Method and packaging machine for closing a rectangular parallelepiped-shaped box open on the top with a lid

Abstract

The invention relates to a method for closing a box by a cover (30) comprising a rectangular central panel (31) and four side flaps (33), said method comprising the steps of: - transferring said box and said cover (30) to a closing station where said cover is superimposed horizontally in line with said box, the two transverse side flaps (33) of said cover being retained, during the transfer of the latter, in a partially folded downward position; - vertically sliding bringing together said box and said cover so that the top edge of this box comes into contact with said central panel; - folding down and pressing for a predetermined duration the four said side flaps against the upper portions of the side walls of the box so as to ensure the fixing by gluing of said cover on said box. Figure to be published with the abstract: Fig. 19

Description

Title of the invention: Method and packaging machine for closing a rectangular parallelepiped-shaped box open at the top with a lid Technical field

[0001] The present invention relates generally to the field of order preparation. It relates in particular to a method and a packaging machine for closing a rectangular parallelepiped-shaped box open at the top with a cover. Prior art

[0002] In the field of order preparation, in other words distribution, it is common to have to ship an order comprising a plurality of objects of different shapes and dimensions. To do this, it is common to use a rectangular parallelepiped-shaped box, open on the top, and generally made of corrugated cardboard.

[0003] Such a box, commonly referred to as a "tray", "American half-box" or "bell box", comprises a base bordered by four side walls joined two by two by an edge. It is marketed in an infinite number of basic generic formats, each having a given width, length and height which define an overall receiving volume of this box.

[0004] Packaging machines are known which reduce the height of the boxes to an optimum height adapted to the products contained in these boxes before applying a cover cap formed from a solid or corrugated cardboard side comprising a rectangular central panel sized to cover the open upper side of the box and four side flaps intended to be folded down and glued to the upper portions of the four vertical side walls of the box.

[0005] The covers may optionally include fold lines formed between their central panel and the side flaps so as to facilitate the folding of the latter.

[0006] These machines conventionally comprise a horizontal conveyor, such as a bar, belt or band conveyor on which cardboard boxes previously filled with products having various heights advance in a direction of advance, in sequence through several stations and under the control of a controller.

[0007] Document US 2009 / 0031676 A1 thus describes such a packaging machine comprising, encountered successively along the conveyor: - a product height detection station 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 folding lines delimiting four upper flaps of variable width, depending on the height of the products packaged in each box; - a flap folding station above the contents of the box; and - a closing station consisting of placing covers on the top of the boxes and to which is associated laterally a cover storage store.

[0008] The box and the cover are thus generally transferred in respectively longitudinal and transverse directions of advance towards such a closing station where this cover is superimposed horizontally 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 cover.

[0009] The box and the cover are then brought together by sliding vertically so that the top edge of this box comes into contact with said central panel of the cover along its peripheral edge, then the four said side flaps of the cover are folded down and pressed for a predetermined time against the upper portions of the side walls of the box so as to ensure the fixing by gluing of the cover on the box.

[0010] The projection of glue onto the lower faces of the two transverse lateral flaps of the cover is conventionally ensured by glue guns positioned below these flaps and emitting jets of glue oriented substantially vertically.

[0011] It is understood that such a vertical arrangement of the gluing guns tends to cause the clogging of their nozzles as well as repetitive soiling in the machine causing frequent stops for cleaning and / or unclogging of these nozzles.

[0012] Furthermore, the caps often tend to exhibit a certain curvature due to the deformation of the corrugated cardboard over time during variations in temperature and humidity.

[0013] The transfer of such curved caps often causes jams, which force operators to throw away entire pallets of caps. This jamming problem is all the more accentuated when the papers used for the two sides of the corrugated cardboard are of different composition. Statement of the invention

[0014] The present invention aims to improve the situation.

[0015] To this end, it proposes a method of closing by a cap comprising a rectangular central panel and four side flaps of a rectangular parallelepiped-shaped box open on the top comprising four vertical side walls extending from a horizontal base, said method comprising the following successive steps: - transfer of said box and said cover in respective longitudinal and transverse directions of advancement towards a closing station where said cover is superimposed horizontally in line with said box, 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 cover during their transfer; - vertical sliding approach of said box and said cover so that the top edge of this box comes into contact with said central panel of the cover along its peripheral edge; - folding and pressing for a predetermined duration the four said side flaps of the cover against the upper portions of the side walls of the body so as to ensure the fixing by gluing of said cover on said body; characterized in that the two transverse lateral flaps of said cover are retained, during the transfer of the latter, in a partially folded downward position.

[0016] Transporting the cover with its two transverse side flaps partially folded down makes it possible to mechanically flatten the central panel of this cover, which may be curved. The invention therefore makes it possible to make the closing process more reliable while considerably limiting cardboard losses due to covers that cannot be processed by the machine.

[0017] In order to considerably limit the risks of soiling and clogging of the nozzles of the gluing guns, the projection of glue onto the lower faces of the two transverse lateral flaps of said cover is advantageously carried out in a substantially horizontal direction. It will be noted that such a substantially horizontal gluing direction is permitted by the fact that the transport of the cover is carried out with its two transverse lateral flaps partially folded downwards.

[0018] In order to obtain optimal flattening of the central panel of the cover and to facilitate the bonding of the two transverse lateral flaps, each of these flaps forms with the central panel, during the transfer of said cover, a first predetermined angle advantageously between 100° and 135° and even more preferably between 110° and 130°.

[0019] Furthermore, and in such a way as to limit the elastic return force of the side flaps of the cover opposing their folding down and therefore considerably reducing the pressing time required for their bonding against the upper portions of the side walls of the box, said method advantageously comprises and prior to the transfer of said cover, a step of pre-folding downwards the four side flaps with respect to the central panel and according to a second predetermined angle greater than 90°.

[0020] In order to obtain an optimal reduction in the pressing time, this second predetermined angle is advantageously between 110° and 150° and even more preferably between 130° and 140°.

[0021] This pressing time will thus preferably be between 0.5 and one second.

[0022] The invention also aims, in a second aspect, at a packaging machine provided with a station for closing by a cover comprising a rectangular central panel and four lateral flaps of a box of rectangular parallelepiped shape open on the top comprising four vertical lateral walls extending from a horizontal bottom, said machine comprising conveying means capable of conveying in a longitudinal direction of advance a said box to said closing station, as well as a transfer subassembly capable of transferring in a transverse direction a said cover to said closing station where said cover is superimposed horizontally in line with said box; characterized in that said transfer subassembly comprises two transverse guide rails capable of gripping said cover so as to retain its two transverse lateral flaps in a partially folded downward position.

[0023] According to a preferred embodiment, the two guide rails define two respective internal concavities extending symmetrically opposite one another and each having a downwardly oriented 7 shape, the internal concavity of each said rail thus being delimited by a horizontal lower stop wall and by an oblique wall extending from the external end of this lower stop wall, forming with the latter a predetermined angle advantageously between 100° and 135° and even more preferably between 110° and 130°.

[0024] According to a preferred embodiment, this machine also comprises a weakening subassembly capable of causing a pre-folding of the four side flaps of said cover with respect to its central panel.

[0025] This weakening subassembly preferably comprises a first pair of transverse pre-bending members rotatably mounted about transverse axes of rotation, as well as a second pair of longitudinal pre-bending members rotatably mounted about longitudinal axes of rotation.

[0026] According to an advantageous conformation, each said pre-folding member thus comprises for example at least one lyre-shaped fork provided with two internal and external branches and mounted to rotate around an axis located close to its concave bottom, the fork(s) of each said pre-folding member being permanently elastically returned, by return means, towards a rest position in which their openings are oriented downwards with their plane of symmetry offset by a predetermined angle on the internal side with respect to the vertical so that the free ends of their external branches are located below those of their internal branches.

[0027] Finally, each said pre-folding member advantageously comprises at least three said forks integral in rotation and regularly spaced from each other along their axis of rotation. Brief description of the drawings

[0028] The description of the invention will now be continued by the detailed description of an exemplary embodiment, given below for illustrative but non-limiting purposes, with reference to the appended drawings, in which: - [Fig.l] represents a schematic top view of a packaging machine according to the invention; - [Fig.2A], [Fig.2B], [Fig.2C], [Fig.2D] and [Fig.2E] are perspective views of a box processed by the machine of [Fig.l] at different stages of the packaging process; - [Fig.3] represents a schematic top view of the pilgrim's step conveyor device included in the packaging machine of [Fig.l]; - [Fig.4] is a schematic top view of one of the carriages of the pilgrim's step conveyor device of [Fig.3]; - [Fig.5A], [Fig.5B], [Fig.5C], [Fig.5D] and [Fig.5E] are schematic top views illustrating the different phases of an operating cycle of the pilgrim step conveyor device of [Fig.3]; - [Fig.6] represents a schematic view of one of the two measuring and cutting stations of the packaging machine of [Fig.l], taken at the moment of arrival of a box at this station and according to a vertical section plane parallel to the direction of advance of the boxes; - [Fig.7] is a schematic top view of the measuring and cutting station of [Fig.6] at the time of arrival of a box at this station; - [Fig.8] represents 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.l], taken at the moment of arrival of a crate at this station and according to a vertical section plane parallel to the direction of advance of the crates; - [Fig. 10] represents a schematic top view of the folding station of [Fig.9] at the time of arrival of a crate at this station; - [Fig. 11] is a view similar to [Fig. 10] but taken after the folding phase of the transverse top flaps created on the box at one of the measuring and cutting stations; - [Fig.l2A], [Fig.l2B] and [Fig.l2C] are enlargements illustrating the different phases of the punching cycle carried out on the box at this folding station; - [Fig. 13] represents an enlargement of the front of a folding cheek ensuring the folding of one of the upper transverse flaps of the box and the punching function; - [Fig. 14] is a schematic view of one of the cover magazines included in the packaging machine of [Fig.l], taken at the time of unstacking of one of the covers from this magazine by a feeder sub-assembly and according to a vertical section plane parallel to the direction of advance of the crates and offset from the axis of circulation of the crates; - [Fig. 15] represents a view similar to [Fig. 14] but taken after the horizontal straightening of this cover by the margin sub-assembly; - [Fig. 16] is a view similar to figures 14 and 15 but taken at the time of the passage of the cover through a sub-assembly of weakening of the fold lines of the side flaps of this cover; - [Fig.l7A], [Fig.l7B] and [Fig.l7C] are enlargements illustrating the different phases of the weakening cycle carried out during the crossing of the cap through this weakening sub-assembly; - [Fig.18] represents a view similar to figures 14, 15 and 16 but taken at the time of force positioning of the cover between the guide rails of a transfer sub-assembly making it possible to bring this cover to a closing station; - [Fig. 19] is an enlarged view in section of the guide rails taken along a transverse vertical section plane located between the magazine and the closing station, where glue guns are installed applying lines of glue to the transverse flaps of the cover during its sliding movement towards this closing station; - [Fig.20] is a schematic view of the closing station of the packaging machine of [Fig.l], taken at the moment of the simultaneous arrival of a box and a cover at this station and according to a vertical section plane parallel to the direction of advance of the boxes; and - [Fig.21] represents a view similar to [Fig.20] but illustrating the phase of gluing the side flaps of the cover against the side walls of the body. Description of the embodiments

[0029] [Fig.l] represents a schematic top view of a packaging machine 1 according to the invention.

[0030] We define with respect to this machine 1 an orthogonal reference frame XYZ comprising three axes perpendicular two by two, namely: - an X axis, defining a longitudinal, horizontal direction, - a Y axis, defining a transverse, horizontal direction, which with the X axis defines a horizontal XY plane, and - a Z axis, defining a vertical direction, perpendicular to the horizontal XY plane.

[0031] In the remainder of the description and with reference to the reference 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.

[0032] On the other hand, 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 relative to the orientation of the Z axis.

[0033] Finally, the use of the term "substantially" will indicate that a slight deviation is permitted from a predetermined nominal position or arrangement, while remaining included 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 permitted within the scope of the invention.

[0034] The machine 1 comprises five successive stations 100, 200, 300, 400, 500 arranged in line in a longitudinal advance direction D oriented from back to front, and over which pass successively and in sequence crates 10 of two different predefined formats resting by their bottom on a horizontal advance table 3 constituted for example by a smooth base or by a free roller conveyor. These crates 10 are previously filled with articles having various heights.

[0035] The first introduction station 100 through which the boxes 10 enter the machine 1 while being loaded onto the advance table 3, comprises means for detecting, not shown, the format of the box 10 arriving at this introduction station 100 from an introduction conveyor 600 arranged in the upstream extension of this machine 1.

[0036] This introduction station 100 typically comprises motorized rollers which advance the box 10 to a stop (not shown) intended to position it precisely along the longitudinal axis of movement. When this box 10 comes into contact with this stop, centering devices (not shown) make it possible to ensure its centering along the transverse direction.

[0037] The means for detecting the format of the box 10 may for example comprise advantageously a barcode reader present on each of the crates 10 and containing in particular the information on its format. This information is then stored by the control-command system of the machine 1 and follows the crate 10 at each station as it progresses from one station to another.

[0038] Alternatively, these means for detecting the format of the boxes 10 may be of a different type and comprise, for example, an optical camera or an infrared sensor associated with a processing module.

[0039] Following this introduction station 100, there is successively a first station 200 for measuring and cutting boxes 10 of the first format (the boxes 10 of the second format not being processed there), then a second station 300 for measuring and cutting boxes 10 of the second format (the boxes 10 of the first format not being processed there).

[0040] These two stations 200, 300 have the function of measuring the height of the tallest article A contained in the box 10 (see [Fig.2A]) and of making certain cuts in the latter in order to form and / or delimit upper flaps of variable height, depending on that of this article A.

[0041] Following these two measuring and cutting stations 200, 300, there is a fourth folding station 400 whose function is to ensure the folding of the upper flaps above the highest product contained in the box 10.

[0042] Finally, a fifth and final closing station 500 has the function of ensuring the installation and fixing by gluing of a cardboard cover 30 of corresponding size on the top of each box 10 in order to close it, before this box 10 is transferred to an evacuation conveyor 700 arranged in the downstream extension of the machine 1.

[0043] For this purpose, two cap storage magazines 800, 900 are associated laterally with this last closing station 500.

[0044] This machine 1 also comprises a controller or control-command system not shown in the figures and in communication with the different stations 100, 200, 300, 400, 500 as well as with the two storage magazines for the headgears 800, 900.

[0045] Configured to control various components of the machine 1, this controller comprises at least one computer associated with a memory module storing control processes.

[0046] [Fig.2A] shows in perspective the type of box 10 processed by the machine 1, this type of box made of solid or corrugated cardboard with single, double or triple fluting being commonly referred to as “tray”, “half-American box” or “bell box”.

[0047] Open on the top, each box 10 has a rectangular horizontal bottom 11 intended to support one or more articles such as article A and bordered by four walls lateral 12, 13 (in this case, two longitudinal lateral walls 12 and two smaller transverse lateral walls 13), so as to delimit an interior volume of rectangular parallelepiped shape. The lateral walls 12, 13 are joined two by two along a respective vertical edge 14.

[0048] With reference to [Fig. 3], the machine 1 comprises a pilgrim's step conveyor device 50 making it possible to advance, from one station to another and in the direction of advancement D, the crates 10 arranged on the advancement table 3.

[0049] As illustrated by this [Fig.3], the pilgrim step conveyor device 50 comprises two longitudinal guide rails 51 fixed to the chassis (not shown) of the machine 1, and extending parallel to the direction of advancement D, on either side of the advancement table 3.

[0050] This pilgrim's step conveyor device 50 also comprises a first series of four carriages 52 mounted to move in longitudinal translation along a first guide rail 51, as well as a second series of four carriages 52 mounted to move in translation along a second guide rail 51 and arranged opposite the carriages of the first series.

[0051] Each carriage 52 comprises for this purpose a sliding guide member 53 on the corresponding rail 51 advantageously comprising ball or roller bearings or even anti-friction pads in order to limit the friction forces.

[0052] Kept apart from each other by the same spacing pitch Pe corresponding to that separating two adjacent stations of the machine 1 (for example via a respective longitudinal toothed belt 54 at two points of the same strand 54A to which they are connected, and which is stretched between two pinions 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 respectively retracted and advanced positions spaced longitudinally by the value of this spacing pitch Pe.

[0053] These first drive means are constituted for example by a pneumatic cylinder 56 whose body and rod are respectively fixed to the chassis of the machine 1 and to one 54A of the strands of the belt 54 associated with this series or vice versa.

[0054] The two series of carriages 52 are further coupled to each other (for example, via a transverse belt or a connecting shaft 57), so that their movement is synchronized and their respective carriages 52 remain permanently opposite each other.

[0055] With reference to [Fig.4], each carriage 52 comprises: - a first support plate 58 on which a sliding guide member 53 is provided; - a second support plate 59 mounted mobile in translation 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 to move in translation relative to the second plate 59 in a longitudinal direction and via guide means comprising, for example, two slides 62.

[0056] The second support plate 59 is capable of moving between three transverse spacing positions relative to the first support plate 58 via second drive means constituted for example by a double-stroke pneumatic or hydraulic cylinder 63 whose body and rod are respectively coupled to one and the other of these plates 58, 59.

[0057] Extending in the same horizontal mean plane slightly surmounting that of the advancement table 3 and symmetrically with respect to a transverse axis of symmetry S, the two gripping members 61 are each intended to grip a respective lower corner zone of a box 10.

[0058] These two gripping members 61 are able to move simultaneously in opposite directions by means of a longitudinal belt 64 stretched between two pulleys 55 and whose two parallel strands 64A, 64B are each connected to a respective gripping member 61. Their movement between three different spacing values ​​is ensured by third drive means constituted for example by a double-stroke pneumatic or hydraulic cylinder 66 whose body and rod are respectively coupled to the second plate 59 and to one 64A of the strands 64A, 64B of the belt 64 or vice versa.

[0059] As illustrated by Figures 5A to 5E, the second and third drive means 63, 66 of each pair of carriages 52 facing each other are synchronized so that their four gripping members 61 occupy one of the following three positions: - a release position illustrated by figures 5A, 5D and 5E, in which these four gripping members 61 have 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 boxes 10 having the largest format in which their longitudinal and transverse spacings correspond to the longitudinal and transverse dimensions of such a box 10 of largest format; and - a position for gripping and centering the boxes 10 having the smallest format in which their longitudinal and transverse spacings correspond to the longitudinal and transverse dimensions of such a box 10 of smaller format.

[0060] In order to ensure good gripping without play of the boxes 10 of a given format which may have relatively large dimensional tolerances, bearing, elastically deformable buffers, not shown and made for example from an elastomer material, are advantageously fixedly attached to the concave internal faces of these gripping members 61.

[0061] The operating cycle of the pilgrim step conveyor device 50 will now be briefly described with reference to these same figures 5A to 5E.

[0062] In the configuration illustrated by [Fig.5A] and immediately following the arrival of a new box 10 at the first station 100 from the introduction 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 occupying their release position.

[0063] Being informed of the formats of the different crates 10 positioned on these first four stations 100, 200, 300 and 400, the controller will then command 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 of these crates 10 as illustrated by [Fig.5B].

[0064] With reference to [Fig.5C], this controller will then command the longitudinal movement of a step Pe in the direction of advance of all the carriages 52 towards their advanced position, so as to cause the simultaneous movement of a step Pe of all these boxes 10 towards the following station (the latter then occupying stations 200, 300, 400 and 500).

[0065] It will be noted on this occasion that the transfer onto the downstream conveyor 700 of the closed box 10 located on the last station 500 is carried out by two pneumatic or hydraulic cylinders 67, mounted on the two carriages 52 located furthest downstream in the longitudinal direction of advancement D. These cylinders 67 occupy a retracted position when the carriages 52 are stationary or in the recoil phase, and come to occupy an extended position when the carriages 52 advance so as to cause, as illustrated by this [Fig.5C], the transfer of this box 10 onto the evacuation conveyor 700.

[0066] The controller will then order the return of the four gripping members 61 of each of the pairs of carriages 52 to their release position, so as to release these boxes 10 (see [Fig.5D]).

[0067] Finally and as illustrated by [Fig.5E], this controller will control the return of all the trolleys 52 to their retracted position before the arrival of a new box 10 at the first station 100 from the introduction conveyor 600 and before the evacuation of the box 10 positioned at the last station 500 towards the evacuation conveyor 700.

[0068] Unlike a conventional motorized conveyor device with rollers or pallets, the use of such a pilgrim step conveyor device 50 thus makes it possible to move crates 10 of different formats while ensuring perfect centering. longitudinal and transverse of these boxes 10 with respect to each of the positions in which they are successively positioned.

[0069] Furthermore, such a pilgrim's step conveyor device 50 offers better acceptability of the dimensional tolerances of the boxes 10 for a given format, so as to allow a significant reduction in the percentage of boxes 10 which cannot be processed by the machine 1 and to significantly reduce the rate of stops due to deformed boxes.

[0070] The number of stations that the packaging machine 1 comprises can vary depending on the circumstances (for example decrease by one unit in the case of processing a single format of boxes 10 or on the contrary increase by one unit in the case of processing three different formats of boxes 10), the number of pairs of facing trolleys that the pilgrim's step conveyor device 50 comprises can therefore vary accordingly so that it is always one unit less than the number of stations of the machine 1.

[0071] We will now focus more particularly on the first station 200 for measuring and cutting the boxes 10 of the first format with reference to figures 6 to 8.

[0072] As illustrated by [Fig.6], this station 200 comprises an elevator 210 capable of lifting the box 10 to make it enter a guide 220 defining a cutting cavity 221 in which there is a mechanical feeler 230 movable in vertical translation and making it possible to measure the height of the highest article A contained in the box 10 when the latter comes into contact with it.

[0073] Still with reference to [Fig.6] and [Fig.7], the station 200 also comprises a cutting subassembly 240 comprising, a few millimeters above the feeler 230, horizontal sliding cutting blades 241, 242 and vertical 243 arranged on the outer periphery of the guide 200, as well as horizontal fixed cutting counter-blades 244, 245 and vertical 246 arranged inside the cutting cavity 221 opposite the cutting blades 241, 242.

[0074] When the highest article A contained in the box 10 touches the mechanical feeler 230, the elevator 210 stops rising so that the top of this highest article A is a few millimeters below the cutting blades 241, 242, 243 and the cutting counter-blades 244, 245, 246.

[0075] As illustrated by [Fig.8], the cutting blades 241, 242, 243 are then slid transversely or longitudinally so as to each pass through a corresponding side wall 12, 13 of the box 10 and to form several total and partial cuts on these side walls as illustrated by [Fig.2B].

[0076] In detail and with reference to this [Fig.2B]: - the horizontal cutting blades 241 arranged opposite the transverse side walls 13 of the body 10 will form two cutting lines in the latter continuous horizontals 15 extending over the entire width of this box 10, slightly above a few millimeters of the highest article A contained therein; - the vertical cutting blades 243 also arranged opposite the transverse side walls 13 of the box 10 will form in the latter two continuous vertical cutting lines 16 each extending from a respective continuous horizontal cutting line 15 to the top of the box 10.

[0077] The production of these continuous cutting lines 15, 16 will thus result in the formation of four transverse upper flaps 17 whose height varies according to that of the tallest article A contained in the box 10.

[0078] Still with reference to [Fig.2B], the horizontal cutting blades 242 arranged opposite the longitudinal side walls 12 of the body 10 will form in the latter two discontinuous horizontal cutting lines 18 extending over the entire length of this body 10, slightly above an offset di of a few millimeters (for example between 2 and 5 mm) of the continuous horizontal cutting lines 15.

[0079] The production of these discontinuous cutting lines 18 will thus result in the delimitation of two longitudinal upper flaps 19 whose height also varies according to that of the tallest article A contained in the box 10.

[0080] The structure and operation of the second measuring and cutting station 300 being similar to those of the station 200 just described, we will not dwell on it.

[0081] We will now focus more particularly on the folding station 400 with reference to figures 9 to 13.

[0082] As illustrated by [Fig.9], this station 400 comprises a folding sub-assembly 410 arranged above the advance table 3 and movable in translation along a vertical axis via an actuator 411. Such an arrangement makes it possible to place said folding sub-assembly 410 at a height corresponding to the discontinuous horizontal cutting lines 18 extending over the entire length of a box 10 as produced at station 200, which height has been memorized by the controller of the machine. This arrangement can also make it possible, as described later in connection with a closing station 500, to position gluing guns 450 on either side of the advance table 3 so as to be able to project jets of glue oriented substantially horizontally towards the upper portions of the longitudinal side walls 12 of the boxes 10 to close the latter with caps 30.

[0083] With reference to [Fig. 10], this folding subassembly 410 comprises four folding modules 412 arranged in the same horizontal mean plane and movable in longitudinal and transverse directions using guide means not shown, so as to be able to surround the four corner zones of a box 10 of first or second format when the latter is positioned at this station. folding 400.

[0084] Each folding module 412 comprises a support 413 carrying three members movable relative to the latter, namely: - a folding cheek 414 movable in rotation along a vertical axis, via an actuator 415; - a beveled punch 416 movable in translation along a transverse axis, via an actuator 417; and - a pusher 418 movable in translation along a transverse axis, via an actuator 419.

[0085] Once the four folding modules 412 have positioned themselves around the four corner zones of the box 10, each folding cheek 414 is closed by pivoting 90°, from its open position illustrated by [Fig. 10], so as to constrain the folding, around a vertical edge 14 of this box 10, of a respective transverse upper flap 17 against the inner face of the longitudinal side wall 12 adjacent to this flap 17 (see figures 11 and 12A).

[0086] As illustrated by [Fig. 12B], each punch 416 is then translated, from its retracted position illustrated by figures 10, 11 and 12A, so as to successively perforate a longitudinal side wall 12, a transverse upper flap 17 then to pass through a folding cheek 414 at the level of an orifice 420 formed in the latter, the perforations made in this longitudinal side wall 12 and this transverse upper flap 17 respectively forming in these two elements two superimposed tabs 20, 21 which fold transversely inside the box 10 while also passing through the orifice 420.

[0087] Once the punches 416 and the folding cheeks 414 are back in their respectively retracted and open position, it will be noted with reference to [Fig. 12C] that the presence of the folded tabs 20, 21 makes it possible to ensure that the transverse upper flaps 17 are held against the longitudinal side walls 12 of the box 10.

[0088] In order to ensure optimal support of the transverse upper flaps 17 while preventing the tabs 20 formed in the longitudinal side walls 12 from protruding through the openings 22 created in these flaps 17 by the punches 416, the latter advantageously have a triangular sectional profile as illustrated in [Fig. 13].

[0089] Still with reference to this [Fig.13], it will be noted that the orifice 420 formed in each folding cheek 414 advantageously has a first portion 420A of complementary shape and of dimension slightly greater than that of the section of the punch 416 passing through it, as well as a second portion 420B of rectangular shape 420B attached to this first portion 420A at the level of the folding line of the tabs 20, 21 created by this punch 416.

[0090] This second portion 420B also has a width slightly greater than that of this same punch 416 and its height is at least twice the thickness of the cardboard forming the box 10 so as to allow the folding of the tabs 20, 21 created by this punch 416 and the return of this folding cheek 414 to the open position without risk of tearing the latter.

[0091] After the punches 416 and the folding cheeks 414 have returned to their retracted and open positions respectively, the pushers 418 are translated, from their retracted position illustrated by FIGS. 10 and 11, so as to constrain the folding, around the discontinuous horizontal cutting lines 18, of the upper longitudinal flaps 19 onto the contents of the box 10 as illustrated by [Fig.2C].

[0092] It will be noted on this occasion that the presence of these discontinuous horizontal cutting lines 18 thus makes it easier to fold the upper longitudinal flaps 19 without, however, risking them becoming detached from the rest of the box 10.

[0093] The offset di in height between these discontinuous horizontal cutting lines 18 and the continuous horizontal cutting lines 15 also makes it possible to ensure a folding of these longitudinal upper flaps 19 of at least 90° without them coming to rest against the tops of the remaining portions of the transverse side walls 13 of the box 10.

[0094] We are now more particularly interested in the last closing station 500 having the function, as illustrated by figures 2D and 2E, of ensuring the installation and fixing by gluing of a cover 30 of corresponding dimension on the top of each box 10.

[0095] The covers 30 are made up of a solid or corrugated cardboard side comprising a rectangular central panel 31 sized to cover the open upper side of a box 10 of corresponding format 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 down and glued onto the upper portions of the four side walls 12, 13 of this box 10.

[0096] Each cover 30 further comprises fold lines 34, 35 formed between the central panel 31 and the side flaps 32, 33.

[0097] As illustrated by [Fig. 1], the caps 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.

[0098] As shown in [Fig. 14] with reference to the magazine 800 storing the first-format caps 30, such a storage magazine conventionally comprises a motorized belt conveyor 810 on which the caps 30 rest flat substantially vertically by one of their edges, being placed next to each other so as to form a stack with a longitudinal axis retained by stop means 820 and advancing as these caps 30 are consumed.

[0099] Still with reference to [Fig. 14], the processing of a cover 30 begins with its extraction from the corresponding magazine 800, 900 chosen by the controller according to the format of the box 10, typically using a feeder subassembly 830 comprising a carrier plate 831 carrying suction cups 832.

[0100] The carrier plate 831 comprises a conduit connecting the suction cups 832 to air pressure and depression means, so as to allow the latter to extract from this store, by suction effect exerted on its central panel 31 and in a substantially longitudinal direction, the first cap 30 of the stack initially retained by the stop means 820.

[0101] After having extracted the cover 30 from one of the magazines 800, 900, the feeder subassembly 830 is able to move, according to suitable kinematics and via drive means constituted for example by two pneumatic or hydraulic cylinders 833, 834 articulated to each other, so as to position this cover 30 in a horizontal plane and plumb from below a weakening subassembly 840 and a transfer subassembly 850 surmounting this weakening subassembly 840 and provided with two transverse guide rails 851 (see [Fig. 15]).

[0102] The weakening subassembly 840 comprises two pairs of pre-folding members 841 arranged in the same horizontal mean plane and pivotally mounted around rotation axes.

[0103] More specifically, this weakening subassembly 840 comprises a first pair of transverse pre-bending members 841 visible in FIGS. 16 and 17A to 17C rotatably mounted around transverse axes of rotation, as well as a second pair of longitudinal pre-bending members not shown rotatably mounted around longitudinal axes of rotation.

[0104] As illustrated by [Fig. 16], the cover 30 carried by the feeder subassembly 830 is then forced by the latter to cross, in a vertical movement oriented from bottom to top, this weakening subassembly 840 so as to cause the downward pre-folding of the four lateral flaps 32, 33 of this cover 30 with respect to its central panel 31 around the fold lines 34, 35 and according to a predetermined angle a greater than 90° (that is to say greater than the angle that these flaps 32, 33 will ultimately have once folded down and stuck against the side walls 12, 13 of a box 10).

[0105] Such a pre-folding operation thus makes it possible to sufficiently weaken the cardboard at these fold lines 34, 35 so as to limit the elastic return force exerted by the latter on the lateral flaps 32, 33 and tending to unfold them. In order to ensure optimal weakening of the cardboard, the pre-folding angle a of these lateral flaps 22 will advantageously be between 110° and 150° (these four flaps lateral thus each forming with the central panel 31 an angle supplementing the angle a of between 30° and 70°).

[0106] Even more preferably, this angle a will be between 130° and 140°, and for example equal to 135°.

[0107] The weakening subassembly 840 and the pre-bending operations will now be described in more detail with reference to FIGS. 17A to 17C.

[0108] Each pre-folding member 841 comprises at least one lyre-shaped fork 842 provided with two branches 843, 844 and rotatably mounted around an axis 845 located close to its concave bottom. Advantageously, each of these pre-folding members comprises at least three forks 842 (for example, four or five) integral in rotation and regularly spaced from each other along their axis of rotation.

[0109] As illustrated by [Fig.17A], the forks 842 of each transverse (respectively longitudinal) pre-folding member 841 are permanently elastically returned, by return means not shown, to a rest position in which their openings are oriented downwards with their plane of symmetry which is offset by a predetermined angle 0 on the internal side with respect to the vertical, that is to say in the direction of the other transverse (respectively longitudinal) pre-folding member 841, so that the free ends 844A of their external branches 844 are located below those 843A of their internal branches 843.

[0110] In this rest position, it will also be noted that the free end 844A of the external branch 844 of each fork 842 of a respective pre-folding member 841 is arranged so as to be located directly above a corresponding lateral flap 32, 33 of the cover 30, while the free end 843A of the internal branch 843 of this fork 842 is arranged so as to be located directly above the central panel 31 of this cover 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.

[0111] The first contacts between the cover 30 and each pre-folding member 841 thus occur at the level of the free ends 844A of the external branches 844 of the forks 842 which come into contact with the lateral flaps 32, 33 of this cover 30 so as to cause the latter to progressively fold around the fold lines 34, 35.

[0112] As illustrated by [Fig. 17B], the continuation of the upward movement of the cover 30 causes contact between the free ends 844A of the external branches 844 of the forks 842 and the central panel 31 of this cover 30, which causes the rotation of the internal side of these forks 842 against the elastic return force and results in the exertion of an additional folding stress on the lateral flaps 32, 33 by the free ends 844A of the external branches 844 of these same forks.

[0113] Once the cap 30 has completely passed through the weakening subassembly 840, the forks 842 of each pre-folding member 841 return to their rest position while the lateral flaps 32, 33 of this cap 30 partially unfold ([Fig.17C]).

[0114] As illustrated by [Fig. 18], the cover 30 carried by the feeder subassembly 830 is then forcibly positioned by the latter, still according to a vertical movement oriented from bottom to top, between the two transverse rails 851 of the transfer subassembly 850 which encloses it so that the two transverse lateral flaps 33 of this cover 30 are retained in a partially folded downward position where they each form with the central panel 31 a predetermined angle [3 advantageously between 100° and 135°, and even more preferably between 110° and 130° (see [Fig. 19]).

[0115] Maintaining these two transverse lateral flaps 33 in a partially folded downward position makes it possible to ensure the flattening of the main panel 31 of this cover 30 which tends to have a certain natural curvature which can lead to refusals of treatment by the closing station 500.

[0116] To do this, the two guide rails 851 define two respective internal concavities 852 extending symmetrically opposite one another and each having a downwardly oriented 7 shape. The internal concavity 852 of each rail 851 is thus delimited by a horizontal lower stop wall 852A and by an oblique wall 852B extending from the external end of this lower stop wall 852A, forming with the latter a predetermined angle Q supplementing the angle [3 (the sum of these two angles Q and [3 being equal to 180°). This angle Q is thus advantageously between 45° and 80° and even more preferably between 50° and 70°.

[0117] The longitudinal spacing e between the internal ends of the lower stop walls 852A is slightly greater by a few millimeters than the longitudinal dimension of the central panel 31 of the cover 30, so that the latter force, when the cover 30 comes into contact with them, the transverse lateral flaps 33 of this cover 30 to fold down almost at 90° in order to allow the passage of this central panel 21.

[0118] These transverse flaps 32 then partially unfold until they come to rest against the oblique walls 852B which ensure their retention in the partially folded downward position.

[0119] As can be seen in [Fig. 1], these two rails 851 extend transversely along a horizontal mean plane between the magazine 800 and the closing station 500, so as to ensure the transfer of the cover 30 to this latter station 500 where it comes to be superimposed horizontally in line with a corresponding box 10.

[0120] The processing of the caps 30 of a second smaller format stored in the magazine 900 until their transfer to the closing station 500 is carried out in an identical manner via second weakening and transfer sub-assemblies not shown and whose constituent elements have dimensions adapted to this second cap format.

[0121] This transfer of the cover 30 is triggered by the departure of a box 10 from the folding station 400. At this moment, the cover 30 is slidably driven along the rails 841 to the closing station 500 by an actuator 853 of this transfer subassembly 850.

[0122] During the journey of the cover 30 towards the closing station 500 and as illustrated by [Fig. 19], lines of hot-melt glue are projected, according to the command of sensors, onto the lower faces of the two transverse lateral flaps 33 partially folded down from this cover 30.

[0123] These lines of hot-melt glue are conventionally produced by glue guns 854 fixed to the frame of the machine 1 and positioned between the two rails 851 so as to be able to project jets of glue oriented substantially horizontally towards the lower faces of the transverse side flaps 33.

[0124] Such an orientation of the glue jets, also permitted by maintaining the two transverse lateral flaps 33 in a partially folded downward position, considerably limits the risks of the appearance of repetitive soiling in the machine 1 and of clogging of the nozzles of these glue guns 854.

[0125] During the journey of the box 10 between the folding station 400 and the closing station 500 and as illustrated by [Fig.l], lines of hot-melt glue are also projected, according to the command of sensors, onto the upper portions of the remaining part, after folding of the flaps 19, of the longitudinal side walls 12.

[0126] These lines of hot-melt glue are conventionally produced by gluing guns 450 fixed to the chassis of the machine 1 and positioned above and on either side of the advance table 3 so as to be able to project jets of glue oriented substantially horizontally in the direction of the upper portions of the longitudinal side walls 12 of the body 10.

[0127] With reference to [Fig.20] and when the cover 30 and a corresponding box 10 are in place superimposed on each other in the closing station 500, an elevator 510 lifts the box 10 with vertical sliding to make it enter a guide 520 controllable by the controller of the machine 1 between two positions defining two rectangular parallelepiped pressing cavities 521 with a vertical axis and different dimensions adapted respectively to the boxes 10 of the first and second format.

[0128] Each pressing cavity 521 thus has a length and a width slightly greater than those of the box 10 of a given format and of the central panel 31 of the corresponding cover 30.

[0129] While rising, the box 10 gradually approaches the cover 30 until the top edge of this box 10 comes into contact with the central panel 31 of the cover 30 along its peripheral edge.

[0130] The continuation of this upward movement of the body 10 thus drives the cover 30 upwards which is then extracted from the guide rails 851 of the transfer subassembly 850 thanks to the elasticity of its transverse lateral flaps 33 which unfold around the fold lines 35.

[0131] This cover 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 introduction and the downward folding of the four longitudinal lateral flaps 32 and transverse 33 of this cover 30 by an angle slightly less than 90° (due to the slightly greater dimensions in length and width of this pressing cavity 521 compared to those of the central panel 31).

[0132] A weighted horizontal plate 522 mounted with free vertical translation makes it possible to keep the cover 30 pressed against the body 10 during their rise through this pressing cavity 521.

[0133] As illustrated by [Fig.21], the elevator 510 stops when the controller is informed by a sensor that these four side flaps 32, 33 have arrived at the level of pressing elements 523 distributed on the four sides of the guide 520.

[0134] The latter then come, through slots made in this guide 520, to fold down and press the four lateral flaps 32, 33 against the upper portions of the lateral walls 12, 13 of the body 10 for a predetermined duration of, for example, between 0.5 and one second, which has the effect of ensuring the fixing by gluing of the cover 30 on the body 10.

[0135] The box 10 thus closed is then lowered onto the advancement table 3 so that it can be evacuated by the pilgrim-step conveyor device 50 towards the evacuation conveyor 700.

[0136] According to alternative embodiments of the invention not shown, the conveying means that the machine 1 comprises may be different from the pilgrim's step conveying device 50 described previously, in particular when this machine only has to process a single format of boxes where the use of a conventional motorized conveyor with blades or rollers is perfectly conceivable.

[0137] The number of measuring and cutting stations 200, 300 can also vary depending on the number of different formats of boxes 10 to be processed. It is also possible to envisage doing without this type of measuring and cutting station entirely by maintaining the height of the boxes at their initial height, which would also result in the removal of folding post 400.

[0138] Many other variant embodiments of the present invention are of course conceivable and it is recalled in this respect that this invention is not limited to the embodiments described above and shown in the figures, but also encompasses all the variant embodiments within the reach of those skilled in the art.

Claims

Claims

1. Method for closing by a cover (30) comprising a rectangular central panel (31) and four side flaps (32, 33) a rectangular parallelepiped-shaped box open on the top (10) comprising four vertical side walls (12, 13) extending from a horizontal bottom (11), said method comprising the following successive steps: - transfer of said box (10) and said cover (30) in respectively longitudinal and transverse directions of advancement to a closing station (500) where said cover (30) is superimposed horizontally in line with said box (10), glue being sprayed respectively onto the upper portions of the longitudinal side walls (12) of said box (10) and onto the lower faces of the two transverse side flaps (33) of said cover (30) during their transfer;- vertical sliding bringing together of said box (10) and said cover (30) so that the top edge of this box (10) comes into contact with said central panel (31) of the cover (30) along its peripheral edge; - folding and pressing for a predetermined duration of the four said lateral flaps (32, 33) of the cover (30) against the upper portions of the side walls (12, 13) of the box (10) so as to ensure the fixing by gluing of said cover (30) on said box (10); characterized in that the two transverse lateral flaps (33) of said cover (30) are retained, during the transfer of the latter in said transverse direction of advance and towards said closing station, in a partially folded downward position.;

2. Closing method according to claim 1, characterized in that the projection of glue onto the lower faces of the two transverse lateral flaps (33) of said cover (30) is carried out in a substantially horizontal direction.

3. Closing method according to one of claims 1 or 2, characterized in that, during the transfer of said cover (30), the two transverse lateral flaps (33) each form with the central panel (31) a first predetermined angle (|3) of between 100° and 135°.

4. Closing method according to claim 3, characterized in that said first predetermined angle (|3) is between 110° and 130°.

5. Closing method according to one of claims 1 to 4, characterized in that it comprises, prior to the transfer of said cover (30), a step of pre-folding downwards the four lateral flaps (32, 33) with respect to the central panel (31) and according to a second predetermined angle (a) greater than 90°.

6. Closing method according to claim 5, characterized in that said second predetermined angle (a) is between 110° and 150°.

7. Closing method according to claim 6, characterized in that said second predetermined angle (a) is between 130° and 140°.

8. Closing method according to one of claims 1 to 7, characterized in that said predetermined duration of pressing of the four lateral flaps (32, 33) of said cover (30) against the upper portions of the lateral walls (12, 13) of said box (10) is between 0.5 and one second.

9. Packaging machine (1) provided with a station (500) for closing by a cover (30) comprising a rectangular central panel (31) and four side flaps (32, 33) a box of rectangular parallelepiped shape open on the top (10) comprising four vertical side walls (12, 13) extending from a horizontal bottom (11), said machine (1) comprising conveying means (50) capable of conveying in a longitudinal direction of advance a said box (10) to said closing station (500), as well as a transfer subassembly (850) capable of transferring in a transverse direction a said cover (30) to said closing station (500) where said cover (30) is superimposed horizontally in line with said box (10);characterized in that said transfer subassembly (850) comprises two transverse guide rails (851) capable of gripping said cover (30) so as to retain its two transverse lateral flaps (33) in a partially folded downward position during its transfer in said transverse direction towards said closing station.;

10. Packaging machine (1) according to claim 9, characterized in that the two guide rails (851) define two respective internal concavities (852) extending symmetrically opposite one another and each having a shape of a 7 oriented downwards, the internal concavity (852) of each said rail (851) being thus delimited by a horizontal lower stop wall (852A) and by an oblique wall (852B) extending from the external end of this lower stop wall (852A) forming with the latter a predetermined angle (Q).

11. Packaging machine (1) according to claim 10, characterized in that said predetermined angle (Q) between said oblique (852B) and lower stop (852A) walls is between 100° and 135°.

12. Packaging machine (1) according to claim 10, characterized in that said predetermined angle (Q) between said oblique (852B) and lower stop (852A) walls is between 110° and 130°.

13. Packaging machine (1) according to one of claims 9 to 12, characterized in that it comprises a weakening subassembly (840) capable of causing a pre-folding of the four lateral flaps (32, 33) of said cover (30) with respect to its central panel (31).

14. Packaging machine (1) according to claim 13, characterized in that said weakening subassembly (840) comprises a first pair of transverse pre-folding members (841) rotatably mounted about transverse axes of rotation, as well as a second pair of longitudinal pre-folding members rotatably mounted about longitudinal axes of rotation.

15. Packaging machine (1) according to claim 14, characterized in that each said pre-folding member (841) comprises at least one lyre-shaped fork (842) provided with two internal (843) and external (844) branches, and rotatably mounted about an axis (845) located near its concave bottom, the fork(s) (842) of each said pre-folding member (841) being permanently elastically returned, by return means, to a rest position in which their openings are oriented downwards with their plane of symmetry which is offset by a predetermined angle (0) on the internal side with respect to the vertical so that the free ends of their external branches (844) are located below those of their internal branches (843).

16. Packaging machine (1) according to claim 15, characterized in that each said pre-folding member (841) comprises at least three said forks (842) integral in rotation and regularly spaced from each other along their axis of rotation (845).

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