EP0130852B1 - Device for making cardboard boxes in a folded shape - Google Patents

Description

The present invention relates to an installation for the continuous production of folded pre-assembled boxes, from cardboard plates or other flexible material of the same kind, installation which includes a cutting station end-to-end to give the plates the developed shape of the boxes. to produce a gluer, a folder, a squaring station and a stapler and which is equipped with means for moving said plates between the cutting station and the output of the stapler, these means including a transfer device provided in the squaring station for advancing the plates without slipping before their introduction into the stapler, at a first speed compatible with the working speed of the latter, the gluing machine and the stapler can also be put into operation separately or simultaneously for ensure the pre-assembly of the boxes in cooperation with the folder.

We know that for storage and transport facilities, the cardboard boxes are not directly produced in their final parallelepiped form, but are simply pre-assembled in a folded form, generally by means of an installation of the type specified above. , and are most often delivered as is to users.

In this installation, each plate from the cutting station has, on one of its lateral edges, a tab which will then be fixed to the opposite lateral edge of the plate, after folding thereof.

In most cases, a simple bonding is sufficient to achieve this attachment, the gluer then being alone in service. However, if the boxes to be produced are intended to support large loads, it must necessarily be done by stapling, by putting the stapling unit into operation and possibly putting the gluer out of service.

In this stapling unit, the squaring station, which is used to position the folded plates laterally and to make the lateral edges of their folded parts coincide on each other before they pass through the stapler, also for the function of advancing the plates one by one without sliding with a view to their introduction under the latter. To this end, the transfer device of the squaring station is formed of pusher members which, because of their particular structure, limit the linear speed of transfer of the plates to a maximum value of 200 m / minute.

However, the passage of the cardboard plates through the gluing machine can be done at very high linear speeds, greater than 360 m / min., Without the quality of the bonding being affected.

Consequently, when the installation is used in the bonding version, its productivity is considerably reduced because of the presence of the stapling unit in the path of the cardboard plates.

To avoid this drawback, the only possibility that currently exists is to remove the stapling unit from the installation when it is desired to work in the bonding version.

However, this operation carries a number of drawbacks. Firstly, it requires the installation of rails allowing the stapling unit to be released laterally. In addition, after this lateral release of the stapling unit, the station for receiving the preassembled boxes, which is normally located after the stapling unit, must be brought back online at the exit of the folder, with there also the need to provide rails for its movement.

Furthermore, when it is desired to operate the installation in the stapling version, the operations described above must be carried out in reverse order with of course the same constraints. Added to this is the fact that replacing the stapling unit in the installation is necessarily accompanied by a certain number of relatively long and tedious adjustments, which must ensure re-centering and resynchronization. of the stapling unit on the other workstations of the installation.

In conclusion, converting an installation for the pre-assembly of cardboard boxes from one operating mode to another by current means is a complex and restrictive operation, which also results in a fairly significant loss of time which destroys a part of the profit from the installation's productivity increase.

The present invention proposes to remedy these drawbacks and, to do this, it relates to an installation of the type specified in the preamble, for producing pre-assembled boxes in folded form, from cardboard plates or other flexible material, installation which is characterized in that the squaring station is equipped with a second transfer device intended to drive the plates at a second speed substantially equal to their speed of passage through the gluing machine, and comprises first control means capable of rendering operational the first transfer device in response to the operation of the stapler and, to make it inactive in response to the operation of the stapler alone, and second control means adapted to operationalize the second transfer device in response to the operation of the stapler alone and to make it inactive in response to the operation of the stapler.

Thus, when it is desired to operate the installation according to the invention only in the bonding version with maximum productivity, it suffices to deactivate the first transfer device normally associated with the stapler and to make the second transfer device operational. This operation is very brief especially more that it can be automated in synchronism with the operation of the gluer and stapler.

Thanks to the invention, cardboard manufacturers no longer have to fear the long and tedious operation of lateral release of the stapling unit nor the operations and the additional adjustments.

Advantageously, the second transfer device comprises a lower planar conveyor carried by the frame of the squaring station and an upper planar conveyor mounted movable above the first, the second control means being therefore designed to, in response to the put the stapler into operation, raise the upper conveyor out of the path of the plates and, in response to the operation of the stapler alone, place it in a low position in which the drive surfaces of the two conveyors delimit, on the path of the folded plates, a passage from a height slightly less than the total thickness of the latter.

In a preferred embodiment, each conveyor is constituted by a train of parallel movable belts each stretched between a motorized pulley and one or more guide pulleys, so as to have a horizontal strand constituting said drive surface.

Thus, when the upper conveyor is in the low position, what is known as a “training sandwich” is produced, the folded plates leaving the folder being grabbed one by one and then drawn between the horizontal strands of the two belts of belts which can be set in motion at a speed equal to the speed of passage of the plates through the gluing machine.

In addition, the upper conveyor is mounted on a movable frame and, in a simple and advantageous embodiment, the second control means ensuring the movement of the upper conveyor comprise at least one jack whose rod is connected to the frame by an articulated connection of the deformable parallelogram type.

Preferably, the articulated connection is connected to the rod of the jack by a connecting piece slidingly mounted on said rod and the free end of the rod of the jack is threaded to receive by screwing a ring for adjusting the height of the passage delimited by the two conveyors.

Thus, to make the second transfer device inactive, it suffices to retract the rod of the jack; indeed, the adjustment ring pushes during this movement the connecting piece thus causing the lifting of the upper conveyor by folding the articulated connection. On the contrary, to make it operational, it suffices to completely relax the cylinder rod, the upper conveyor automatically collapsing by gravity until the connecting piece abuts against the adjustment ring which, by its adjustable position, determines the height of the passage formed between the two conveyors.

Finally, in a preferred embodiment, the first transfer device consists of one or more parallel mechanical chains, stretched between toothed wheels mounted on the chassis of the squaring station, so as to have drive strands horizontal extending just below the plane of advance of the plates, these chains carrying tabs which are arranged in rows perpendicular to the direction of advance of the plates and which are retractable over an inactive section of the chain drive strands, located just upstream of the stapler, the first control means being designed to stop the movement of the chains once all the cleats are on said inactive section of the drive strands and / or on the second strand of the chains.

It is thus possible, in a simple manner, to make the first transfer device inactive. Furthermore, to make it operational, it will suffice to keep the cleats in the raised position on the active part of their path, which can be achieved by rails extending just below the horizontal drive strands of the chains, on the section of these preceding said inactive section, these rails being able to be moved in the direction of the chains.

• la figure 1 est une vue latérale schématique d'une installation conforme à la présente invention ;
• la figure 2 est une vue en plan d'une plaque de carton telle qu'elle se présente à la sortie de la station de découpage de l'installation de la figure 1 ;
• les figures 3 et 4 sont respectivement une vue en plan et une vue de face de cette plaque de carton telle qu'elle se présente à la sortie de la plieuse de l'installation ;
• la figure 5 est une vue de côté agrandie de la station d'équerrage de cette installation, représentée en version agrafage ;
• la figure 6 est une vue en coupe transversale de la station d'équerrage telle que représentée sur la figure 5 ;
• la figure 7 est une vue de côté de la station d'équerrage représentée en version collage ; et
• la figure 8 est une vue en coupe transversale de la station d'équerrage telle que représentée sur la figure 7.

An embodiment of the present invention will now be described, only by way of nonlimiting example, with reference to the accompanying drawings in which:

• Figure 1 is a schematic side view of an installation according to the present invention;
• Figure 2 is a plan view of a cardboard plate as it appears at the outlet of the cutting station of the installation of Figure 1;
• Figures 3 and 4 are respectively a plan view and a front view of this cardboard plate as it appears at the outlet of the folder of the installation;
• Figure 5 is an enlarged side view of the squaring station of this installation, shown in stapling version;
• Figure 6 is a cross-sectional view of the squaring station as shown in Figure 5;
• Figure 7 is a side view of the squaring station shown in bonding version; and
• FIG. 8 is a cross-sectional view of the squaring station as shown in FIG. 7.

As can be seen in Figure 1, the installation according to the invention, for the pre-assembly of cardboard boxes in the folded state, is in the form of a production line capable of operating continuously.

At the start of the chain, there is first of all a feeder 1 which keeps in place a perfectly ordered stack 2 of cardboard plates. At the outlet of this feeder 1, an automatic gripping device (not shown) is provided for gripping the cardboard plate constituting the bottom of the stack 2 and depositing it on the tray of a cutting station 3, which is designated more commonly under the Anglo-Saxon term "slot- ter ". A printer can optionally be placed between the feeder 1 and the cutting station 3, to print on the cardboard plates the inscriptions relating to the future contents of the boxes.

The cutting station 3 is equipped with tools known per se which give each cardboard plate the developed shape of the box to be pre-assembled, visible in FIG. 2. As can be seen in this figure, these tools form on the plate 4, on the one hand, the notches 5 which define the flaps 6 of the box and, on the other hand, fold lines 7 which delimit its lateral faces 8a to 8d. In addition, a tab 9 is cut on the free edge of an end face 8a, this tab 9 being intended, as will be seen below, to be fixed, after folding of the plate 4, to the free edge 10 of the other end face 8d.

Downstream of the cutting station 3 is arranged a splicer 11 which is followed by a folder 12. A stapling unit, constituted by a stapler 13 preceded by a squaring station 14, is further provided downstream of the folder 12. Each of these work stations 11, 12, 13 and 14 is equipped with transfer devices which ensure continuous movement of the cardboard plates, from the entry to the exit of the installation. It is known that, depending on the use to which it will be put, the boxes can be pre-assembled, either by stapling, or by gluing the tab 9 on the opposite free edge 10 of each plate. This is why the installation shown in FIG. 1 can be used either in the stapling version by disabling the gluing machine 11, or in the gluing version by disabling the stapling machine 13.

In the stapling version, the cardboard plates 4 from the cutting station 3 are directly transferred, one after the other, to the folder 12, in the direction of advance indicated by arrow A of the figure 2.

As can be seen in Figures 3 and 4, the folder flaps the two end faces 8a and 8d on the two central faces 8b and 8c of the plate, so that the edge 10 comes to rest on the tab 9.

The plates 4 thus folded then pass through the squaring station 14 where they undergo an appropriate lateral positioning before their introduction under the stapler 13 which then intervenes to staple the edge 10 on the tab 9 of each plate 4, at at least two points distant from each other in the direction of advance A of the plates. Each folded pre-assembled box thus obtained at the outlet of the stapler 13, then comes to rest on a stack 15 of pre-assembled boxes, formed in a reception station 16.

If the installation is now operated in the bonding version, each plate 4, coming from the cutting station 3, is subjected, through the gluing machine 11, to the action of a gluing roller not visible in the figures, which deposits a film of glue on the tab 9 of the plate 4. The latter is then folded, as shown in FIGS. 3 and 4, during its passage through the folder 12, the glued side of the tab 9 coming from 'apply against the edge 10 of the plate. The plate thus folded is then conveyed, through the stapling unit 13 and 14 taken out of service, to the receiving station 16 where, under the weight of the stack 15, the tab 9 is definitively fixed to the edge 10 by the adhesive film after squaring by means of a device integrated into the receiving station 16.

The squaring station 14 which is more precisely the object of the present invention, will now be described with reference to FIGS. 5 and 6.

According to the first characteristic of the invention, the squaring station 14 is equipped with two separate transfer devices 17 and 34 which can be made separately operational for respectively advancing the cardboard plates 4 without sliding, when the installation is operating in version stapling, and drive them at their speed of passage through the splicer 11, when the installation operates in bonding version.

As can be seen in Figures 5 and 6 which show the squaring station 14 on a larger scale, the first transfer device 17 consists of four parallel mechanical chains 18 which each have a horizontal strand 19 extending just at - below the plates advance plan. Each of these chains 18 is wound around two toothed wheels 20 and 21 mounted on the chassis 22 of the squaring station 14, respectively near the inlet and the outlet thereof, the downstream toothed wheels 20 chains 18 being mounted on the shaft of a common drive motor 23 with adjustable speed.

Referring more specifically to FIG. 5, it can be seen that four retractable lugs 24a to 24d are articulated at equal intervals on each of the chains 18, all of these lugs being grouped in four rows perpendicular to the chains.

Furthermore, a horizontal retracting rail 25 extends from the entrance to the squaring station, just below the horizontal strand 19 of each of the chains 18 and along only part of it. this. Each rail 25 is slidably mounted on the chassis 22 and its position can be adjusted in the direction of advance A of the plates, by means of a motorized pinion 26 which cooperates with a rack 27 formed on the underside of the rail.

Two pairs of motorized rollers 28, 29 mounted one above the other around horizontal axes, on either side of the chain train 18, are also provided at the entrance to the station. squaring, to delimit a forced passage for the plates 4. Two pairs of identical rollers 30, 31 are arranged at the outlet of the squaring station.

Finally, two rows of rollers 32, 33 are, in a manner known per se, mounted to rotate freely, around vertical axes, on the chassis 22 of the squaring station 14, so as to define, on the path of the plates, a corridor which tapers slightly towards the stapler 13, until it has a width equal to the half-developed a (see figure 4) of the plate.

The second transfer device 34 is formed in turn by two conveyors 35, 36 arranged one above the other.

The upper conveyor 35 is constituted by two parallel movable belts 37, 38 extending on either side of the group of chains 18 (see FIG. 5). The two belts 37, 38 are respectively wound around a motorized pulley 39 and a guide pulley 40 both carried by a movable frame 41 movable in a vertical plane, and each having a horizontal drive strand 37a, 38a tensioned by a row of rollers 42 mounted to rotate freely on the frame 41 (see FIG. 5).

The movable frame 41 is mounted on a fixed frame 43 by means of two articulated connections 44 of the deformable parallelogram type. Each link 44 consists of two bent arms 45, 46 whose ends are respectively articulated on the one hand on the frame 41, at two points located near the ends of the latter, and on the other hand on a common crosspiece 47. In addition, the two arms 45, 46 are articulated, at the level of their elbow, on the fixed frame 43.

The connections 44 are associated with a jack 48 whose cylinder is pivotally mounted on the frame 43 and the rod 49, which extends parallel to the crosspieces 47, is connected to the latter by a connecting piece 50. The connecting piece 50 is mounted to slide freely on the jack rod 49, the end of which is threaded to receive by screwing an adjustment ring 51.

The lower conveyor 36 is itself formed by two parallel movable belts 52, 53 each winding around a motorized pulley 54, several guide pulleys 55 and a tension pulley 56, carried by the chassis 22 and positioned so that the belts 52, 53 have two horizontal strands 52a, 53a, respectively located directly above the two horizontal strands 37a, 38a of the belts 37, 38.

We will now describe the operation of the squaring station 14, when the installation is used in the stapling version, with reference to FIGS. 5 and 6.

The rod 49 of the jack 48 is retracted beforehand either by a manual control, or by an automatic control synchronized with the starting of the stapler; the adjustment ring 51 thus displaces the connecting piece 50 in the direction of folding the articulated connections 44, which has the effect of raising the train of upper belts 37, 38 to the position shown in FIGS. 5 and 6.

The gearwheel drive motor 23 and the input rollers 28, 29 are then rotated at the same speed.

Therefore, the plates 4 from the folder 12 are introduced one after the other in the squaring station, between the input rollers 28, 29.

Once completely introduced beyond these rollers, each plate 4 is pushed flat along the lower belts 52, 53 and a horizontal table 57, visible in FIG. 7, by a row of tabs 24a, 24b. 24c or 24d, kept raised by their support on the rails 25. Of course, for the transfer of the plates to take place correctly, the passage of the rows of cleats between the two pairs of input rollers 28, 29 must be synchronized with the complete introduction of the plates beyond these, which can be done by a very simple initial adjustment.

Once the front end of each folded plate 4 is grasped between the output rollers 30 and 31, the tabs tilt beyond the front edge 25a of the rails 25, the position of the rails being initially adjusted by means of the pinion assemblies- rack 26, 27, so that the distance separating their front edge 25a from the axes of the rollers 30, 31 is equal to the thrust b of the plates (see FIG. 3).

Therefore, the advance of the plates is only ensured by the pairs of rollers 30, 31 which are linked to the transfer device of the stapler to be driven at the speed of passage of the plates through the latter.

During their transfer through the squaring station 14, the plates 4 are also correctly positioned, between the two rows of horizontal rollers 32 and 33, with a view to their introduction into the stapler 13.

If now it is desired to operate the installation in bonding version, the motor 23 is rotated at low speed, before starting the gluing machine 11, until the three rows of tabs 24a, 24b, 24c are below the horizontal upper strand 19 of the chains 18 and that the tabs 24d of the fourth row tilt beyond the edge 25a of the rails, as shown in FIG. 7.

Then, the rod 49 of the jack 48 is completely relaxed, in synchronism with the starting of the gluer 11, so that the upper conveyor 35 collapses, by its own weight, until the connecting piece 50 comes into abutment against the adjusting ring 51. In this position, shown in FIGS. 7 and 8, the two conveyors 35, 36 delimit, on the path of the plates 4, a passage whose height h can be adjusted, thanks to the adjustment ring 51, so as to be very slightly less than the thickness of the folded plates coming from the folding machine 12. In this way, what is known as a drive sandwich is produced in which the plates can be transferred by blocking between the two moving conveyors.

Therefore, the motorized pulleys 39, 54 of the belts 37, 38 and 52. 53 are rotated at the speed of passage of the plates through the gluer 11. At the same time, the transfer devices of the folder 12 and the stapler 13, also constituted by drive sandwiches, as well as the rollers 28, 29 and 30, 31 which are respectively coupled to the latter, are driven at the same speed.

Thus, the plates 4 are driven, over the entire length of the installation, at their speed of passage through the gluer 11, and the presence of the stapling unit 13 and 14 no longer constitutes an obstacle to use with maximum productivity of the installation in bonding version.

You may also have to use both the stapler and the gluer to pre-assemble the crates. In this case, of course, only the first transfer device 17 will be made operational in the manner described above.

It goes without saying that the invention is not limited to the embodiment described. One can for example provide more than two parallel belt trains for the upper 35 and lower 36 conveyors; these can also be provided with other drive means, such as simple motorized rollers mounted side by side. Similarly, the first transfer device 17 may include more than four cleat chains; a single chain, which would carry cleats covering the entire width of the squaring station, may even be sufficient. Finally, the jack and the articulated connections can be replaced by any other means capable of ensuring a displacement in height of the upper conveyor 35.

Claims (9)

1. An installation for the continuous production of folded, preassembled cases from cardboard sheets or another flexible material of the same kind, comprising end to end a cutting out station (3) for giving to the sheets the unfolded form of the cases to be produced, a glueing unit (11), a folding unit (12), a positioning station (14) and a stapler (13), and equipped with means for moving said sheets between the cutting out station (3) and the outlet of the stappler (13), such means including a transfer device (17) provided in the positioning station for driving the sheets without slippage before introduction into the stapler, at a first speed compatible with the working speed of the latter, the glueing unit (11) and the stapler (13) being further operable separately or simultaneously for preassembling the cases in cooperation with the folding unit (12), said installation being characterized in that the positioning station (14) is equipped with a second transfer device (34) for driving the sheets (4) at a second speed substantially equal to the speed of passage thereof through the glueing unit (11), and comprises first control means which can render the first transfer device (17) operative in response to setting the stapler (13) into operation and inoperative in response to setting the glueing unit (11) alone into operation, and second control means which can render the second transfer device (34) operative in response to setting the glueing unit (11) alone into operation and inoperative in response to setting the stapler (13) into operation.

2. The installation according to claim 1, characterized in that the second transfer device (34) comprises a lower flat conveyor (36) supported by the chassis (22) of the positioning station (14) and an upper flat conveyor (35) movably mounted above said lower flat conveyor, the second control means (48) being designed, in response to setting the stapler into operation, for raising the upper conveyor (35) out of the path of the sheets and, in response to setting the glueing unit alone into operation, for placing it in a low position in which the driving surfaces (37a, 38a and 52a, 53a) of the two conveyors define, in the path of the folded cases, a passage of a height slightly less than the thickness of the latter.

3. The installation according to claim 2, characterized in that each conveyor is formed of a train of parallel mobile belts (37. 38 or 52, 53) each being tensioned between a motor driven pulley (39 or 54) and one or more guide pulleys (40 or 55, 56), so as to exhibit an horizontal run (37a, 38a or 52a, 53a) forming said driving surface.

4. The installation according to claim 3, characterized in that each of the lower horizontal runs (37a, 38a) of the upper conveyor belts (37, 38) is supported on a row of idler rollers (42).

5. The installation according to any of claims 2 to 4, characterized in that the upper conveyor (37, 38) is mounted on a mobile frame (41), and in that said second control means comprise a cylinder (48) the rod (49) of which is connected to the frame (41) through at least one hinged connection (44) of the deformable parallelogram type.

6. The installation according to claim 5, characterized in that the hinged connection (44) is connected to the rod (49) of the cylinder (48) through a connecting piece (50) which is slidably mounted on said rod (49) with the free end of the cylinder rod (49) carrying a stop element (51).

7. The installation according to claim 6, characterized in that the free end of the rod (49) of the cylinder (48) is threaded over a certain length and the stop element is formed of an adjusting ring (51) which is screwed on the threaded part of the free end of the rod (49) the cylinder (48).

8. The installation according to any of claims 1 to 7, characterized in that the first transfer device (17) is formed of one or more parallel mechanical chains (18) tensioned between toothed wheels mounted on the chassis (22) of the positioning station (14), so as to exhibit horizontal driving runs (19) extending just below the plane of advance of the sheets, such chains (18) carrying studs (24a to 24d) disposed in rows perpendicular to the advancing direction of the sheets and retractable on an inactive portion of the driving runs (19) of the chains (18), which is located just upstream of the stapler (13), the first control means being designed to stop the movement of the chains (18), once all the studs (24a to 24d) are on said inactive portion of the driving runs (19) and/or on the second run of the chains (18).

9. The installation according to claim 8, characterized in that rails (25) extend just below the horizontal driving runs (19) of the chains (18) along the portion thereof preceding said inactive portion, such rails being movable in the direction of the chains.

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