27, the covering veil 16, is supported, on the side opposite the front mat 24, by a rear belt 41. This passes over rollers 42 carried by the accumulator carriage 29 and bypasses on the carriage lapper 27 a roller 43 on which the rear carpet defines the other side of the unwinding slot 28, facing the roller 34. The rest of the path of the rear carpet 41 is defined by fixed position rotary rollers 44, 46, also passing by a 180 ° loop on a roller 47 carried by a carriage compensator 48 which is constantly moving at speed equal and in opposite direction of the lapper carriage 27. Thus, the path followed by the rear belt 41 has a constant length because any variation in the length of the 180 ° loop formed by the rear belt 41 around the roller 43 of the carriage lapper 27 is compensated by an opposite variation of the length of the 180 ° loop formed by the same mat on the compensating carriage 48.

The accumulator cart 29 is connected to the cart compensator 38 associated by means of an inextensible cable 49 making a global 180 ° turn between one of its ends coupled to the accumulator carriage 29 and its other end coupled to the associated compensating carriage 38. This 180 ° turn is carried out at least in part on a pulley drive 51 coupled to a two-wheel drive motor 52 direction of travel which is of the servo-motor type, stepper motor not, or the like. In each direction of rotation, the cable 49 pulls the accumulator cart 29 or respectively the cart compensator 38 in the direction extending the loop formed on him by the carpet before 24. Considering the length unchanging of the carpet before 24, the other loop must necessarily shorten and bring the other cart back into the intended meaning. If necessary, in a known manner, to avoid the resulting traction on the front belt 24 and wear mat, a second cable can connect the accumulator carriage 29 and its compensating carriage 38 in passing on the other side of the exit mat, as described in EP-B-522 893.

The control of the lapper carriage 27 and the carriage associated compensator 48 is produced substantially from the as described for the accumulator carriage 29 and the carriage associated compensator 38. A cable 53 connects the two carriages 27, 48 by performing a 180 ° turn at least partially on a pulley 54 mounted in a fixed position and connected to a servo motor, stepping motor or the like with two directions of travel 56. In each of its directions of movement, the motor 56 pulls the carriage 27 or 48 in the direction extending the loop made on this carriage by the rear carpet 41. The other carriage is then moves in the opposite direction thanks to the invariability the length of the rear carpet 41 or using a cable additional passing through the other side of the exit belt 26.

In addition, the speed of movement of the front belt 24 is defined by a servo motor, stepper motor or analog 57 associated with one 31 of the fixed cylinders supporting the front belt 24 in the entry section 23. The speed of circulation of the rear belt 41 is defined by a servo motor, stepper motor or the like 58 associated with the cylinder fixed 44 supporting the rear belt 41 along its section return between the compensating carriage 48 and the accumulator trolley 29.

In operation, the covering veil 16 is routed by the inlet section 23 of the front belt 24, crosses then the accumulator cart 29 then the lapper cart 27, and forms segments on the output belt 26 which overlap with an obliquity alternately in a sense and in the other. The rear edges of these segments, relative to the direction of movement of the output belt 26, are visible at 59 in Figure 2.

The spreader-lapper also includes a command 61 which manages the positions at all times respective angulars to be produced by motors 52 and 56 of control of the position of the accumulator carts 29 and lapper 27 along their back and forth course, and by the two motors 57 and 58 defining the circulation of the carpet front 24 and rear carpet 41. Not shown, the control unit 61 can also control a motor drive belt 26 according to a method known, for example at a constant speed or on the contrary a speed proportional to that of the lapper carriage 27 as FR-A-2 234 395 teaches.

The device further comprises a control unit 62 associated with the card and commanding in a coordinated manner the rotational speed of motors 6, 8, 14a, 14b and 22 already described and shown as well as various other motors, not shown for reasons of clarity, including the detaching cylinder 19a, the condensing cylinders 17 and 18 and the detaching cylinder 19b respectively. All these engines are able, if necessary using a loop regulation passing through the control unit 62, to execute a speed instruction and preferably even a angular position instruction determined at each instant, from which it also results in a speed of rotation determined at all times.

One of the control units, preferably the control unit command 61 associated with spreader-lapper 2, is programmable in a way that allows the operator to define, for each position of the lapping carriage 27 along its travel back and forth, the desired surface weight for the veil of nappage 16 in the section undergoing deposition by the carriage lapper 27 on the output belt. So whenever the lapper carriage will pass at a determined point in its travel back and forth, the covering veil 16 will have a surface weight determined and consequently the tablecloth produced, consisting of all points of a constant number of sail segments superimposed, will itself, at each point of its width, a areal weight respectively determined. This programming is possible before the start of a production, perfected realizations allowing to modify the programming during operation.

The variations in surface weight of the sections of successive veils which are unwound by the lapping carriage 27 on the output belt 26 result from an adjustment controlled by continuous by the central unit 62 of the card 1. In the example shown in Figure 1, this setting can affect speed of rotation of the motor 8 of the food 7 relative to the speed of rotation of the motor 6 driving the drum 4. If motor 8 rotates faster, food 7 provides more fiber around the periphery of drum 4. Therefore, after a determined peripheral route corresponding to a fraction of a turn of cylinder 10 and a fraction of a turn of drum 4, more fibers 11 reach the combers 13a and 13b. This results in the production of sails elementaries 15a and 15b having a higher surface weight. Conversely, a slower rotation of the motor 8 food 7 produces elementary veils, having a lower surface weight.

The area weight setting can also consist, at least in part, in a variation of the speed of carding drum 4. Plus carding drum rotates quickly compared to the combers 13a and 13b, the more elementary sails 15a and 15b collected by them are heavy, per unit area. A variation in the speed of rotation of the drum 4 can if necessary be accompanied by a corresponding variation in the speed of rotation of motors driving the fiber transfer devices located upstream, namely the food 7 and the cylinder 10 in the example shown.

The setting can also affect one and / or the other combers 13a and 13b. If their engine drives them to a higher speed compared to carding drum 4 they produce elementary sails 15a at faster speed and 15b having a lower surface weight. On the contrary, if we slow down the rotation speed of at least one of the combers 13a or 13b, this produces at lower speed a veil having a greater surface weight. all variation of the speed of rotation of a doffer for the purpose to modify the surface weight of the elementary veil must be accompanied by a corresponding variation, i.e. principle in the same proportion, of the speed of the organs sail transfer downstream, so the detacher 19a and the intermediate belt 21 with regard to the painter 13a, and the condensers 17 and 18 and the detacher 19b in this which concerns the painter 13b, in the example shown. he is also appropriate to change the speed of the stretch input 23 of the front belt 24 by an appropriate control of the motor 57 for driving this mat, as will be explained in more detail later.

We usually make sure that the speeds of the two elementary sails 15a and 15b on arrival on the section input 23 of the front carpet 24 are little different one of the other and the speed of circulation of this section, knowing that in practice speed differences of the order 10 to 15% are tolerable.

Adjusting the surface weight of at least one veil elementary 15a or 15b can also consist of an adjustment of the speed of rotation of the condensers 17 and 18 with respect to the speed of the doffer 13b located upstream, so that more or less condensing the elementary veil produced by the painter 13b. The condensation is all the stronger, and by consequently the surface weight all the higher, as the condenser speed is reduced compared to that of painter 13b. You can change the speed of the first condenser 17 relative to the speed of the doffer 13b and vary the speed of the second condenser 18. The speed of rotation of the condenser 18 relative to that of the condenser 17, whether this is in a constant or variable relationship with that of the painter 13b. In all cases, the speeds of transfer defined by the detacher 19b and the section input 23 of the spreader-lapper vary in proportion to that of the condenser 18, if we want these elements located downstream of the condenser 18 transmit without modification the variations in surface weight of the elementary veil 15b.

It is still possible to modify the surface weight a veil 15a and / or 15b by varying the speed of rotation of the respective detacher 19a and / or 19b with respect to the speed of rotation of the fiber transfer member located immediately upstream, i.e. the painter 13a in as regards the detacher 19a, and the condenser 18 in that concerning the detacher 19b.

If the speed of the detacher is varied 19a compared to that of the painter 13a, we vary correspondingly the speed of the intermediate belt 21. In addition, here again, the speed of the inlet section is adjusted. 23 from the mat 24 to variations as the weight setting induced surface area on the production speed of the sails 15a and 15b.

Another mode of realization of card 1, according to which at least one painter 13, as well as the condenser 17, 18 and the detacher 19 associated are all supported on a cart 63 which is mobile relative to the frame 3 of the card 1 in a direction of translation varying the spacing E between the drum card 4 and the painter 13. The movement of the carriage 63 is controlled by a positioning motor 64 receiving control signals from the control unit 62. The motor 64 actuates the carriage 63 for example by means of a screw mechanism 66. When by an appropriate control of the motor 64 the control unit 62 causes an increase in interval E, this results in a reduction in weight area of the veil taken by the painter 13 without it it is necessary to vary the speed of rotation of the comber 13, condensers 17, 18 and detacher 19, therefore without variation of the speed at which the elementary veil corresponding is produced. It is therefore not necessary adjust the speed of entry into the spreader-lapper when the adjustment of the surface weight of the elementary veil is produced only by a variation of the spacing E. A adjustment of the surface weight obtained by varying the speed of rotation of the drum 4 or of any other fiber transfer, such as food 7, located upstream or combers such as 13, has the same advantage.

In practice, the area weight adjustment by variation of the distance between the comber (s) and the card drum is very advantageous because it does not impose any speed variation, neither upstream nor downstream. In card at least two combers, elementary sails having different surface weights and varying so different or time-shifted one from the other can be produced and delivered to the post of superimposition at a constant speed which is the same for the at least two elementary sails, this speed being also that of the inlet section 23, in principle. We can achieve a similar result by combining a variation of the speed of the drum 4 or of an organ situated upstream and a variation of the spacing E of one of the combers relative to the drum 4 to modify the weight of one of the elementary sails compared to the variable weight of the other sail.

We will now expose, with reference to FIG. 4, how, according to the invention, the speed can be varied of the incoming section 23 of the front belt 24 without disturbing the rest of the operation of the spreader-lapper, and in particular without modifying the speed at which the lapper carriage unwinds the veil on the exit belt 26.

In this figure, all speeds are shown with arrows corresponding to the positive counted direction, which is the direction to the right (direction of routing by the section entering 23) for horizontal speeds and direction descending for vertical speeds.

The belts 24 and 41 have in the area between the carriages 27 and 29 a speed V ₂ , given by the following relationship: V 2 = V 3 - W

Given the stretching factor k (if k = 1, there is neither stretching nor compression) due to a difference between | V ₃ | and | W |, we have the relation: V 3 = | W | / k

The result is: V2 = | W | / k - W (R1)

We also see that, if V ₁ is the speed of movement of the section 23 and U is the speed of movement of the accumulator carriage 29: V 2 = -V 1 + 2U from which it results: U = (V1 + V2) / 2 and therefore, taking into account the relation (R1): U = (V 1 + | W | / k - W) / 2 (R2)

The application of these calculations results in practice in the following way:

Depending on the speed at which the elementary veil is produced, the central unit 61 sends an instruction to the motor 57 to adjust the speed of the motor 31 in correspondence so as to give the input speed V ₁ of the belt before 24 the suitable value. Furthermore, the lapping carriage 27 can for example follow a predetermined periodic speed law, according to which the value of the speed of movement W of the lapping carriage 27 is determined for each point of the reciprocating stroke.

Consequently, the motor 52 for driving the lapping carriage 27 is controlled so as to generate the desired speed law for the speed of movement W of the lapping carriage 27 as a function of its position along its reciprocating stroke. V ₁ and W being fixed at each instant as has just been said, the relation (R2) gives the value "U", the stretching factor "k" being also programmed or in any case known from the construction of the spreader for each point of the stroke of the lapping carriage 27. We therefore control from the central unit 61, the motor 52 for driving the accumulator carriage 29 to give it the speed U determined as we have just expose according to relation (R2). The motor 58 for driving the rear belt 41 is controlled so that the speed V ₄ of circulation of the rear belt 41 in the area adjacent to the entry into the accumulator carriage 29 is such that V ₄ = V ₂ = 2U - V ₁ . It will easily be verified that in this way each zone of the rear belt 41 has the same speed as each zone of the front belt 24 which faces it in the path comprised between the accumulator carriage 29 and the lapping carriage 27.

The mathematical laws which have been given above do not are just an example to show the feasibility of the process according to the invention. In detail, these laws may vary depending on the kinematics of the spreader-lapper used. It exists many types of spreader-lappers sold or known in the literature.

It will be understood that the calculations exposed above will give the same results every time the cart lapper will go through any given position. It is therefore not necessary for the control unit 61 redo the calculations each time. It will suffice that she once at the start of a given production, then it stores them in memory as an array giving all the speeds or angular positions to be achieved for each position of the lapper carriage 27.

The process which has just been described is applicable even if the law giving the speed "W" of the lapper carriage 27 in depending on its position along its back and forth path is not a constant law fixed once and for all in the control unit 61, but on the contrary a law that the unit command 61 is able to modify for example for optimize the distribution of speeds and accelerations by function of various parameters such as width of the sheet to achieve, average working speed of the spreader-lapper, spatial distribution law of any stretching, etc ...

In implementing the method according to the invention, it is furthermore ensured that: V 1 medium = V 3 way on each round trip of the lapper carriage. Thus, the amount of haze accumulated in the spreader fluctuates only between two limit values, and it is therefore possible to ensure that the accumulator carriage 29 only moves between two limit positions compatible with the material construction of the machine. .

Instead of driving the sections of the belts 24 and 41 directing towards the accumulator carriage 29, the motors 57 and 58 can also train, each, any other guide roller for the mat respectively associated.

They can in particular, as shown in dotted lines in FIG. 4, be positioned respectively at 57a and 58a to drive one of the fixed rollers 36 and respectively 46 guiding the front belt 24 and respectively the rear belt 41 at the outlet of the lapper carriage 27. In this case, the operating conditions already described are achieved if the motor 57a gives the front belt 24 a speed V ₅ such that: V 5 = W - V 3 = W - | W | / k and if the motor 58a gives the rear carpet 41 a speed V ₆ such that: V 6 = V 3 + W = W + | W | / k

We will now expose in more detail certain features of the process according to the invention.

Figure 5 schematically illustrates the production, on the output belt 26 of the spreader-lapper which is not entirely represented, of a sheet 67 by means of a covering veil 16 whose surface weight varies thanks to to an adjustment made in card 1 which also is only partially shown.

In this example, we describe for simplicity the case where the covering veil 16 is obtained from a single veil elementary 15 whose surface weight is adjusted by variation of the rotator speed 13.

In a first step also, it will be considered that there is no element between the comber 13 and the lapping carriage 27 of the spreader-lapper, such as a condenser or the like varying the surface weight and / or the circulation speed of the veil 15, 16. It is further assumed that the speed V ₃ at which the veil 16 is unwound through the lapping carriage 27 is permanently equal to the absolute value of the speed W of translation of the lapping carriage, so that none stretching or compression does not occur at the time of deposition on the output belt 26.

The sheet 67 is generally intended to be consolidated in a consolidation machine such as for example a needling machine which must produce a continuous textile product 68 on an output belt 69 of the consolidation machine or other suitable support. For illustrative purposes, the thickness of product 68 was greatly exaggerated by compared to the width shown. It is also illustrated that consolidated product 68 is slightly narrower that tablecloth 67 as a result of a certain shrinkage which, from known manner, is generated by the needling process.

In this example, the invention aims to manufacture a textile product having, over part of its width from on one edge, a relatively thick area 681, on another part of its width from the other edge an area 682 thinner, and between them a transition zone 683. Such a textile product can be useful for certain applications, especially for the floor mats used in the automobile, the part 682 is thinner, therefore less robust, used to fill areas less exposed to wear, like for example the vertical part going up towards the threshold door.

According to the invention, the speed of the comber 13 is adjusted. so that each section of sail takes, where it undergoes the weight per area adjustment, a value of areal weight corresponding to that which will be desired taking into account the position where the lapper carriage will be 27 along its back and forth stroke when that same section will in turn be deposited by the lapper carriage.

For this, account is taken of the cumulative length of veil that there is between the section S ₁ being deposited on the output belt 26 (or more exactly on the segment of veil 71 previously deposited from the web 67 ), and section S2 whose surface weight is being determined by the speed of the doffer 13 at the instant considered. As the web 15, 16 is in this example transported and deposited without compression or extension of any kind along the path that section S2 will travel until it is deposited on the sheet already formed, this length of web is equal to the total length of a certain number, in general not an integral number, of the strokes of the lapping carriage 27. It can thus be known that the lapping carriage 27 will have, when the section S ₂ is being deposited, a position that one can foresee, for example position 27a in the situation represented in FIG. 5. This position 27a is represented in dotted lines, it corresponds to a determined surface weight and therefore the speed of the motor 14 is controlled so that this surface weight either made by the painter 13 in section S ₂ .

To determine the length of sail 15, 16 between sections S ₁ and S ₂ , the control unit 61 takes into account the respective positions of the carriages 27 and 29. It knows these positions from the angular positions of the motors 52 and 56 which control the position of the carriages 29 and 27 respectively. With this information, the control unit 61 is able to calculate the length of sail .15, 16 between the sections S ₁ and S ₂ even if this length varies. We have seen that this length could vary to allow the input speed V ₁ and / or the speed V ₃ to vary.

We will therefore, as shown, produce a veil 15 having longitudinal regions 151 of relatively large thickness intended to be part of zone 681 of the product finished, and having a length twice the width of the area corresponding 671 of the tablecloth 67, alternating with zones 152 of thinner thickness having a length twice the width of the corresponding zone 672 of the ply 67, separated by transition zones 153 stacked in zone 673 of the tablecloth 67.

If, as a variant, the web 15, 16 undergoes at a point in its path between the sections S ₂ and S ₁ a drawing operation (true drawing or compression) with a drawing factor k ₂ as indicated in point 71 , the entire length between section S ₂ and point 71 must be taken into account not for its actual value but for a corrected value corresponding to the actual length multiplied by the factor k ₂ .

For example, if k ₂ = 1.1 (actual stretch of + 10%), the entire length between section S ₂ and point 71 should be counted with an increase of 10%. This method of calculation is particularly involved when condensers operate downstream from the point where the area weight adjustment is made.

In the example of Figure 6, two illustrations are illustrated. arrangements, independent of each other, in relation to the example of figure 5.

According to a first arrangement, a process is explained to adjust the surface weight in a coordinated manner on two elementary sails 15a and 15b which contribute, all two in the same proportions, in each section transverse of the web 16, to create variations in thickness desired for the web 16 along its length.

In a first variant of the first arrangement, it is assumed that the surface weight of each of the sails 15a and 15b is modified by varying the spacing between each painter 13a or 13b and the drum 4. It is further assumed that the sections S2 of the web 15a and S3 of the web 15b which undergo the surface weight adjustment are separated by lengths of web different from the section S ₁ undergoing the deposition. It is intended according to the invention to calculate these two delay lengths separately and to control the two adjusting members, that is to say in the example the two combers 13a and 13b, in a differentiated manner so that the thickness variations produced coincide with each other when the two elementary webs are superimposed at 72 so that the covering web 16 has the desired surface weight at the time of deposition on the web 67 at each point. In the case shown where it is sought that the two elementary veils 15a and 15b vary by achieving at every point in the length of the covering veil each a constant proportion of the surface weight of the covering veil 16, it is understood that the elementary veil having the most long journey to be covered undergoes in time advance over the other each modification of thickness desired for the covering veil 16.

Even if the desired modifications for both elementary veil lead to each veil elementary 15a or 15b achieves a variable proportion of the areal weight of the covering veil 16 along the length of the latter, it will be understood that the surface weight elementary veil with the longest distance to travel must be settled with greater temporal anticipation than the other elementary veil. The difference between commands applied to the two combers 13a and 13b is therefore a time lag, although this offset may need to vary if the speed at which the web 16 enters the spreader varies and / or if the speed at which the veil is deposited on the sheet 67 already constituted varied.

In a second variant of the first arrangement, which will only be described for its differences from the first variant, it is assumed that the surface weight of each of the elementary webs 15a and 15b is modified by variation of the speed of rotation of the associated painter 13a or 13b. In addition, it has been arranged that the two elementary webs have between the section S ₂ or respectively S ₃ undergoing adjustment, and the section S ₁ being deposited, substantially the same length of delay. This is true at all times since possible variations due to the movements of the accumulator carriage 29 affect the two delay lengths in the same way. The two elementary webs 15a, 15b always contribute in the same proportion to the surface weight of the covering web 16. Under these conditions, the motors 14a and 14b are controlled so that the rotational speeds of the two combers 13a and 13b undergo variations which are at each instant in the same proportion with respect to each other, so that the production speeds of the elementary webs 15a and 15b are, at each instant, substantially equal to each other. Thus, at station 72, the two elementary webs 15a and 15b arrive at the same speed, which varies over time, and it is at all times possible, in particular by appropriate control of the movement of the accumulator carriage 29, to give the section d entry 23 of the front belt 24 of the spreader-lapper (FIG. 4) a speed corresponding to the speed of arrival of the web 16 at this instant. Depending on the configuration of the card, the special feature of equalizing the two delay lengths as much as possible can be achieved by adjusting the surface weight of each sail with different means, respectively. One can for example adjust the speed of the comber for one of the elementary veils, and the speed of rotation of a condenser for the other elementary veil.

The other layout, also shown in Figure 6 but independent of the use of two elementary sails 15a and 15b, relates to the production of thinned edge zones 674 and 676, for example to pre-compensate a classic fault thickening of edge areas 684 and 686, product by needling. With thinned edge areas 674 and 676 of FIG. 6, these extra thicknesses are eliminated and the profile of the edge zones of the needled product takes the form shown in phantom in Figure 5.

To produce such edge zones, it is possible, for example by means of an appropriate control of the motor 14a and / or of the motor 14b, to correspondingly modify the longitudinal profile of at least one of the elementary webs 15a and 15b. It is also possible to create in these zones a reduction in the speed V ₃ of unwinding of the web by the lapping carriage 27, compared to the absolute speed | W | of the lapper carriage, this reduction being more and more strong until the reversing of the direction of travel of the lapper carriage 27 and then gradually reducing to disappear when the lapper carriage 27 crosses the limit separating the edge area 674 from the thick area 671 and respectively the limit between the edge zone 676 and the relatively thin zone 672.

When the web is thus deposited on the sheet 67 already formed with a drawing factor which is different from 1 over at least part of the travel of the lapping carriage, one of the possible calculation methods for determining the thickness settings to give to sections S2 and S3 consists in reasoning in fictitious strokes of the lapping carriage 27. A fictitious stroke is that which the lapping carriage would have carried out if it had moved at every moment with a speed whose absolute value | W | would have been equal to the speed V ₃ of unwinding of the web at the point considered. In addition, a central table 61 is created in correspondence between each point of the fictitious course, each point of the real course and the desired surface weight for the covering veil, before stretching, at each of these points. We calculate the delay length for sections S2 and S3 respectively undergoing the adjustment, we convert these delay lengths into the number of fictitious strokes, and we interpret the decimal part of this number to know the fictitious position or positions that the carriage will have lapper when it deposits sections S ₂ and S ₃ . The surface weight to be given to each of the sections S ₂ and S ₃ is then deduced from the correspondence table.

Of course, the invention is not limited to examples described and shown. We can, very many different ways, combine different modes of setting surface weights which have been described by way of examples.

The invention can be used to produce using adjustment means provided in the card a ply profile which is simply intended to compensate for defects in excess thickness at the edges introduced into the needling machine or other consolidation machine, or in certain types of less sophisticated design able to control the speed of unwinding the veil all points of the lapping carriage stroke.

It can be advantageous, in the case of a card producing at least two elementary veils such as 15a and 15b, to produce different longitudinal profiles for these two sails. For example, in the example in Figure 6, the adjustment made on the veil 15b could be used to achieve the two zones 671 and 672 of different thickness as well as the transition zone 673 and the veil 16a could undergo the settings producing thinned edges 674 and 676.

Since it is preferred according to the invention to control the whole process according to the actual position or fictitious of the lapper carriage at all times, and according to the position taken correlatively by the accumulator carriage 29, it is also preferred that the control unit 61 of the spreader-lapper has a master role in the implementation of the process. This control unit 61 sends the machine production of sail and in particular to its control unit 62 of the instructions which the control unit 62 transforms into commands applied to the motor (s) affecting the adjustment of the areal weight of the elementary veil (s). House could also conceive of programming being done on the control unit 62 of the production machine veil, which could then, at any moment, call for the control unit 61 of the spreader-lapper the information which it would need to determine at all times the commands to apply, especially information relating to the position of the two carriages 27, 29.

We can still imagine that the two units of control 61, 62 are grouped into one, the production of sail and the spreader-lapper no longer forming then, conceptually, only one machine.

In some installations, especially when the sail production machine is pre-existing, the unit of command 62 may take, at least in part, the form of a reported intermediate module, capable of taking into account and inject into the machine control circuit production of variable setpoints for motors affecting the area weight setting. Alternatively, the unit of command 61 may include outputs capable of being directly connected to the sail production machine.

The invention enables all kinds of profiling, especially with more than two thickness zones different across the width of the tablecloth, or with a profile of thickness which varies throughout at least one area or the entire width of the web, to produce a profile which can be concave, convex or alternatively concave and convex.

The invention is not limited to assemblies in which possible variations in production speed of the veil are compensated by variation of an accumulation in the spreader-lapper. It is also possible to do vary the working speed of the whole spreader-lapper, and for example to create a variable accumulation in downstream of the spreader-lapper or to vary so corresponding to the speed of the following machines, such qu'aiguilleteuse.

Claims (47)

1. A method of producing a textile fleece (67) in which there is produced at least one elementary web (15, 15a, 15b) and then, by means of a crosslapper (2), a lappable web (16) incorporating said elementary web is folded, alternately in one direction and in the other, on a transverse output belt (26) of the crosslapper, wherein by substantially modifying at least one adjustment upstream of the crosslapper (2) the lappable web (16) fed into the crosslapper is given a weight per unit area which varies along the longitudinal direction of the lappable web in such a way that the fleece (67) obtained at the output of the crosslapper has over its width a substantially predetermined distribution of weight per unit area, characterized by realizing a condition of correspondence between the speed of production of the web having a variable weight per unit area and the instantaneous speed (V₁) of an input member (23) of the crosslaper (2).
2. A method according to claim 1, characterized by the step of varying the length of a web accumulation path upstream of a web cross-section (S₁) in the process of being deposited onto the output belt (26) in the crosslapper (2).
3. A method according to claim 2, characterized by varying said length of the accumulation path with the assistance of a means of accumulating a length of lappable web (16) within the crosslapper.
4. A method according to claim 3, characterized by varying said length of the accumulation path thereby to control a relationship between the speed at which a lapper carriage (27) of the crosslapper delivers the web onto the output belt (26) and the displacement speed of the lapper carriage.
5. A method according to one of claims 1-4, characterized in that said adjustment which is being modified upstream of the crosslapper (2) results in a variation of the speed of production of the web having a variable weight per unit area, and an accumulation path length variation is controlled as a function of the variations of the speed of production of the web having a variable weight per unit area.
6. A method according to one of claims 1-4, characterized in that said adjustment which is being modified upstream of the crosslapper results in a variation of the speed of production of the web having a variable weight per unit area, and the instantaneous speed (V₁) of the input member (23) of the crooslapper is caused to vary in correspondence with the variation of the speed of production of the web.
7. A method according to one of Claims 1 to 6, characterized in that in order to modify the weight per unit area of the elementary web there is modified, with respect to the speed of a carding doffer (13, 13a, 13b), the speed of at least one condensing device (17, 18) placed downstream of the doffer.
8. A method according to one of Claims 1 to 7, characterized in that in order to modify the weight per unit area of the elementary web there is modified, with respect to the speed of a carding doffer (13, 13a, 13b), the speed of a detacher (19a, 19b) delivering the elementary web (15a, 15b) at the output of the carding machine (1).
9. A method according to one of Claims 1 to 8, characterized in that in order to modify the weight per unit area of the elementary web there is modified the speed of a detacher (19b) delivering the elementary web (15b) at the output of the carding machine, with respect to the speed of transit of the fibres defined by a condensing device (18) receiving fibres taken by a carding machine doffer (13b).
10. A method according to one of claims 1 to 9, characterized in that in order to modify the weight per unit area of the elementary web there is modified the speed of rotation of a carding machine doffer (13a, 13b) with respect to the speed of rotation of a carding machine drum (4).
11. A method according to one of claims 1 to 4, characterized in that in order to realize the condition of correspondence between the speed of production of the web having a variable weight per unit area and the speed of the input member of the crosslapper, there is modified an adjustment during operation upstream of the crosslapper which is independent from the speed of production of the elementary web.
12. A method according to Claim 11, characterized in that the adjustment which is being modified upstream of the crosslapper comprises an adjustment affecting a carding machine (1) in a zone located downstream of a drum (4) of the carding machine, with respect to the direction of transit of the fibres (11, 16) in the carding machine, and independently from the speed of rotation of a doffer (13; 13a, 13b) taking from the carding machine drum (4) the fibres (11) intended to constitute the elementary web (16, 16a, 16b).
13. A method according to Claim 11, characterized in that said adjustment consists in modifying a separation (E) between a drum (4) of the carding machine and a doffer (13) taking on the drum the fibres (11) intended to constitute the elementary web (16).
14. A method according to Claim 13, characterized in that the adjustment affects the speed of transit of the fibres in the carding machine (1) upstream of at least one doffer (13, 13a, 13b) of the carding machine.
15. A method according to Claim 14, characterized in that the speed of rotation of a drum (4) of the carding machine (1) is varied.
16. A method according to one of the preceding Claims, characterized in that, according to the length of web contained between a first web cross-section (S₁) in the process of being deposited on the output belt (26) in the crosslapper (2) and a second web cross-section (S₂, S₃) located at the point in the path of the fibres where said adjustment influences the weight per unit area of the elementary web (15, 15a, 15b) upstream of the crosslapper, there is determined the point (27a) in the width of the fleece where the second cross-section (S₂, S₃) will be deposited and said adjustment is carried out according to the weight per unit area programmed for said point in the width of the fleece.
17. A method according to Claim 16, characterized in that in order to determine the point in the width of the fleece where the second cross-section of the web will be deposited, account is taken of at least one stretching factor (k, k2) applied to the web downstream of the said point in the path of the fibres.
18. A method according to claim 16 or 17, characterized in that there is programmed, at least by zones (671, 672, 673), the distribution of weight per unit area desired for the lappable web (16) arriving in a lapper carriage (27) of the crosslapper at each point in the travel of the lapper carriage and, as a function of this programme, control equipment (61, 62) sends, at each instant, data or instructions on the said adjustment to be carried out upstream of the crosslapper (2) at that instant.
19. A method according to one of the preceding claims, characterized in that the lappable web (16) is produced by superimposing at least two elementary webs (15a, 15b), and in that said adjustment is modified differently for each of the elementary webs.
20. A method according to Claim 19, characterized in that said adjustment, for each of the elementary webs respectively, is modified according to laws which are offset with respect to each other.
21. A method according to Claim 19, characterized in that the adjustment is left constant for one of the elementary webs.
22. A method according to one of Claims 19 to 21, characterized in that the adjustment which is modified upstream of the crosslapper has no effect on the speed of production of the elementary webs.
23. A method according to Claim 19, characterized in that the adjustment which is modified affects the speed of production of the elementary webs, in that this adjustment is modified such that the production speeds of the elementary webs (15a, 15b) are equal to each other at each instant, and in that the lengths of web each contained between a first web cross-section (S₁) in the process of being deposited on the output belt (26) in the crosslapper and a second web cross-section (S₂, S₃) located at the point in the path of the fibres where said adjustment influences the weight per unit area of a respective elementary web (15a, 15b) are, at each instant, substantially equal to one another.
24. A method according to one of Claims 1 to 23, characterized in that the distribution of weight per unit area over the width of the fleece (67) is predetermined such that a consolidated textile product (68) obtained at the output of at least one consolidation machine placed downstream of the crosslapper (2) has a distribution of weight per unit area varying at least by zones (681, 682, 683) over the width of the consolidated textile product.
25. A device for implementing a method according to one of Claims 1 to 24, comprising:

    a crosslapper (2) including a lapper carriage (27) with a transverse reciprocating motion above an output belt (26),

    a device (1) for producing at least one elementary web (15, 15a, 15b) for composing the lappable web (16) sent to the crosslapper, said device including, in order to adjust the weight per unit area of the elementary web, a means of adjustment during operation under at least indirect action of a programmable control (61, 62),

    characterized in that the device comprises means for realizing a condition of correspondence between the speed of production of the web having a variable weight per unit area and the instantaneous speed (V₁) of an input member (23) of the crosslapper.
26. A device according to claim 25, characterized in that it comprises accumulation means for causing variation of a length of web upstream of a web cross-section (S₁) in the process of being deposited on the output belt (26) of the crosslapper (21).
27. A device according to claim 26, characterized in that the accumulation means (29) accumulate lappable web (16) in a variable amount within the crosslapper.
28. A device according to claim 26 or 27, characterized in that the accumulation means are controlled thereby to control the relationship between the speed at which web is fed in the lapper carriage (27) and the speed of displacement of the lapper carriage (27).
29. A device according to one of Claims 26 to 28 characterized in that the speed (V₃) at which the lapper carriage (27) feeds the lappable web (16) onto the output belt (26) can be in a variable ratio with the speed (W) of displacement of the lapper carriage.
30. A device according to one of claims 25 to 29, characterized in that the means of adjustment of the weight per unit area of the web is of a type causing variation of the production speed of the lappable web having a variable weight per unit area, and in that the device comprises accumulation path adjustment means as a function of the speed of production of the lappable web having a variable weight per unit area.
31. A device according to one of claims 25 to 29, characterized in that the adjustment in operation results in causing variation of the production speed of the lappable web, means being provided for causing variation of the speed (V₁) of the input member of the lappable web (16) into the crosslapper for realizing said condition of correspondence with the production speed of the web having a variable weight per unit area.
32. A device according to Claim 31, characterized in that the means of causing variation in the input speed (V₁) are means of causing variation in the operating speed of the whole of the crosslapper.
33. A device according to one of Claims 27 to 32, characterized in that the adjustment means is a selected form among :

    a means of adjustment of the speed of at least one condenser member (17, 18) mounted downstream of a carding machine doffer with respect to the speed of rotation of said doffer;

    a means of adjustment of the speed of a detacher (19a, 19b) delivering elementary web (15a, 15b) at the outlet of a carding machine (1) with respect to the speed of a doffer of said carding machine (13, 13a, 13b);

    a means of adjustment of the speed of rotation of a doffer (13a, 13b) with respect to the speed of rotation of a carding machine drum (4); and

    a means of adjustment of a speed of a detacher (19b) delivering the elementary web (15b) at the outlet of a carding machine with respect to a condenser member (18) receiving fibres taken on a doffer (13b) of said carding machine.
34. A device according to one of Claims 25 to 33, characterized in that it comprises a control unit (61, 62) which comprises:

    means (61, 62) making it possible to program a distribution of weight per unit area over the width of the fleece to be produced;

    means of knowing at each instant the length of lappable web contained between a first web cross-section (S₁) in process of being deposited onto the output belt (26) and a second web cross-section (S₂, S₃) located at the point of the travel of the fibres where said adjutement influences the weight per unit area of the elementary web (15, 15a, 15b), and/or, respectively, knowing the point in the reciprocating travel of the lapper carriage where the cross-section (S₂, S₃) of elementary web in the process of undergoing the effect of the means of adjustment of the weight per unit area will be deposited;

    means of controlling the means of adjustment of the web production device (1) according to the programmed weight per unit area at said point in the width of the fleece.
35. A device according to one of Claims 25 to 29, characterized in that the means for realizing the condition of correspondence between the speed of production of the lappable web and the speed of the input member into the crosslapper comprise the selection of a means of adjustment during operation which is independent from the instantaneous speed of the input member (23) of the web into the crosslapper.
36. A device according to one of Claims 25 to 29, characterized in that the device for producing elementary web is a carding machine, the adjustment means being chosen from among:

    a means of adjusting a separation (E) between a doffer (13) and a drum (4) of the carding machine (1),

    a means of adjustment of the speed of rotation of a condenser (17, 18) with respect to the speed of rotation of a doffer (13) of the carding machine,

    a means of adjustment of the speed of rotation of a detacher (19, 19a, 19b) with respect to the speed of rotation of a fibre transfer device, such as a doffer (13, 13a) or a condenser (17, 18), located immediately upstream; and

    a means of adjustment of the speed of a fibre transfer device (4, 7) located upstream of the doffer.
37. A device according to one of Claims 25 to 36, characterized in that it comprises at least two paths of production of elementary web, which join together at a station of superimposition (72) of the two webs, and
       in that it furthermore comprises at least one adjustment means during operation, under the action of a programmable control (61, 62) of the weight per unit area of one at least of the elementary webs (15, 15a, 15b), whereby a lappable web (16) obtained by superimposition of the elementary webs has a weight per unit area which varies along its longitudinal direction.
38. A device according to Claim 37, characterized in that it comprises at least one adjustment means for each web production path, and in that the programmable control (61, 62) actuates, at least indirectly, the two adjustment means in a different and coordinated manner.
39. A device according to Claim 38, characterized in that the programmable control (61, 62) actuates at least indirectly, the two adjustment means with a time shift which is such that elementary web cross-sections (15a, 15b) having weights per unit area which are similarly affected by the adjustment become superimposed within the lappable web (15).
40. A device according to Claim 38 or 39, characterized in that the adjustment means are of different type for each of both paths.
41. A device according to one of Claims 37 to 40, characterized in that the adjustment means of one of the paths is an adjustment means of the speed of rotation of a doffer (13a, 13b) with respect to the speed of rotation of a drum of the carding machine (4).
42. A device according to Claim 37, characterized in that the second production path maintains constant the thickness of the corresponding elementary web during operation.
43. A device according to one of Claims 37 to 41, characterized in that it comprises, for each elementary web production path, a means of adjustment affecting the speed of production of each elementary web, in that a length of web contained between the cross-section (S₁) in the process of being deposited on the output belt (26) and each cross-section (S₂, S₃) undergoing the adjustment of weight per unit area is the same for all of the elementary webs, and in that the programmable control (61, 62) actuates, at least indirectly, the two adjustment means such that the speed of production of the elementary webs are equal to each other at each instant.
44. A device according to one of Claims 25 to 43, comprising

    the crosslapper (2) receiving a lappable web (16) incorporating said at least one elementary web and driving the lappable web along a path of variable geometry up to a lapper carriage (27) having a transverse reciprocating motion above an output belt (26), and

    the programmable control (61, 62) capable of sending, at least indirectly, to said adjustment means a control signal for the weight per unit area to be given to the elementary web (15, 15a, 15b) at each instant as a function of the position of the lapper carriage,

       characterized in that the programmable control (61, 62) comprises means for taking into account the length of web between a first web cross-section (S₁) in the process of being deposited on the output belt (26) of the crosslapper (2) and a second web cross-section (S₂) undergoing the adjustment, and a total distance which the lapper carriage will have to travel in order to deposit this length, in order to determine the point (27a) in the width of the fleece where the second web cross-section (S₂) will be deposited, and in order to form the said control signal as a function of the weight per unit area desired for the fleece (67) at the point (27a) in the width of the fleece where this second web cross-section will be deposited.
45. A device according to Claim 44, characterized in that, during the taking into account of said length of web and of said total distance, the programmable control takes into account a stretching factor (k, k2) to which the web is subjected downstream of the zone in which the said adjustment is carried out.
46. A device according to Claim 44 or 45, characterized in that, during the taking into account of said length of web and of said total distance, the programmable control takes into account a succession of stretching factors (k) which the lappable web is subjected to in each position of the lapper carriage (27) due to a variable difference between the speed (W) of displacement of the lapper carriage and the speed (V₃) at which the lapper carriage (27) feeds the lappable web (16) onto the output belt (26).
47. A device according to one of Claims 44 to 46, characterized in that, during the taking into account of the web length, the programmable control takes account of the position of an accumulator carriage (29) provided in the crosslapper (2) in order to vary in time the length of web accumulated in the crosslapper (2).

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