EP0323296A1 - Process for the formation of zig-zag piles using an endless web of flexible material, and machine for carrying out this process - Google Patents

Abstract

The invention relates to a method and a machine for forming zigzag stacks from an endless strip of paper. According to the method, the strip (3) is deposited and folded on an appropriate support (1) and, at the end of the formation of a stack (2), causes the strip (3) to rupture along a line of predetermined folding, causes the first folding flap of the next stack to be formed in a predetermined position, stops the movement of advancement of the strip and discharges the stack which has just been completed. The method is characterized in that the rupture by the tensile force of the strip (3) is exerted during the advancing movement of the latter, by applying the strip by one of its surfaces, advantageously at the level of the breaking line. predetermined, against fixed means (20) by deflection of the strip downstream and upstream of its part in application, from its normal trajectory advantageously perpendicular to the plane of the strip, while guiding the latter. The invention can be used for folding a strip of paper printed by a computer printer.

Description

The invention relates to a method for forming stacks from a continuous strip of flexible material, such as paper, by zigzag folding the strip along pre-established transverse fold lines, such as transverse perforation lines, and a machine for implementing this process.

The formation of the stacks by zigzag folding must be able to be carried out at a relatively high speed, in particular when it is a question of paper coming from a laser printer where it has been printed. It is well known that such printers work at high speeds. It turned out that under these conditions the deposit and especially the retention of a folding flap on the part of the pile already established constitutes a delicate problem. Even more difficult to execute is the installation of the last flap of a pile which lives to be formed and of the first flap of the following pile.

According to a known method and the mac ine for its implementation, the zigzag deposition of the flaps, from an endless band is carried out with the idea of a pendulum device which performs a pivoting movement above 'a stack support table. This continuous strip is pre-cut at the edge of the fold line in the form of a line of weakening of the material constituting the strip and connecting the last flap of the stack in formation and the first flap of the next stack. To accomplish this separation operation of the strip, it is stopped when the separation line to be carried out is just upstream of the balance. Then pinch said last flap between two clamping rings and moves said first flap in the direction opposite to that of the movement of advancement of the strip. Under the effect of the tensile force thus imposed on the port [on of the strip which comprises the separation line, the strip is caused to rupture. Then the band advancing means are restarted, in its normal direction, until the front edge of said first flap comes out of the pendulum. Then the pil which has just been finished with the installation of the last flap is evacuated. After this operation, the movement for advancing the strip is retriggered with a view to the formation of a new stack.

It is obvious that this known process and the machine which implements it do not present a satisfactory solution to the problem which has just been set out above. In fact, the numerous operations necessary to obtain separation of the strip, even including a drive operation behind it, are incompatible with the operating mode of laser printers working at high speeds.

The present invention aims to provide a method and a machine which no longer suffers from the drawbacks of the state of the art which has just been stated.

To achieve this object, the method according to the invention is characterized in that the tensile breaking force of the strip is exerted during the advancing movement of the latter by applying the strip through one of its surfaces, advantageously at the center. at the predetermined breaking line, against fixed means, by deflection of the strip downstream and upstream of its part in application, from its normal path, substantially perpendicular to the plane of the strip, while guiding the band.

According to an advantageous characteristic of the invention, the movement of advancement of the strip is interrupted and the stack formed is evacuated, when the front edge of said first flap is in its position of the first flap of the new stack to be formed and is retained in this position by transient support means.

According to another advantageous characteristic of the invention, the aforementioned transient support means are part of the means for folding the strip in its zigzag configuration.

The machine for implementing the method according to the invention is characterized in that the separating means intended to cause the rupture of the strip at a predetermined breaking line comprise a device provided with breaking edges arranged so as to come in contact with one of the surfaces of the strip and located between two devices for deviating the strip from its normal trajectory, each comprising at least one roller whose axis extends perpendicularly to the longitudinal direction of the strip and parallel to the plane of the latter, on the side of the other surface of the strip and movable perpendicularly to the plane of the latter to come into contact with this surface to produce said deviation of the strip with forced application of the latter against said device with edges rupture, and in that means forming guide paths of the strip at and downstream of the point of rupture of the strip are provided.

According to an advantageous characteristic of the invention, the pendulum device intended for the formation of the stack in a zigzag configuration comprises elements for driving the strip of paper in the direction advancement.

According to another advantageous characteristic of the invention, the machine comprises a device for transient support and retention of the first folding flap of a new stack, which comprises four discs mounted to rotate in synchronism with the movement of the pendulum, in parallel planes in the plane of installation of the folding flaps for the formation of a stack, each at a corner of the stack to be formed, next to a longitudinal edge of the flaps, so as to be able to engage by a part of its surface in the loop formed by a folding flap during its installation for the formation of a stack, and, associated with each disc, a member mounted to rotate around an axis parallel to the folding lines of the flaps deposited, situated above said laying surface and of the part of the disc engaging in said loop, a distance from the upper surface of this part such that the part forming the front edge of said first flap can come into a position of tight engagement between the peripheral surface of said rotary member and said upper surface of the disc and advantageously be brought into the position it will occupy in the formed stack, each disc and its associated rotary member rotating in the direction of rotation in the direction of folds of the deposited flaps, in synchronism with each other.

According to yet another advantageous characteristic of the invention, an aforementioned rotary member is formed by a brush, the cross section of which is perpendicular to its axis of rotation advantageously has the shape of a segment of a circle.

• La figure 1 est une vue schémati]ue en élévation, d'une machine selon la présente invention ;
• La figure 2 montre, de façon sch matique, à plus grande échelle la partie indiquée en II à la figure 1 ;
• La figure S est une vue en direction de la flèche III-III de la figure 2, la pile en cours de formation et la partie inférieure de la machine ayant été supprimées ;
• La figure 4 est une vue partiellen direction de la flèche IV de la figure 2 ;
• Les figures 5a, 5b et a, 6b illustrent deux phases du fonctionnement de la machine selon l'invention, par des vues respectivement latérale (a) et de dessus (b) ;
• Les figures 7 à 9 représentent schématiquement trois phases du procédé et du fonction ement de la machine selon l'invention, aboutissant à la pose du dernier volet d'une pile et l'acheminement et la retenue du premier volet d'une nouvelle pile, a et b étant des vues respectivement latérale et de dessus ; et
• La figure 10 illustre un autre mode de réalisation d'une brosse selon la figure 5a.

The invention will be better understood and other objects, characteristics, details and advantages thereof will appear more clearly during the description. Explanatory which will follow made with reference to the attached schematic drawings given solely by way of example illustrating an embodiment of the invention and in which:

• Figure 1 is a schematic view in elevation of a machine according to the present invention;
• Figure 2 shows, schematically, on a larger scale the part indicated in II in Figure 1;
• Figure S is a view in the direction of arrow III-III of Figure 2, the stack being formed and the lower part of the machine having been removed;
• Figure 4 is a partial view in the direction of arrow IV of Figure 2;
• FIGS. 5a, 5b and a, 6b illustrate two phases of the operation of the machine according to the invention, by respectively lateral (a) and top (b) views;
• FIGS. 7 to 9 schematically represent three phases of the method and of the operation of the machine according to the invention, leading to the installation of the last flap of a stack and the routing and retention of the first flap of a new stack, a and b being respectively lateral and top views; and
• FIG. 10 illustrates another embodiment of a brush according to FIG. 5a.

Figure 1 schematically shows the machine according to the invention which is adapted to form on a support device 1 batteries 2 in a zigzag configuration, from an endless band 3 in one suitable flexible material, in particular paper, which is supplied by a preceding machine, not shown, for example a computer printer, of the laser type. This endless strip has longitudinal perforations of the Caroll hole type and transverse weakening lines, such as perforation lines which constitute the fold lines of the strip in its zigzag configuration on the support 1. The longitudinal and transverse perforations are known per se and are not shown.

The machine comprises, according to the embodiment shown, successively in the direction of the advancement movement of the ban 3, indicated by the arrow F1, essentially a device 5 comprising two toothed belts with spikes 6 intended to engage in the Caroll holes in the strip 3 to ensure the drive of the strip 3 forming upstream of the device 5 a loop 7, edge cutting ganes 8, a separation assembly 9 for the strip intended to break the strip along a predetermined breaking line formed by a transverse perforation line, a device 10 for returning the strip to a bala cier device 11 known per se which performs a pendulum movement in an angular zone β depending on the format of the flaps folding delimited between two lines of weakening and folding adjacent to the strip. This balancing device has the function of depositing the endless belt 3 on the support 1 in a zigzag configuration for the formation of a stack. The machine further comprises, at each lateral edge indicated at 12, a set of flattening and retaining the flaps on a stack in formation and the first flap of a new stack, as will be described in detail below. The reference symbols 15 and 16 respectively designate means for moving the support device 1 and the means for discharging a completed battery from the machine according to the invention.

Referring to FIGS. 2 to, the various important devices constituting the machine shown in FIG. 1 will be described in more detail below.

As is apparent from FIGS. 1 and 2, the device 9 for separating the strip S along the rupture line formed by the transverse perforation line connecting the last flap of the stack in formation to the first flap of the new stack, comprises essentially two pairs 18 ′ 19 of rollers located respectively upstream and downstream of a certain number of elements 20 with breaking edges which are juxtaposed just below the strip 3 in the transverse direction relative to the strip. The two rollers 21 22 of the two pairs of rollers 18, 10 are arranged respectively below and above the strip, at a predetermined distance, their axis extending perpendicularly to the direction of the movement of advance of the strip 3 , parallel to the plane of the latter when it is in its normal advancing position indicated in the form of a solid line. The two lower rollers 21 are rotatably mounted around fixed axes and are advantageously driven in rotation by suitable motor means as indicated by arrows F2. The two upper rollers 22 are rotatably mounted around movable axes perpendicular to the plane of the strip 3, using appropriate hydraulic cylinders mounted in a common support 23. The rollers 22 are movable in translation between the position shown far from the upper surface of the strip 3 and a position in which they deflect the strip perpendicular to its normal position until it comes into close contact against the peripheral surface of the lower drive rollers 21.

In this position the strip 3 is in the position shown in broken lines. Under the effect of the thrust force of the rollers 22, the elements with breaking edges 20 cause the strip to rupture, the lowering of the rollers 22 being controlled when the transverse perforation line forming the set rupture line is at the level of elements 20.

It has been found that the roller 22 of the pair 19 must be able to carry out a slight sliding on the roller 21 until the moment when the transverse perforation line reaches the breaking device 20. It would then be advantageous to produce this roller in the form a brush.

To guide the strip 3 during its normal routing and said last and first flaps, after the separation of the strip, there is provided a device 25 for guiding the strip at the top and at the bottom, which extends from from a position upstream of the first pair 18 of rollers to the deflection device 10, widening in the direction perpendicular to the plane of the strip, as indicated in FIG. 2. This guide channel 25 has recesses in its upper and lower walls which allow the rollers 21 and 22 to penetrate inside the channel. Regarding the deflection device 10, it comprises a drive roller 26 which advantageously extends over the entire width of the strip, like the rollers 21 and 22 and for example, two or more brushes 27 which are axially juxtaposed over the width of the strip 3, parallel to the axis of the rollers 26 and arranged so as to ensure the application of the strip against the peripheral surface of the drive roller 26 by coming into pressed contact with the other surface of the strip.

As shown in FIG. 2, the guide channel 25 achieves a tape buffer guiding and storage effect up to the level of the band engagement between the roller 26 and the brushes 27. The paper strip 3 pinched between the roller 26 and the brushes 27 is introduced into the balance assembly 11 essentially comprising flat belts 29 rotating at the speed of toothed belts 6 by guiding the band 3 between them and rollers 30, one of which is a motor, located at the free end of the balance Thus the band is driven up to the pendulum exit. The balance assembly alternately distributes the folding flaps to the flattening and retaining 13 sets of the flaps.

With particular reference to FIG. 3, it can be seen that each assembly 31 essentially comprises two disc-shaped members 31 mounted to rotate around axes situated on either side of the support device 1, in a plane parallel to the plane of poses flaps on this device, close to stop elements 32 of the folds of the flaps. Each disc is rotated in the direction of arrow F3 and is produced, in the example shown, in the form of a substantially semi-circular disc, the front part 33 of which at an angle of 45 ° is folded upwards, according to a predetermined angle as a function of the format of the folding flaps and followed by a horizontal part 34. As the figures show, the discs 31 are arranged in such a way that they engage during their rotation in the installation space flaps of the support device 1, for the purpose which will be explained in detail below. Each of the discs 31 is associated with a rotary member 35 advantageously in the form of a segment of a circle with an angle equal to or somewhat greater than 180 ° and formed by a brush. Each of these brushes 35 is rotated about an axis extending parallel to the laying plane and to the folds of the flaps located on the support 1, at a distance and a place above the plane of installation of the flaps and of the planes of the discs 31 so that they can come into contact with the peripheral zone of the planar upper surface 34 of the discs 31 when the disc in the shape of a semicircle engages in the space for fitting the flaps, as is clear from the figures. Thanks to this relative arrangement of the discs 31 and the brushes 35, the first flap of a new zigzag stack on the support 1 can be retained in a defined position, by being pinched between these members as will be explained below. Each set 13 further comprises two members 36 called hammers arranged symmetrically with respect to the center line YY of the laying plane between the two brushes 35. Each hammer is mounted to rotate about an axis advantageously coincident with the axis of rotation of the brushes 35. Each hammer has a part 37 forming a head and a part forming a shank 38. As can be seen in particular from FIG. 2, the shank has a substantially cylindrical peripheral surface whose diameter is substantially equal to the diameter of the brushes 35, while the part forming head 37 is eccentric towards the axis of rotation of the hammer. The radius of curvature of the head portion increases progressively towards the tail 38. This configuration of the hammers makes it possible, during their rotation, to flatten the loops of the strip progressively during its zigzag deposition on the support 1. The hammers are driven in rotation by motor means, at a speed equal to that of the brushes and in synchronism with the advancement movement of the band 3 and the pendulum movement of the balance device 11. The angular position of the hammers 36 relative to that of the brushes 35 and discs 31 is well defined to ensure the cooperation of these different organs, which will be described later.

Each assembly 13 also comprises between the two hammers a member forming a measuring propeller 40 which rotates in synchronism with the discs also in the form of a propeller 31. The front part 41 of the propeller 40 is folded upwards at a predetermined angle, on an angular extent of for example 90 °, this raised part being followed by a horizontal part 42, that is to say the plane of which is parallel to the horizontal part 34 of the discs 31. The measuring helix 40 is freely movable mounted upwards on its axis of rotation. It is arranged so that it engages by a part of its surface in the zigzag laying space of the strip 3, so as to be displaced upwards when increasing the height of a pile during training on the support device 1. With the measuring propeller 40 is associated a contact of an electrical circuit (not shown) which controls the breaking of a brake 44 and the starting of a motor reducer 45, forming part of the support device 1 (FIG. 1).

The battery support device 1 essentially comprises a receiving table 47 mounted vertically mobile, under the effect of chain wheels 48 and a jack 49. For the descent, the table 47 is driven by the chain wheels 48, the jack 49 being ineffective. This movement stops when the propeller 40 ceases to mount on the flaps forming the stack. The upward movement is controlled by the jack 49. The reception table 47 has a comb structure as can be seen clearly from FIGS. 3 and 4. The flaps arranged in a zigzag fashion thus rest on vertical wall elements 50 which are arranged parallel to each other. to the others, leaving a space between two adjacent elements which serves for the passage of a conveyor element in the form of an endless belt 52. All of these juxtaposed conveyor elements constitutes an endless conveyor belt 53 (FIG. 1), for discharging the finished stacks from the machine, as illustrated in FIG. 1. It can be seen that such a wall 50 is located below each brush 35 and each hammer 36 and therefore serves as a bearing surface. In this FIG. 1, 55 and 56 also show upper and lower limit switch contacts of the receiving table 47, by cooperating with a boss 57 associated with the table 47, more precisely with a chain passing over the wheels. 48.

The operation of the machine which has just been described and the method according to the present invention will be described below:

With particular reference to FIGS. 2, 5 and 6, the procedure for installing the flaps will be described in a zigzag configuration on the support device 1. FIG. 2 shows the balance device 11 in its substantially vertical position in during the installation of a flap of the strip 3, moving in the direction of the arrow F4. The strip 3 at the outlet of the balance 11 forms a loop having the configuration shown schematically in 1. At this instant of time approximately, the discs 31 of the flattening and retaining assembly 13, located on the right in the figure, begin to engage by their raised front part 33 in the loop. The brushes 35 and the hammers 36 which are driven therein in synchronism with the rotary movement of the discs 31 occupy an angular position where they are not yet in contact with the loop. When the balance is in the angular position β1, the band forms the loop designated by B. The relative position of the discs 31, the brushes 35 and the hammers 36 is shown in Figures 2 and 3. It can be seen that the raised front part 33 discs is coming out of the loop and the part horizontal 34 of these discs is engaged on the last component already deposited. Lesm areaux 36 occupy an angular position in which the head 37 just begins to flatten the loop B in the shape of a warhead. The brushes are not yet in the loop attack position. Figures 5 and 6 show two subsequent phases illustrating the gradual flattening of the loop by the hammers, first by their head 37 and then their tail portion 38, as well as by the action of the brushes 35 which come to support the strip 3 on the top of the half-discs 31, the raised front part 33 of which is taken out of the loop formed by the strip 3. Finally, when also the horizontal part 34 of the discs is taken out of the loop, now practically flattened, the folding is finished and the hammers 36 hold by their shank 38 the two flaps whose fold has just been formed and which are pressed against each other and on the pile being formed. It should be noted that the cheek-shaped stops 32 stop the movement of the flaps while letting the brushes 35 and the hammers 36 pass through suitable windows. It should also be added that the discs, brushes and hammers of the flattening and retaining assembly 13, located on the left side of FIGS. 1 and 3 are 180 ° out of phase with respect to the discs, brushes and hammers. the assembly which has just been described and flatten the loop which the balance 11 will form thereafter, on the left side in the figures.

During this stack formation operation, the measurement propellers 40 rotate in synchronism with the semi-discs 31. The propellers are freely movable upwards on their axis of rotation under the effect of the increase in the number of flaps deposited on the reception table 47. They can pass over the stack of shutters deposited thanks to their raised part 41. Passed a defined height, the corresponding propeller controls, by means of an electrical contact, the breaking of the brake 44 and the starting of the geared motor 45. The reception table 47 then descends, driven by the chain wheels 48. The movement stops when the propeller stops rising on the batteries of the flaps removed.

The end of the formation of a pile, the evacuation of the latter from the machine and the preparation for the formation of a new pile will be described below with particular reference to FIGS. 2 and 7 to 9. When a detector cell represented at 59 in FIG. 1, at the level of the device 5 with toothed belts reads a code present on the strip 3, it programs in time the jacks 23 of the strip separation device 9, which lower the rollers upper 22 covered with rubber when the perpendicular line of perforation of rupture is between the two pairs of rollers 18 and 19 of the device 9, but preferably before the separating rollers 20. The roller 21 of the pair 18 rotates at speed belts 6 while the roller 21 of the pair 19 advantageously turns a little faster when the transverse perforation line passes over the breaking elements 29. This causes the strip to break. The two cylinders 23 of the device 9 then raise the rollers 22.

The end of the strip, that is to say the last flap of the pile being formed and the first flap of the new pile to be formed are held between the guides of the device 25. The roller 26 and the brushes 27 hold the strip separated at the speed of the belts 6. The balance assembly 11 with its belts 29 and the rollers 30 pushes the last flap of the strip designated by the reference symbol 60 in FIG. 7a towards the semi-discs 31 corresponding. It can be seen that the first flap of the stack to be formed bears the reference 61. The difference between the two flaps 60 and 61 is very small. As shown in Figures 7 to 9, which show three successive phases of the final operation of the formation of a stack, the hammers 36 ensure the deposition and plating of the last flap 60 on the stack, while the first flap 61 passes over the semi-discs 31 and is applied by the brushes 35 to the upper surface of these discs. Being pinched between the disc and the brushes, the flap is driven towards the abutment cheeks 32. When the strip exceeds a predetermined width, the air jet nozzles 43 are activated.

It is at this moment that the order is given to begin the cycle of evacuation of the stack, by stopping the belts 6, the rollers 21, 26, the brushes 27, the balance 11 with its belts 29 and the rollers 30, semi-discs 31, brushes 35, hammers 36 and propellers 40. The brake 44 is released and the jack 49 quickly lowers the reception table 47. The latter being in the form of a comb, it passes through the belts of the conveyor belt 53. The closing of the contact elements 27 and 57 stops the descent of the table and controls the starting of the motor 54 which sets the bands 52 of the evacuation belt 53 in motion so that it evacuates the stack or the finished package, as shown in FIG. 1. When the evacuation of the stack is finished, the jack 49 causes the receiving table 47 to go up rapidly until the boss 57 engages the contact 56 , which controls the end of the table rise, the application of brake 44 and re-engages the drive devices îlement of the strip 3 so that the balance 11 and the flattening and retaining assemblies 13 can form the new stack.

Many modifications and refinements can be made to the invention without departing from the scope thereof.

Thus, FIG. 10 presents means making it possible to obtain a crushing of the folds of the flaps of the stacks, so as to avoid excess thickness of the stacks at the level of the folds relative to the center. This effect is achieved by an appropriate conformation of the brushes 35. As shown in the figure, such an improved brush has a hub 60 which is eccentric with respect to the axis of rotation 61 of the brush so that the bristles shown at 63 vary lengthwise around the periphery of the hub as shown. The length of the bristles increases in the opposite direction to the direction of rotation of the brush. The lining of the bristles also has a front portion 63 in which the length of the bristles decreases progressively with respect to the diameter of the brush in the direction of rotation thereof. Thanks to this front portion 63, the brush 38 has a shape which ensures that the brush comes into contact with the loop of the strip 3 in a gentle manner without there being the risk of the formation of a crease primer in one place. other than the transverse perforation line separating two adjacent flaps.

The hub 60 carries, downstream of the lining of the bristles 62, a hammer device 64 for crushing the folds. This device comprises a support arm 65 of a hammer element 66 of an oblong shape. The support arm is mounted at the periphery of the hub 60, pivoting about an axis 67 substantially parallel to the axis 61 of the brush, against a compression spring 68 oriented substantially in the direction of periphery of the brush and bearing on an element 69 integral with the hub 60. The element 69 is located downstream of the support arm 65, relative to the direction of rotation of the brush. The hammer member 66 has an angle of par example 120 ° relative to the support arm 65 and is oriented in the opposite direction to the direction of rotation of the brush. Under these conditions, the hammer member exerts pressure on the folding zone already flattened before by the bristle lining of the brush and ensures the crushing of this zone under the effect of the spring then compressed 68. It is easily understood that in in this case the hammers 36 could be eliminated.

One could also equip the machine according to the invention with an auxiliary support device 70 of a new stack of shutters, during the evacuation of the stack which has just been formed by the rapid lowering of the support 1 under the cylinder effect 49.

The additional support device 70 comprises a number of horizontal parallel rods 71 which are arranged so as to form a comb configuration horizontally displaceable by a double-acting cylinder 72, as illustrated by the arrows. The rods 71 are laterally offset with respect to the vertical wall 50 of the receiving table 47 of the support 1 so that they can be substituted for these when the table is lowered. Once the evacuation of the stack is complete, the table 1 is reassembled and the auxiliary support formed by the comb configuration of the rods 71 is removed by the jack 72 without this producing any discomfort for the formation of the new stack already In progress.

Consequently, the equipment of the machine of the auxiliary support 70 allows the evacuation of finished stacks and the formation of new stacks without it being necessary to stop the machine.

The machine can also be equipped with means ensuring that the balance 11 always stops at the same position extreme angular, such as for example that indicated at 73 in FIG. 1. To ensure this result, an additional motor 74 is provided for driving an eccentric 75 for controlling the balance 11 and one revolution of which corresponds to the length of two shutters. With the eccentric 75 is associated a synchronization finger 76. Thanks to these measures, it is possible, after the command to stop the strip, to bring the balance 11 still in its predetermined stop position, which provides batteries where the top panel has the information printed on its visible side.

To ensure that the bursting of the strip with a view to forming a new pile always takes place in a precise manner, independently of the speed of advance of the strip, the machine further comprises, as indicated in the figure 1, a detector 78 of the speed of advance of the strip 3 by counting the teeth of the pins 6 and a microprocessor 79 which calculates from the values and signals received from the detector cell 59 of the separation code present on the strip 3, as indicated above, and from the detector 78 the instant of time at which the detected rupture perforation line will arrive in its rupture position at the level of the separation rollers 20. The microprocessor 72 then consequently controls the jacks 23 of the device separating strip 9. In fact, knowing at all times the speed of advancement or of movement of the strip and the time of movement of the jacks being constant, independently of the speed of the strip, it is possible to decide the control of the jacks as a function of the speed of the bandaged. To this end, the numbers of the teeth from which the jacks 23 must be controlled have been stored in memory, according to the linear speed of the strip. Thus, during the start and stop phases, the function commands remain synchronized. This is valid for all orders such as for example the control of the air jet device 43 and of the pendulum stop movement 11 during a transfer. This method ensures the separation of the strip whatever the format of the flaps, without having to mechanically modify the distance between the separation rollers, or to stop the machine.

Claims (18)

1. Method for forming stacks from an endless strip of flexible material, such as paper, by zigzag folding of the strip along pre-established transverse fold lines, such as transverse perforation lines, whereby the strip is deposited and folded on a suitable support and, at the end of the formation of a stack, causes a rupture of the strip along a predetermined fold line, brings the first folding flap of the stack next to be formed in a predetermined position, stops the advancement movement of the strip and discharges the pile which has just been completed, characterized in that the rupture by traction force of the strip (3) is exerted during the movement d advancement thereof by applying the strip through one of its surfaces, advantageously at the level of the predetermined breaking line, against fixed means (20) by deflecting the strip downstream and upstream from its part in application, its normal trajectory, advantage wear perpendicular to the plane of the strip, while guiding the latter. 2. Method according to claim 1, characterized in that the movement of advancement of the strip is interrupted and the stack formed is discharged, when the front edge of the first flap (61) is in its position of the first flap of the new stack to be formed and is retained in this position by transient support means (31, 35). 3. Machine for forming piles from an endless strip of flexible material, such as paper, comprising a balance assembly suitable for depositing the strip on a support device, in a zigzag configuration, means for separation of the strip between the folding flaps intended to constitute respectively the last flap of the stack in formation and the first flap of a new pile and a device for discharging the batteries after their formation, the separation means being arranged upstream of the balance assembly, characterized in that the means for separating (9) the strip comprises a device provided with breaking edges (20) arranged so as to come into contact with one of the surfaces of the strip and situated between two devices (18, 19) for deflecting the strip its normal trajectory, each comprising at least one roller (22) whose axis extends perpendicular to the longitudinal direction of the strip and parallel to the plane of the latter, on the side of the other surface of the strip and advantageously movable perpendicular to the plane thereof, to come into contact with this other surface to produce a deviation of the strip, from its normal position, with forced application of the latter against said device with breaking edges (20), and in that than means forming guides (25) of the strip at and downstream of the rupture zone are provided. 4. Machine according to claim 3, characterized in that each deflection roller (22) is associated with a motor counter-roller (21) located on the other side of the strip (3), the latter being pinched between these two rollers in its deflected position. 5. Machine according to one of claims 3 or 4, characterized in that the separation device (9) comprises a plurality of rollers axially juxtaposed perpendicular to the longitudinal axis of the strip, each roller having at its periphery an edge of circumferential rupture. 6. Machine according to one of claims 3 to 5, characterized in that the balance assembly (11) provided for the formation of a stack in a zigzag configuration comprises elements for guiding and driving the strip (3) in its direction of advance, advantageously comprising driving belts (29) and rollers (30) located at the free end of the balance device and one of which is a motor. 7. Machine according to one of claims 3 to 6, characterized in that it comprises a device serving both as a device for folding the flaps of a stack in formation and as a support and transient retaining device (13) of the first folding flap (61) of a new stack, which comprises four discs (31) rotatably mounted in synchronism with the movement of the balance (11), in planes parallel to the plane of installation of the folding flaps for the formation of a pile, each at a corner of the pile to be formed, next to a longitudinal edge of the flaps, so as to be able to engage by a part of its surface in the loop formed by a flap folding during its installation for the formation of a stack, and, associated with each disc (31), a member (35) rotatably mounted around an axis parallel to the fold lines (12) of the deposited flaps, situated above the laying plane and the disc part engaging in said loop, at a distance from the upper surface d e this part such that the part forming the front edge of said first flap (60) can come into a position of tight engagement between the peripheral surface of said rotary member (35) and said upper surface (34) of the disc (31) and advantageously be brought into the position it will occupy in the stack formed, each disc (31) and its associated rotary member (35) rotating in the direction of rotation in the direction of its folds (12) of the deposited flaps, in synchronism with one 'other. 8. Machine according to claim 7, characterized in that that a rotary member (35) mentioned above is formed by a brush whose cross section perpendicular to its axis of rotation advantageously has the shape of a segment of a circle. 9. Machine according to one of claims 7 or 8, characterized in that a disc (31) is produced in the form of a segment of a circle, advantageously 180 °, the front part of which is raised at an angle predetermined. 10. Machine according to one of claims 7 to 9, characterized in that each support and retaining device (13) mentioned above is associated with at least one flattening hammer (36) of the folding zones of two successive flaps to be laid, which is rotatably mounted in synchronism with the aforementioned discs (31), about an axis parallel to the fold lines above the laying plane and has a circumferential contact surface with the fold zone to be flattened into shape a cam comprising a front part forming a head (37) eccentric towards the axis of rotation in the manner of a spiral part and a cylindrical part forming a tail (38), the axis of the flattening member ( 36) being disposed above the laying plane at a distance substantially equal to the diameter of the tail portion (38). 11. Machine according to claim 10, characterized in that two flattening hammers (36) are associated with each support and retaining device (13) mentioned above, located symmetrically on either side of the longitudinal center line of the plane for installing the flaps, the battery support device (1). 12. Machine according to one of reve dications 6 to 11, characterized in that it comprises on each side lateral of the flap installation plane, substantially in the middle, a stack height measurement and lowering control device for the stack support device (1), in the form of a rotary propeller in synchronism with the discs (31) above, about a substantially vertical axis, freely movable upward on its axis and arranged to come to bear on the area of the upper fold. 13. Machine according to one of claims 10 to 12, characterized in that the support device (1) comprises a receiving table (47) with a vertical cross section in the shape of a comb and comprising a plurality of parallel vertical walls, juxtaposed , extending in the longitudinal direction of the support device, the horizontal front surfaces of which form the battery support surface and which are located so that a wall is located below each brush-like rotating member (35) and flattening hammers (36). 14. Machine according to one of claims 8 to 13, characterized in that the brush (35) has a general shape of a segment of a circle with an angle equal to or somewhat greater than 180 °. 15. Machine according to claim 14, characterized in that the brush (35) comprises a hub (60) eccentric for supporting a set of bristles (62) arranged so that the length of the bristles (62) decreases around the periphery of the hub in the direction opposite to the direction of rotation of the brush, that this lining (62) has in its front part an area (63) where the length of the bristles decreases in the direction of rotation of the brush so that the lining comes into contact with a loop of the strip to be deposited, gently and gradually, and in that the hub (60) carries, in downstream of the lining (22) a device for crushing the folds of the flaps, which comprises a hammer member (66) capable of exerting a crushing pressure on the folds, under the effect of a spring (68). 16. Machine according to one of claims 13 to 15, characterized in that it comprises an auxiliary support device (70) in the form of a comb which is horizontally movable so as to temporarily replace the reception table (47 ) when a finished battery is discharged. 17. Machine according to one of claims 3 to 16, characterized in that it comprises means (74) for stopping the pendulum (11) in a predetermined angular position (73) independently of the instant of stopping the machine. 18. Machine according to one of claims 3 to 17, characterized in that it comprises a detector for the speed (78) of advancement of the strip, a detector (59) for a separation code on the strip and a calculation device such as a microprocessor (79) adapted to calculate the control instant of the deviation devices (18, 19) of the strip from data received from the detectors (59) and (78).

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