EP0005671B1 - Machine for folding drawings to a determined size - Google Patents

Description

The present invention relates to a machine for folding the planes and more precisely to a machine for folding according to the so-called "folding folding wallet with single hinge said hereinafter folding portfolio, a plane or similar surface already folded in accordion.

The state of the art is illustrated in particular by document FR-A-2 120525 which sets out the problem to be solved. The plan or similar surface is first folded in alternating folds so as to obtain a strip folded in accordion, the width of a fold being equal to one of the sides of the format, in general the short side. This operation can be carried out in a correct manner with the machine described with reference to FIG. 1 of the document FR-A-2120 525. It is then necessary to carry out a folding “wallet to fold the band folded over itself for the first time. accordion to form a pan of length double that of the other side of the format, in general the long side, the rest of the length of the strip being superimposed on this pan of defined length and then fold it once again on itself so that the rest of the length of the strip is inside the portfolio thus formed. Is this folding method recommended by different standards and is preferred by interested parties.

The machine described in the French patent above and illustrated in Figure 3 of this patent, which is reproduced to illustrate the art known as Figure 1 of this patent, comprises a conveyor belt 1 which leads the strip folded in accordion between two crushing rollers 2 and 3, a table 4 following said conveyor belt and which has in its middle a free space 5, a folding blade 6 mounted above this table in front of the free space 5 and capable of move vertically to engage the strip through the free space 5 between the call rollers 7 and 8 rotating in opposite directions to form the fold and lead the folded strip to rollers 9 and 10 for deviating from the plane. The downward movement of the blade 6 is controlled by the abutment of the front end of the strip folded in accordion against a stop 11 located at a distance 2L from the blade, L being the length of the side of the format to be produced, this stop controlling contacts under the action of the pushing of the strip. The strip thus folded for the first time is received on a second table 12 similar to the first but whose stop 13 is only at a distance L from the blade 14, which ensures the second folding by engagement of the strip already folded for the first time. through a slot 15 between pinch rollers 16 and 17 cooperating with deflection rollers 18 and 19 which direct the plane thus folded in the portfolio on an evacuation conveyor belt 20.

The machine described above did not give satisfactory results, the main defects noted being the imprecision of the folding format and the “biasing of the strip, the final folded plane having offset or biased edges for the different folds.

An in-depth analysis of the operating mode of the previous machine led to think that these defects resulted from the large distance and necessarily greater than 2L over which the folded strip pushed by the rollers 2 and 3 rubbed on the table 4 mainly by its lower fold , to the fact that over this distance the strip had to cross the interval 5 with the risk that, under the effect of the elasticity of the accordion fold, the lower fold catched by one or the other of its corners on the edge of the slot constituting the interval 5, to the fact that the control of the folding operation was ensured by mechanical pushing of a free strip over a great length and whose buckling rigidity is essentially variable according to the number of folds and to the fact that the strip folded for the first time and the front edge of which also controlled the second folding operation by mechanical abutment could also be "inflated by elasticity, which further reduced the precision of the second fold.

In addition, the machine described in the above patent had in itself disadvantages resulting from the difficulty of installing the second folding bench with its blade with vertical movement below the first bench, given above all that in contrast to this which is illustrated, the rollers 2 and 3 had to be much closer to the slot 5 in order to be able to fold formats in which the "tail or excess of length of the strip relative to 2L is reduced. On the other hand, adapting the machine to different formats required moving the stops 11 and 13 and their contacts. Finally it was impossible to positively accompany the folded strip on the table 4 between the slot 5 and the stop, due to the extremely rapid reversal of the direction of movement itself rapid on this part of the table. The folded strip could not be guided positively on this part, even whose position detection controlled the operation of the machine.

The object of the present invention is to remedy these drawbacks and its subject is a machine for folding portfolio with a single hinge to a determined format of a strip having, in the direction of the length of this strip, a length greater than double of the length of the format by carrying out a first folding, started by a blade and guided by cylinders, at a distance from one end of the strip equal to twice the length L of the format and from a second folding, started by a second blade and guided by cylinders, in the middle of the length of the strip folded for the first time.

In accordance with the invention, the machine comprises a positively driven continuous conveyor element comprising three strands which follow one another while being substantially perpendicular. res two by two, the two extreme strands being parallel and flowing in opposite directions and the strip to be folded is introduced into the machine with the surface to constitute the two outer surfaces of the portfolio situated below and at the rear of the strip for come into contact under the pressure of pressure elements with the first strand of the continuous conveyor, the control of the folding blades being subject to detection, by a detector situated upstream at a distance at least equal to twice the length of the format folding, from the rear edge of the strip, the double folding taking place in two substantially perpendicular directions, the strip brought into contact with the first strand and folded a first time by a blade whose path is substantially parallel to the second strand being moved in contact with this second strand by being applied against this strand by pressure elements then folded a second time by a second blade whose trajectory is st substantially parallel to the third strand to then be moved in contact with this third strand by being applied against this third strand by pressure elements, the rear part of the strip corresponding to the folding format remaining during the entire folding in guiding contact with the first to third strands of the continuous conveyor element.

With this machine, the strip, from its introduction to the first folding blade, always flows in the same direction, being pulled and not pushed. It is therefore possible to guide it positively, if necessary, between belts or pressing cylinders as close as possible to the point of formation of the fold. The length of strip, the detection of which determines the fixing of the fold, is pulled and not pushed, which avoids all the disadvantages of the prior machine.

According to another characteristic of the machine according to the invention, the double folding is carried out in two substantially perpendicular directions, the strip brought horizontally and folded a first time being moved vertically then folded a second time to then be moved substantially horizontally according to a direction opposite to that in which it is brought to the unfolded state.

This characteristic makes it possible to ensure the entire portfolio folding with the rear part of the strip corresponding to the folding format, that is to say in practice the cartridge, in guide contact with a positively driven continuous conveyor element. This continuous conveyor element can be constituted by an endless belt or belts, guided on rollers or pulleys or by multiple rollers arranged in the same layout.

According to another characteristic, the folding blades are each carried by an oscillating frame which also carries a drive element which comes into clamping contact, with the interposition of the strip to be folded, with a second drive element so as to ensure the positive drive of said part of the strip in a direction ensuring its engagement between the elements for forming the fold in the direction of travel of the part carrying the cartridge.

Said oscillating drive element may consist of a roller or a belt or endless belts. It can be positively driven or be mounted free.

As a whole, the machine according to the invention comprises a feed surface of which at least the part close to the line of action of the folding blade is constituted by a positive drive element of the strip to be folded with at at least one guide element holding said strip in abutment against the positive drive element, a folding blade movable in a direction substantially perpendicular to that of the supply surface to engage the fold of the band to be folded formed by this blade , in the above direction, between a positive drive element and a guide element holding the folded strip in abutment against the latter positive drive element, a second folding blade movable in a direction substantially parallel to that of the feed surface for engaging the fold of the strip formed by this blade, in the above direction, between a positive drive element and a guide element holding the folded strip in abutment against the latter el positive drive element and means for evacuating the folded strip in the portfolio thus obtained.

According to an additional characteristic of the present invention, the supply surface is constituted by an inclined plane, preferably at 45 °, the strip drive element being constituted by a toothed belt. To avoid adhesion of the strip on the inclined plane, its upper surface is preferably provided with longitudinal ridges.

• La figure 1 est une vue en élévation latérale de la machine à plier en portefeuille de l'art antérieur ;
• la figure 2 est une vue correspondante pour une machine conforme à l'invention au moment du déclenchement de la première opération de pliage ;
• la figure 3 est une vue conforme à la figure 2 immédiatement après l'amorçage du premier pli ;
• la figure 4 est une vue correspondante après l'amorçage du deuxième pli ;
• la figure 5 est une vue en coupe schématique d'un mode de réalisation de la surface d'amenée de la machine conforme à la présente invention.

Other characteristics of the machine for folding a strip into a portfolio, in particular a plane previously folded in accordion, in accordance with the invention will appear on reading the description of an embodiment made below with reference to the schematic drawings below. - annexed in which:

• Figure 1 is a side elevational view of the portfolio folding machine of the prior art;
• Figure 2 is a corresponding view for a machine according to the invention at the start of the first folding operation;
• Figure 3 is a view according to Figure 2 immediately after the initiation of the first fold;
• Figure 4 is a corresponding view after the initiation of the second fold;
• Figure 5 is a schematic sectional view of an embodiment of the supply surface of the machine according to the present invention.

The machine in the embodiment illustrated in FIGS. 2 to 4 comprises a feed table 21 which could be constituted by an endless belt or a ply of parallel endless belts 3. Rollers 22 driven ensure the progression of the strip. Pressure elements, rollers or endless strip (not shown) could keep the strip 23 to be folded resting on the table, the strip 23 moving in the direction of the arrow F.

The main conveyor element in contact with which the surface of the cartridge is in contact during the entire folding is constituted by an endless band 24 guided on cylinders 25. Said band comprises a strand 24a which extends the table 21, then, after a quarter of turn around the cylinder 25a, a substantially vertical strand 24b then, after a quarter turn around a cylinder 25b, a substantially horizontal strand 24c and finally after passing around a cylinder 25c a strand back towards the strand 24a.

The guide of the folded strip 23 in contact with the strip 24 and also the flattening of the folds are ensured, in the embodiment shown, by a cylinder 26 which supports it in line with the upper generatrix of the cylinder 25a, by a endless band 27, cooperating with the vertical strand 24a and which is guided by an upper cylinder 28 spaced from the cylinder 25a above to leave a wedge gap 30 between the strands 24b and 27b of the two pressure bands, but positioned in such a way so that its upper surface is lower than the upper surface of the cylinder 25a in order to allow the strip 23 to pass on the way out, by a cylinder 29 which supports the strand 27b against the strand 24b, by a cylinder 30 which elastically supports the strip 27 against the strip 24 in line with the cylinder 25b and a return cylinder 31 (the strip 27 is driven at the same speed as the strip 24 in the direction F ') and finally by an endless strip 32 which is guided on a cylinder 33 to the right of cylinder 2 5b to form a wedge gap 34 and by cylinders 35 which maintain its upper strand in contact with the strand 24c (the strip 32 is driven in the direction of the arrow F "at the same speed as the strip 24).

The folding blades comprise a first blade 36 carried by a frame 37 mounted oscillating around an axis 38 and controlled so as to descend to push the strip to be folded 23 towards the endless strip 24 along a line slightly beyond the upper generator of cylinder 25a. The frame 37 also carries a cylinder 39, which can be driven in the direction of the arrow F "', and which, at the end of the descent of the folding blade 36, comes to tighten the part 23' or tail of the strip to be folded against the endless strip 27 in line with the cylinder 28. It should be noted that the portion 23 ′ or tail of the strip is free and only supported in the event of excessive bending by an inclined plate 40. When folding the part of the strip forming the tail is clamped between the roller 39 and the strip 27 and the air trapped between the accordion folds is expelled, which improves the formation of the fold. The second folding blade ensuring the portfolio folding has the same elements designated by the same references with prime but its stroke is horizontal and it brings a transverse line of the already folded strip and the first fold of which descends freely being guided between vertical plates 41, in contact with the strip 24 in the vicinity of the generator lower of the cyli note 25b. At this moment the cylinder 39 'clamps the upper end of the folded strip engaged between the plates 41 against the strip 32 which rotates in the direction of the arrow F ". The folded strip is therefore forced by driving its two parts located from on either side of the fold initiated by the blade 36 'in the corner space 34. If the tail has a length less than L, its free edge 42 is between the plates 41 but because of the guidance provided by these plates the fold 43 cannot open and its surface is reapplied against the part 23a of the strip to be folded during the engagement between the strip 32 and the cylinder 39 '. If the tail 23' has a length greater than L, it will found folded by the blade 36 'when the fold 43' is formed.

The detectors for the position of the rear end 44 of the strip can be of the mechanical, optical or other type. A first detector 45 is placed at a distance 2L from the line of action of the blade 36 and its position is adjustable with precision as a function of the driving speed of the strip to be folded and the delay of the known means, not shown, controlling the oscillation of the frame 37 and of the blade 36. The detector working at the passage of the rear end of a pulled folded strip, the precision is much higher since it cannot be influenced by a random buckling of that -this. The second detector 46 is located at a distance L, measured along the path followed by the strip to be folded 23 along the table and the strip 24 of the line of action of the folding blade 36 '. Its position is also adjustable with precision and it can be corrected according to the results obtained. It is true that the adjustment of the folding format can also be carried out easily by adjusting the positions of the detectors 45 and 46.

To avoid the biasing of the strip to be folded, it is possible to provide on the table 21 side stops not shown and this is all the easier since the strip 23 circulates on this table being always pulled in the same direction.

It has also proved to be advantageous for obtaining a flat forming and without air obstruction between the folds, to give the lower horizontal path the shape shown with a slight concavity of the strand 24c. A tray 47 which can be a transporter receives the folded plans in the portfolio.

In the embodiment shown in FIG. 5, the feed surface is constituted by a table 100 inclined at 45 ° onto which the strip 23 is brought manually or mechanically. A toothed belt 101 driven in rotation at the same tangential speed as the endless strip 24 drives under the effect of its own weight the strip 23 towards the cylinders 26 and 25a with a view to carrying out the first folding as mentioned above. To prevent the strip 23 from adhering to the table 100, the latter is provided with longitudinal ridges 102. The flank clamp 103 serves to prevent the band 23 folded in accordion from opening too much.

The embodiments described above by way of example are capable of receiving various modifications without departing from the scope of the invention as defined by the claims below.

Claims (4)

1. A machine for folding portfolio-wise with a single hinge and to a determined format a band (23) having, in the direction of the length of said band, a length superior to the double of the length of the format by making a first folding, initiated by a blade (36) and guided by cylinders, at a distance of one end of the band which is equal to the double of the length (L) of the format, and a second folding initiated by a second blade (36') and guided by cylinders, in the middle of the length of the band already folded a first time, characterized in that the machine comprises a continuous conveyor element (24) positivily driven and including three strands (24a, 24b, 24c) following each other while being substantially perpendicular two by two, the two extreme strands being parallel and moving in reverse directions, and in that the band (23) to be folded is introduced in the machine with the surface having to form the two outer surfaces of the portfolio situated below and at the rear of the band in order to come in contact, under the pressure of pressure elements (26a), with the first strand (24a) of the continuous conveyor (24), the control of the folding blades being under the control of the detection by a detector (45) placed upstream at a distance at least equal to twice length of the folding format of the rear edge of the band, the double folding being effected in two directions substantially perpendicular, the band brought in contact with the first strand (24a) and folded a first time by a blade (36) the path of travel of which is substantially parallel to the second strand (24b) being moved in contact with said second strand (24b) by being applied against said strand by pressure elements (27 to 30), then folded a second time by a second blade (36') the path of travel of which is substantially parallel to the third strand (24c) in order to be then moved in contact with said third strand (24c) by being applied against said third strand by pressure elements (32 to 35), the rear portion of the band which corresponds to the folding format remaining, during the totality of the folding operation, in guiding contact with the first to third strands (24a, 24b and 24c) of the continuous conveyor element (24).

2. A machine according to claim 1, wherein the folding blades (36 to 36") are each carried by an oscillating frame (37, 37') carrying also a driving element (29) which comes into clamping contact, with interposition of the band to be folded, with a second driving element (27 to 32) so as to provide the positive driving of the portion of the band which has passed beyond the relevant folding blade in a direction causing its engagement between the fold formation elements in the running direction of the portion carrying the inset.

3. A machine according to any one of claims 1 and 2, wherein the input surface (21) is formed of an inclined plane (100), the band (23) being fed to the positive driving element (24) the initial strand (24a) of which, prior to the first folding blade (36), prolongates said input surface by a belt (101) moving at the base of said inclined plane at the same speed as the positive driving element (24).

4. A machine according to claim 3, wherein belt (101) is a timing belt, the upper surface of the inclined plane (100) being provided with longitudinal serrations.

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