EP0390620A1 - Folding unit for approximately flat flexible textile products - Google Patents

Abstract

Folding unit for a substantially flat flexible textile product, comprising a conveyor band (1) having a carrier surface (7) transporting said product and two secondary driving bands (2, 3) located opposite one another and delimiting a drive corridor (4) terminating at one of its ends in an orifice opposite the carrier surface (7), the product (39) being driven in the drive corridor (4) by being gripped between the said bands (2, 3), said folding unit also comprising means (35, 36) making it possible to lift the product (39) by one of its parts from the carrier surface (7) of the conveyor band (1) as far as the orifice of the drive corridor (4), the bands (2, 3) being actuable both ways in the driving direction. <IMAGE>

Description

The present invention relates to a folding unit for a substantially flat and flexible textile product, and in particular for quilts and thick blankets. In particular, such a folding unit can be used when packaging these quilts or these blankets.

Folding units are already known for quilts or thick blankets and in particular, folding units which operate in the following way: the blanket or the quilt is transported flat by a conveyor belt, up to a knife, which just lift said quilt or cover from below to, on the one hand, thus form a fold on its edge, and, on the other hand, present the cover (or quilt) at the level of the fold thus formed in the mouth of a corridor, where the two thicknesses of the cover (or duvet) folded over each other will be led to another end of the corridor, from where the cover (or duvet) comes out perfectly folded with two thicknesses folded over each other.

Such a device poses a problem of certain size, since it requires a complicated conveyor belt circuit and over several heights, and in particular: a conveyor belt intended to transport the product to present it in front of the knife; conveyor belts in the folded product drive corridor, these conveyor belts being in a plane different from the plane of the first conveyor belt; conveyor belts making it possible to receive the folded product at the exit of the drive corridor and to transport it to a new folding unit, this band being in a plane different from the planes of the other bands of conveying.

In addition, if it is desired to obtain from such a device, a folding of a product according to several folds, as is most often the case when performing a folding of a duvet or blanket in view packaging and that one seeks, therefore, to obtain a relatively compact presentation of the folded product, it is necessary to have as many folding units as desired folds on the product, a folding unit does can perform only one folding. However, the conveying circuit is all the more complicated and the folding errors are all the more numerous the more there are folding units. In addition, the use of a multitude of folding units makes the cost of packaging expensive.

The present invention aims to overcome these drawbacks. It offers, on the one hand, a folding unit with a smaller footprint, the conveyor belt, which transports the products to the drive corridor at the level of which a fold is obtained, also serving to recover and store them. evacuate from the folding unit, once the folding has been carried out in the drive lane, said products engaging and withdrawing from the drive lane by the same end thereof, the direction of drive in said lane can be reversed. In addition, a device according to the invention allows a product to be folded in several folds, with a single passage of said product in a folding unit, the number of folding units necessary to obtain the desired folding for packaging being , therefore, notoriously diminished.

The present invention therefore relates to a folding unit for a substantially flat and flexible textile product, comprising on the one hand, a strip of conveying, mounted on support elements integral with a fixed frame and having a carrying surface moving in its plane, by means of motor means, in a conveying direction and direction according to which said carrying surface transports said product from an introduction zone, the folding unit comprising, on the other hand, two secondary drive bands, mounted on support elements and facing one another, the opposite faces of these two bands being substantially parallel and delimiting a drive corridor terminated at one of its ends by an opening opposite the carrying surface, opening the center line of which is substantially perpendicular to the conveying direction, said opposite faces being both animated, by motor means controlled by a control device, of a driving movement with the same speed and in substantially the same driving direction ement and in the same direction, the products being driven in the drive passage by clamping between said faces, said folding unit also comprising means making it possible to lift the product, by one of its parts, from the carrying surface of the strip of conveying until the opening of the drive lane, the drive faces of the lane being actuable by the control device, in both directions of the drive direction, the carrying surface of the conveyor belt extending , in the conveying direction, beyond the opening of the drive passage, and transporting the product, after passing through said drive passage, to a reception zone.

In an advantageous embodiment, the support elements of one of the drive belts are integral with a frame movable relative to the support elements of the other drive band, a displacement of said movable frame spreading or bringing together, the faces of the drive corridor. The movable frame can be subjected to forces of approach whose action tends to bring the two drive faces closer, and, when a product is engaged in the drive channel, to reaction forces of said product on said faces, said reaction forces moving apart the drive faces when introducing a thickness of a product into said passage, the forces of approximation bringing said faces together when ejecting a product from said passage. The closing forces may include gravity forces, the mobile chassis being connected to the fixed chassis by a link which guides the mobile chassis on a path on which a vertical movement of said mobile chassis is accompanied by a horizontal movement of said mobile chassis. The connection between the mobile chassis and the fixed chassis can be obtained by means of at least one assembly comprising a rod integral with one of the two chassis and sliding axially in a sleeve integral with the other of the two chassis, the common axis of this sleeve and of this rod being inclined with respect to vertical and horizontal directions. The sleeve of an assembly which provides the connection between the mobile chassis and the fixed chassis may be a ball sleeve.

Preferably, that of the drive belts which is not integral with the movable chassis is integral with the fixed chassis, the conveying direction going, at the level of the opening of the drive corridor, from the drive face of the belt. secured to the fixed frame to the drive face of the face secured to the movable frame. The drive belt from that of the faces of the drive corridor, towards which the direction of conveying at the opening of said passage, can extend said surface, beyond said opening, by a face which is opposite the carrying surface of the conveyor belt and which is substantially parallel to said carrying surface. The folding unit can also include, at least one flattening strip arranged with respect to the conveying direction before the two drive belts, and / or, at least one flattening strip arranged, with respect to the conveying direction , after the two drive belts, a flattening band comprising a surface facing the carrier surface of the conveyor belt, substantially parallel to said carrier surface and animated in a movement in substantially the same direction, the same direction and the same speed as that of the bearing surface.

Advantageously, the conveyor belt comprises belts arranged lengthwise in the direction of conveyance, two adjacent belts being separated from each other by a separation space. The means making it possible to lift a product up to the opening of the drive corridor may comprise at least one mechanical member, the part of which intended to be in contact with a product is provided with a curved guide ramp which, in the position of guide, extends from the carrying surface of the conveyor belt to said opening, the concavity of the curved guide ramp being substantially opposite to the direction of conveyance. A mechanical member can then be mounted on a pivot on the side opposite the drive corridor with respect to the carrying surface of the conveyor belt and can be pivotally actuated from the control device, the guide ramp passing from one side to the other the carrying surface of the conveyor belt by crossing said carrying surface in a separation space.

Advantageously, the folding unit comprises, at least one infrared cell connected to the control device and detecting the passage of a product on the conveyor belt. It can also include, at the opening of the drive corridor, at least one element making it possible to eject an air jet directed towards the bearing surface of the conveyor belt in a direction included in the dihedral upstream of the corridor drive on the conveyor belt with respect to the conveyor direction and delimited by said drive passage and the bearing surface of said conveyor belt. The folding unit can be used in series with other substantially identical folding units and / or in series with a transfer machine.

The invention also relates to a method of folding a substantially flat and flexible textile product from such a folding unit by which, in a preferred implementation, to obtain at least one fold, it is transported by the conveyor belt, said product from a location upstream of the drive passage with respect to the direction of conveyance until its leading edge is opposite the opening of the drive passage; lifting the leading edge of said product until the opening of said corridor; said product is driven inside the drive passage, by clamping said product by the faces of the moving passage, in a first direction of the drive direction, the leading edge moving away from the bearing surface; the direction of drive of the faces of said corridor is changed, when the product is partly, engaged in said corridor and partly still, on the supporting surface; the part of said product engaged in the corridor is driven by the moving drive faces, in the second direction of direction drive, the part of said product ejected from the drive channel being folded down by forming a fold, on the part of said product transported, by the carrying surface of the conveyor belt, downstream of the drive channel with respect to the direction of conveying.

According to a second advantageous embodiment of the folding process, in order to obtain at least one fold, said product is transported, by the conveyor belt, from a place upstream of the drive corridor with respect to the direction conveying, until part of its surface faces the opening of the corridor; training; lifting, by forming a fold, said part up to the opening of said passageway, driving said part thus folded inside said passageway by clamping said product folded by the moving drive faces, salt in a first sense of the drive direction, the folded part moving away from the bearing surface; the direction of drive of the faces of said passage is changed, when the folded product is fully engaged in said passage; said product is driven by the moving drive surfaces, in the second direction of the drive direction, its part released from the drive passage being transported by the carrying surface of the conveyor belt, downstream of said passage drive relative to the conveying direction.

In another embodiment of this folding process, in order to obtain at least two folds, the product is transported, by the conveyor belt, from a place upstream of the drive corridor with respect to the direction of conveying, until a part of its surface is opposite the opening of the drive corridor; lifting, by forming a fold, said part up to said opening; driving said folded part inside said aisle, by clamping said product folded by the moving drive faces, in a first direction of the drive direction, the folded part moving away from the bearing surface; the direction of entrainment of the faces of the passage is changed, the product being partly engaged in said passage and partly on the support surface of the conveyor belt, upstream of said drive passage with respect to the direction of conveyance; the folded part of the product is driven inside the drive passage, by the drive faces in movement, in the second direction of the drive direction, the part of said product ejected from said passage being folded down, forming a second fold, on the part of said product transported, by the carrying surface of the conveyor belt, downstream of the drive corridor relative to the direction of conveyance.

It is also possible to implement the folding process by combining the preceding modes of implementation.

To better understand the object of the invention, there will be described below, purely by way of illustration and not limitation, an embodiment and several modes of implementation shown in the accompanying drawing.

• - la figure 1 est une vue en perspective d'une unité de pliage;
• - la figure 2 est une vue en perspective avec arraché d'un détail de l'unité de pliage de la figure 1;
• - les figures 3 à 3d représentent schématiquement différentes étapes d'un procédé de pliage à l'aide de l'unité de pliage de la figure 1, selon un premier mode de mise en oeuvre;
• - les figures 4a à 4e représentent schématiquement les différentes étapes d'un procédé de pliage à l'aide de l'unité de pliage de la figure 1, selon un deuxième mode de mise en oeuvre;
• - les figures 5a à 5d représentent schématiquement les différentes étapes d'un procédé de pliage à l'aide de l'unité de pliage de la figure 1, selon un troisième mode de mise en oeuvre;
• - les figures 6a à 6h, enfin, représentent schématiquement les différentes étapes d'un procédé de pliage à l'aide de l'unité de pliage de la figure 1, selon un quatrième mode de mise en oeuvre.

On this drawing :

• - Figure 1 is a perspective view of a folding unit;
• - Figure 2 is a perspective view with cutaway of a detail of the folding unit of Figure 1;
• - Figures 3 to 3 d schematically represent different stages of a folding process using the folding unit of Figure 1, according to a first embodiment;
• - Figures 4 a to 4 e show schematically the different steps of a folding process using the folding unit of Figure 1, according to a second embodiment;
• - Figures 5 a to 5 d schematically show the different stages of a folding process using the folding unit of Figure 1, according to a third embodiment;
• - Figures 6 a to 6 h, finally, schematically illustrate different stages of a bending process using the Figure 1 folding unit according to a fourth embodiment.

In FIGS. 1 and 2, it can be seen that the folding unit comprises a main conveyor belt 1 and two drive belts 2 and 3 delimiting between them a drive passage 4.

The main conveyor belt 1 is a band closed on itself and stretched between two carrier cylinders 5 and 6 which can pivot on their axes, referenced respectively by 9 and 10̸, these two cylinders 5 and 6 being identical, opposite, and d 'axes 9 and 10̸ parallel. This conveyor belt 1 has two substantially rectangular surfaces 7 and 8, arranged one below the other, longitudinally, between these two cylinders 5 and 6 and tangentially thereto, these two surfaces 7 and 8 being parallel , horizontal and facing each other. The axes 9 and 10̸ of the two carrying cylinders 5 and 6 are each secured to the same chassis 11, the vertical walls of which frame the conveyor belt 1 in length, this chassis 11 being intended to carry the folding unit. The conveyor belt 1 consists of parallel belts 12, looped around themselves and stretched between the two cylinders 5 and 6, two adjacent belts 12 being separated longitudinally from one another by a separation space 13.

The drive belt 2, the same width as the conveyor belt 1, is that of the two drive belts which is closest to the cylinder 5, and is a band made up, like the conveyor belt 1, of belts 12 adjacent. It is closed on itself and passed over two identical cylinders 14 and 15, of diameter substantially smaller than that of cylinders 5 and 6. The axes of these two cylinders 14 and 15, referenced respectively by 16 and 17, are parallel and arranged in a plane perpendicular to the direction of the lengths of the conveyor belt 1. They are both integral, at their ends, with the walls of the chassis 11. The cylinder 15 is that of the two cylinders which is closest to the surface 7 It is arranged just above said surface 7, its length substantially coinciding with the width of the conveyor belt 1. The two surfaces of the drive belt 2 arranged tangentially between these two cylinders 14 and 15 are parallel to it. one to the other and substantially perpendicular to the plane of the surfaces 7 and 8. That of these surfaces of the drive belt 2 which is closest to the cylinder 5 is referenced by 18, the other being referenced ée by 19.

The drive belt 3, consisting of adjacent belts 12, and, of the same width as the conveyor belt 1 and that the drive belt 2, is arranged stretched on three cylinders, referenced by 21, 22 and 23, the axes 27 are parallel to axes 16 and 17 and are arranged to form the longitudinal edges of a straight prism whose base is a triangle. The surface 24 of the drive band 3, which is that of the surfaces of said band between the cylinders 21 and 22, is directly opposite the surface 19 of the drive band 2 and is substantially parallel to this surface 19 , the cylinder 22 being opposite cylinder 15, cylinder 21 being disposed with respect to cylinder 22, on the side opposite surface 7, the length of this surface 24 being slightly less than the length of surface 19. This surface 24 delimits, with the surface 19, the drive passage 4. A second surface of the entrainment band 3, referenced by 25 and comprised between the cylinders 22 and 23, is directly opposite the surface 7 of the conveyor belt 1, and extends the surface 24 perpendicularly, on the side opposite to the drive belt 2 relative to the corridor 4, the cylinder 23 being relative to the surface 7, at the same height as the cylinders 15 and 22. The third surface of this drive belt 3, referenced by 26, is between the cylinders 21 and 23 and is inclined relative to the surfaces 24 and 25, the cylinders 14, 21 and 23 being substantially in the same plane. Each of the axes 27 of the cylinders 21, 22 and 23 is secured, at each of its two ends, to a rod 28, each of the six rods 28 thus defined being itself integral with a movable and sliding frame (not shown) axially in a ball sleeve 29, integral with a wall of the chassis 11. The axes of the rods 28 and of the sleeves 29 are all parallel and inclined relative to the planes of the surfaces 24 and 25, a sliding of the rods 28 relative to the sleeves 29 causing a translational movement of the mobile chassis and of the strip 3 relative to the fixed chassis 11.

On each side of the assembly formed by the drive strip 2 and by the drive strip 3, there is disposed a flattening strip 31 or 32 facing the surface 7 and on the same side as the strips 2 and 3 relative to this surface 7, that of these two bands, which is between the cylinder 5 and the band 2 being referenced by 31, the other being referenced by 32. Each of these two bands 31 and 32 is mounted on a pair of cylinders, referenced respectively by 33 and 34, whose axes are parallel to axes 9 and 10̸, these cylinders being arranged at the same height as the cylinder 15, with respect to the surface 7. The surfaces of each of these two flattening bands 31 and 32, which are between the cylinders 33 or 34, which carry them, and which are tangent, are parallel to the surface 7 and of the same width as the latter. The bands 31 and 32 also consist of spaced belts 12.

The folding unit is, moreover, provided with a rigid member 36, which comprises a rod 35 parallel to the axes 9 and 10̸ and pivotally mounted on the frame 11, between the surfaces 7 and 8 of the conveyor belt 1 , substantially at the same level, relative to the length of the conveyor belt as the cylinder 15, the length of this rod being substantially equal to the length of the cylinders 5 and 6. The rigid member 36 comprises a plurality of double blades 30̸ extending from the rod 35 to their edge where the two blades which form them meet, said edges being substantially at the level of the drive corridor 4 relative to the length of the conveyor belt 1. That of the two blades a double blade 30̸, which is directly opposite the surface 7 is a guide ramp, referenced by 37, curved, and which has a concavity directed towards the quarter plane delimited by the surface 18 and the surface 7 and is next to a spacing 13 between two co urries 12, its width being slightly less than the width of the space 13 to which it corresponds. When the rod 35 pivots on its axis, the double blades 30̸ of the member 36 are raised and pass through the spaces 13, the guide ramps 37 extending, in part, from the surface 7 to their edge which is then at the opening of the drive passage 4. The folding unit further comprises, at the opening of the drive passage 4, a hollow tube 38, which is disposed axially between the cylinders 14 and 15, parallel to the axis 17 and whose length is equal to the width of the conveyor belt 1. This hollow tube 38, integral with the chassis 11, is provided with a multitude of holes on a line opposite that of the openings of the drive corridor 4, which is closest to the bearing surface 7. It is connected at one of its ends to a device putting it under pressure and allowing an air jet to pass through the holes of this tube 38, passing through the belts 12 of the surface 19 and striking the supporting surface 7 on a line across the width of this surface 7.

The conveyor belt 1, the drive bands 2 and 3 and the flattening bands 31 and 32 are each driven on the cylinders, which carry them, by means of motors (not shown), these motors driving the belts 12 constituting these different bands by means of rollers rotating on these belts 12. The surfaces of these bands, between the cylinders which carry them, are displaced in their plane with speeds substantially all identical in standards. The motors associated with them are all controlled by a programmable control unit. This programmable control unit also controls the pivoting of the rigid member 36 as well as the pressurization of the tube 38. It is, moreover, connected to an infrared emitting-receiving cell 20̸, disposed between the surfaces 7 and 8, substantially facing the flattening strip 31, this 20̸ transmitter-receiver cell making it possible to detect, through the spacings 13, the passage of an object over the surface 7 at the level of the flattening strip 31. The conveyor belt 1 is preferably driven in a conveying direction by which an object placed on the surface 7 is transported from the cylinder 5 towards cylinder 6. It is nevertheless possible to program the control unit so that this conveying direction is reversed. The flattening bands 31 and 32 accompany the movement of the conveyor belt 1, their surface directly facing the surface 7, being animated by a movement similar to that of the surface 7. The drive bands 2 and 3 , for their part, rotate so that the surfaces 19 and 24 are always driven by the same movement, this movement being in one or the other of the two directions of the driving direction.

Subsequently, the area of this unit, which is between the drive channel 4 and the cylinder 5, has been designated by "upstream part" of the folding unit, and by "downstream part", the area of this unit. , which is between the drive channel 4 and the cylinder 6. The part of the surface 7 which is located between the strip 31 and the cylinder 5 is called "introduction zone" and, "reception zone ", the part of the folding unit opposite the insertion zone on the conveyor belt 1.

The folding unit can be used to implement a method for folding substantially flat and flexible textile products and in particular quilts or thick blankets. A first implementation of this folding process, shown in FIGS. 3 a to 3 d , using the folding unit, consists in presenting a product 39, generally rectangular, by positioning it on the support surface 7 of the conveyor belt 1, downstream of the folding unit, in the insertion zone, at flat on said support surface 7. This product 39 is then transported to the drive corridor 4. The “leading edge” of a product is called the edge, referenced by 40̸ which is, when the product 39 is upstream of the drive corridor 4, the closest to said corridor 4. When the product 39 passes through the strip 31, it is detected by the infrared photoelectric cell 20̸, which transmits the information of its passage to the unit of ordered. This is programmed to trigger, when the leading edge 40̸ of the product 39 arrives at the opening of the drive corridor 4, the pivoting of the rigid member 36 whose guide ramps 37 are raised to pass through the gaps 13 and extend from the surface 7 to the opening of the drive passage 4. The leading edge 40̸ is then pushed, by the conveyor belt 1 and the air jets of the tube 38, on the ramps 37, which guide it to said opening of the corridor 4. The drive faces 19 and 24 of said corridor 4 are then actuated in a movement going from the carrying surface 7 towards the end of said corridor 4 la further from said carrier surface 7, as indicated by the arrows symbolizing the pivoting of the cylinders 15 and 22 in FIGS. 3 a and 3 b . Product 39 driven by the movement of the faces 19 and 24 which clamp the edge of attack 40, engages, as indicated in Figure 3b, in the corridor drive 4, its thickness pushing the strip drive 3 and the movable frame carrying the support cylinders 21, 22 and 23 downstream of said folding unit, the rods 29 entering the ball sleeves 30̸. The surface 25 of the drive belt 3 then lifts slightly relative to the surface 7. Simultaneously, the pivoting member 36 is returned to its initial rest position, between the carrying surface 7 and the surface 8 of the conveyor belt 1, as indicated by the arrow in FIG. 3 b at the level of the member 36.

When the place of said product where it is desired to obtain a fold, arrives at the opening of the corridor 4, the control unit reverses the movement of the drive belts 2 and 3, the direction in which the sides 19 and 24 of lane 4 now being directed from the end of said lane 4 furthest from surface 7 towards said surface 7, the movement of cylinders 15 and 22 being that indicated in FIG. 3 c . The part of the product which remained, during the first stages of the operation, on the carrying surface 7, upstream of the corridor 4, is then transported by it on the other side of the corridor 4, while the part of said product 39, which was engaged in the drive corridor, 4 descends on said support surface 7 and folds down, forming a fold under the action of the air jets of the tube 38, on the part of product 39 carried by the surface 7 and downstream of the corridor 4. Once the product 39 is completely disengaged from the corridor 4, the movable frame and the drive belt 3 return to their initial position, the rods 28 partially disengaging from the ball sleeves 29, under the effect of gravity forces, and the product 39 can, for example, be transported to the reception area downstream of the corridor 4.

In a second embodiment of the method (FIGS. 4 a to 4 e ), the product 39 is transported by the conveyor belt 1 until the opening of the corridor 4, the control unit being programmed so that the rigid member 36 does not pivot, after detection of the passage of said product 39 by the infrared cell 20̸, until the leading edge 40̸ is downstream of the folding unit, part of the product 39, remaining upstream of the corridor 4. By pivoting, the rigid member 36 lifts, by the edges of the double blades 30̸, said product 39 until the opening of the drive corridor 4, the air jets of the tube 38 pressing said product 39 onto the ramp 37 and thus sketch a fold at its edges. The faces 19 and 24 of the drive corridor 4 are simultaneously actuated in a directed movement from the surface 7 towards the end of the corridor 4, which is the furthest away from it, as indicated by the arrows symbolizing the pivoting of the cylinders 15 and 22, in FIGS. 4 a and 4 b . We see in Figure 4b , that the product 39, engaged in the corridor 4, is driven by clamping the faces 19 and 24 in double thickness towards the end of the corridor 4 opposite the surface 7, its fold being its part the further from the bearing surface 7, the movable frame being pushed downstream of the folding unit, the rods 28 returning to the ball sleeves 29. The control unit is furthermore programmed so that, once the product 39 fully engaged in the drive lane 4, the direction of drive of the faces 19 and 24 of this lane 4 is reversed as indicated by the arrows symbolizing the movement of the cylinders 15 and 22, in FIG. 4 d . The product 39 then descends towards the support surface 7. It falls folded thereon and is driven, for example, downstream of the folding unit by said surface 7, the movable frame returning to its initial position.

It should be noted that these two modes of implementation of the folding process both make it possible to obtain a folding according to a single fold, the difference in folding occurring at the surfaces of the product 39 which are folded over one another, the first mode of implementation making it possible to fold down on itself the surface of the product 39 which is not, in the introduction zone, directly in contact with the support surface and which is intended to be in contact with the strip 31, the second embodiment of this method making it possible to fold the product surface 39 onto itself which is upstream of the corridor 4, in contact with the carrying surface 7.

In a third embodiment shown in Figures 5 a to 5 d , the product 39 is, in the same way as in the previous embodiment, transported to the corridor 4, until a part of this product 39 is located upstream of said corridor 4 and that part is located downstream. The previously programmed control unit then rotates the rigid member 36 which engages, in the same way as previously, the product 29, in the corridor 4 by forming a fold on the edges of its double blades 30̸, the faces 19 and 24 of said corridor 4 driving the product 39 folded in a direction going from the carrying surface 7 towards the end of the corridor 4 opposite to said surface 7. By engaging in the corridor 4, the product 39 exerts an action against the surface 24 of the drive belt 3, which pushes the movable frame downstream of the folding unit and upwards, and widens the lane 4. The direction of drive of the faces 19 and 24 of said lane 4 is then reversed, while part of said product 39 is still upstream of the folding unit, on the carrying surface 7. The part of product 39 engaged in the passage 4 driven in the second direction of the drive direction , emerges from lane 4 down and down on the part of the product 39 which has remained on the support surface 7 and transported by the latter to the downstream zone of the folding unit. A second fold on the product 39 is thus formed, under the action of the air jets of the tube 38, at the place of the latter which, when the direction has been reversed drive of the corridor 4, was substantially at the angle of the surface 19 and the surface 7. The folded product is then, for example, evacuated to a reception area.

There is shown in Figures 6 a to 6 h , a fourth embodiment of the method which uses, the second and third embodiments described above, in combination. In a first series of steps represented in FIGS. 6 a to 6 c , the product is folded according to two folds using the steps of the third embodiment of the method, that of the parts of the product 39 on which the part is folded of product 39 engaged in lane 4, being, once the latter cleared from said lane 4, both upstream and downstream of said lane 4. In a second series of steps repeating the steps of the second embodiment described, the control unit actuates the rigid member 36, while the folded part of the product 39 is downstream of the drive passage 4 and part of the product 39 on the carrying surface 7 is still upstream of said passage 4, so as to lift the product 39 to form a third fold, which can be, as shown by way of example in the figures, substantially at the same level as the first of the folds formed. The direction of entrainment is then again reversed, which is thus directed towards the end of the corridor 4 opposite the support surface 7. The product, folded in four thicknesses, then rises inside the drive corridor 4, these four thicknesses engaging in said corridor 4 and pushing the movable frame downstream of the folding unit. Once all the product 39 is engaged in the drive corridor 4, as shown in FIG. 6 f , the direction of the cylinders 15 and 23 is reversed and the product comes back down folded in three folds on the carrying surface 7, which drives it, for example, towards the reception area.

It should be noted that the lengths of a product 39 between a fold and an edge or between two folds are all adjustable and are a function of the adjustment over time of the movements of the rigid member 36 and of the reversals of the directions of training. In addition, other combinations, from the previously explained modes of implementation, are possible. In particular, it is possible, for example, to use several folding units mounted in series, a product passing successively through each of these folding units so as to be folded in one or more folds each time. It is also possible to use, in series with such folding units, transfer units which make it possible to change the direction of presentation of the products on the folding units and therefore to change the direction of folding on the products, which is generally necessary when you want to fold a product in two directions of orthogonal folding to prepare it for packaging by compacting it as much as possible. A transfer unit may consist of an assembly, substantially identical to that of a folding unit, comprising a conveyor belt and a drive corridor delimited by two drive belts, the planes of this corridor and of these drive belts being, unlike those of a folding unit, not perpendicular but parallel to the conveying direction. When a product arrives in front of a driveway, a knife comes up to lift this product upside down to present it in front of the driveway whose walls close mechanically hard the product to drive it folded, usually in proportions one third / two thirds, in a direction, which is perpendicular, in the plane of said product, in the direction in which it was transported on the conveyor belt and in which it was folded in the folding units in which it passed. It can then be introduced again on new folding units which will fold it according to this new direction of transport.

Claims (19)

1 - Folding unit for a substantially flat and flexible text product, comprising, on the one hand, a conveyor belt (1), mounted on support elements (5, 6) integral with a fixed frame (11) and having a load-bearing surface (7) moving in its plane, by means of motor means, in a direction and a direction of conveyance according to which said load-bearing surface (7) transports said product from an introduction zone, the folding unit comprising, on the other hand, two secondary drive bands (2, 3), mounted on support elements (14, 15; 21, 22, 23) and facing each other, the faces (19, 24) facing these two bands (2, 3) being substantially parallel and delimiting a drive passage (4) terminated at one of its ends by an opening opposite the carrying surface (7), opening the center line of which is substantially perpendicular to the conveying direction, said facing faces (19, 24) being to utes two driven, by motor means controlled by a control device, with a drive movement in substantially the same drive direction and the same direction, the product (39) being driven in the drive lane (4) by clamping between said faces (19, 24), said folding unit also comprising means (35, 36) making it possible to lift the product (39), by one of its parts, from the bearing surface (7) of the conveyor belt (1) up to the opening of the drive passage (4) and being characterized in that the drive faces (19, 24) of the passage (4) can be actuated by the control device , in both directions of the drive direction, the support surface (7) of the conveyor belt (1) extending, in the direction of conveyance, beyond the opening of the drive passage (4) , and transporting the product, after passing through said drive corridor (4), to a reception area. 2 - Folding unit according to claim 1, characterized in that the support elements (21, 22, 23) of one (3) of the drive belts are integral with a frame movable relative to the support elements (14 , 15) of the other drive belt (2), a displacement of said movable frame separating or bringing together, the faces (19, 24) of the drive passage (4). 3 - Folding unit according to claim 2, characterized in that the movable frame is subjected to forces of approach, whose action tends to bring the two drive faces (19, 24), and, when a product (39) is engaged in the drive passage (4), at reaction forces of said product (39) on said faces (19, 24), said reaction forces separating the drive faces (19, 24 ) during the introduction of a thickness of a product (39) into said passage (4), the forces of approximation bringing said faces (19, 24) during the ejection of a thickness of a product from said corridor (4). 4 - Folding unit according to claim 3, characterized in that the approximation forces include gravity forces, the movable frame being connected to the fixed frame (11) by a link which guides the movable frame on a path on which a vertical movement of said mobile chassis is accompanied by a horizontal movement of said mobile chassis. 5 - Folding unit according to claim 4, characterized in that the connection between the movable frame and the fixed frame (11) is obtained by means of at least one assembly comprising a rod (28) integral with one of the two chassis and sliding axially in a sleeve (29) integral with the other of the two chassis, the common axis of this sleeve (29) and this rod (28) being inclined relative to to vertical and horizontal directions. 6 - Folding unit according to claim 5, characterized in that the sleeve (29) of an assembly (28, 29) which provides the connection between the movable frame and the fixed frame (11) is a ball sleeve. 7 - Folding unit according to claims 2 to 6, characterized in that that (2) of the drive belts which is not integral with the movable chassis is integral with the fixed chassis (11), the conveying direction going, at the opening of the drive corridor, from the drive face (19) of the band (2) secured to the fixed frame (11) to the drive face (24) of the band (3) secured of the mobile chassis. 8 - Folding unit according to one of claims 1 to 7, characterized in that the drive strip (3) of those (24) of the faces of the drive passage (4), towards which the direction is directed conveying at the opening of said passage (4), extends said face (24), beyond said opening, by a face (25), which is opposite the bearing surface (7) of the strip of conveying (1) and which is substantially parallel to said carrying surface (7). 9 - Folding unit according to one of claims 1 to 8, characterized in that it comprises, at least one flattening strip (31) disposed relative to the conveying direction, before the two drive strips ( 2, 3), and / or, at least one flattening strip (32) arranged, relative to the conveying direction, after the two strips drive (2, 3), a flattening strip (31, 32) having a surface facing the support surface (7) of the conveyor belt (1), substantially parallel to said support surface (7) and animated by a movement in substantially the same direction, the same direction and the same speed as that of the carrying surface (7). 10 - folding unit according to one of claims 1 to 9, characterized in that the conveyor belt (1) has belts (12) arranged in length in the direction of conveyance, two adjacent belts (12) being separated from each other by a separation space (13). 11 - Folding unit according to one of claims 1 to 10̸, characterized in that the means (35, 36) for lifting a product (39) until the opening of the drive corridor (4) comprise at least one mechanical member (36), the part of which intended to be in contact with a product is provided with a curved guide ramp (37) which, in the guide position, extends from the bearing surface (7) of the conveyor belt (1) up to said opening, the concavity of the curved guide ramp (1) being substantially opposite to the direction of conveyance. 12 - Folding unit according to claims 10̸ and 11 taken in combination, characterized in that a mechanical member (36) is mounted on a pivot (35) on the side opposite to the drive corridor (4) relative to the carrier surface (7) of the conveyor belt (1) and is pivotally actuated from the control device, the guide ramp (37) passing from one side to the other of the carrier surface (7) of the conveyor belt (1) crossing said supporting surface (7) in a separation space (13). 13 - Folding unit according to one of the comprises at least one infrared cell (20̸) connected to the control device and detecting the passage of a product (39) on the conveyor belt (1). 14 - Folding unit according to one of claims 1 to 13, characterized in that it comprises, at the opening of the drive passage (4), at least one element (38) for ejecting an air jet directed towards the support surface (7) of the conveyor belt (1) in a direction included in the dihedral, which is arranged upstream of the drive passage (4) on the conveyor belt (1) with respect to the conveying direction and which is delimited by said drive passage (4) and the carrying surface (7) of said conveyor belt (1). 15 - Folding unit according to one of claims 1 to 14, characterized in that it is used in series with at least one other substantially identical folding unit and / or in series with at least one transfer machine. 16 - Method of folding a substantially flat and flexible textile product from a folding unit according to one of claims 1 to 15, characterized in that, to obtain at least one fold, it is transported by the band conveying (1) said product (39) from a location upstream of the drive passage (4) relative to the conveying direction until its leading edge (40̸) is opposite the opening of the drive corridor (4) lifting said leading edge (40̸) of said product (39) until the opening of said corridor (4); said product (39) is driven, inside the drive passage (4), by clamping said product (39) by the faces (19, 24) of the movement passage (4), in a first direction of the drive direction, leading edge (40̸) moving away from the bearing surface leading edge (40̸) moving away from the bearing surface (7); the direction of drive of the faces (19, 24) of said passage (4) is changed, when the product (39) is partly engaged in said passage (4) and partly still on the carrying surface (7); the part of said product (39) engaged in the passage (4) is driven by the drive faces (19, 24) in movement, in the second direction of the drive direction, the part of said product (39) ejected from the driveway (4) which folds down, forming a fold, on the part of said product (39) transported, by the carrying surface (7) of the conveyor belt (1), downstream of the driveway (4 ) with respect to the conveying direction. 17 - A method of folding a substantially flat and flexible textile product from a folding unit according to one of claims 1 to 15, characterized in that, to obtain at least one fold, it is transported by the band conveying (1) said product (39), from a location upstream of the drive passage (4) relative to the conveying direction until a part of its surface is opposite the opening of the drive corridor (4); lifting, by forming a fold, said part up to said opening; driving said folded part inside said passage (4) by clamping said product (39) folded by the drive faces (19, 24) in movement in a first direction of the drive direction, the folded part moving away from the carrying surface (7); the direction of drive of the faces (19, 24) of said passage (4) is changed, when said folded product (39) is fully engaged in said passage (4); said product (39) is driven by the drive faces (19, 24) in movement in the second direction of the drive direction, its part released from the corridor drive (4) being transported by the carrying surface (7) of the conveyor belt (1), downstream of the drive passage (4) relative to the direction of conveyance. 18 - A method of folding substantially flat and flexible textile products from a folding unit according to one of claims 1 to 15, characterized in that, to obtain at least two folds, is transported by the strip of conveying (1), said product (39) from a location upstream of the drive passage (4) relative to the conveying direction, until a part of its surface is opposite the opening of the drive corridor (4); lifting, by forming a fold, said part up to said opening; driving said folded part inside said passage (4), by clamping said product folded by the drive faces (19, 24) in movement, in a first direction of the drive direction, the folded part s' moving away from the supporting surface (7); the direction of drive of the faces (19, 24) of said corridor is changed, the product (39) being partly engaged in said corridor (4) and partly on the supporting surface (7), upstream of said drive corridor (4) relative to the conveying direction; the folded part of the product (39) is driven inside the drive passage (4) by the drive faces (19, 24) in movement in the second direction of the drive direction, the part of said product (39) ejected from said passage (4) which folds down, forming a second fold, on the part of said product (39) transported, by the carrying surface (7) of the conveyor belt (1), downstream from the passage (4) with respect to the conveying direction. 19 - Process for folding substantially flat and flexible textile products from at least one folding unit according to one of claims 1 to 15, characterized in that the folding is obtained by a combination of the methods of claims 16 to 18.

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