EP0122817B1 - Automatic feeding method and device for a machine treating flat objects - Google Patents

Abstract

An apparatus for the automatic supply of the magazine of the feeder on a slotter/printer with a high production rate for making cases consisting of corrugated cardboard, comprising a device (3, 10, 4) intended for separating a bundle from the top of a stack of blanks (14) by placing this bundle upright on its edge, a retractable device (4) intended for causing the virtually vertical drop of this bundle, and a guide and receiving device (5, 7) making it possible to stop the bundle, still standing on its edge, a device (6) for squaring the bundle laterally after its drop, a device (27, 7, 8) for raising the bundle to a horizontal position, and a device (9) for receiving and discharging this bundle.

Description

The present invention relates to a method and a device for the automatic feeding of a machine for treating plate products, and more particularly for the automatic filling of the feed magazine of a machine for treating blanks in plates. This is how it applies particularly effectively, for example, to the automatic feeding of the feeder magazine on a printer slotter with a high production rate for the shaping of corrugated boxes.

The production of corrugated cardboard packaging boxes involves a first phase in which the corrugated cardboard is produced in a continuous strip, in a corrugating machine, then cut into rectangular blanks whose dimensions correspond to the development of the box to be produced. In a second phase, the blanks are most often taken one by one in a machine called "slotter-printer", in which they undergo various cuts to form for example the flaps of the box. Such a machine includes an input element called "feeder", with a feed magazine where the blanks are stacked to be extracted one by one from the bottom of the stack, at a rate in synchronism with the rotary cutting elements or printing. Between the corrugating machine and the slotter, the cardboard blanks are stacked awaiting passage on the shaping machines, slotter or flat cutting machine.

Currently, the filling of the slotter supply magazine is generally done manually, by successive removal of packets of plates from a waiting pile. The reserve formed in the slotter magazine generally provides sufficient flywheel, at the end of each stack of blanks, to have time to bring another stack to the slotter and avoid stopping the machine.

However, it can be seen that the production of modern slotters, capable of very high mechanical rates, is in fact limited by the possibilities of manual feeding. Even if the full capacity of the slotter is not used, manually loading the plates in the magazine is extremely strenuous work. We have therefore sought to automate and above all to mechanize the filling operation of the blank store in such high-speed shaping machines. The solutions proposed so far to solve this problem have generally led to devices in which the plates are removed one by one from the top of the waiting stack; these plates are then transported to the feeder store by conveyor belts on which they are generally arranged overlapping each other.

These various devices all have the drawback of not constituting any buffer reserve between the main stack and the small stack which forms in the feeder magazine. As a result, when a stack is fully discharged into the feeder, the low reserve of the feeder is depleted in less time than it takes to bring another stack into place and readjust the device to begin the transfer of new plates. There is thus a break in the supply of the slotter and loss of production.

Furthermore, the stacking of the plates during their transport between the corrugating machine and the shaping machines is never strictly vertical. If therefore, the upper part of the stack has been correctly centered so that the plates arrive well in the axis of the slotter, it is frequent to note that when one arrives at the lower part of the stack, the centering is not more correct and the plates still hardly enter the feeder magazine.

• - amenée d'une pile en attente à un poste de prélèvement où elle reste en position verticale, et élévation progressive de cette pile, après chaque prélèvement,
• - séparation de la pile en paquets, en décalant d'abord à chaque fois la partie supérieure de la pile par poussage horizontal vers l'arrière avec retenue de la partie inférieure, puis en soulevant légèrement le bord arrière décalé du paquet ainsi formé et en appuyant sur la partie supérieure de la pile restante pour la maintenir en place,
• - déplacement horizontal vers l'avant du paquet supérieur ainsi formé vers un poste de débit plaque par plaque, vers le magasin de la machine, par prélèvement par dessous, la partie inférieure de la pile restant maintenue en place, chaque transfert d'un paquet vers le poste de débit n'étant effectué qu'à la fin du débit du paquet précédent, ce transfert entraînant à son tour un nouveau cycle d'élévation de la pile en attente et la séparation d'un nouveau paquet à sa partie supérieure.

To overcome these drawbacks, the applicant has already proposed, in its French patent 2,313,294, a process for automatic filling of the feed store of a machine for processing blanks in plates, said store serving to constitute a stack of plates forming a small reserve for feeding the machine, with plate by plate sampling at the bottom of the reserve for introduction into the machine, and reconstitution of the reserve by adding new plates to its upper part, these new plates being taken on a pending stack. This process involved the following operations:

• - brought from a waiting pile to a sampling station where it remains in the vertical position, and progressive elevation of this pile, after each sampling,
• separation of the stack into bundles, by first shifting the upper part of the stack each time by horizontal pushing backwards with retention of the lower part, then slightly lifting the offset rear edge of the bundle thus formed and pressing the top of the remaining stack to hold it in place,
• - horizontal displacement forwards of the upper package thus formed towards a plate-by-plate flow station, towards the machine magazine, by sampling from below, the lower part of the stack remaining held in place, each transfer of a package towards the debit station being carried out only at the end of the debit of the preceding packet, this transfer in turn causing a new cycle of elevation of the stack on standby and the separation of a new packet at its upper part.

This type of process has not been found to be satisfactory for its implementation, since it requires complex mechanics, which are therefore expensive to manufacture and maintain, as well as a long and difficult development. We were also forced to make excessively long changes of settings when the format sheets of cardboard were changing. Furthermore, because of the weight of the packages formed, it was not possible to subject them to a lateral squaring without risking damaging the sheets, especially when working with sheets of medium or poor quality.

In addition, this kind of process allows only one package to be obtained at a time, which can constitute, with high rates, an insufficient reserve when a battery change is carried out.

Finally, the implementation of this type of process does not allow an easy reversal of the package before it is debited from below plate by plate. However, there are certain types of printers, called "high flexographic printers", the implementation of which requires a prior reversal of the blanks.

In the French document FR-A-2 406 587, there is described an automatic feeding of a machine for treating plate products. According to this embodiment, the packets of plates extracted from the stack are directly laid down and conveyed forward. On the contrary, according to the invention, the packets undergo an important intermediate treatment.

Document DE-A-3 021 367 relates to a device for unloading a pallet on which are linked bundles each forming a block in itself. This document simply shows the tilting of the battery, which is only a secondary element of the invention.

• - amenée d'une pile en attente en position debout,
• - extraction d'un paquet de flans du haut de la pile, ledit paquet restant debout sur sa tranche,
• - chute de ce paquet vers le bas jusqu'à ce qu'il s'arrête toujours debout sur sa tranche,
• - équerrage latéral de ce paquet,
• - remontée du paquet dans un mouvement le ramenant à peu près à l'horizontale, et évacuation de ce paquet.

The invention relates to a method and a device for automatic feeding, that is to say without direct manual intervention by an operator, of a machine for treating plate products not having this type of disadvantages. The method of the invention is characterized in that it includes the following automatic operations:

• - brought from a battery in standby position,
• extraction of a packet of blanks from the top of the stack, said packet remaining standing on its edge,
• - drop this packet down until it still stops standing on its edge,
• - lateral squaring of this package,
• - lifting of the package in a movement bringing it more or less horizontally, and evacuation of this package.

The invention will be better understood with the aid of the following description of some nonlimiting exemplary embodiments, with reference to the appended drawings in which:

• - Figure 1 is a perspective view of the automatic feeding machine for implementing the invention
• - Figure 2 is a side view of the automatic feeding machine of the invention
• - Figure 3 is a plan view of the machine of the invention
• - Figure 4 is a schematic perspective view of the package separation device fitted to the machine according to Figures 1 to 3
• - Figure 5 is a schematic perspective view of one of the elements of the tilting deck, stack elevator-translator, equipping the machine of the invention
• - Figure 6 is a partial perspective view of the retractable stack top support device associated with the tilting deck of Figure
• - Figure 7 is a schematic perspective view of the packet fall accompanying device fitted to the machine of the invention and Figure 7a is a detail section along the direction aa
• - Figure 8 is a schematic perspective view of the lateral squaring device with joggers fitted to the machine of the invention
• - Figure 9 is a very schematic side view of the device for raising packages horizontally fitted to the machine of the invention
• - Figure 10 is a schematic longitudinal section of the package receiving device fitted to the machine of the invention
• FIGS. 11 to 15 illustrate, in association with FIG. 2 to which they follow, the successive phases of the formation and of the transfer of the packets of plates from the stack to the debit station,
• FIGS. 16 to 23 illustrate the successive phases of operation of an automatic device for eliminating the last sheet of each stack which can be fitted to the machine of the invention,
• FIG. 24 is a perspective view of the stop device, in the intermediate lowering position in accordance with FIGS. 22 and 23, of the horizontal ascent table fitted to the machine of the invention,
• FIG. 25 is a perspective view of the device with tilting flaps allowing, in accordance with FIGS. 22 and 23, the evacuation of the last sheet,
• FIG. 26 is a perspective view of the device for shifting and retaining the last sheet fitted to the automatic elimination device according to FIGS. 16 to 23.
• FIG. 27 is a schematic representation in side view of an alternative embodiment of the machine according to FIGS. 1 to 10, comprising a device for turning over the packages,
• FIGS. 28 to 31 illustrate the successive phases of operation of the machine in FIG. 27.
• FIG. 32 is a perspective view of another embodiment of the package reception and evacuation device fitted to the machine of the invention,
• - Figures 33 to 38 illustrate the successive phases of operation of the device in Figure 32.

• - un châssis porteur 2,
• - un tablier-élévateur basculant 3, d'un type largement répandu dans la technique et décrit par exemple dans le brevet français 2.273.656,
• - un dispositif (4, 10) destiné à séparer des paquets du sommet de la pile,
• - un dispositif 5 destiné à accompagner la chute verticale des paquets,
• - un dispositif 6 d'équerrage latéral des paquets après leur chute verticale,
• - un dispositif (7, 8) de remontée à l'horizontale des paquets,
• - un dispositif 9, déplaçable longitudinalement, de réception et évacuation des paquets.

Referring to all of Figures 1 to 3. the automatic feeding machine packages according to the invention is a compact machine, mobile on casters 11, and essentially comprising:

• - a supporting frame 2,
• a tilting lifting platform 3, of a type widely used in the art and described for example in French patent 2,273,656,
• - a device (4, 10) intended to separate packets from the top of the stack,
• a device 5 intended to accompany the vertical fall of the packages,
• a device 6 for squaring the packets laterally after their vertical fall,
• - a device (7, 8) for raising the packages horizontally,
• - A device 9, movable longitudinally, for receiving and removing packages.

The machine 1 is normally positioned adjacent to a standby conveyor 12 for supplying batteries (13, 14). These are for example stacks of cardboard plates at the outlet of a corrugator, said plates being intended to be introduced, via the device of the invention, one by one into a machine for forming and printing cardboard boxes. corrugated.

The tilting lifting platform 3 is provided with forks 15 which can be moved along a conveyor frame 16 which is orthogonal to them. In its "standing" position shown in dotted lines in FIG. 2, it receives one of the waiting piles, such as the pile 14, the forks 15 being in their extreme low position so as to be inserted in the supply conveyor 12 , the latter being provided with longitudinal spaces accordingly.

The tilting of the apron 3 is carried out, in a very conventional manner for this kind of tilting apron, by output from the rod of a jack 17, the base of which is articulated on the chassis 2 of the machine. The apron 3 then swings around the shaft 18 to the almost horizontal position shown in the drawings.

The conveyor frame 16 is extended, with a downward offset as seen in the drawings, by a retractable support 4 constituted by forks 19 assembled on a cross member 20 retractable using a jack 21. This support 4 allows you to create a staircase intended to separate by gravity a package from the top of the stack. Its retraction also makes it possible to then drop said package downwards.

The top of the conveyor frame 16 is also provided with a device 10 facilitating the separation of packages from the top of the stack, moved by a jack 22 and essentially comprising a separating blade 23, and which will be described in more detail below.

The device 5 intended to accompany each pack in its quasi-vertical fall after the separation operation consists of a fork 25 composed of teeth fixed on a crosspiece 26 animated by a cyclic movement back and forth vertically, synchronism with the withdrawal of the support 4. This device 5 will also be described in more detail later.

A plate 7 lined with idle rollers is articulated at 29 on the chassis 2 at the level of the support 4, and is used, in its quasi-vertical position shown in FIGS. 1 and 2, to laterally support the packages during their quasi-vertical fall, as well as at the end of this fall. This plate can be raised psr rotation about the axis 29 until it reaches a quasi-horizontal position, by exiting the rod of a jack 27, articulated at its other end on the chassis 2 of the machine.

The lateral squaring device for standing packages comprises two joggers 28 adjustable in position according to the format of the blanks, the operation of which will be explained later. Facing the plate 7, when the latter is in the quasi-vertical position, there are three left sheets 8 curved as shown in a slightly enlarged spiral arc.

The packet 9 for receiving and discharging the packets is in itself of a new type. It has the advantage of allowing the reception of successive packets by placing these packets in a line, one behind the other as closely as possible, even if the first packet in the series is awaiting evacuation at downstream end of block 9, and even if the packets arrive on block 9 randomly. At any time, the leading packet can be alone evacuated to a processing station located downstream, and replaced in the waiting position it occupied by the second packet without the operation of arriving new packets at the back of the line is embarrassed.

• - une table à galets fous 30, dans cet exemple en pente douce vers l'avant, sur laquelle roulent les paquets à réceptionner,
• - un convoyeur sans fin 31 destiné aussi bien à entraîner les paquets qu'à les retenir s'ils descendent trop vite et constitué d'une courroie entraînée 32 garnie d'éléments de retenue constitués dans l'exemple considéré de griffes plates et souples 33 que l'on voit d'ailleurs mieux sur la vue de côté du schéma explicatif de la figure 10. Comme on le voit sur la figure 3, le convoyeur 31 est positionné au milieu de la table 30 et il s'étend à peu près sur la même longueur,
• - un convoyeur motorisé 34, contigü vers l'aval à la table 30 et au convoyeur 31 destiné à arrêter, et évacuer au moment voulu, le paquet de tête.

The operation of block 9 will be explained later using the explanatory diagram in FIG. 10, but we can already see in FIGS. 1 to 3 that it includes:

• a mad roller table 30, in this example gently sloping towards the front, on which the packages to be received roll,
• an endless conveyor 31 intended both to drive the packages and to retain them if they descend too quickly and consisting of a driven belt 32 furnished with retaining elements constituted in the example considered by flat and flexible claws 33 which can be seen more clearly in the side view of the explanatory diagram in FIG. 10. As can be seen in FIG. 3, the conveyor 31 is positioned in the middle of the table 30 and it extends approximately on the same length,
• - A motorized conveyor 34, contiguous downstream to the table 30 and to the conveyor 31 intended to stop, and evacuate at the desired time, the head pack.

Furthermore, the whole of the block 9 is movable from front to back, this to allow access to the machine without the need to move it on its rollers 11. For this purpose, one of the lower sides of the table 30 is furnished with a rack 35 meshing with a toothed wheel 36, the motorization of which is ensured, as shown diagrammatically in the drawings, by a conventional chain device 37, traction cylinder 38, and return toothed wheel 39.

Figure 4 is a perspective view of the separation device 10. It comprises a separating blade 23, furnished with teeth as shown, and carried by a roller 24 which can be moved back and forth by retracting and leaving the rod of the jack 22, itself connected to a crankshaft 40 carrying the roller 24 and mounted idly on the axis of the downstream pulleys of the conveyor 16.

Such a separation device is not new in itself, and could very well be replaced by an equivalent device, for example by that described in French patent No. 923,939.

The perspective view of FIG. 5 makes it possible to realize how the forks 15 can move along the conveyor structure 16. A motor 41 drives, via a transmission 42 of a shaft 43 and d 'a gear 44, a chain 45 on which is fixed the fork 15. The fork 15 can roll back and forth on the frame 16 by rollers 460 and is integral with the conveyor belt as shown. This device is a direct equivalent to the devices known according to French patents 2,273,656 and 2,359,052, which could very well be used here.

Figure 6 is a partial perspective view of the above device 4. It comprises forks 19 fixed on a cross member 20 and supported at the front by a transverse bar 47 fixed to the chassis and furnished with idle rollers 48 each placed under one of the forks. Longitudinal guide elements 49 fitted with lights 50 allow, thanks to rollers 51, the longitudinal sliding of the cross-member 20 by retraction or exit of the rod of the jack 21.

Figures 7 and 7a show, in partial perspective and section along aa, the structure of the support device 5 intended to accompany, by their lower edge, the packages in their fall. The cross member 26 carrying the two forks 25 is slidably mounted on quasi-vertical guides 52. The reciprocating movement from top to bottom is given, from a motor 53 fixed to the chassis, by a conventional transmission of the rod-crank type comprising a wheel 54, a first articulated connecting rod 55, and a second articulated connecting rod 56. The connecting rod 56 has one of its ends articulated on the chassis of the machine and its other end mounted sliding along the crosspiece 26 by means of a roller. bearing 57.

The device 6 for squaring the packets laterally after their fall is shown diagrammatically in FIG. 8. It comprises two conventional joggers 28, the bases of which can slide in two parallel slides (60, 61) fixed to the chassis of the machine. Said bases are fixed at the end of the rods of two jacks (62, 63) placed in each of the slides (60, 61) and held in these slides by sliding parts (64, 65) each provided with a vertical rod (66, 67) whose end comes out of said slides.

The extended ends of the rods (66, 67) are fixed, as shown, to the two parallel strands of an endless chain 68 winding around two toothed wheels (69, 70) whose rotational bearings, not shown, are connected to the chassis. The wheel 70 is driven in rotation using a transmission 71 and a motor 72 fixed to the chassis.

Depending on the lateral format of the blanks, by adjusting the wheel 70 in one direction or the other by a sufficient amount, the position of the supports (64, 65) of the jacks (62, 63), these these having their rod extended in the rest position. The position of the jacks (62, 63) is chosen in the rest position. The position of the jacks (62, 63) is chosen so that the spacing of the joggers is greater than the lateral format of the blanks by an amount equal to or slightly less than the sum (c + d) of the strokes of the rods of the jacks ( 62, 63). The sudden retraction of the rods of said jacks thus makes it possible to perform a lateral squaring of the blank pack by action of the joggers 28.

The diagram in FIG. 9 makes it possible to explain the action of raising a package 58 horizontally, after its lateral squaring using the device of FIG. 8.

As can be seen in the drawing, the left sheet 8 has a concave curved shape, widened in a spiral by an angle relative to the arc of a circle C with a center 29.

When the table 7 rises by pivoting about its axis 29, it carries with it the package 58, the edge of which slides on the left sheet 8, thus progressively advancing along the spiral formed by this sheet. When the table 7 finishes its course to reach the quasi-horizontal position appearing on figure 9, in reality in slight slope downwards and downstream as is already the block 9, the package 58 is animated by a speed vector V whose horizontal component h is not zero. This component h makes it possible to give the packet 58 a pre-acceleration in the direction of the reception block 9.

As seen in Figure 10, where the forward slope of the endless conveyor 32 of block 9 has been greatly exaggerated, the package 58 then descends along the conveyor 32, as well as the idler roller table 30 ( Figure 3), and its stroke is retained by the claws 33. The endless conveyor 32 is driven in continuous rotation by the motor 73 fixed to the frame of the block 9 and by the transmission 74. Its rotation can be stopped for example to create spacing between packages.

The package 58 is then stopped at 59 on the motorized conveyor 34. The conveyor 34 is an ordinary conveyor with belts, motorized as shown using the motor 75 fixed to the chassis of the block 9 and the transmission 76. The stop at waiting for the packet 59 to be evacuated at the end of the conveyor 34 is triggered by stopping the latter due to the blackout by the front of the packet 59 of a photocell 77. We can see that we can then pile up in line behind the head packet 59 as many packets 58 as it is possible to stack in dimensions, while the packet 59 remains awaiting evacuation on the conveyor 34, which was not possible with the devices classics known until then.

Obviously, the various operating phases of the machine are slaved to each other by conventional means, not shown, of photoelectric cells and limit switches, etc., such as those described for example in the aforementioned French patent 2,359,052. , relating to a semi-automatic machine.

The operation of the machine which has just been described will now be explained with the aid of FIG. 2 and of FIGS. 11 to 15.

In FIG. 2, a stack of cardboard blanks 13 is brought, for example from a corrugator, into a standing position on the supply conveyor 12. The tilting apron 3 is then in a standing position, as shown in dotted lines, so that it can receive the stack, shown at 14, on its four forks 15 which are in the low position and inserted into the conveyor 12.

The rod of the jack 17 is then brought out, which causes the apron 3 to tilt about its axis 18, until it reaches the almost horizontal position, with a slight slope towards the rear, drawn in full trits. in Figure 2. Because of the staircase created between the val end of the conveyor frame 16 and the forks 19, then in the extended position some plates already fall from the top of the stack and stand on their edge on the support retractable 4, as shown in Figure 2.

The roller (24, figure 4) of the separator 10 is then made to rotate about half a turn in the opposite direction to the hands of a watch, which allows the blade 23 (figure 4), in combination with a slight lifting action due to the roller 24, and possibly to idle rollers (78, 79, Figure 3) optionally mounted on the same axis, to be introduced between two sheets so as to clearly separate a package (80. Figure 11) from the top of stack 14, in exactly the same way as in the aforementioned French patent No. 923,939. The separate package 80 then rests substantially upright on its edge on the retractable support 4 as seen in FIG. 11. Furthermore, the device 5 intended to accompany the fall of the packages is in its extreme high position.

The support device 4 is then suddenly retracted by re-entry of the rod of the jack 21, as it appears in FIG. 12, so that the package 80 drops down along the table 7. It is accompanied in its fall by the simultaneous descent of the accompanying device 5.

As shown in FIG. 13, the quasi-vertical fall of the package 80 stops when the accompanying device also stops in its extreme low position. The package 80 is then almost always upright on its edge as shown, and the two tabs 28 are then actuated which cause easy lateral squaring of the package since the latter is upright on its edge. During this time, the forks 15 are advanced along the frame 16 by a calibrated quantity, sufficient to allow the subsequent separation of a new package 81, the support 4 having of course been previously released and the blade 23 of the separator 10 brought back.

Referring then to FIG. 14, as well as to what has been said about FIG. 9, the package 80 is brought up by output from the rod of the jack 27, which allows rotation upwards. of the table 7 around its axis of articulation 29. The table 7 then stops, as previously mentioned, in a quasi-horizontal position, slightly inclined towards the front, in alignment with the slope of the block 9. The shape of the sheets 8 gives, as previously shown, a first acceleration h in the direction of the receiving block 9.

The package 80 then descends gently on the block 9, according to the diagram of Figure 10 explained above, to finally stop on the conveyor 34 as seen in Figure 15. Simultaneously, the rod of the cylinder 27 retracts and the table 7 descends to its initial quasi-vertical position.

Meanwhile, the separation device 10, which had returned to its original position, was again put into action, so that a new package (81, Figure 14) was separated from the top of the stack.

The support 4 retracts again, causing the package 81 to fall to its low position appearing in FIG. 15, where it is squared laterally by the cleats 28.

With the dimensions of the packages and of the block 9 shown in the drawings, there is room on the block 9 only for a single package 80. The package 81 therefore remains in its position drawn in FIG. 15, awaiting ascent to the horizontal, until package 80 is conveyed by the conveyor 34. With smaller plate sizes, there could be room on the block for several packages in line behind each other, so that table 7 could be raised horizontally to evacuate the package 81 on the block 9, and we could still process at least one package from the top of the stack.

Following the conveyor 34 is placed a conventional debit station 82 with motorized conveyor 83 and margin stop 84. Such a device which in itself is not an integral part of the invention, is for example, as described in the French patent 2,313,294 cited above.

When the preceding packet 85, being processed on the debit station 82, is completely evacuated sheet by sheet, towards the store of the "slotter-printer" for example, the conveyor 37 is set in motion, which makes it possible to replace the packet 85 by package 80 on the debit table. The table 7 is then raised and the packet 81 replaces the packet 80 on the receiver unit 9. The operations thus continue until the stack 14. The forks 15 are then brought back while the deck 3 is tilted back into its "standing" position to receive a new battery which is again treated as stack 14. Since in total at least three packets, such as packets 81, 80, and 85 in Figure 15, are being processed, this stack change operation has time to s '' do so without risking a break in the supply of sheets to the printer slotter.

The device which has just been described makes it possible to separate and process packets 80 whose thickness does not exceed a few tens of centimeters to fix ideas.

It is possible with this machine to process thicker packages, since the lateral squaring of a package standing on its edge is done quite easily. In this case, the forks 25 equipping the accompanying device 5 are advantageously replaced by a belt conveyor, motorized at least in the high position of this conveyor, and of sufficient length. In this case, the retractable support 4 can be omitted because the processing of successive packets can be slower. Obviously also, the retractable support 4 can be eliminated in the machine of FIG. 1 when a lower operating speed can be tolerated.

To bring each stack of waiting cardboard plates in a standing position to a machine according to the invention, motorized roller conveyors (12, FIG. 2) are more and more often used as part of an automation. general of the factory, more and more desired at present.

These roller conveyors nevertheless have the disadvantage of flattening and smearing the bottom sheet of the stack. Such a sheet thus laminated and soiled is undesirable to the presentation of a printed and folded cardboard box which in itself would not be too serious because it would suffice to provide the user with an additional box per stack, but it is in addition detrimental to the operation of the shaping machine which it risks blocking by creating a "jam", that is to say an obstruction at the level of the introduction of the plates one by one into the slotter-printer. Indeed, the margin knives are adjusted in height to let pass a plate of normal thickness and to prevent the passage of two of these plates. There is therefore certainly a space between the plate which passes under the knives and the base of these, so that there is a good chance that this last sheet, of thinner thickness, happens to be introduced in same time as the previous one under the margin knives, most of the time causing the two sheets to jam under these knives, and consequently stopping the machine.

According to a variant of the invention, it is possible to overcome these drawbacks by a complementary operation of separation and automatic elimination of the last sheet of the last packet of each stack, ie the sheet below this stack. It consists more particularly in delaying the last sheet of this last pack during the operation of quasi-vertical fall of this one, to retain this last sheet during the operation of evacuation of this pack, then to eliminate this last sheet by evacuating it on another way.

Reference will now be made to FIGS. 16 to 26 which schematically describe the operation and the production of an additional device making it possible to automatically separate and eliminate the last sheet from each stack.

FIG. 16 shows the last packet of a stack, such as the stack 14 of FIG. 2, in a standing position on the retractable support 4. The support device 5 is being raised to its upper upper position . The presence on the support 4 of the last packet 95, presence which triggers the operation of eliminating the last sheet which will be described, is detected by the automaton controlling the running of the machine using an encoder or a contactor, not shown, placed at the level of the downstream end of the conveyor frame 16.

The support 4 is then retracted, and the last package 95 begins its almost vertical fall, accompanied therein by the support device 5. But, this time, the support device 5 is stopped during road, about halfway through its usual course, stopping with it the package 95 as seen in Figure 17.

Two sawtooth attachment ramps 96, hitherto retracted below the level of the idle rollers fitted to the ascent table 7, are then removed so that their teeth are planted in the last sheet of the package 95 , immobilizing it.

Then, as shown diagrammatically in FIG. 18, the brake of the motor (53, FIG. 7) for driving the accompanying device 5 is released, so that the pack 95 ends its almost vertical fall, with the exception of course of the last sheet 97 which remains attached to the ramps 96.

The ramps 96 are then retracted and, as shown diagrammatically in FIG. 19, the assembly constituted by the package 95 and its last sheet 97, offset backwards, is caught in the movement of ascent in a quasi-horizontal position of the table 7. When the latter has reached its top dead center, the assembly constituted by the packet 95 and the offset sheet 97 descends in a gentle slope towards the reception and evacuation block 9, represented here by a belt conveyor.

Then, as shown diagrammatically in FIG. 20, when the packet 95 is engaged on the reception block 9 by a value slightly less than the offset between this packet 95 and the last sheet 97, value which is detected by an encoder or a contactor, not shown, placed on block 9, the attachment ramps 96 have come out again, which causes, as will be seen below with reference to FIG. 26, the simultaneous exit of two claws 98 downstream of the table 7, which come into light support under the underside of the penultimate sheet of the package 95. The package 95 continues on its way to the block 9, but the last sheet 97 remains on the table 7, stopped in its forward stroke by the two claws 98.

As can be seen in FIG. 21, when the package 95 is engaged on the block 9 by an amount sufficient for stability on the block 9 to be ensured, for example of a value equal to two-thirds of its width, detected by a contactor not shown placed on the block 9, the table 7 again lowers, bringing with it the sheet 97.

However, table 7 does not go down completely this time. As shown diagrammatically in FIGS. 22 and 23, it is immobilized for about a third of its travel in front of flaps 99, the tilting of which then makes it possible to make an opening 100 in the left sheets 8.

The claws 98 are then retracted, which allows the sheet 97 to descend to a storage store 101 for these latter sheets, or to a discharge device such as a transverse conveyor, or destruction such as a crusher.

FIGS. 23 to 25 make it possible to appreciate the constitution and the location of the device for controlling the tilting of the flaps 99 and of the device for stopping the table 7 facing these flaps.

As can be seen in FIGS. 23 and 24, the table 7 abuts on two latches 102 fixed on a transverse bar 103 which can turn on itself by a quarter of a turn under the control of a jack 104 articulated on a connecting rod 105 integral with this bar. In the position shown, the rod of the jack 104 is out and the locks 102 stop the descent of the table 7 which consequently carries elastic buffers 106. By returning the rod of the jack 104, the locks 102 are rotated towards the low and therefore their erasure, which allows the table 7 to complete its descent.

Referring now to FIGS. 23 and 25, the flaps 99 are also fixed to a transverse bar 107 which can rotate a quarter of a turn under the action of a jack 108 articulated on a connecting rod 109 secured to the bar 107. In the position shown in Figure 25, the cylinder rod 108 is extended, and the flaps 99 are closed. By bringing in the rod of the jack 108, the bar 107 is rotated a quarter of a turn clockwise, and therefore the opening of the flaps 99.

FIG. 26 represents the constitution and the implantation of one of the devices with hooking ramp 96 and claw 98 combined. This device is arranged in the same structure 110 of the ascent table 7. As can be seen in the drawing, the movement of the attachment ramp 96 is given by a jack 111 with double rod which, by means of an articulated link 112, pushes the ramp 96 on two inclined faces 113, 114, thereby giving it a vertical movement causing it to come out of its housing 115. Furthermore, the claw 98 is fixed in an articulated manner around a transverse axis 116 and is associated with a counterweight 117 which normally causes it to come out of its housing 118. A lock 119 secured to the other rod of the jack 111 allows, by its translation in the direction of the claw 98, to retract the latter in its housing 118.

As seen in the drawing, the exit and retraction of the ramp 96 and the claw 98 are simultaneous.

The machine which has just been described does not allow the packages to be turned over before they are delivered plate by plate. It is perfectly suited to supplying the feeder store with a "slotter-printer" using a printer from below.

If, on the contrary, a printer is used from the top, it is necessary to turn the packages over before extracting the plates one by one. We will then use a slightly modified machine which will now be described with reference to FIGS. 27 to 31.

Figure 27 is a very schematic side view of this variant. There are the chassis 2, the tilting apron 3, the retractable support 4, the lateral squaring device 6, the receiving and evacuation block 9. On the other hand, as can be seen in the drawing, the positions of the ascent table 7 and left sheets 8 are inverted with respect to the machine of FIG. 2, and the sheets 8 have the shape of an arc of a circle slightly narrowed in a spiral, instead of being widened in a spiral as before. The axis 29 of rotation of the table 7 and its control cylinder 27 are carried downstream as seen in the drawing. The device 5 for accompanying the fall of the packets is not shown, since its function can be performed by the table 7 itself as will be seen below.

Furthermore, the machine of FIG. 27 comprises a device for turning over packages consisting of one or more rods 90, articulated at the bottom around an axis 91, passing between two sheets 8, and which can be moved with a movement of back and forth by exit from the rod of a jack 92 articulated on the chassis 2 of the machine. The forward tilting of the flat rod 90 makes it possible to give the package, after it has dropped along the sheets 8 and stopped standing on its edge, a thrust causing it to tip over onto the table 7, which allows to return it as will now be seen with reference to FIGS. 28 to 31 which schematize the operation of the device in FIG. 27.

In FIG. 28, a packet 93 has been separated from a stack 94 as in the case of the embodiment in FIG. 2 and rests on the retractable support 4. The table 7 is raised to the high position as shown, by rotation around its axis 29, then located downstream.

Figure 29 shows the following operation during which. the support 4 having retracted, the package 93 falls downward, accompanied in its fall by the descent of the table 7 caused by the retraction of the rod of the jack 27. The squaring device 6 is then actuated as in the case of the preceding machine.

Referring to FIG. 30, the actuator 92 is then actuated by bringing out its rod, so that the rod 90 rotates around its axis 91 and gives the package 93 a lateral thrust causing it to tilt on the table 7 then in position .extreme bass.

Then, as shown in FIG. 31, the rod of the jack 92 having been retracted, the table 7 is raised in a quasi-horizontal position, with a slight slope descending downstream as before. The packet 93 is then received by the block 9 as before and the cycle begins again.

All the examples of implementation described above lead, as can be seen in FIG. 15, for example, to supply the magazine of the feeder fitted to the shaping and printing machine, or slotter-printer, placed after the machine of the invention, via a sheet-by-sheet debit station with motorized conveyor and margin stop. The use of such a debit station between the machine of the invention and the feeder magazine has the drawback of appreciably increasing the length of the machine, often resulting in prohibitive bulk for certain cardboard boxes.

• - au moins un premier convoyeur sans fin motorisé associé à au moins une butée, indépendante et escamotable, d'arrêt d'au moins un paquet se trouvant sur ce convoyeur,
• - au moins un second convoyeur sans fin motorisé, faisant suite au premier et associé à son extrémité aval à des moyens fous de roulement du paquet sur ces moyens,
• - des moyens rétractables permettant de pousser l'arrière du paquet en le faisant rouler sur lesdits moyens fous de roulement.

We will now describe an alternative embodiment comprising another form of block 9 for receiving and discharging packages, per se of a new type, and not leading to this kind of drawback, since it allows the packages leaving the machine to be discharged. of the invention directly in the input feeder store of the slotter-printer, or other plate processing machine. According to this alternative embodiment, the device 9 for receiving and evacuating packets comprises:

• - at least one first motorized endless conveyor associated with at least one stop, independent and retractable, for stopping at least one package located on this conveyor,
• at least one second motorized endless conveyor, following on from the first and associated at its downstream end with crazy means for rolling the package on these means,
• - retractable means for pushing the rear of the package by rolling it over said crazy rolling means.

FIG. 32 shows an example of a packet 9 for receiving and discharging packets, substantially different from that described above, and allowing the implementation of this alternative embodiment.

The block 9 shown diagrammatically in FIG. 32 comprises: - a completely classic first endless conveyor 120, composed of two endless belts 121 each rotating between two pulleys 122, 123, the motorization of these belts being ensured by a shaft 124 connecting the downstream pulleys 123, this shaft being itself driven, by means of a conventional translation 125 with sprockets and chain, by an electric motor 126 fixed as the rest to the chassis of the block 9, not shown in this drawing.

• - un second convoyeur sans fin 129, faisant suite au convoyeur 120 comme on le voit sur le dessin, et comportant également deux courroies sans fin 130 tournant chacune entre deux poulies 131, 132, la motorisation de ces courroies étant assurée à l'aide d'un arbre 133 qui, par l'intermédiaire d'une transmission 134 à pignons et chaînes, est entraîné par un moteur électrique 135 fixé, comme le reste, au châssis du bloc 9.

Furthermore, an articulated stop 127 is arranged between the belts 121 so as to be able to come out, under the action of a vertical jack 128 fixed, also to the chassis of the block 9, above the plane formed by the upper strands of the belts 121, and obviously return below the level of this plane, always under the action of jack 128.

• - A second endless conveyor 129, following the conveyor 120 as seen in the drawing, and also comprising two endless belts 130 each rotating between two pulleys 131, 132, the motorization of these belts being ensured using a shaft 133 which, by means of a transmission 134 with sprockets and chains, is driven by an electric motor 135 fixed, like the rest, to the chassis of block 9.

Usually for two successive conveyors of this kind, the level of the plane formed by the upper strands of the belts 130 is slightly above (a few millimeters to one centimeter) of the plane formed by the upper strands of the belts 121, which makes it possible to '' ensure a positive transfer of material between the upstream conveyor 120 and the downstream conveyor 129.

• - Un pousseur escamotable 137 placé entre les courroies 130 de manière à être escamoté en-dessous de leur niveau supérieur. Ce pousseur est, comme on le voit sur le dessin, constitué de deux chariots 138 et 139 circulant le long de deux glissières communes 140 et 141.

At the downstream end of the conveyor 130, slightly set back from this end as shown in the drawing, and between the belts 130, are placed, connected to the chassis of the block 9, two idle wheels 136 which protrude slightly, by a centimeter for example, from the level of the upper strands of the belts 130.

• - A retractable pusher 137 placed between the belts 130 so as to be retracted below their upper level. This pusher is, as can be seen in the drawing, made up of two carriages 138 and 139 circulating along two common slides 140 and 141.

The upstream carriage 138 rolls along the slides 140 and 141 with a low coefficient of friction and is moved in translation by a pneumatic cylinder 142 fixed, like the rest, to the chassis of the block 9. The downstream carriage slides, with a high coefficient of friction, along the slides 140 and 141, and it constitutes the articulation of the shutter 143 of the pusher, this shutter itself being connected, by an articulated link 144, to the upstream carriage 138.

The operation of the pusher 137 is as follows:

When, the carriage 138 being in the maximum retracted position and therefore the assembly retracted under the upper level of the conveyor 129, the jack 142 pushes the carriage 138 forward, it subjects the flap 143 by means of the rod 144 to an inclined force whose horizontal component is less than the force required to push the downstream carriage 139 on the slides 140 and 141. The upstream carriage 138 therefore approaches the downstream carriage 139, causing the deployment of the flap 143 above the level upper part of the conveyor 130. When the flap 143 is fully deployed and is therefore in a vertical position, the upstream carriage 138 comes abut against the downstream carriage 139 and consequently push it, with the flap deployed 143. forward. The return and retraction of the flap 143 takes place in the reverse process when the jack 142 brings the upstream carriage 138 backwards.

We could obviously replace the device 137 which has just been described by a conventional device with an endless chain fitted with pusher pins, but such a conventional device requires a considerable space downwards, so that this space would prevent any passage man under block 9, passage which remains permitted thanks to the pusher 137 of the invention which has a small mechanical bulk in height.

A description will now be given, with reference to FIGS. 33 to 38, of the operation of the packet reception and evacuation block 9 shown in FIG. 32.

In FIG. 33 is schematized the first phase of operation of the block 9 of FIG. 32. A package of blanks 145 having been raised horizontally by the table 7 of the machine of the invention, this package advances gently the belts of the conveyor 120. The conveyor 120 then tows the package 145, at low speed ((of the order of 0.3 m / sec for example) so as not to deform it, until the stop 127, in high position as shown, come and stop this package, it then being sufficiently engaged on the conveyor 120 to hold it by itself.

The belts of the conveyor 120 continue to rotate for a few seconds, allowing the sheets at the bottom of the packet 145 which could have been more or less delayed during the previous manipulations to be reintroduced completely under the latter. A timer, not shown, set previously when the table 7 was raised, then stops the movement of the conveyor 120.

Then, as shown in FIG. 34, the second conveyor 129 being free, which a photoelectric cell not shown detects, the rod of the jack 128 (FIG. 32) is retracted so that the stop 127 disappears, the two conveyors 120 and 129 are started at low speed (0.3 m / sec), so that the package 145 is transferred slowly, towards the feeder magazine, on the belts of the conveyor 129, and stops at the end of them. below after its front part has engaged, as shown, on the idler wheels 136 slightly protruding from the level of the conveyor 129. The stop of the conveyor 129 is triggered by a photoelectric cell not shown.

In the meantime, as can be seen in FIG. 35 where the feeder magazine has been represented diagrammatically at 147, another package 146 has come to settle on the conveyor 120 where it remains waiting, stopped by the stop 127, raised as shown .

Then as shown in FIG. 36, the magazine 147 having emptied enough to receive the packet 145, which is detected by a photoelectric cell not shown, the conveyor 129 is again started, and the packet 145 advances towards store 147.

Before the package 145 begins to fall into the magazine 147 of the feeder, while its support on the belts of the conveyor 129 becomes weaker and weaker, the rod of the cylinder 142 is extended so that, as can now be seen in FIG. 37, the pivoting flap 143 deploys rapidly and comes to push, over the entire height of its rear part, the pack 145, causing it to roll on the idle wheels 136 while accelerating it very appreciably (by 0.3 m / more than 1 m / sec). The force of inertia due to this acceleration makes it possible to maintain the cohesion of the package 145 during its fall into the magazine 147 of the feeder.

As shown in FIG. 38, the flap 143 is then brought back by retraction of the rod of the jack 142. It then folds back and returns to its standby position under the upper level of the conveyor 129. The longitudinal alignment of the blanks of cardboard constituting the package just delivered in the store 147 is then advantageously perfect by a jogger 148 which, moved by a jack 149, taps in a reciprocating movement the rear of the package.

Of course, the invention is not limited to the embodiments which have just been described by way of examples, but it also covers the embodiments which would differ therefrom only in details, variant embodiments, or by the use of equivalent means. Although the tilting stack treatment method is currently preferred and widely used, it is not absolutely essential to lay the stack on its side before extracting a packet standing on its edge. One could very well maintain the stack in a standing position, as in the case of the aforementioned French patent 2,313,294, extract a packet therefrom as is done in said patent, then lay this packet on its edge using an apron tilting similar or identical to the deck 3 but treating only one package, and then continue to treat it according to the present invention.

Claims (30)

1. A method of automatically supplying a machine for processing plate or sheet products, characterised in that it comprises the following operations:

- supplying a stack waiting in upright position,

- extracting a group of blanks from the top of the stack and positioning the group upright on its edge,

- dropping the group until it stops falling, still upright on its edge,

- laterally squaring the group,

- raising the droup in a movement which brings it nearly back to the horizontal and

- discharging the group.

2. A method according to claim 1, characterised in that the stack is inclined until it rests on its side.

3. A method according to claim 2, characterised in that the group is brought almost back to horizontal by moving it in an arc of a circle which is widened or narrowed into a spiral so as to give the group a horizontal pre- acceleration in the discharge direction.

4. A method according to claim 1, characterised in that the group, after being brought into an almost horizontal position, is lowered on to a first idle conveyor equipped with a retaining device, and the group is stopped on a second adjacent motor-driven conveyor.

5. A method according to claim 2, characterised in that the treatment of the last group in the stack also comprises the operations of separating and automatically removing the last sheet from the group.

6. A method according to claim 5, characterised in that it consists in delaying the last sheet in the last group during the operation of dropping it, in retaining the sheet during the operation of discharging the last group, and then in discharging the sheet along another channel.

7. A method according to claim 6, characterised in that the last operations for processing the first group are performed as follows:

- the group is dropped and the last sheet in the group is gripped during the fall of the group,

- the group is then squared and brought back to horizontal,

- the group is discharged while retaining the last sheet, and

- the last sheet is removed by discharging it along another channel.

8. A method according to claim 7, characterised in that the group is brought back to the horizontal without continuing to grip the last sheet.

9. A method according to claim 2, characterised in that after the group has been stopped upright on its edge, it is turned by tilting it before bringing it into an almost horizontal position.

10. A device for automatically supplying a machine for processing products in sheet or plate form, for working the method according to claim 1, of the kind comprising a means capable of extracting groups of plates or sheets from a stack and laying them down so as to place them on a conveyor, characterised in that it comprises:

- a device (3, 10, 4) for separating a group (80) from the top of a stack of blanks (14) by placing the group upright on its edge,

- a device (4) for dropping the group substantially vertically and a guiding and receiving device (5, 7) for stopping the group after it has fallen and while it is still upright on its edge,

- a device (6) for laterally squaring the group after falling,

- a device (7, 8) for bringing the group back to the horizontal and

- a device (9) for receiving and discharging groups.

11. An automatic supply device according to claim 10, characterised in that the group- dropping device (4) comprises a retractable support (19).

12. An automatic supply device according to claim 10 or claim 11, characterised in that the device for guiding and receiving the group during its fall comprises a device (25) for accompanying the edge of the group during its fall.

13. An automatic supply device according to claim 12, characterised in that the accompanying device comprises a support (25) driven vertically downwards.

14. An automatic supply device according to claim 13, characterised in that the support comprises a conveyor, motor-driven at least in its top position.

15. An automatic supply device according to any of claims 10 to 14, characterised in that the device for returning the group to the horizontal comprises a table (7) inclinable by rotation around a top shaft (29) and a curved surface (8) facing it.

16. An automatic supply device according to claim 15, characterised in that the inclinable table (7) is disposed upstream of the curved surface (8) and the curved surface has the shape of an arc of a circle widened (a) in a spiral downstream (Fig. 9).

17. A device according to any of claims 10 to 16, characterised in that it comprises:

- means for detecting the presence of the last group (95, Fig. 16) in the stack;

- means (96) for gripping the last sheet (97) of the group while moving during its almost vertical fall;

- means (98) for holding the last sheet during discharge (Fig. 20) of the group after raising it to the horizontal, and

- means (102, 99) for discharging the last sheet along another channel (101).

18. A device according to claim 17, characterised in that the means (96) for gripping the last sheet and the means (98) for retaining it are retractable and coupled (Fig. 26).

19. A device according to claim 10, characterised in that it comprises a group- transferring conveyor (7) articulated around one of its two ends and means for positioning the conveyor in front of an auxiliary station (99, 101) for discharging the aforementioned last sheet along another channel.

20. An automatic supply device according to claim 15, characterised in that the inclinable table (7) is disposed downstream of the curved surface (8), and in that it also comprises a device (90, 92) for tilting the group (93) on the inclinable table after the group has fallen almost vertically (Figs. 10, î 8, 20).

21. A device according to claim 10, characterised in that it comprises a group supply table (30) equipped with at least one group- retaining device (33) and a motor-driven conveyor (34) downstream of the table for stopping the front group (59) waiting to be discharged.

22. A device according to claim 10, characterised in that the retaining device comprises claws (33) disposed on an endless conveyor (32).

23. A device according to claim 10, characterised in that the group supply table (30) is positioned so that it has a slight descending slope downstream.

24. A device according to any of claims 10 to 18, or according to claim 20, characterised in that it comprises:.

- at least one motor-driven endless conveyor (120) associated with at least one independent retractable abutment (127) for stopping at least one group (145) on the conveyor,

- at least one second motor-driven endless conveyor (129) following the first and associated at its downstream end with idle means (136) for bearing and conveying the group, and

- retractable means (137) for pushing the front of the group and moving it on the idle bearing means (Fig. 32).

25. A device according to claim 24, characterised in that the retractable means (137) for pushing the front of the group comprise two slides (138, 139) moving in the longitudinal direction on contiguous tracks (140,141), the downstream slide (139) moving along its track with greater friction than the upstream slide (138) on its own track, the two slides being connected by two elements (143, 144) articulated to one another and to each slide, the downstream element (143) constituting the pusher.

26. A device according to claim 24 or claim 25, characterised in that it is positioned so as to open directly into the magazine of the feeder of a machine for processing the aforementioned blanks.

27. A device according to any of claims 20 to 26, characterised in that it is mounted on the automatic supply device using means (35, 39) which move it longitudinally.

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