PACKAGING METHOD AND MACHINE INCLUDING CONVEYOR FOR BOX

Description

The present application is a continuation of U.S. application Ser. No. 19/475,958 filed Oct. 16, 2025, which is the U.S. National Stage of PCT/FR2024/050502 filed Apr. 16, 2024, and claims the benefit of FR2303902 filed Apr. 19, 2023, the entire content of each of which is incorporated by reference herein.

The present application relates to a packaging method and machine including a conveyor for a box. Such a packaging method and machine can be configured to, for example, close a rectangular parallelepiped box that is open at the top with a lid.

In the field of order preparation, that is, distribution, it is common to have to dispatch an order comprising a plurality of objects of different shapes and sizes. For this purpose, it is common to use a rectangular parallelepiped box which is open at the top and generally made of corrugated cardboard.

Such a box, commonly referred to as a “tray” or “half-slotted box”, comprises a bottom bordered by four side walls joined in pairs by an edge. It is sold in an infinite number of basic generic formats, each with a given width, length and height, which define the overall volume of this box.

Packaging machines are known which reduce the height of boxes to an optimum height for the products contained within these boxes, before affixing a covering lid formed from a blank of solid or corrugated cardboard comprising a rectangular central panel dimensioned to cover the open upper side of the box and four side flaps designed to be folded down and glued to the upper portions of the four vertical side walls of the box.

The lids can optionally comprise fold lines formed between their central panel and the side flaps so as to facilitate folding of the latter.

These machines conventionally include a horizontal conveyor, such as a bar, belt or band conveyor, on which cardboard boxes pre-filled with products of varying heights are advanced in sequence through a number of stations in an advancement direction, under the control of a controller.

Document US 2009/0031676 A1 thus discloses such a packaging machine comprising, encountered successively along the conveyor:

• • a station for detecting the height of the products inside each box;
  • a station for cutting the boxes along their vertical edges to a certain height;
  • a station for marking the sides of the boxes to form horizontal fold lines delimiting four upper fold-over panels of variable width, depending on the height of the products packaged in each box;
  • a station for folding the fold-over panels over the contents of the box; and
  • a closing station consisting in placing lids on the top of the boxes, the closing station having a laterally associated lid storage magazine.

The box and the lid are thus generally transferred in longitudinal and transverse advancement directions, respectively, to such a closing station, where this lid is superimposed horizontally, vertically in line with said box. During these transfers, glue is sprayed respectively onto the upper portions of the longitudinal side walls of the box and onto the lower faces of the two transverse side flaps of the lid.

The box and the lid are then brought together by sliding vertically such that the top edge of this box comes into contact with the central panel of the lid along its peripheral edge, then said four so-side flaps of the lid are folded and pressed for a predetermined time against the upper portions of the side walls of the box to ensure the attachment of the lid is to the box by gluing.

Glue is sprayed onto the lower faces of the two transverse side flaps of the lid using conventional glue guns positioned underneath these flaps and emitting jets of glue oriented substantially vertically.

It is understood that this vertical arrangement of the glue guns tends to lead to clogging of their nozzles, as well as repetitive soiling of the machine, causing frequent stoppages for cleaning and/or unclogging of these nozzles.

In addition, the lids often tend to have a certain curvature due to the deformation of the corrugated cardboard over time as a result of variations in temperature and humidity.

Transferring such curved lids often causes jams, forcing operators to throw away entire pallets of lids. This jamming problem is all the more accentuated when the papers used for the two sides of the corrugated cardboard have different compositions.

The present invention aims to improve the situation.

To this end, a method is proposed for closing a box with a lid comprising a rectangular central panel and four side flaps, the box being a rectangular parallelepiped that is open at the top and comprises four vertical side walls extending from a horizontal bottom, said method comprising the following successive steps:

• • transferring said box and said lid in longitudinal and transverse advancement directions, respectively, to a closing station where said lid is superimposed horizontally, vertically in line with said box, with glue being sprayed respectively onto the upper portions of the longitudinal side walls of said box and onto the lower faces of the two transverse side flaps of said lid during their transfer;
  • bringing said box and said lid together by sliding vertically such that the top edge of this box comes into contact with said central panel of the lid along its peripheral edge;
  • folding and pressing said four side flaps of the lid for a predetermined time against the upper portions of the side walls of the box so as to ensure the attachment of said lid to said box by gluing;
    characterized in that the two transverse side flaps of said lid are retained, during the transfer of the latter in said transverse advancement direction and toward said closing station, in a partially folded-down position.

Transporting the lid with its two transverse side flaps partially folded down enables the central panel of this possibly curved lid to be mechanically flattened. The invention therefore makes the closing process more reliable, while considerably limiting cardboard losses due to lids that cannot be processed by the machine.

In order to considerably limit the risks of soiling and clogging of the nozzles of the glue guns, glue is advantageously sprayed onto the lower faces of the two transverse side flaps of said lid in a substantially horizontal direction. It should be noted that this substantially horizontal gluing direction is made possible by the fact that the lid is transported with its two transverse side flaps partially folded down.

In order to achieve optimum flattening of the central panel of the lid and to facilitate the gluing of the two transverse side flaps, each of these flaps forms a first predetermined angle with the central panel, advantageously between 100° and 135° and even more preferably between 110° and 130°, during the transfer of said lid.

In addition, and in order to limit the elastic return force of the side flaps of the lid which prevents them from being folded, and thus considerably reduce the pressing time required to glue them to the upper portions of the side walls of the box, said method advantageously comprises, prior to transferring said lid, a step of pre-folding the four side flaps downwards with respect to the central panel and at a second predetermined angle greater than 90°.

In order to achieve an optimum reduction in pressing time, this second predetermined angle is advantageously between 110° and 150°, and even more preferably between 130° and 140°.

This pressing time is thus preferably between 0.5 and one second.

A second aspect of the invention relates to a packaging machine provided with a closing station for closing a box with a lid comprising a rectangular central panel and four side flaps, the box being a rectangular parallelepiped that is open at the top and comprises four vertical side walls extending from a horizontal bottom, said machine including conveying means capable of conveying such a box to said closing station in a longitudinal advancement direction, as well as a transfer sub-assembly capable of transferring such a lid in a transverse direction to said closing station where said lid is superimposed horizontally, vertically in line with said box; characterized in that said transfer sub-assembly comprises two transverse guide rails capable of gripping said lid so as to retain its two transverse side flaps in a partially folded-down position during its transfer in the transverse direction to said closing station.

According to a preferred embodiment, the two guide rails define two respective internal concavities extending symmetrically opposite one another and each having the shape of a downwardly oriented 7 the internal concavity of each such rail thus being delimited by a horizontal lower abutment wall and by an oblique wall extending from the outer end of this lower abutment wall and forming a predetermined angle therewith of advantageously between 100° and 135° and even more preferably between 110° and 130°.

According to a preferred embodiment, this machine also includes a weakening sub-assembly capable of causing pre-folding of the four side flaps of said lid with respect to its central panel.

This weakening sub-assembly preferably comprises a first pair of transverse pre-folding members rotatably mounted about transverse axes of rotation, and a second pair of longitudinal pre-folding members rotatably mounted about longitudinal axes of rotation.

According to an advantageous conformation, each such pre-folding member thus comprises, for example, at least one lyre-shaped fork which is provided with two branches, inner and outer, and is mounted so as to rotate about an axis located close to its concave bottom, the fork(s) of each such pre-folding member being permanently elastically returned, by return means, to a rest position in which their openings are oriented downwards with their plane of symmetry offset by a predetermined angle on the inner side with respect to the vertical so that the free ends of their outer branches lie below those of their inner branches.

Lastly, each pre-folding member advantageously comprises at least three such forks that rotate together and are evenly spaced apart from one another along their axis of rotation.

An illustrative and non-limiting detailed description of an exemplary embodiment of the invention will now be given with reference to the appended drawings, in which:

FIG. 1 shows a schematic top view of a packaging machine according to the invention;

FIGS. 2A, 2B, 2C, 2D and 2E are perspective views of a box processed by the machine of FIG. 1 at different stages of the packaging process;

FIG. 3 shows a schematic top view of the pilgrim's step conveyor device used in the packaging machine shown in FIG. 1;

FIG. 4 is a schematic top view of one of the carriages of the pilgrim's step conveyor device shown in FIG. 3;

FIGS. 5A, 5B, 5C, 5D and 5E are schematic top views showing the different phases of an operating cycle of the pilgrim's step conveyor device of FIG. 3;

FIG. 6 shows a schematic view of one of the two measuring and cutting stations of the packaging machine shown in FIG. 1, taken at the moment a box arrives at this station and in a vertical sectional plane parallel to the advancement direction of the boxes;

FIG. 7 is a schematic top view of the measuring and cutting station shown in FIG. 6, at the moment a box arrives at this station;

FIG. 8 shows a view similar to FIG. 6, but taken during the cutting phase;

FIG. 9 is a schematic view of the folding station of the packaging machine of FIG. 1, taken at the moment a box arrives at this station and in a vertical sectional plane parallel to the advancement direction of the boxes;

FIG. 10 shows a schematic top view of the folding station of FIG. 9, at the moment a box arrives at this station;

FIG. 11 is a view similar to FIG. 10, but taken after the folding phase of the transverse upper fold-over panels created on the box at one of the measuring and cutting stations;

FIGS. 12A, 12B and 12C are enlargements showing the various phases of the punching cycle carried out on the box at this folding station;

FIG. 13 shows an enlarged front view of a folding jaw that folds one of the transverse upper fold-over panels of the box and performs the punching function;

FIG. 14 is a schematic view of one of the lid magazines of the packaging machine of FIG. 1, taken when one of the lids in this magazine is unstacked by a feeder sub-assembly, in a vertical sectional plane parallel to the advancement direction of the boxes and offset from the circulation axis of the boxes;

FIG. 15 shows a view similar to FIG. 14, but taken after this lid has been straightened horizontally by the feeder sub-assembly;

FIG. 16 is a view similar to FIGS. 14 and 15, but taken as the lid passes through a sub-assembly for weakening the fold lines of the side flaps of this lid;

FIGS. 17A, 17B and 17C are enlargements showing the various phases of the weakening cycle performed as the lid passes through this weakening sub-assembly;

FIG. 18 shows a view similar to FIGS. 14, 15 and 16, but taken at the moment of forced positioning of the lid between the guide rails of a transfer sub-assembly for bringing this lid to a closing station;

FIG. 19 is an enlarged cross-sectional view of the guide rails in a vertical cross-sectional plane between the magazine and the closing station, where glue guns are installed to apply glue lines to the transverse fold-over panels of the lid as it slides toward this closing station;

FIG. 20 is a schematic view of the closing station of the packaging machine of FIG. 1, taken at the moment a box and a lid simultaneously arrive at this station and in a vertical sectional plane parallel to the advancement direction of the boxes; and

FIG. 21 shows a view similar to FIG. 20, but showing the gluing phase of the side flaps of the lid to the side walls of the box.

FIG. 1 shows a schematic top view of a packaging machine 1 according to the invention.

An orthogonal reference frame XYZ is defined with respect to this machine 1, comprising three axes perpendicular to one another in pairs, namely:

• • an X axis, defining a longitudinal, horizontal direction,
  • a Y axis, defining a transverse, horizontal direction, which together with the X axis defines a horizontal XY plane, and
  • a Z axis, defining a vertical direction, perpendicular to the horizontal XY plane.

In the remainder of the description and with reference to the reference frame defined above, the terms “longitudinal” or “longitudinally” will refer to a direction parallel to the X axis, the terms “transverse” or “transversely” will refer to a direction parallel to the Y axis, and the terms “vertical” or “vertically” will refer to a direction parallel to the Z axis.

Moreover, the terms “front” and “rear” will be used to specify the longitudinal positioning of certain elements relative to the orientation of the X axis. Similarly, the terms “upper” and “lower” will be used to specify the relative position of certain elements with respect to the orientation of the Z axis.

Finally, the use of the term “substantially” will indicate that a slight deviation from a predetermined nominal position or arrangement is permissible, while remaining within the scope of the invention. For example, “substantially horizontal” will indicate that a deviation of the order of 10° to 20° from a strictly horizontal orientation is permissible within the scope of the invention.

The machine 1 includes five successive stations 100, 200, 300, 400, 500 arranged in line along a longitudinal advancement direction D oriented from the rear to the front, and on which boxes 10 of two different predefined formats pass successively and in sequence, resting with their bottom on a horizontal advancement table 3 consisting, for example, of a smooth sole piece or a free roller conveyor. These boxes 10 are pre-filled with articles of various heights.

The first infeed station 100 through which the boxes 10 enter the machine 1 by being loaded onto the advancement table 3 includes detection means, not shown, for detecting the format of the box 10 arriving at this infeed station 100 from an infeed conveyor 600 arranged in the upstream extension of this machine 1.

This infeed station 100 typically comprises motorized rollers which advance the box 10 to a stop (not shown) designed to position it precisely along the longitudinal axis of movement. When this box 10 comes into contact with this stop, centering devices (not shown) ensure its centering in the transverse direction.

For example, the means for detecting the format of the box 10 may advantageously comprise a barcode reader present on each of the boxes 10 and containing in particular information on its format. This information is then stored by the control system of the machine 1 and follows the box 10 as it moves from one station to the next.

Alternatively, these means for detecting the format of the boxes 10 may be of a different type, for example an optical camera or an infrared sensor associated with a processing module.

Following this infeed station 100 is a first station 200 for measuring and cutting boxes 10 of the first format (boxes 10 of the second format are not processed here), then a second station 300 for measuring and cutting boxes 10 of the second format (boxes 10 of the first format are not processed here).

The function of these two stations 200, 300 is to measure the height of the tallest article A contained in the box 10 (see FIG. 2A) and to make certain cuts in the latter in order to form and/or delimit upper fold-over panels of variable height, depending on the height of this article A.

Following these two measuring and cutting stations 200, 300 is a fourth folding station 400, whose function is to fold the upper fold-over panels over the tallest product contained in the box 10.

Finally, the function of a fifth and last closing station 500 is to place and attach, by gluing, a correspondingly sized cardboard lid 30 onto the top of each box 10 to close it, before this box 10 is transferred to a discharge conveyor 700 in the downstream extension of the machine 1.

To this end, two lid storage magazines 800, 900 are associated laterally with this last closing station 500.

This machine 1 also comprises a controller or control system not shown in the figures, in communication with the various stations 100, 200, 300, 400, 500 and with the two lid storage magazines 800, 900.

Configured to control various components of the machine 1, this controller comprises at least one computer associated with a memory module storing control processes.

FIG. 2A shows a perspective view of the type of box 10 processed by the machine 1, this type of box, made from solid or corrugated cardboard with single, double or triple fluting, being commonly referred to as a “tray” or “half-slotted box”.

Open at the top, each box 10 has a rectangular horizontal bottom 11 which is designed to support one or more articles such as the article A and is bordered by four side walls 12, 13 (in this case, two longitudinal side walls 12 and two smaller transverse side walls 13), so as to delimit a rectangular parallelepiped-shaped interior volume. The side walls 12, 13 are joined in pairs along a respective vertical edge 14.

Referring to FIG. 3, the machine 1 includes a pilgrim's step conveyor device 50 for advancing the boxes 10 placed on the advancement table 3 from one station to the next in the advancement direction D.

As shown in FIG. 3, the pilgrim's step conveyor device 50 comprises two longitudinal guide rails 51 attached to the frame, not shown, of the machine 1, and extending parallel to the advancement direction D, on both sides of the advancement table 3.

This pilgrim's step conveyor device 50 also includes a first series of four carriages 52 movably mounted for longitudinal translation along a first guide rail 51, as well as a second series of four carriages 52 movably mounted for translation along a second guide rail 51 and arranged opposite the carriages of the first series.

To this end, each carriage 52 comprises a sliding guide member 53 on the corresponding rail 51, advantageously comprising ball or roller bearings or even anti-friction pads to limit friction forces.

Maintained at a distance from one another of the same spacing pitch Pe corresponding to that between two adjacent stations of the machine 1 (for example, via a respective toothed longitudinal belt 54 at two points of the same strand 54A from which they are connected, and which is tensioned between two sprockets 55 arranged respectively upstream of the first station 100 and downstream of the last station 500), the four carriages 52 of the same series are able to move, via first drive means 56, between two positions, retracted and advanced respectively, which are spaced apart longitudinally by the value of this spacing pitch Pe.

These first drive means consist, for example, of a pneumatic cylinder 56 whose body and rod are respectively attached to the frame of the machine 1 and to one 54A of the strands of the belt 54 associated with this series, or vice versa.

The two series of carriages 52 are further coupled to one another (via a transverse belt or a connecting shaft 57, for example), so that their movements are synchronized and their respective carriages 52 remain permanently facing one another.

Referring to FIG. 4, each carriage 52 comprises:

• • a first support plate 58 on which a sliding guide member 53 is arranged;
  • a second support plate 59 mounted so as to be translationally movable with respect to the first plate 58 in a transverse direction and via guide means comprising, for example, two slides 60; and
  • two square-shaped gripping members 61 mounted for translational movement relative to the second plate 59 in a longitudinal direction and via guide means comprising, for example, two slides 62.

The second support plate 59 can be moved between three transversely spaced positions with respect to the first support plate 58 by means of second drive means consisting, for example, of a double-stroke pneumatic or hydraulic cylinder 63, the body and rod of which are respectively coupled to one and the other of these plates 58, 59.

Extending in the same mean horizontal plane slightly above that of the advancement table 3 and symmetrically with respect to a transverse axis of symmetry S, the two gripping members 61 are each designed to grip a respective lower corner region of a box 10.

These two gripping members 61 are able to move simultaneously in opposite directions via a longitudinal belt 64 tensioned between two pulleys 55, the two parallel strands 64A, 64B of which are each connected to a respective gripping member 61. Their movement between three different spacing values is ensured by third drive means consisting, for example, of a double-stroke pneumatic or hydraulic cylinder 66, the body and rod of which are respectively coupled to the second plate 59 and to one 64A of the strands 64A, 64B of the belt 64, or vice versa.

As shown in FIGS. 5A to 5E, the second and third drive means 63, 66 for each pair of opposing carriages 52 are synchronized so that their four gripping members 61 occupy one of the following three positions:

• • a release position shown by FIGS. 5A, 5D and 5E, in which these four gripping members 61 are at their greatest longitudinal and transverse spacing so as to be away from the boxes 10 arranged on the advancement table 3;
  • a position for gripping and centering the larger-format boxes 10, in which their longitudinal and transverse spacing corresponds to the longitudinal and transverse dimensions of such a larger-format box 10; and
  • a position for gripping and centering the smaller-format boxes 10, in which their longitudinal and transverse spacing corresponds to the longitudinal and transverse dimensions of such a smaller-format box 10.

To ensure play-free gripping of boxes 10 of a given format, which may have relatively large dimensional tolerances, elastically deformable buffers, which are not shown and are made for example of an elastomer material, are advantageously securely attached to the concave inner faces of these gripping members 61.

The operating cycle of the pilgrim's step conveyor device 50 will now be briefly described with reference to these same FIGS. 5A to 5E.

In the configuration shown in FIG. 5A, immediately following the arrival of a new box 10 at the first station 100 from the infeed conveyor 600, the four pairs of carriages 52 are arranged in their retracted position opposite the first four stations 100, 200, 300 and 400, with their gripping members 61 in their release position.

Having been informed of the formats of the various boxes 10 positioned on these first four stations 100, 200, 300 and 400, the controller will then control the appropriate movement of the four gripping members 61 of each of the pairs of carriages 52, so as to cause the simultaneous gripping of all these boxes 10, as shown in FIG. 5B.

Referring to FIG. 5C, this controller will then control the longitudinal movement by one pitch Pe in the advancement direction of all the carriages 52 toward their advanced position, so as to cause the simultaneous movement by one pitch Pe of all these boxes 10 toward the next station (the latter then occupying stations 200, 300, 400 and 500).

It should be noted here that the transfer of the closed box 10 located at the last station 500 onto the downstream conveyor 700 is performed by two pneumatic or hydraulic cylinders 67, mounted on the two carriages 52 located furthest downstream in the longitudinal advancement direction D. These cylinders 67 occupy a retracted position when the carriages 52 are stationary or moving backwards, and occupy an extended position when the carriages 52 are moving forwards, so as to transfer this box 10 onto the discharge conveyor 700, as shown in FIG. 5C.

The controller will then command the four gripping members 61 on each of the pairs of carriages 52 to return to their release position, thereby releasing these boxes 10 (see FIG. 5D).

Finally, as shown in FIG. 5E, this controller will control the return of all the carriages 52 to their retracted position before the arrival of a new box 10 at the first station 100 from the infeed conveyor 600, and before the discharge of the box 10 positioned at the last station 500 to the discharge conveyor 700.

In contrast to a conventional motorized roller or pallet conveyor device, the use of a pilgrim's step conveyor device 50 allows boxes 10 of different formats to be moved while ensuring perfect longitudinal and transverse centering of these boxes 10 with respect to each of the stations in which they are successively positioned.

In addition, such a pilgrim's step conveyor device 50 offers greater acceptability of the dimensional tolerances of boxes 10 for a given format, so as to enable a significant reduction in the percentage of boxes 10 that cannot be processed by the machine 1, and to significantly reduce the rate of stoppages due to deformed boxes.

As the number of stations comprised by the packaging machine 1 may vary based on circumstances (for example, decrease by one when processing a single format of boxes 10, or increase by one when processing three different formats of boxes 10), the number of opposing pairs of carriages on the pilgrim's step conveyor device 50 may vary accordingly, so that it is always one less than the number of stations on the machine 1.

The first station 200 for measuring and cutting boxes 10 of the first format will now be examined in more detail, with reference to FIGS. 6 to 8.

As shown in FIG. 6, this station 200 includes an elevator 210 capable of lifting the box 10 into a guide 220 defining a cutting cavity 221 in which a mechanical sensor 230 is located, which is vertically mobile and capable of measuring the height of the tallest article A contained in the box 10 when the latter comes into contact with it.

Still referring to FIG. 6 and FIG. 7, the station 200 also includes a cutting sub-assembly 240 comprising, a few millimeters above the sensor 230, sliding horizontal 241, 242 and vertical 243 cutting blades arranged on the outer periphery of the guide 200, as well as fixed horizontal 244, 245 and vertical 246 counter-cutting blades arranged inside the cutting cavity 221 opposite the cutting blades 241, 242.

When the tallest article A in the box 10 touches the mechanical sensor 230, the elevator 210 stops moving upwards, so that the top of this tallest article A is a few millimeters below the cutting blades 241, 242, 243 and the counter-cutting blades 244, 245, 246.

As shown in FIG. 8, the cutting blades 241, 242, 243 are then slid transversely or longitudinally so that they each pass through a corresponding side wall 12, 13 of the box 10 and form multiple full and partial cuts on these side walls as shown in FIG. 2B.

In detail and with reference to this FIG. 2B:

• • the horizontal cutting blades 241 arranged opposite the transverse side walls 13 of the box 10 will form, in the latter, two continuous horizontal cutting lines 15 extending over the entire width of this box 10, slightly above, by a few millimeters, the tallest article A contained therein;
  • the vertical cutting blades 243, also arranged opposite the transverse side walls 13 of the box 10, will form two continuous vertical cutting lines 16 in the latter, each extending from a respective continuous horizontal cutting line 15 to the top of the box 10.

The creation of these continuous cutting lines 15, 16 will thus result in the formation of four transverse upper fold-over panels 17 whose height varies according to that of the tallest article A contained in the box 10.

Still referring to FIG. 2B, the horizontal cutting blades 242 arranged opposite the longitudinal side walls 12 of the box 10 will form, in the latter, two discontinuous horizontal cutting lines 18 extending along the entire length of this box 10, slightly above, by an offset d1 of a few millimeters (between 2 and 5 mm, for example), the continuous horizontal cutting lines 15.

The creation of these discontinuous cutting lines 18 will thus result in the delimiting of two longitudinal upper fold-over panels 19 whose height also varies based on that of the tallest article A contained in the box 10.

As the structure and operation of the second measuring and cutting station 300 are similar to those of the station 200 just described, no further details will be given here.

The folding station 400 will now be examined in more detail with reference to FIGS. 9 to 13.

As shown in FIG. 9, this station 400 includes a folding sub-assembly 410 arranged above the advancement table 3 and movable in translation along a vertical axis via an actuator 411. Such an arrangement makes it possible to position said folding sub-assembly 410 at a height corresponding to the discontinuous horizontal cutting lines 18 extending along the entire length of a box 10 as produced at the station 200, which height has been stored by the machine controller. This arrangement can further be used, as described below in connection with a closing station 500, to position glue guns 450 on both sides of the advancement table 3 so as to be able to spray glue jets oriented substantially horizontally toward the upper portions of the longitudinal side walls 12 of the boxes 10 to close the latter with lids 30.

With reference to FIG. 10, this folding sub-assembly 410 comprises four folding modules 412 arranged in the same horizontal mean plane and movable in longitudinal and transverse directions by means of guide means, not shown, so as to be able to surround the four corner regions of a box 10 in a first or second format when the latter is positioned at this folding station 400.

Each folding module 412 includes a support 413 carrying three members which are movable with respect to the latter, namely:

• • a folding jaw 414 that can be rotated about a vertical axis via an actuator 415;
  • a beveled punch 416 which can be moved in translation along a transverse axis via an actuator 417; and
  • a pusher 418 which can be moved in translation along a transverse axis via an actuator 419.

Once the four folding modules 412 have been positioned around the four corner regions of the box 10, each folding jaw 414 is closed by pivoting through 90° from its open position shown in FIG. 10, so as to force a respective transverse upper fold-over panel 17 around a vertical edge 14 of this box 10 against the inner face of the longitudinal side wall 12 adjacent to this fold-over panel 17 (see FIGS. 11 and 12A).

As shown in FIG. 12B, each punch 416 is then translated from its retracted position shown in FIGS. 10, 11 and 12A, so as to successively perforate a longitudinal side wall 12, a transverse upper fold-over panel 17 and then pass through a folding jaw 414 at a hole 420 provided in the latter, the perforations made in this longitudinal side wall 12 and this transverse upper fold-over panel 17 respectively forming two superimposed tongues 20, 21 in these two elements, which fold transversely inside the box 10 and also pass through the hole 420.

Once the punches 416 and the folding jaws 414 have returned to their retracted and open positions, respectively, it is noted with reference to FIG. 12C that the presence of the folded tongues 20, 21 ensures that the transverse upper fold-over panels 17 are held against the longitudinal side walls 12 of the box 10.

To ensure optimum retention of the transverse upper fold-over panels 17 and prevent the tongues 20 formed in the longitudinal side walls 12 from protruding through the openings 22 created in these fold-over panels 17 by the punches 416, the latter advantageously have a triangular cross-sectional profile as shown in FIG. 13.

Still with reference to FIG. 13, it should be noted that the hole 420 formed in each folding jaw 414 advantageously has a first portion 420A of complementary shape and slightly larger size than the cross-section of the punch 416 passing through it, as well as a second portion 420B of rectangular shape 420B adjoining this first portion 420A at the folding line of the tongues 20, 21 created by this punch 416.

This second portion 420B also has a width slightly greater than that of this same punch 416 and its height is at least twice as great as the thickness of the cardboard forming the box 10, so as to enable the tongues 20, 21 created by this punch 416 to be folded back and this folding jaw 414 to be returned to the open position without the risk of them being torn off.

After the punches 416 and the folding jaws 414 have returned to their retracted and open positions, respectively, the pushers 418 are translated from their retracted position shown in FIGS. 10 and 11, so as to force the longitudinal upper fold-over panels 19 to fold over the contents of the box 10 around the discontinuous horizontal cutting lines 18, as shown in FIG. 2C.

It should be noted here that the presence of these discontinuous horizontal cutting lines 18 makes it easier to fold the longitudinal upper fold-over panels 19 without the risk of them becoming detached from the rest of the box 10.

The offset d1 in height between these discontinuous horizontal cutting lines 18 and the continuous horizontal cutting lines 15 further ensures that these longitudinal upper fold-over panels 19 can be folded by at least 90° without coming into contact with the tops of the remaining portions of the transverse side walls 13 of the box 10.

The last closing station 500 will now be examined, whose function, as shown in FIGS. 2D and 2E, is to place and glue a correspondingly sized lid 30 to the top of each box 10.

The lids 30 consist of a solid or corrugated cardboard flank comprising a rectangular central panel 31 sized to cover the open upper side of a correspondingly sized box 10 and four side flaps 32, 33 (in this case, two longitudinal side flaps 32 and two smaller transverse side flaps 33) intended to be folded over and glued to the upper portions of the four side walls 12, 13 of this box 10.

Each lid 30 further comprises fold lines 34, 35 formed between the central panel 31 and the side flaps 32, 33.

As shown in FIG. 1, the lids 30 intended to close the boxes 10 of the first format are stored in the first storage magazine 800, while those intended to close the boxes 2 of the second format are stored in the second storage magazine 900.

As shown in FIG. 14 with reference to the magazine 800 storing the first-format lids 30, such a storage magazine conventionally comprises a motorized belt conveyor 810 on which the lids 30 lie flat, substantially vertically, on one of their edges, and are placed side by side so as to form a stack with a longitudinal axis which is retained by stop means 820 and advances as these lids 30 are consumed.

Still referring to FIG. 14, the processing of a lid 30 begins with its extraction from the corresponding magazine 800, 900 chosen by the controller based on the format of the box 10, typically using a feeder sub-assembly 830 comprising a carrier plate 831 carrying suction cups 832.

The carrier plate 831 comprises a duct connecting the suction cups 832 to air pressure and vacuum means, so as to enable the latter to extract from this magazine, by a suction effect exerted on its central panel 31 and in a substantially longitudinal direction, the first lid 30 of the stack initially retained by the stop means 820.

Once the lid 30 has been extracted from one of the magazines 800, 900, the feeder sub-assembly 830 is able to move, according to adapted kinematics and via drive means consisting for example of two pneumatic or hydraulic cylinders 833, 834 articulated to one another, so as to position this lid 30 in a horizontal plane and vertically in line below a weakening sub-assembly 840 and a transfer sub-assembly 850 mounted on this weakening sub-assembly 840 and equipped with two transverse guide rails 851 (see FIG. 15).

The weakening sub-assembly 840 comprises two pairs of pre-folding members 841 arranged in the same horizontal mean plane and pivotally mounted about axes of rotation.

More specifically, this weakening sub-assembly 840 comprises a first pair of transverse pre-folding members 841 visible in FIGS. 16 and 17A to 17C, rotatably mounted about transverse axes of rotation, and a second pair of longitudinal pre-folding members, not shown, rotatably mounted about longitudinal axes of rotation.

As shown in FIG. 16, the lid 30 carried by the feeder sub-assembly 830 is then forced by the latter to pass through this weakening sub-assembly 840, in a vertical upward movement, so as to pre-fold the four side flaps 32, 33 of this lid 30 with respect to its central panel 31 around the fold lines 34, 35 and at a predetermined angle α greater than 90° (that is, greater than the angle that these flaps 32, 33 will have when finally folded and glued against the side walls 12, 13 of a box 10).

This pre-folding operation sufficiently weakens the cardboard at the fold lines 34, 35, so as to limit the elastic return force exerted by the latter on the side flaps 32, 33 with a tendency to unfold them. To ensure optimum weakening of the cardboard, the pre-folding angle α of these side flaps 22 will advantageously be between 110° and 150° (these four side flaps thus each forming, with the central panel 31, an angle in addition to the angle α of between 30° and 70°).

Even more preferably, this angle α will be between 130° and 140°, and for example equal to 135°.

The weakening sub-assembly 840 and the pre-folding operations will now be described in more detail, with reference to FIGS. 17A to 17C.

Each pre-folding member 841 comprises at least one lyre-shaped fork 842 which is provided with two branches 843, 844 and is mounted so as to rotate about an axis 845 located in the vicinity of its concave bottom.

Advantageously, each of these pre-folding members comprises at least three forks 842 (for example, four or five) that rotate together and are evenly spaced apart from one another along their axis of rotation.

As shown in FIG. 17A, the forks 842 of each transverse (or longitudinal) pre-folding member 841 are permanently elastically returned by return means, not shown, toward a rest position in which their openings are oriented downwards with their plane of symmetry offset by a predetermined angle θ on the inner side with respect to the vertical, that is, in the direction of the other transverse (or longitudinal) pre-folding member 841, so that the free ends 844A of their outer branches 844 lie below those 843A of their inner branches 843.

In this rest position, it should also be noted that the free end 844A of the outer branch 844 of each fork 842 of a respective pre-folding member 841 is arranged so as to be vertically in line with a corresponding side flap 32, 33 of the lid 30, while the free end 843A of the inner branch 843 of this fork 842 is arranged so as to be vertically in line with the central panel 31 of this lid 30, the fold line 34, 35 separating this flap 32, 33 and this central panel 31 thus being located opposite the opening of this same fork 842.

Initial contact between the lid 30 and each pre-folding member 841 takes place at the free ends 844A of the outer branches 844 of the forks 842, which strike the side flaps 32, 33 of this lid 30, causing the latter to be progressively folded around the fold lines 34, 35.

As shown in FIG. 17B, the continued upward movement of the lid 30 causes the free ends 844A of the outer branches 844 of the forks 842 to come into contact with the central panel 31 of this lid 30, causing the inner side of these forks 842 to rotate against the elastic return force, resulting in an additional folding stress being exerted on the side flaps 32, 33 by the free ends 844A of the outer branches 844 of these same forks.

Once the lid 30 has completely passed through the weakening sub-assembly 840, the forks 842 of each pre-folding member 841 return to their rest position, while the side flaps 32, 33 of this lid 30 partially unfold (FIG. 17C).

As shown in FIG. 18, the lid 30 carried by the feeder sub-assembly 830 is then forced into position by the latter, still in a vertical upward movement, between the two transverse rails 851 of the transfer sub-assembly 850, which are designed to grip said lid 30 so that the two transverse side flaps 33 of this lid 30 are retained in a partially folded-down position, where they each form a predetermined angle β with the central panel 31, advantageously between 100° and 135°, and even more preferably between 110° and 130° (see FIG. 19).

Keeping these two transverse side flaps 33 in a partially folded-down position ensures that the main panel 31 of this lid 30, which tends to have a certain natural curvature that can lead to refusals to process by the closing station 500, is leveled out.

For this purpose, the two guide rails 851 define two respective internal concavities 852 extending symmetrically opposite one another and each having the shape of a downwardly oriented 7. The internal concavity 852 of each rail 851 is thus delimited by a horizontal lower abutment wall 852A and by an oblique wall 852B extending from the outer end of this lower abutment wall 852A, forming a predetermined angle Ω therewith additional to the angle β (the sum of these two angles Ω and β being equal to 180°). This angle Ω is advantageously between 45° and 80°, and even more preferably between 50° and 70°.

The longitudinal spacing e between the inner ends of the lower abutment walls 852A is slightly greater by a few millimeters than the longitudinal dimension of the central panel 31 of the lid 30, so that, when the lid 30 comes into contact therewith, they force the transverse side flaps 33 of this lid 30 to fold back almost 90° to allow this central panel 21 to pass through.

These transverse flaps 32 then partially unfold until they come to rest against the oblique walls 852B, which retain them in a partially folded-down position.

As can be seen in FIG. 1, these two rails 851 extend transversely in a mean horizontal plane between the magazine 800 and the closing station 500, so as to transfer the lid 30 to this last station 500, where it is superimposed horizontally, vertically in line with a corresponding box 10.

The lids 30 of a second, smaller format, stored in the magazine 900 until they are transferred to the closing station 500, are processed in the same way using second weakening and transfer sub-assemblies (not shown), the components of which have dimensions adapted to this second lid format.

This transfer of the lid 30 is triggered by the departure of a box 10 from the folding station 400. At this point, the lid 30 is slid along the rails 841 to the closing station 500 by an actuator 853 of this transfer sub-assembly 850.

As the lid 30 travels toward the closing station 500, as shown in FIG. 19, lines of hot-melt glue are sprayed, according to the sensor command, onto the lower faces of the two transverse side flaps 33, partially folded downwards, of this lid 30.

These hot-melt glue lines are typically produced by glue guns 854 attached to the frame of the machine 1 and positioned between the two rails 851 so as to spray glue jets oriented substantially horizontally toward the lower faces of the transverse side flaps 33.

This orientation of the glue jets, which is also made possible by keeping the two transverse side fold-over panels 33 in a partially folded-down position, considerably reduces the risk of repetitive soiling of the machine 1 and clogging of the nozzles of these glue guns 854.

As the box 10 travels from the folding station 400 to the closing station 500, as shown in FIG. 1, lines of hot-melt glue are also sprayed, according to the sensor command, onto the upper portions of the remaining part of the longitudinal side walls 12 after the fold-over panels 19 have been folded.

These hot-melt glue lines are typically produced by glue guns 450 attached to the frame of the machine 1 and positioned above and on both sides of the advancement table 3 so as to spray glue jets oriented substantially horizontally toward the upper portions of the longitudinal side walls 12 of the box 10.

Referring to FIG. 20, when the lid 30 and a corresponding box 10 are positioned one on top of the other in the closing station 500, an elevator 510 lifts the box 10, with vertical sliding, so that it enters into a guide 520 that can be controlled by the machine 1 controller between two positions defining two rectangular parallelepiped pressing cavities 521 with vertical axes and different dimensions suitable for the boxes 10 in the first and second format, respectively.

Each pressing cavity 521 thus has a length and width slightly greater than those of the box 10 of a given format and the central panel 31 of the corresponding lid 30.

As it rises, the box 10 gradually approaches the lid 30 until the top edge of this box 10 comes into contact with the central panel 31 of the lid 30 along its peripheral edge.

This continued upward movement of the box 10 thus drives the lid 30 upwards, which is then extracted from the guide rails 851 of the transfer sub-assembly 850 by virtue of the elasticity of its transverse side flaps 33, which unfold around the fold lines 35.

This lid 30 then penetrates with the upper part of the box 10 into the pressing cavity 521, the lower edges of which are advantageously flared so as to facilitate their insertion and the folding-down of the four longitudinal 32 and transverse 33 side flaps of this lid 30 at an angle slightly less than 90° (due to the slightly greater dimensions in length and width of this pressing cavity 521 compared with those of the central panel 31).

A weighted horizontal plate 522 mounted for free vertical translation keeps the lid 30 pressed against the box 10 as it rises through this pressing cavity 521.

As shown in FIG. 21, the elevator 510 stops when the controller is informed by a sensor that these four side flaps 32, 33 have arrived at pressing elements 523 distributed on the four sides of the guide 520.

The latter then fold and press the four side flaps 32, 33 against the upper portions of the side walls 12, 13 of the box 10, through slots in this guide 520, for a predetermined time of for example between 0.5 and one second, thereby ensuring the attachment of the lid 30 to the box 10 by gluing.

The box 10 thus closed is then lowered back onto the advancement table 3 so that it can be discharged by the pilgrim's step conveyor device 50 to the discharge conveyor 700.

According to embodiment variants of the invention which are not shown, the conveying means comprised by the machine 1 may be different from the pilgrim's step conveyor device 50 described above, particularly when this machine has to handle only one box format, where the use of a conventional motorized blade or roller conveyor is perfectly conceivable.

The number of measuring and cutting stations 200, 300 can also vary based on the number of different formats of boxes 10 to be processed. It may also be possible to dispense with this type of measuring and cutting station altogether, by maintaining the height of the boxes at their initial height, which would also mean dispensing with the folding station 400.

Numerous other embodiment variants of the present invention are, of course, conceivable, and in this respect it should be recalled that this invention is not limited to the embodiments described above and shown in the figures, but also encompasses all execution variants within the abilities of a person skilled in the art.