WO2025153962A1

WO2025153962A1 - A line and method for the automated production of cardboard boxes

Info

Publication number: WO2025153962A1
Application number: PCT/IB2025/050423
Authority: WO
Inventors: Giuseppe Capoia; Carlo Capoia
Original assignee: Panotec SRL
Current assignee: Panotec SRL
Priority date: 2024-01-15
Filing date: 2025-01-15
Publication date: 2025-07-24
Anticipated expiration: 2026-07-15

Abstract

A production line (1) for the automated production of cardboard boxes (B), comprising, in succession, a first operating unit (2) for feeding cardboard sheets (F) along a longitudinal direction (L), a second operating unit (5) for cutting, creasing and gluing the cardboard sheet (F) so as to produce a flat semi-finished product (D) with a central panel (D1), two end panels (D2, D3) and two side panels (D4, D5), a third operating unit (8) having a die assembly (10) defining a central opening (20) and a punch assembly (11) with a movable forming device (21) having a shape in plan view coinciding with the central opening (20) of the die assembly (10). The die assembly (10) and the punch assembly (11) comprise adjustment means configured to automatically and in real-time vary the transverse and/or longitudinal shape and size of the central opening (20) and the forming device (21) so as to instantly adapt it to the shape and size of the box (B) to be produced.

Description

A LINE AND METHOD FOR THE AUTOMATED PRODUCTION OF CARDBOARD BOXES

DESCRIPTION

Field of the invention

[0001] The present invention generally relates to the technical field of packaging, and particularly relates to a line for the automated production of cardboard boxes starting from cardboard sheets.

[0002] The invention also relates to a method for the automated production of empty cardboard boxes.

Background art

[0003] Automated lines for the production of custom-made boxes starting from cardboard sheets have long been known. Generally, these lines comprise means for picking up and advancing the cardboard sheets in a longitudinal direction in the form of sheets or strips towards a first cutting and creasing unit to produce a flat semi-finished blank product.

[0004] The semi-finished cardboard cut and creased is advanced towards a forming unit equipped with tools which cooperate with the semi-finished product. Some edges of the semi-finished product are covered with glue for gluing the walls together to form the box.

[0005] The box thus formed is deposited on a conveyor belt so as to be carried towards a collecting unit or towards a filling unit with objects to be boxed.

[0006] An example of such prior art machines is shown in EP59600 which discloses a machine having a storage unit for cardboard sheets adapted to place one sheet at a time on a conveyor belt, a thrust device which acts on the cut and creased sheet to force it to pass through a forming area configured to lift the side walls of the box. Below the plane for advancing the sheet there are elastic pressing elements adapted to facilitate the gluing of the walls to each other so as to form an open box.

[0007] Other examples of systems of this type are described and claimed in KR100769083 and JP3486732. [0008] One drawback of such prior art machines lies in the fact that both the die and thrust device have a fixed configuration so as to obtain boxes with predetermined shape and size in plan view.

[0009] If boxes of different sizes are to be produced, one has to stop the machine, set up the line again replacing the die and thrust device, restart the machine and resume the processing, resulting in increasing the cost for operating the plant and setting up the machine as a whole.

Technical problem

[0010] In the light of the prior art, the technical problem addressed by the present invention is optimisation of the structure of the cardboard box production line so as to allow the production of boxes of different sizes without having to stop the line to change the setup thereof.

Summary of the invention

[0011] The object of the present invention is to solve the aforementioned problem by providing an automated line for producing cardboard boxes that is highly efficient and significantly cost-effective.

[0012] A particular object of the present invention is to provide an automated line for producing cardboard boxes capable of changing the setup in real-time without having to shut down the line.

[0013] A further object of the present invention is to provide a highly automated line for producing cardboard boxes.

[0014] Another object of the present invention is to provide a line for producing cardboard boxes having a particularly high production speed.

[0015] Yet another object is to devise a method for producing boxes which can be adapted in real time to boxes of different shapes and size without shutting down the line.

[0016] The objects mentioned above and others which will be more apparent hereinafter, are achieved by an automated production line for producing cardboard boxes according to claim 1 .

[0017] The line comprises, in succession, a first operating unit for feeding cardboard sheets along a longitudinal direction, a second operating unit for cutting, creasing and gluing the cardboard sheet having means for producing a substantially cross-shaped flat semi-finished product comprising a central panel joined to two end panels provided with gluing flaps and two side panels glued to said central panel, a third operating unit having a die assembly defining a central opening and a punch assembly with a movable forming device having a shape in plan view coinciding with the central opening of the die assembly.

[0018] According to the invention, the die assembly and the punch assembly comprise adjustment means configured to automatically and in real-time vary the transverse and/or longitudinal shape and size of the central opening of the forming device so as to instantly adapt it to the shape and size of the box to be produced.

[0019] Due to such configuration, the production line will be fully automated and instantly set up without having to shut down the line to change the shape and size of the boxes to be produced.

[0020] The advantage obtained by this configuration consists in the possibility of automatically changing the size of the central opening of the die assembly so as to adapt it almost instantaneously to a different shape and size of a semifinished product.

[0021] In one embodiment, the die assembly comprises a frame substantially horizontal and substantially coplanar to the work surface, in the frame there being mounted a first and a second pair of mutually opposed and substantially rectangular occlusion members having internal edges perpendicular to each other adapted to delimit said central opening.

[0022] In one embodiment, the first and the second pair of occlusion members are movable transversely and longitudinally between a position of minimum distance so as to delimit with their internal edges a central opening of minimum width and a position of maximum distance so as to define with their internal edges a central opening of maximum width.

[0023] Therefore, this will allow to change the size of the box in a predetermined range between a maximum value and a minimum value. [0024] In one embodiment, the frame comprises therein a first pair of transverse guides along which a first pair of occlusion members slides, there being provided first movement means so as to translate the first pair of occlusion members in the transverse direction.

[0025] This will facilitate the sliding of the occlusion members so as to easily change the size and shape of the box to be obtained.

[0026] In one embodiment, the frame comprises therein a second pair of horizontal transverse guides along which a second pair of occlusion members slides, there being provided second movement means for translating the second pair of occlusion members in the transverse direction to change along with the first pair of occlusion members the width of the box to be produced.

[0027] Suitably, the second pair of transverse guides is mounted on a sliding assemble in turn mounted along a third pair of horizontal longitudinal guides integrally joined with the frame.

[0028] In one embodiment, the movable body of the punch assembly comprises a plurality of transverse rods that are movable vertically and parallel thereto. The transverse rods have lower ends configured to interact with the flat semi-finished product, and they are mounted on an adjustable movement structure to instantaneously change the position and the mutual distance of the rods in the transverse and longitudinal direction.

[0029] This configuration will allow to change the size of the movable body so as to easily adapt it to the size of the central opening.

[0030] In one embodiment, the plurality of vertical rods comprises at least one pair of rear rods and at least one pair of front rods with respect to the advancement direction, wherein the movement structure comprises for each pair of front and rear rods a carriage mounted on a transverse beam, respectively front and rear. Furthermore, each of the beams having transverse ends slidably mounted on a second pair of longitudinal guides integrally joined with the work surface above it.

[0031] Still, with the first and second transverse beam there are associated first and second longitudinal translation means configured to collectively translate the movable body of the punch assembly from an initial receded position superimposed on the work surface to pick up with suction-cup means a flat semi-finished product at a final advanced position to superimpose said punch assembly to said die assembly and release the flat module with the bottom wall thereof aligned with said central opening.

[0032] Preferably, with the first and second transverse beam and with the second transverse beam there are associated first and second longitudinal translation means configured to collectively translate the movable body of the punch assembly from an initial receded position superimposed on the work surface to pick up with suction-cup means a flat semi-finished product at a final advanced position to superimpose the punch assembly to the die assembly and release the flat module with the bottom wall thereof aligned with the central opening.

[0033] Suitably, said first and second longitudinal translation means are configured to confer to each transverse beam an independent longitudinal translation to change the mutual distance of the pair of rear rods and of the pair of front rods in the longitudinal direction and adapt to the length of the bottom wall of the box to be formed.

[0034] Furthermore, each carriage of the first and second pair of rods has respective first and second transverse adjustment means to change the transverse mutual distance of the rods of each pair and therefore the width of the box to be formed.

[0035] In one embodiment, downstream of the second automated unit there are provided means for discharging the finished box towards a possible third unit for filling or collecting finished boxes.

[0036] According to an embodiment, the first, second, third, fourth, fifth and sixth movement means, together with sensor means for controlling the position and the coordinated operation of the various components of the line, are connected to a PLC of the line, there being provided an interface device connected to the PLC and accessible by an operator so as to modify the setup of the line by adapting the shape and size of the central opening of the die assembly and of the movable forming device of the punch assembly according to the box to be produced.

[0037] In a second aspect of the invention, there is provided a method for the automated production of cardboard boxes by means of the line as described above.

[0038] Advantageous embodiments of the invention are attained according to the dependent claims.

Brief description of the drawings

[0039] Further features and advantages of the invention will be more apparent in the light of the detailed description of a preferred but not exclusive embodiment of a line for the automated production of cardboard boxes, shown by way of non-limiting example with reference to the drawings below, wherein: FIG. 1 is an axonometric view of a production line for producing cardboard boxes according to the invention;

FIG. 2 is a lateral view of the production line of FIG. 1 ;

FIG. 3 is a top view of the production line of FIG. 1 ;

FIG. 4 is a plan view of a cardboard sheet subjected to cutting and creasing operations to obtain a spread semi-finished product;

FIG. 5 shows some steps for forming a box starting from a semi-finished product of FIG. 4;

FIG. 6 is an axonometric view of a first assembly of the production line FIG. 1 in a first operative step;

FIG. 7 is a top view of the assembly of FIG. 6;

FIG. 8 is a first lateral view of the assembly of FIG. 6;

FIG. 9 is a second lateral view of the assembly of FIG. 6;

FIG. 10 is an axonometric view of the assembly of FIG. 6 in a second operative step;

FIG. 11 is a top view of the assembly of FIG. 10;

FIG. 12 is an axonometric view of a second assembly of the production line of FIG. 1 ;

FIG. 13 is a top view of the assembly of FIG. 12; FIG. 14 is a lateral view of the assembly of FIG. 12 in a first operative step;

FIG. 15 is an axonometric view of a particular assembly of FIG. 12;

FIG. 16 is a front view of the detail of FIG. 15;

FIG. 17 is a front view of the assembly of FIG. 14 in a first operative step;

FIG. 18 is a front view of the assembly of FIG. 14 in a second operative step;

FIG. 19 is a lateral view of the assembly of FIG. 12 in a second operative step; FIG. 20 is a lateral view of the assembly of FIG. 12 in a third operative step;

FIG. 21 is a block flow diagram of the method for producing a box by means of a production line of FIGS.1-20;

FIGS. 22-30 show some operating steps reported in the block flow diagram of FIG. 21 ;

FIGS. 30-34 show some details and some operating steps of the line of FIG. 1.

Detailed description of a preferred embodiment

[0040] With particular reference to the figures, there is shown a production line for the automated production of cardboard boxes B, indicated in its entirety with reference numeral 1 starting from cardboard sheets F, gathered into one or more stacks P.

[0041] The line extends in a longitudinal direction L and comprises a first operating unit 2 having a first framework carrying anchored to the ground which defines a storage unit for gathering one or more stacks P of sheets F.

[0042] The cardboard sheets F are joined at a transverse edge so as to produce a continuous module folded in a fan-like fashion for example as described in patent application WO2022243924 on behalf of the Applicant in question. In one embodiment, the sheets F may have a different format so as to optimise processing and reduce scraps so as to reduce cardboard consumption. For example, instead of a sheet F made of a single format, there may be provided sheets of different formats and the stacks P may also be differentiated each to gather a different format.

[0043] In a preferred embodiment, the first operating unit 2 for feeding the sheets F is provided with automated picking means 3 for picking up one sheet F at a time and with advancing means 4 for advancing the sheets F in the direction L. Should there be provided sheets of various formats, there is provided a device for selectively picking up the most appropriate format and advance it along the line.

[0044] Downstream of the feeding unit 2, the line 1 comprises a second die cutting operating unit, indicated in its entirety with 5, designed to operate on cardboard sheets F for obtaining flat semi-finished products D which will be used to form the cardboard boxes B and which will be described in greater detail below.

[0045] In one embodiment, the automated unit 5 comprises a base 6 anchored to the ground which has a flat work surface 7 on which the cardboard sheets F are transferred.

[0046] The second automated unit 5 comprises completely automated creasing and gluing means, not shown in the figures and of the per se known type to form a flat semi-finished product D at a time, as schematically illustrated in FIGS. 4 and 5.

[0047] In a preferred embodiment, the flat semi-finished product D, similar but not identical to the one described in EP3562748 owned by the Applicant in question, is obtained from a unitary sheet F having a longitudinal axis Lo. The sheet F is cut so as to obtain two longitudinal sections. The first section is formed by a central panel D1 joined to two end panels D2, D3 at the transverse creasing C2, C3. Furthermore, the two end panels D2, D3 were subjected to cuts to remove portions R along the side edges and obtain gluing flaps W by means of respective longitudinal creasings Cw. The second section is obtained from the sheet F by means of respective cutting lines S4, S5 to obtain two detached panels D4, D5 both provided with longitudinal creasings Cw to form two closing flaps A.

[0048] As better shown in FIG. 4, the central panel D1 will correspond to the bottom wall of the box B and the two end panels D2, D3 correspond to a pair of transverse flaps of the box B. [0049] In the second automated unit 5 the detached panels D4, D5 will be picked up and suitably positioned and glued to the central panel D1 along the end edges so as to form the substantially cross-shaped semi-finished product D

[0050] Hereinafter, the expression “transverse flaps” will be used to indicate the side flaps or walls of the box which are perpendicular to the longitudinal axis Lo of the semi-finished product D.

[0051] Hereinafter, the expression “longitudinal flaps” will be used to indicate the side flaps or walls of the box B which are parallel to the longitudinal axis Lo of the semi-finished product D.

[0052] In one embodiment, the base material of the sheet F is corrugated board with corrugations O perpendicular to the longitudinal direction L, as shown in FIG. 4, so that side panels D4, D5 have corrugations parallel to the cutting lines S4, S5 and end panels D2, D3 have corrugations parallel to the transverse creasings C2, C3 of the central panel D1.

[0053] The substantially cross-shaped flat semi-finished product D is designed to be folded and formed so as to generate the finished box B, with the free closing flaps A.

[0054] The latter may be folded and joined with a conventional tape N after filling the box B.

[0055] Downstream of the second operating unit 5, line 1 provides for a third forming operating unit, indicated in its entirety with 8, for the interaction with the flat semi-finished product D so as to produce a finished box B.

[0056] In one embodiment, the third operating unit 8 comprises a base 9 anchored to the ground, having a first portion 9’ which supports a die assembly 10 and a second portion 9” which supports a punch assembly 11 , both configured to interact with each other and with the flat semi-finished product D.

[0057] Downstream of the third forming unit 8 there is provided an area 12 for discharging the formed boxes B provided with advancement means 13 for advancing the boxes towards a warehouse or a subsequent filling unit, not shown in the figures.

[0058] In one embodiment, the die assembly 10, shown in greater detail in FIGS. 6-9 comprises a peripheral frame 14 made of metal sections which are substantially rectangular-shaped and defining a transverse axis X and a longitudinal axis Y.

[0059] Inside the frame 14 there are housed a first pair of occlusion members 15, 16 on opposite sides with respect to the longitudinal axis Y and a second pair of occlusion members 17, 18 also on opposite sides with respect to the longitudinal axis Y.

[0060] In one embodiment, occlusion members 15, 16 and 17, 18 are prismatic blocks with a shape - in plan view - approximately rectangular or square-shaped so as to delimit with their internal edges 19 facing each other and orthogonal a central opening 20.

[0061] In one embodiment, the punch assembly 11 comprises a movable forming device 21 having a shape in plan view identical to that of the central opening 20 of the die assembly 10 less than the thickness of the base material of the semi-finished product D to interact with the latter and with the die assembly 10 to form a box.

[0062] In particular, the movable forming device 21 is substantially parallelepiped in shape and is configured to slide in the vertical direction according to the vertical axis Z, compress the central panel D1 and gradually push it into the central opening 20 so as to force the end D1 , D2 and side D4, D5 panels of the flat semi-finished product to fold inwards in order to make the inner and outer flaps of the box B to be produced.

[0063] Preferably, the mobile forming device 21 is provided with means for depositing glue on the gluing flaps W of the semi-finished product D, which will be described in greater detail below, to glue the transverse and longitudinal flaps of the semi-finished product D to each other, leaving the two closing flaps C free. [0064] According to the invention, the die assembly 10 and the punch assembly 11 comprise separate and distinct adjustment means, configured to vary automatically and in real time the transverse and/or longitudinal shape and size of the central opening 20 and of the forming device 21 , to mutually adapt them to the shape and size of the box to be produced.

[0065] In one embodiment, the means for adjusting the die assembly 10 comprise a first pair of transverse guides 22, 23 on which there are slidably mounted by means of wheels or rollers the occlusion members 15, 16 of the first pair to mutually move towards/away from and symmetrically with respect to the longitudinal axis Y.

[0066] First movement means, preferably of the rack-and-pinion type with a gear train driven by an electric motor 24, as better shown in FIG.9, act on the occlusion members 15, 16 in order to control the mutual approaching/moving away movement in the transverse direction X and symmetrically with respect to the longitudinal axis Y. It is clear that rack and pinion means can be replaced by other types of movement means, for example screw and nut screw or belt or chain, with an entirely equivalent effect.

[0067] Inside the frame 12 there is provided a second pair of transverse guides 25, 26 on which there are slidably mounted the occlusion members 17, 18 of the second pair.

[0068] Second movement means, also in this case preferably of the rack-and- pinion type with a gear train driven by an electric motor 27 act on the occlusion members 17, 18 of the second pair to promote the approaching/moving away movement in the transverse direction X of the occlusion members 17, 18 symmetrically with respect to the median line Y.

[0069] By changing the distance of the occlusion members 15, 16 and 17, 18 of the first and of the second pair, respectively in the transverse direction X simultaneously and in a coordinated manner, there is obtained the change in the width of the bottom wall of the box to be produced.

[0070] To change the length of the bottom wall of the box to be produced, the second pair of transverse guides 25, 26 is mounted on a mobile equipment consisting of a pair of longitudinal slides 28, 29 slidably mounted on guides 30, 31 integrally joined with the frame 14.

[0071] The slides 28, 29 are coupled to third movement means, for example of the belt type 32, 33 driven by a single electric motor 34, so as to approach/move away the second pair of occlusion member 17, 18 to/from the first pair of occlusion members 15, 16 according to the direction of the longitudinal axis Y and selectively change the length of the box to be produced. [0072] Actuating the first, second and third movement means, allows to continuously change the relative position of the occlusion members 15, 16 and 17, 18, along the transverse X and longitudinal Y axes so as to change the width of the central opening 20 between a minimum value Smin and a maximum value Smax, indicated with a dashed line in FIGS. 7 and 11.

[0073] In one embodiment of the punch assembly 11 , the movable forming device 21 is configured to gradually push the semi-finished product D into the central opening 20 so as to fold the end D2, D3 and side D4, D5 panels thereof. [0074] In one embodiment, the forming device 21 is mounted on the second portion 9” of the base 9 and comprises two groups of three vertical thrust rods, indicated respectively with 35, 36.

[0075] The rods of each group 35, 36 are substantially aligned and according to a first transverse direction parallel to the transverse axis X of the die assembly 10. Furthermore, the two groups of rods 35, 36 are longitudinally staggered along a longitudinal direction parallel to the axis Y of the die assembly so as to cover the entire development of the bottom wall of the box to be produced, corresponding to the panel D1 of the semi-finished product D. [0076] In one embodiment, the first group of rods 35 comprises a central rod 37, located on the centreline of the line 1 , and two lateral rods 38, 39 equally spaced from the central rod 37. Similarly, the second group of rods 36 comprises a central rod 40 and two lateral rods 41 , 42 equally spaced from the central rod 40, as better shown in FIGS. 15 and 17. [0077] The central rods 37, 40 are fixed and the lateral rods 38, 39 and 41, 42 are movable in the transverse direction so as to adapt the shape of the forming device in plan view to the size of the box to be produced.

[0078] The lower end of each of the fixed central rods 37, 40 is provided with an oscillating foot respectively indicated with 43, 44, while the lower ends of the lateral rods 38, 39 and 41 , 42 are provided with elongated plates 45, 46 and 47, 48 hinged at the respective ends to easily interact with the panel D1 corresponding to the bottom wall of the box to be formed when forming the semi-finished product D.

[0079] Hereinafter, for the sake of simplicity, the first group of rods 35 will be referred to as “front” while the second group of rods 36 will be referred to as “rear” with respect to the advancement direction of the line along the longitudinal direction L.

[0080] Also, the transverse position of the lateral rods can be adjusted using fourth adjustment means. In one embodiment, the fourth adjustment means comprise on the upper ends of the lateral rods 38, 39 and 41, 42 respective carriages 49, 50 and 51 , 52 which are slidably mounted on respective transverse guides 53, 54 in turn anchored to vertical frames 55, 56.

[0081] Each of the carriages 49, 50 and 51 , 52 is connected to a respective annular belt 57, 58 and 59, 60 wounds on pulleys arranged at the vertices of the vertical frames, not shown in the drawings, and each driven by an electric motor 61 , 62.

[0082] Actuating the motors 61 , 62 will allow to adjust the distance of the lateral rods 38, 39 and 41 , 42 with respect to the central rods 37, 38 in order to change the width of the movable forming device 21 and therefore of the box to be formed.

[0083] On the smaller sides of the vertical frames 55, 56 there are formed respective slides 63, 64 and 65, 66 which slide along corresponding vertical guides 67, 68 and 69, 70 in turn fixed to two horizontal beams 71 , 72, better visible in FIG. 17. [0084] The vertical movement of the slides 63, 64 and 65, 66, to which there are integrally joined the rods 37, 38, 39 and 40, 41 , 42, is carried out by means of fifth actuation means which comprise pairs of vertical belts 73, 74 and 75, 76 supported by end pulleys integrally joined with the vertical guides 67, 68 and 69, 70 and driven in rotation by respective electric motors 77, 78.

[0085] The front 37, 38, 39 and rear 40, 41 , 42 groups of rods, joined to the vertical frames 55, 56 and to the horizontal beams 71 , 72 together form two carriages, referred to as front carriage 80 and rear carriage 81 which are mounted on respective slides 82, 83 e 84, 85 slidable on a pair of longitudinal guides 86, 87 integrally joined with the sides of the base portion 9”.

[0086] The independent movement of the front carriage 80 and rear carriage 81 is controlled by sixth movement means which comprise, for each carriage, a pair of external toothed belts 88, 89, respectively internal 90, 91 , fixed to the outermost 82, 83 and innermost 84, 85 slides and actuated by respective electric geared motors 92, 93, as clearly shown in FIGS. 12, 13, 17 and 18.

[0087] For the sake of completeness, it should be observed that each plate 45, 46 and 47, 48 hinged at the lower ends of the lateral rods 38, 39 and 41 , 42 can be controlled by respective jacks 94 to prevent the rotation of the pairs of external flaps of the box being formed during the sliding movement of the vertical rods and of said punch assembly, and to unlock the rotation thereof during the ascent of the punch assembly, as shown in FIG. 34.

[0088] Furthermore, each of the front and rear carriages 80, 81 comprises at least one pair of dispenser devices 95 for applying glue on the gluing flaps W of the flat module, as shown in FIGS. 12, 17, 31.

[0089] Lastly, the die assembly 10 comprises compression means comprising two pairs of pressing members 96 formed by L-shaped plates provided with rollers, arranged below the frame 14 and simultaneously acting in diagonal direction on the edges of the box to ensure the adhesion of the gluing flaps against the external flaps of the flat semi-finished product, as better shown in FIGS. 28, 32, 33 [0090] Furthermore, it should be observed that the front carriage 80 and the rear carriage 81 are provided in the lower part with suction-cup means, not shown in the drawings and of the per se known type, adapted to lift the semifinished product D by a few millimeters and transfer it by horizontal translation along the guides 21 , 87 toward the die assembly, in a position such to superimpose the panel D1 of the semi-finished product D at the centre of the central opening 20 before performing the lowering of the forming device 21 along the axis Z.

[0091] All the automated units and in particular the first, second, third, fourth, fifth and sixth movement means are connected to a PLC, not shown in the figures, together with position and proximity sensors, to control the coordinated operation of the line.

[0092] Furthermore, there is provided an interface device, not shown in the drawings and of the per se known type, accessible by an operator so as to modify the setup of the production line by adapting the shape and size of the central opening of the die assembly and the movable forming device of the punch assembly according to the box to be produced.

[0093] In a second aspect of the invention, there is provided a method for the automated production of cardboard boxes using the line described above.

[0094] The method comprises the following steps: a. picking up a cardboard sheet F from a stack P of a first operating unit 2; b. cutting, creasing and gluing the sheet F in a second operating unit to produce a flat semi-finished product D with a central panel D1 joined to two end panels D2, D3 with gluing flaps W and two side panels D4, D5 glued to the central panel D1 ; c. picking up the flat semi-finished product D from the work surface 7 of the second operating unit 5 and transfer thereof to a third forming unit 8 so that the central panel D1 of the semi-finished product D is superimposed on the central opening 20 of the die assembly of the third operating unit, as shown in FIGS. 22 and 23; d. applying glue on the gluing flaps W of the end panels D2, D3 of the flat semi-finished product D; e. aligning the punch assembly 21 with said central opening 20 and starting the descent thereof so as to engage the central panel D1 of the flat semi-finished product D with the lower end thereof, as shown in FIG. 24; f. starting the descent the forming device 21 into the central opening 20 so as to cause the gradual folding of the end D2, D3 and side D4, D5 panels with respect to the central panel D1 , as shown in FIGS. 25 and 26; g. completing the descent of the forming device 21 into the central opening 20 to achieve the complete 90° folding of the panels D2, D3, D4, and D5 with respect to the central panel D1 , as shown in FIGS. 26 and 27; h. compressing the glue-covered gluing flaps W of the end panels D2, D3 against the edges of the side panels D4, D5, as shown in FIG. 28; i. removing the finished box B and placing it on a conveyor belt 13 and simultaneous raising the forming device 21 from said central opening 20, as shown in FIG. 29.

According to the invention, at the end of the forming of the box according to steps a)- i) and before forming another box with different shape and size, there are activated means for adjusting the die assembly 10 and the punch assembly 11 so as to adjust the shape and size in plan view both of the central opening 20 and of the forming device 21 in real-time and without interrupting the operation of the line.

[0095] In the light of the description above, it is clear that the production line according to the invention achieves the pre-established objects and in particular it allows real-time modification of the setup without having to shut down the line. Furthermore, it provides a method for producing boxes that allows to adapt the production line to different boxes of different shapes and sizes without shutting down the operation thereof.

[0096] The machine according to the invention is susceptible to numerous modifications and variants all falling within the inventive concept outlined in the attached claims. [0097] Even though the machine has been described with reference to the attached figures, the reference numbers utilised in the description and in the claims are meant for improving the intelligibility of the invention and thus do not limit the claimed scope of protection in any manner whatsoever. [0098] Throughout the description, reference to “an embodiment” or “the embodiment” or “some embodiments” indicate that a particular characteristic, structure or element described is comprised in at least one embodiment of the object of the present invention.

[0099] Furthermore, the particular characteristics, structures or elements may be combined in any appropriate fashion in one or more embodiments.

Industrial applicability

[00100] The present invention can be applied at industrial level because it can be manufactured on industrial scale by industries belonging to the field of machines for manufacturing packages.

Claims

1 . A production line (1) for the automated production of cardboard boxes (B), comprising sequentially:

- a first operating unit (2) for feeding cardboard sheets (F) along a longitudinal direction (L);

- a second operating unit (5) for cutting, creasing and gluing the cardboard sheet (F) having means for producing a substantially cross-shaped flat semi-finished product (D) comprising a central panel (D1) joined to two end panels (D2, D3) provided with gluing flaps (W) and two side panels (D4, D5) glued to said central panel (D1); characterised in that it comprises a third operating unit (8) having a die assembly (10) defining a central opening (20) and a punch assembly (11) with a movable forming device (21) having a shape in plan view coinciding with the central opening (20) of said die assembly (10), wherein said die assembly (10) and said punch assembly (11) comprise adjustment means configured to automatically and in real-time vary the transverse and/or longitudinal shape and size of said central opening (20) and of said forming device (21) so as to instantly adapt it to the shape and size of the box (B) to be produced, wherein said forming device (21) and said die assembly (10) respectively comprise means for depositing glue on said gluing flaps (W) and compression means so as to ensure the adhesion of said gluing flaps (W) to the side panels (D4, D5).

2. Line as claimed in claim 1 , characterised in that said means for depositing glue comprise at least one pair of dispenser devices (95), said compression means comprising two pairs of pressing members (96) formed by L-shaped plates provided with rollers and simultaneously acting in diagonal direction on the comers of the box (B) so as to ensure the adhesion of said gluing flaps (W) against the side walls of the box (B).

3. Line as claimed in claim 1 , wherein said die assembly (10) comprises a substantially horizontal frame (14) internally housing a first pair of occlusion members (15, 16) and a second pair of mutually opposed and substantially rectangular occlusion members (17, 18) having internal edges (19) orthogonal to each other adapted to delimit said central opening (20).

4. Line as claimed in claim 3, wherein said adjustment means for adjusting the die assembly (10) comprise a first pair of transverse guides (23, 24) along which said first pair of occlusion members (15, 16) slides, there being provided first movement means for translating said first pair of occlusion members (15, 16) according to a transverse axis (X).

5. Line as claimed in claim 3, wherein said adjustment means for adjusting the die assembly (10) further comprise a second pair of transverse guides (25, 26) along which said second pair of occlusion members (17, 18) slides, there being provided second movement means for translating said second pair of occlusion members according to said transverse axis (X) to change along with the first pair of occlusion members (15, 16) the width of the box (B) to be produced.

6. Line as claimed in claim 5, wherein said pair of transverse guides (17, 18) is mounted on a sliding equipment in turn mounted along a third pair of longitudinal guides (30, 31) integrally joined with said frame (14).

7. Line as claimed in claim 6, wherein there are provided third movement means acting on said sliding equipment to translate said second pair of occlusion members (17, 18) along a direction parallel to a longitudinal axis (Y) so as to selectively change the length of the box (B) to be produced.

8. Line as claimed in claim 3 to 7, wherein said first and second pairs of occlusion members (15, 16; 17, 18) are movable transversely and longitudinally between a position of minimum distance so as to delimit with their internal edges a central opening (20) of minimum width (Smin) and a position of maximum distance so as to define with their internal edges (19) a central opening (20) of maximum width (Smax).

9. Line as claimed in the preceding claims, wherein said movable forming device (21) comprises a plurality of vertical rods (37, 38, 39; 40, 41 , 42) movable parallel thereto along a vertical axis (Z).

10. Line as claimed in claim 9, wherein said plurality of rods comprises a front group of rod (37, 38, 39) and a rear group of rod (40, 41 , 42) with respect to the advancement direction of the semi-finished product (D), the central rod (37; 40) of each group being stationary, the side rods (38, 39; 41 , 42) of each group being movable with respect to said central rods (37; 40).

11. Line as claimed in claim 10, wherein the upper ends of said movable side rods (38, 39; 41 , 42) of each group are provided with respective trolleys (49, 50; 51 , 52) slidably mounted on transverse guides (53; 54) integrally joined with respective vertical frames (55; 56).

12. Line as claimed in claim 11 , wherein each of the trolleys (49, 50; 51 , 52) is connected to a respective annular belt (57, 58; 59, 60) wound on pulleys arranged at the vertices of said vertical frames (55, 56), each annular belt (57, 58; 59, 60) being driven by an electric motor (61 , 62) so as to adjust the distance of said lateral rods (38, 39; 41 , 42) with respect to said central rods (37, 40) to vary the width of the movable forming device (21) and therefore of the box (B) to be formed.

13. Line as claimed in claim 11 , wherein on the shorter sides of said vertical frames (55, 56) there are provided slides (63, 64; 65, 66) configured to slide along corresponding vertical guides (67, 68; 69, 70) in turn fixed to two horizontal beams (71 , 72).

14. Line as claimed in claim 13, wherein there are provided fifth actuation means which comprise pairs of vertical belts (73, 74; 75, 76) supported by end pulleys integrally joined with said vertical guides (67, 68; 69, 70) and driven in rotation by respective electric motors (77, 78) to promote the vertical movement of said slides (63, 64; 65, 66) and therefore of said front and rear groups of rod (37, 38, 39; 40, 41 , 42).

15. Line as claimed in claim 13, wherein said front group (37, 38, 39) and rear group of rods (40, 41, 42) joined to said vertical frames (55, 56) and to said horizontal beams (71 , 72) form a front carriage (80) and a rear carriage (81), each mounted on respective slides (82, 83; 84, 85) slidable on a pair of longitudinal guides (86, 87) integrally joined with the sides of a base portion (9”).

16. Line as claimed in claim 15, wherein there are provided sixth movement means which comprise, for each carriage (80, 81), a pair of toothed belts (88, 89; 90, 91) fixed to said outer slides (82, 83; 84, 85) and actuated by respective electric motors (92, 93) to promote the movement of said carriages (80; 81) in the longitudinal direction (L).

17. Line as claimed in one or more of the preceding claims, wherein said first, second, third, fourth, fifth and sixth movement means, together with sensor means for controlling the position and the coordinated operation of the various components of the line, are connected to a PLC, there being provided an interface device connected to said PLC and accessible by an operator so as to modify the setup of the line by adapting the shape and size of the central opening (20) of the die assembly (10) and of the movable forming device (21) of the punch assembly (11) according to the box (B) to be made.

18. A method for the automated production of cardboard boxes (B) using the line as claimed in one or more of the preceding claims, comprising the following steps: a) picking up a cardboard sheet (F) from a stack (P) of a first operating unit (2); b) cutting, creasing and gluing the sheet (F) in a second operating unit (5) to create a substantially cross-shaped flat semi-finished product (D) formed by a central panel (D1) joined to two end panels (D2, D3) with gluing flaps (W) and two side panels (D4, D5) glued to said central panel (D1); c) picking up the flat semi-finished product (D) from said second operating unit (5) and transferring it to a third operating unit (8) so that said central panel (D1) is superimposed on the central opening (20) of the die assembly (10) of said third operational unit (8); d) applying glue on the gluing flaps (W) of said end panels (D2, D3); e) aligning the punch assembly (21) with said central opening (20) and starting the descent thereof so as to engage said central panel (D1) with the lower end thereof; f) introducing the forming device (21) into the central opening (20) so as to cause the gradual folding of the end (D2, D3) and side panels (D4, D5) with respect to said central panel (D1); g) completing the descent of the forming device (21) into the central opening (20) to achieve the complete 90° folding of said end (D2, D3) and side panels (D4, D5) with respect to said central panel (D1); h) compressing the glue-covered gluing flaps (W) of the end panels (D2, D3) against the edges of the side panels (D4, D5); i) removing the finished box (B) and placing it on a conveyor belt and raising the forming device (21) from said central opening (20); wherein at the end of the forming of a box (B) according to steps a)-i) and before forming another box with different shape and size, there are activated means for adjusting the die assembly (10) and the punch assembly (11) so as to adapt the shape and size in plan view both of the central opening (20) and of the forming device (21) in real-time and without interrupting the operation of the line.