FR3161904A1 - Packaging method and machine for closing a rectangular parallelepiped-shaped box open at the top with a lid - Google Patents

Abstract

The invention relates to a method for closing a crate with a lid (30) comprising a rectangular central panel (31) and four lateral flaps (33). The method comprises the following steps: - transferring the crate and lid (30) to a closing station where the lid is positioned horizontally above the crate, the two transverse lateral flaps (33) of the lid being held in a partially downward-folded position during the transfer; - sliding the crate and lid vertically together so that the top edge of the crate comes into contact with the central panel; - folding and pressing the four lateral flaps against the upper portions of the crate's side walls for a predetermined duration to ensure that the lid is bonded to the crate. Figure to be published with the abbreviation: Fig. 19

Description

Packaging method and machine for closing a rectangular parallelepiped-shaped box open at the top with a lid

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 lid.

In the field of order preparation, or distribution, it is common to have to ship an order containing a variety of items of different shapes and sizes. To do this, a rectangular box, open at the top, and usually made of corrugated cardboard, is commonly used.

Such a crate, commonly called a "tray," "half-crate," or "bell crate," consists of a base bordered by four side walls joined in pairs by a ridge. It is sold in an infinite number of basic generic sizes, each with a given width, length, and height that define the overall volume for receiving that crate.

We know of packaging machines which reduce the height of the crates to an optimal height adapted to the products contained in these crates before applying a cover formed from a side of solid or corrugated cardboard comprising a central rectangular panel sized to cover the open upper side of the crate and four side flaps intended to be folded down and glued onto the upper portions of the four vertical side walls of the crate.

The headpieces may optionally include fold lines formed between their central panel and the side flaps so as to facilitate the folding down of the latter.

These machines typically include a horizontal conveyor, such as a bar, belt or band conveyor, on which cardboard boxes pre-filled with products of various heights advance in a direction of advancement, in sequence through several stations and under the control of a controller.

US document 2009/0031676 A1 describes such a packaging machine as follows, comprising, encountered successively along the conveyor:
- a product height detection station inside each crate;
- a cutting station for the crates along their vertical edges over a certain height;
- a marking station for the sides of the crates to form horizontal folding lines delimiting four upper flaps of variable width, depending on the height of the products packed in each crate;
- a station for folding flaps above the contents of the crate; and
- a closing station consisting of placing caps on top of the crates and to which is associated laterally a storage store for caps.

The body and the cap are thus generally transferred along longitudinal and transverse directions respectively to a closing station where the cap is horizontally superimposed directly above the body. During these transfers, adhesive is sprayed onto the upper portions of the longitudinal side walls of the body and onto the lower faces of the two transverse side panels of the cap.

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

The application of glue to the undersides of the two transverse side panels of the cap is conventionally achieved by gluing guns positioned below these panels and emitting jets of glue oriented almost vertically.

It is understood that such a vertical arrangement of the gluing guns tends to cause their nozzles to become clogged, as well as repeated soiling in the machine, causing frequent stops for cleaning and/or unclogging of these nozzles.

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.

The transfer of such curved end caps often causes jams, forcing operators to discard entire pallets of end caps. This jamming problem is further exacerbated when the papers used for the two sides of the corrugated cardboard are of different compositions.

The present invention aims to improve the situation.

To this end, it proposes a closing method using a cap comprising a central rectangular panel and four lateral flaps of a rectangular parallelepiped-shaped box open at the top comprising four vertical lateral walls extending from a horizontal base, said method comprising the following successive steps:
- transfer of said box and said cap along directions of advancement respectively longitudinal and transverse to a closing station where said cap is placed horizontally on top of said box, glue being projected respectively on the upper portions of the longitudinal side walls of said box and on the lower faces of the two transverse side flaps of said cap during their transfer;
- vertical sliding approach of said box and said cap so that the top edge of this box comes into contact with said central panel of the cap along its peripheral edge;
- folding and pressing for a predetermined time the four said lateral flaps of the cap against the upper portions of the side walls of the case so as to ensure the fixing by gluing of the said cap to the said case;
characterized in that the two transverse lateral flaps of said cap are retained, during the transfer of the latter, in a partially folded downwards position.

Transporting the cap with its two transverse side flaps partially folded downwards allows the central panel of this potentially curved cap to be mechanically flattened. The invention thus improves the reliability of the closing process while significantly reducing cardboard waste due to caps that cannot be processed by the machine.

To significantly reduce the risk of soiling and clogging of the gluing gun nozzles, the glue is advantageously sprayed onto the undersides of the two transverse side panels of the cap in a nearly horizontal direction. It should be noted that this nearly horizontal gluing direction is possible because the cap is transported with its two transverse side panels partially folded downwards.

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

Furthermore, in order to limit the elastic return force of the side flaps of the headgear opposing their folding and thus considerably reducing the pressing time required to glue them against the upper portions of the side walls of the case, said process advantageously includes, prior to the transfer of said headgear, a pre-folding step downwards of the four side flaps with respect to the central panel and according to a second predetermined angle greater than 90°.

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

This pressing time will therefore preferably be between 0.5 and one second.

The invention also relates, in a second aspect, to a packaging machine having a closing station by a cap comprising a central rectangular panel and four lateral flaps of a rectangular parallelepiped-shaped box open at the top comprising four vertical lateral walls extending from a horizontal bottom, said machine comprising conveying means capable of conveying said box in a longitudinal direction of advancement to said closing station, as well as a transfer sub-assembly capable of transferring said cap in a transverse direction to said closing station where said cap is superimposed horizontally on said box;
characterized in that said transfer sub-assembly comprises two transverse guide rails suitable for enclosing said cap so as to retain its two transverse lateral flaps in a partially folded downwards position.

According to a preferred embodiment, the two guide rails define two respective internal concavities extending symmetrically opposite each other and each having a downward-oriented 7 shape, the internal concavity of each said rail being thus delimited by a horizontal lower abutment wall and by an oblique wall extending from the external end of this lower abutment wall, forming with the latter a predetermined angle 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 a pre-folding of the four lateral flaps of said headgear with respect to its central panel.

This weakening subset preferably comprises a first pair of transverse pre-bending elements mounted to rotate about transverse axes of rotation, and a second pair of longitudinal pre-bending elements mounted to rotate about longitudinal axes of rotation.

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

Finally, each said pre-folding organ advantageously comprises at least three said forks that are fixed together in rotation and regularly spaced from each other along their axis of rotation.

The description of the invention will now be continued by a detailed description of an example embodiment, given below by way of illustration but not limitation, with reference to the attached drawings, on which:
- FIG. 1 represents a schematic top view of a packaging machine according to the invention;
- FIG. 2 , FIG. 2 , FIG. 2 , FIG. 2 And FIG. 2 are perspective views of a crate processed by the machine of the FIG. 1 at different stages of the packaging process;
- FIG. 3 represents a schematic top view of the pilgrim's step conveyor system included in the packaging machine. FIG. 1 ;
- FIG. 4 is a schematic top view of one of the trolleys of the pilgrim-step conveyor device of the FIG. 3 ;
- FIG. 5 , FIG. 5 , FIG. 5 , FIG. 5 And FIG. 5 These are schematic top views illustrating the different phases of an operating cycle of the pilgrim's step conveyor device. FIG. 3 ;
- FIG. 6 represents a schematic view of one of the two measuring and cutting stations of the packaging machine. FIG. 1 , taken at the time of the arrival of a crate at this station and according to a vertical cutting plane parallel to the direction of advancement of the crates;
- FIG. 7 is a schematic top view of the measuring and cutting station of the FIG. 6 at the time a crate arrives at this station;
- FIG. 8 represents a view similar to the FIG. 6 but taken during the cutting phase;
- FIG. 9 is a schematic view of the folding station of the packaging machine of the FIG. 1 , taken at the time of the arrival of a crate at this station and according to a vertical cutting plane parallel to the direction of advancement of the crates;
- FIG. 10 represents a schematic top view of the folding station of the FIG. 9 at the time a crate arrives at this station;
- FIG. 11 is a view similar to the FIG. 10 but taken after the folding phase of the upper transverse flaps created on the crate at one of the measuring and cutting stations;
- FIG. 12 , FIG. 12 And FIG. 12 are enlargements illustrating the different phases of the punching cycle carried out on the crate at this folding station;
- FIG. 13 represents a front enlargement of a folding cheek ensuring the folding of one of the upper transverse flaps of the case and the punching function;
- FIG. 14 is a schematic view of one of the headgear stores included in the packaging machine of the FIG. 1 , taken at the time of unstacking one of the crates from this store by a feeder sub-assembly and according to a vertical cutting plane parallel to the direction of advancement of the crates and offset from the axis of circulation of the crates;
- FIG. 15 represents a view similar to the FIG. 14 but taken after the horizontal straightening of this cap by the margining sub-assembly;
- FIG. 16 is a view similar to figures 14 and 15 but taken at the moment of the passage of the headdress through a subset of weakening of the fold lines of the lateral flaps of this headdress;
- FIG. 17 , FIG. 17 And FIG. 17 are enlargements illustrating the different phases of the weakening cycle carried out during the passage of the cap through this weakening subset;
- FIG. 18 represents a view similar to figures 14, 15 and 16 but taken at the moment of force positioning of the cap between the guide rails of a transfer sub-assembly allowing this cap to be brought to a closing station;
- FIG. 19 is an enlarged cross-sectional view of the guide rails taken along a transverse vertical cutting plane located between the store and the closing station, where gluing guns are installed applying lines of glue to the transverse flaps of the cover as it slides towards this closing station;
- FIG. 20 is a schematic view of the closing station of the packaging machine of the FIG. 1 , taken at the moment of the simultaneous arrival of a crate and a cap at this station and according to a vertical cutting plane parallel to the direction of travel of the crates; and
- FIG. 21 represents a view similar to the FIG. 20 but illustrating the phase of gluing the side flaps of the hood against the side walls of the body.

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

With respect to this machine 1, we define an orthogonal XYZ coordinate system comprising three axes perpendicular to each other in pairs, namely:
- an X-axis, defining a longitudinal, horizontal direction,
- a Y-axis, defining a horizontal, transverse 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 following 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.

On the other hand, the terms "front" and "back" 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.

Finally, the use of the term "substantially" indicates that a slight deviation is permitted from a predetermined nominal position or arrangement, while remaining within the scope of the invention. For example, "substantially horizontal" indicates that a deviation of approximately 10° to 20° from a strictly horizontal orientation is permitted within the scope of the invention.

Machine 1 comprises five successive stations 100, 200, 300, 400, 500 arranged in a line along a longitudinal direction of travel D oriented from back to front, over which pass successively and sequentially crates 10 of two different predefined sizes, resting by their bottoms on a horizontal conveying table 3 consisting, for example, of a smooth floor or a free-roller conveyor. These crates 10 are pre-filled with items of varying heights.

The first infeed station 100 through which the crates 10 enter the machine 1 after being loaded onto the feed table 3, includes means for detecting, not shown, the format of the crate 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 includes motorized rollers that advance the crate 10 to a stop (not shown) designed to position it precisely along the longitudinal axis of travel. When this crate 10 comes into contact with this stop, centering devices (not shown) ensure its centering along the transverse direction.

The means of detecting the format of crate 10 could, for example, advantageously include a barcode reader present on each crate 10, containing information on its format. This information is then stored by the control system of machine 1 and follows crate 10 at each station as it progresses from one station to the next.

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

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

These two stations, 200 and 300, are used to measure the height of the tallest item A contained in crate 10 (see FIG. 2 ) and to make certain cuts in the latter in order to form and/or delimit upper flaps of variable height, depending on that of this article A.

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 crate 10.

Finally, a fifth and final closing station 500 has the function of ensuring the placement and fixing by gluing of a cardboard cap 30 of corresponding dimensions on the top of each crate 10 in order to complete its closure, before this crate 10 is transferred to an evacuation conveyor 700 arranged in the downstream extension of machine 1.

For this purpose, two storage stores for head coverings 800, 900 are associated laterally with this last closing station 500.

This machine 1 also includes a controller or control system not shown in the figures and in communication with the various stations 100, 200, 300, 400, 500 as well as with the two storage stores for the caps 800, 900.

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

There FIG. 2 shows in perspective the type of box 10 processed by 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".

Open at the top, each crate 10 has a horizontal rectangular base 11 designed to support one or more items such as item A and 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 define an internal volume in the shape of a rectangular parallelepiped. The side walls 12, 13 are joined in pairs along a respective vertical edge 14.

With reference to the FIG. 3 , machine 1 includes a pilgrim step conveyor device 50 allowing the crates 10 arranged on the advancement table 3 to be moved from one station to another and according to the direction of advancement D.

As illustrated by this FIG. 3 , the pilgrim step conveyor device 50 comprises two longitudinal guide rails 51 fixed to the unshown frame of the machine 1, and extending parallel to the direction of advancement D, on either side of the advancement table 3.

This pilgrim-step conveyor device 50 also includes a first series of four trolleys 52 mounted mobile with longitudinal translation along a first guide rail 51, as well as a second series of four trolleys 52 mounted mobile with translation along a second guide rail 51 and arranged opposite the trolleys of the first series.

Each trolley 52 includes for this purpose a sliding guide element 53 on the corresponding rail 51 advantageously comprising ball or roller bearings or even anti-friction pads in order to limit friction forces.

Kept apart from each other by the same spacing step Pe corresponding to that separating two adjacent stations of 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 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 respectively retracted and advanced spaced longitudinally by the value of this spacing step Pe.

These first means of drive consist for example of 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.

The two sets of trolleys 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 trolleys 52 remain permanently opposite each other.

With reference to the FIG. 4 Each 52-cart includes:
- a first support plate 58 on which a sliding guide element 53 is provided;
- a second support plate 59 mounted movably to translate relative to the first plate 58 in a transverse direction and via guiding means comprising, for example, two slides 60; and
- two right-angled gripping members 61 mounted movable in translation vis-à-vis the second plate 59 in a longitudinal direction and via guiding means comprising for example two slides 62.

The second support plate 59 is able to move between three transverse spacing positions relative to the first support plate 58 via second drive means consisting for example of 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.

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

These two gripping members 61 are capable of moving simultaneously in opposite directions by means of a longitudinal belt 64 stretched between two pulleys 55, the two parallel strands of which 64A, 64B are each connected to a respective gripping member 61. Their movement between three different gap 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 illustrated by Figures 5A to 5E, the second and third drive means 63, 66 of each pair of opposite trolleys 52 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 organs 61 present their greatest longitudinal and transverse spacing so as to be away from the crates 10 arranged on the advancement table 3;
- a gripping and centering position for the crates 10 with the largest format in which their longitudinal and transverse spacing corresponds to the longitudinal and transverse dimensions of such a crate 10 of the largest format; and
- a gripping and centering position for the boxes 10 with the smallest format in which their longitudinal and transverse spacing correspond to the longitudinal and transverse dimensions of such a box 10 of the smallest format.

In order to ensure a good grip without play of the crates 10 of a given format which may have relatively large dimensional tolerances, elastically deformable pads, not shown and made for example of an elastomer material, are advantageously fixedly attached to the concave inner faces of these gripping members 61.

We will now quickly describe the operating cycle of the pilgrim step conveyor device 50 with reference to these same figures 5A to 5E.

In the configuration illustrated by the FIG. 5 and immediately following the arrival of a new crate 10 on the first station 100 from the infeed conveyor 600, the four pairs of trolleys 52 are arranged in their rearward position opposite the first four stations 100, 200, 300 and 400 with their gripping devices 61 which occupy their release position.

Having been 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 devices 61 of each of the trolley pairs 52, so as to cause the simultaneous clamping of all these crates 10 as illustrated by the FIG. 5 .

With reference to the FIG. 5 , this controller will then command the longitudinal movement of a step Pe in the direction of advancement of all the trolleys 52 towards their advanced position, so as to cause the simultaneous movement of a step Pe of all these crates 10 towards the next station (the latter then occupying stations 200, 300, 400 and 500).

It should be noted that the transfer of the closed container 10, located at the last station 500, onto the downstream conveyor 700 is carried out by two pneumatic or hydraulic cylinders 67, mounted on the two carriages 52 located furthest downstream in the longitudinal direction of travel D. These cylinders 67 are in a retracted position when the carriages 52 are stationary or moving backward, and are extended when the carriages 52 move forward, thus causing the following effect, as illustrated by this... FIG. 5 , the transfer of this crate 10 onto the evacuation conveyor 700.

The controller will then order the return of the four gripping devices 61 of each of the trolley pairs 52 to their release position, so as to release these crates 10 (see FIG. 5 ).

Finally, and as illustrated by the FIG. 5 , this controller will command the return of all the trolleys 52 to their rearward position before the arrival of a new crate 10 on the first station 100 from the infeed conveyor 600 and before the evacuation of the crate 10 positioned on the last station 500 to the evacuation conveyor 700.

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

Furthermore, such a pilgrim step conveyor system 50 offers better acceptability of the dimensional tolerances of the crates 10 for a given format, so as to allow a significant reduction in the percentage of crates 10 not treatable by machine 1 and to significantly reduce the stoppage rate due to deformed crates.

Since the number of stations included in the packaging machine 1 can vary depending on the circumstances (for example, decreasing by one unit when processing only one format of cases 10 or increasing by one unit when processing three different formats of cases 10), the number of pairs of trolleys facing each other in the pilgrim's step conveyor device 50 can therefore vary accordingly so that it is always less than one unit than the number of stations of the machine 1.

We will now focus more specifically on the first station 200 for measuring and cutting crates 10 of the first format with reference to figures 6 to 8.

As illustrated by the FIG. 6 , this station 200 includes an elevator 210 capable of lifting the crate 10 to make it enter a guide 220 defining a cutting cavity 221 in which there is a mechanical probe 230 mobile in vertical translation and allowing to measure the height of the tallest article A contained in the crate 10 when the latter comes into contact with it.

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

When the tallest item A contained in the crate 10 touches the mechanical probe 230, the elevator 210 stops rising so that the top of this tallest item A is a few millimeters below the cutting blades 241, 242, 243 and the cutting counter-blades 244, 245, 246.

As illustrated by the FIG. 8 The cutting blades 241, 242, 243 are then slid transversely or longitudinally so that each passes through a corresponding side wall 12, 13 of the case 10 and forms several total and partial cuts on these side walls as illustrated by the FIG. 2 .

In detail and with reference to this FIG. 2 :
- 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 a few millimeters of the tallest item A contained therein;
- the vertical cutting blades 243 arranged also opposite the transverse side walls 13 of the box 10 will form in the latter two continuous vertical cutting lines 16 extending each 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 upper transverse flaps 17 whose height varies according to that of the tallest item A contained in the box 10.

Still referring to the FIG. 2 , 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 over the entire length of this box 10, slightly above an offset d ₁ of a few millimeters (for example between 2 and 5 mm) of continuous horizontal cutting lines 15.

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

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

We will now focus more specifically on the 400 folding station with reference to figures 9 to 13.

As illustrated by the FIG. 9 This station 400 includes a folding sub-assembly 410 arranged above the feed table 3 and movable along a vertical axis via an actuator 411. This arrangement allows the folding sub-assembly 410 to be positioned at a height corresponding to the discontinuous horizontal cutting lines 18 extending along the entire length of a crate 10, as produced at station 200. This height has been memorized by the machine controller. Furthermore, as described later in connection with a closing station 500, this arrangement allows gluing guns 450 to be positioned on either side of the feed table 3 so as to project jets of glue oriented substantially horizontally towards the upper portions of the longitudinal side walls 12 of the crates 10 to close them with caps 30.

With reference to the FIG. 10 , this folding sub-assembly 410 comprises four folding modules 412 arranged in the same horizontal mean plane and mobile along longitudinal and transverse directions using unrepresented guide means, so as to be able to surround the four corner areas of a first or second format crate 10 when the latter is positioned at this folding station 400.

Each folding module 412 includes a support 413 carrying three movable parts relative to the latter, namely:
- a movable folding cheek 414 rotating along a vertical axis, via an actuator 415;
- a beveled punch 416 that moves 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.

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

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

Once the punches 416 and the folding cheeks 414 have returned to their respectively retracted and open positions, it will be noted with reference to the FIG. 12 that the presence of the folded tabs 20, 21 ensures that the upper transverse flaps 17 are held against the longitudinal side walls 12 of the box 10.

In order to ensure optimal support of the upper transverse flaps 17 by 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 cross-sectional profile as illustrated by the FIG. 13 .

Still referring to this FIG. 13 , it will be noted that the orifice 420 made in each folding cheek 414 advantageously presents 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.

This second portion 420B also has a width slightly greater than that of the same punch 416 and its height is at least twice greater than 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 them off.

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

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 risking that they detach from the rest of the box 10.

The offset d ₁ in height between these discontinuous horizontal cutting lines 18 and the continuous horizontal cutting lines 15 also allows these upper longitudinal flaps 19 to fold 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.

We are now particularly interested in the last closing station 500, whose function, as illustrated by figures 2D and 2E, is to ensure the installation and fixing by gluing of a cap 30 of corresponding dimensions on the top of each box 10.

The covers 30 consist of a side made of solid or corrugated cardboard comprising a central rectangular panel 31 dimensioned to cover the open upper side of a box 10 of corresponding size 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.

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

As illustrated by the FIG. 1 , the 30 caps intended to close the 10 crates of the first format are stored in the first storage store 800, while those intended to close the 2 crates of the second format are stored in the second storage store 900.

As shown by the FIG. 14 with reference to the store 800 storing the first format caps 30, such a storage store classically includes a motorized belt conveyor 810 on which the caps 30 rest flat substantially vertically by one of their edges being placed side by side so as to form a stack with a longitudinal axis held by stop means 820 and advancing as these caps 30 are consumed.

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

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

After extracting the cap 30 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 each other, so as to position this cap 30 in a horizontal plane and directly below a weakening sub-assembly 840 and a transfer sub-assembly 850 surmounting 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-bending elements 841 arranged in the same horizontal mean plane and mounted pivotally around axes of rotation.

More specifically, this weakening subset 840 comprises a first pair of transverse pre-bending elements 841 visible in Figures 16 and 17A to 17C mounted rotatably around transverse rotation axes, and a second pair of longitudinal pre-bending elements not shown mounted rotatably around longitudinal rotation axes.

As illustrated by the FIG. 16 , the cap 30 carried by the feeder sub-assembly 830 is then forced by the latter to cross, according to a vertical movement oriented from bottom to top, this weakening sub-assembly 840 so as to cause the pre-folding downwards of the four lateral flaps 32, 33 of this cap 30 vis-à-vis its central panel 31 around the fold lines 34, 35 and according to a predetermined angle α greater than 90° (that is to say greater than the angle which these flaps 32, 33 will have in the end once folded down and glued against the lateral walls 12, 13 of a box 10).

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

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

We will now describe in more detail the weakening subset 840 and the pre-bending operations with reference to figures 17A to 17C.

Each pre-folding member 841 comprises at least one lyre-shaped fork 842 having two arms 843, 844 and rotatably mounted about an axis 845 located near its concave base. Advantageously, each of these pre-folding members comprises at least three forks 842 (for example, four or five) that are rotationally fixed and regularly spaced from one another along their axis of rotation.

As illustrated by the FIG. 17 , the forks 842 of each transverse (respectively longitudinal) pre-folding member 841 are elastically returned continuously, by means of return 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 θ on the inner side with respect to the vertical, i.e. 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.

In this rest position, it will 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 in line with a corresponding lateral flap 32, 33 of the cap 30, while the free end 843A of the inner branch 843 of this fork 842 is arranged so as to be in line with the central panel 31 of this cap 30, the fold line 34, 35 separating this flap 32, 33 and this central panel 31 being thus located opposite the opening of this same fork 842.

The first contacts between the cap 30 and each pre-folding member 841 thus occur at the free ends 844A of the external branches 844 of the forks 842 which come to strike the lateral flaps 32, 33 of this cap 30 so as to cause the progressive folding of the latter around the fold lines 34, 35.

As illustrated by the FIG. 17 , the continuation of the upward movement of the cap 30 causes contact between the free ends 844A of the external branches 844 of the forks 842 and the central panel 31 of this cap 30, which causes the internal side of these forks 842 to rotate against the elastic restoring force and results in the exercise of an additional bending stress on the lateral flaps 32, 33 by the free ends 844A of the external branches 844 of these same forks.

Once the cap 30 has fully passed through the weakening subassembly 840, the forks 842 of each pre-folding element 841 return to their rest position while the lateral flaps 32, 33 of this cap 30 partially unfold ( FIG. 17 ).

As illustrated by the FIG. 18 The cap 30, carried by the feeder sub-assembly 830, is then forcibly positioned by the latter, again in a vertical movement oriented from bottom to top, between the two transverse rails 851 of the transfer sub-assembly 850 which encloses it, so that the two transverse lateral flaps 33 of this cap 30 are held in a partially folded downward 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 downwards position ensures that the main panel 31 of this cap 30, which tends to have a certain natural curvature that can lead to refusals of processing by the closing station 500, is flattened.

To achieve this, the two guide rails 851 define two respective internal concavities 852 extending symmetrically opposite each other, each having a downward-facing figure-eight shape. 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 with it a predetermined angle Ω, the supplement of angle β (the sum of these two angles Ω and β being equal to 180°). This angle Ω is thus advantageously between 45° and 80°, and even more preferably between 50° and 70°.

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

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

As can be seen on the FIG. 1 , these two rails 851 extend transversely along a medium horizontal plane between the store 800 and the closing station 500, so as to ensure the transfer of the cap 30 to this last station 500 where it comes to be superimposed horizontally in line with a corresponding box 10.

The processing of the smaller second format caps 30 stored in the store 900 until their transfer to the closing station 500 is carried out in the same way via second weakening and transfer sub-assemblies not shown and whose constituent elements have dimensions adapted to this second cap format.

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

During the journey of the cap 30 to the closing station 500 and as illustrated by the FIG. 19 , lines of hot melt glue are projected, according to sensor commands, onto the lower faces of the two transverse side flaps 33 partially folded down from this cap 30.

These hot melt glue lines are classically made by gluing guns 854 fixed to the chassis 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.

Such an orientation of the glue jets, also made possible by keeping the two transverse side flaps 33 in a partially folded downwards position, considerably limits the risks of repeated soiling in the machine 1 and clogging of the nozzles of these gluing guns 854.

During the journey of crate 10 between folding station 400 and closing station 500, and as illustrated by the FIG. 1 , lines of hot melt glue are also projected, according to sensor commands, onto the upper portions of the remaining part, after folding the flaps 19, of the longitudinal side walls 12.

These hot melt glue lines are classically made by gluing guns 450 fixed to the chassis of the machine 1 and positioned above and on either side of the feed 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 box 10.

With reference to the FIG. 20 and when the cap 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 vertically to bring it into a guide 520 controllable by the controller of the machine 1 between two positions defining two rectangular parallelepiped pressing cavities 521 with vertical axis and different dimensions adapted respectively to the boxes 10 of first and second format.

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

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

The continuation of this upward movement of the crate 10 thus causes the cap 30 to rise, which then emerges from the guide rails 851 of the transfer sub-assembly 850 thanks to the elasticity of its transverse side flaps 33 which unfold around the fold lines 35.

This cap 30 then enters with the upper part of the case 10 into the pressing cavity 521 whose lower edges are advantageously flared so as to facilitate their introduction and the folding downwards of the four longitudinal lateral flaps 32 and transverse flaps 33 of this cap 30 at 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).

A weighted horizontal plate 522 mounted with free vertical translation allows the cap 30 to be held against the case 10 during their ascent through this pressing cavity 521.

As illustrated by the FIG. 21 , the elevator 510 stops when the controller is informed by a sensor that these four side flaps 32, 33 have reached the level of pressure elements 523 distributed on the four sides of the guide 520.

These then, through slots provided in this guide 520, fold down and press the four side flaps 32, 33 against the upper portions of the side walls 12, 13 of the case 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 cap 30 on the case 10.

The closed crate 10 is then lowered back onto the advance table 3 so that it can be evacuated by the pilgrim step conveyor 50 towards the evacuation conveyor 700.

According to unrepresented variants of the invention, the conveying means included in the machine 1 may be different from the pilgrim step conveying device 50 described previously, in particular when this machine only has to process a single format of crates where the use of a conventional motorized conveyor with blades or rollers is perfectly feasible.

The number of measuring and cutting stations (200, 300) can also vary depending on the number of different crate sizes (10) to be processed. It is also possible to eliminate this type of measuring and cutting station entirely by maintaining the crate height at its initial height, which would also eliminate the folding station (400).

Many other embodiments of the present invention are of course conceivable and it is recalled in this regard that this invention is not limited to the embodiments described above and represented in the figures, but also encompasses all the variants of execution within the reach of a person skilled in the art.

Claims (9)

Packaging machine (1) having stations arranged in a line along a longitudinal direction of travel (D) and over which crates (10) resting on their bottoms on a horizontal conveying table (3) pass successively and sequentially, said machine (1) being characterized in that it comprises a conveying device (50) allowing said crates (10) arranged on the conveying table (3) to be advanced from one station to the other along said direction of travel (D), said conveying device (50) comprising:
- a first and a second longitudinal guide rail (51) extending parallel to the direction of advancement (D) on either side of the advancement table (3);
- a first series of trolleys (52) mounted mobile with longitudinal translation along said first guide rail (51) and a second series of trolleys (52) mounted mobile with longitudinal translation along said second guide rail (51) and arranged opposite the trolleys (52) of said first series,
each trolley (52) comprising a sliding guide element (53) on the corresponding rail (51), said trolleys (52) being kept apart from each other by the same pitch of gauge (Pe) corresponding to that separating two adjacent stations of said machine (1),
the carriages (52) of the same series being capable of moving, via first drive means (56) between two positions respectively rearward and forward spaced longitudinally by the value of said spacing pitch (Pe),
the first and second series of trolleys (52) being coupled to each other so that their movement is synchronized and their respective trolleys (52) remain permanently opposite each other,
each trolley (52) comprising a gripping member (61) mounted movable to translate in a direction perpendicular to the direction of advancement (D) intended to come and grip a crate (10). Packaging machine (1) according to the preceding claim, wherein each trolley (52) has two right-angled gripping members (61) each intended to grip a respective lower corner area of a crate (10). Packaging machine (1) according to the preceding claim, wherein the two gripping members (61) of each carriage (52) are capable of moving simultaneously in opposite directions. Packaging machine (1) according to any one of the preceding claims, wherein the drive means (56) consist of a longitudinal toothed belt (54) stretched between two sprockets (55) arranged respectively upstream of the first and downstream of the last of the stations, to which each carriage (52) is connected. Packaging machine (1) according to any one of the preceding claims, wherein each trolley (52) comprises:
- a first support plate (58) on which the said sliding guide element (53) is provided,
- a second support plate (59) of said gripping member (61) mounted movable in translation vis-à-vis the first plate (58) in a transverse direction and via guiding means (60). Packaging machine (1) according to claims 3 and 5, wherein the two gripping members (61) of each trolley (52) are mounted movable in translation vis-à-vis the second plate (59) of said trolley (52) in a longitudinal direction and via guiding means (62). Packaging machine (1) according to any one of the preceding claims, comprising a controller for controlling the longitudinal and/or transverse movements of the trolleys (52) and their respective gripping member (61). Method for controlling the movements of trolleys (52) and their respective gripping members (61) of a packaging machine (1) according to claim 7, said method being implemented by the controller of said packaging machine (1), characterized in that it comprises:
- a step in which said gripping member (61) of each trolley (52) occupies a first position called release position in which said respective gripping members (61) of two trolleys (52) facing each other have the greatest transverse distance so as to be away from the crates (10) arranged on said advance table (3),
- a step in which said gripping member (61) of each trolley (52) occupies a second position called gripping and centering position in which said respective gripping members (61) of two trolleys (52) facing each other have a transverse spacing corresponding to the transverse dimension of a crate (10),
- a step to control the longitudinal displacement of a spacing step (Pe) corresponding to that separating two adjacent stations of said machine (1) in the direction of advance of all the trolleys (52) towards their advanced position, so as to cause the simultaneous displacement of said step (Pe) of all these crates (10) towards the next station,
- a step to order the return of the respective gripping devices (61) of the trolleys (52) to their release position so as to release the crates (10),
- a step to command the return of the trolleys (52) to their rearward position. Method for controlling the movements of trolleys (52) and their respective gripping members (61) of a packaging machine (1) according to claim 7, said method being implemented by the controller of said packaging machine (1) according to the preceding claim, when said packaging machine (1) conforms to claim 3, wherein:
- the step in which said gripping member (61) of each trolley (52) occupies a first position called release position consists further in that the two gripping members (61) of each trolley (52) have the greatest longitudinal spacing so as to be away from the crates (10) arranged on said advance table (3),
- the step in which said gripping member (61) of each trolley (52) occupies a second position called gripping and centering position further consists in the fact that the two gripping members (61) of each trolley (52) have a longitudinal spacing corresponding to the longitudinal dimension of the crate (10) which they enclose.