EP3526025A1 - Device and method for removing a box from a chuck - Google Patents

Abstract

The present invention relates to a device for removing a box or box part with a polygonal section from a chuck (51) comprising an upper face (511) and an application face (510) interconnected by lateral faces and an end face (514), on which chuck the box has been previously formed from a blank (1). It comprises a plate (64) comprising first gripping means and translatably movable between a deployed position in which the plate is near the end face (514) of the chuck on which the lateral flaps (16a to 16d) are intended to be folded and a folded position in which the plate (64) is away from the chuck (51). The chuck (51) itself is movable between a first forming position, in which the outer cross-section thereof corresponds to the inner cross-section of the box or box part, and a second retracted position, in which the outer cross-section thereof is smaller than the inner cross-section of the box or box part.

Description

 DEVICE AND METHOD FOR EXTRACTING A BOX FROM A CHUCK

The present invention relates to a device for extracting a box or portion of polygonal section box from a mandrel on which it was previously formed from a blank of sheet material.

 It also relates to a method of extracting a box or portion of box polygonal section from a mandrel.

 Such a flan of sheet material conventionally comprises a sequence of at least three flaps, namely two extreme flaps located on either side of at least one intermediate flap, said flaps being connected to each other by lines of parallel folding and provided with side flaps, respectively connected to said flaps by fold lines perpendicular to the fold lines connecting said flaps, the free edge of one of the end flaps being provided with a tongue connected to said end flap by a fold line parallel to the fold lines connecting said flaps.

 When the blank has three flaps, it allows to obtain a part of a box (cover or bottom). When it has at least four parts, it makes it possible to obtain a box.

To obtain a box or part of a box, an adhesive is deposited on one side, on two side flaps and on the other hand, on said tongue of an end flap or near the free edge of the end flap opposite said tongue.

 Then, the flaps are wound around a mandrel with a polygonal section whose external cross section corresponds to the internal cross section of the box or part of the box to be obtained, the tongue is fixed against the free edge of the other end flap. pressing on the upper face of the mandrel, and the flaps on the same side of said flaps and some of which comprise an adhesive are folded against a corresponding end face of the mandrel and then fixed to each other.

 The box or part of the box thus formed is then extracted from the mandrel to proceed in particular to its filling, marking or any other action.

 This invention finds a particularly important, although not exclusive, application in the field of reinforced corrugated boxes.

 Numerous methods and devices are already known for extracting a polygonal box from a mandrel.

It is particularly possible to cite the document EP 0 334 707 which describes a method and a device consisting of taking the blanks successively in a magazine and placing them on a table provided with driving fingers. They slide the blank on the table to bring it under the mandrel. During transfer to the mandrel, the blank encounters Gluing machines positioned above and below the table that lay lines of adhesive on the blank.

 The forming of the blank around the mandrel, the fixing of the tongue and the formation of the bottom of the box is provided with the aid of several actuators.

 Once the box is formed, it is ejected from the mandrel by acting on a cylinder, capable of moving a transverse plate, disposed inside the mandrel and serving as an end face thereto.

 Under the effect of the jack, the box switches over a first conveyor, then a second conveyor located at a lower level. The box is then evacuated by this second conveyor, on which it rests by its bottom.

 Many variants of this device have been proposed and they provide overall satisfaction.

 These devices nevertheless have disadvantages because the fact of dropping the box does not ensure, in all cases, a good positioning thereof. Moreover, this generally requires subsequent recovery of the box by appropriate means, which breaks the cycle of treatment of the box and limits the rates that can be obtained.

The object of the invention is to overcome these drawbacks by proposing a device and a method for extracting a box or portion of box with a polygonal section from a mandrel making it possible to perform this extraction continuously and with great precision, while being of a simple design and / or implementation.

For this purpose, the invention proposes in particular a device for extracting a box or part of box with a polygonal section from a mandrel comprising an upper face, a lower face connected by side faces and an end face, mandrel on which it has been previously formed from a blank having a sequence of at least three flaps, namely two flaps extreme on either side of at least one intermediate flap, said flaps being connected to each other by parallel fold lines and provided with lateral flaps, respectively connected to said shutters by folding lines perpendicular to the fold lines connecting said shutters, characterized in that it comprises a plate comprising first gripping means and movable in translation between a extended position in which the plate is close to the end face of the mandrel on which side flaps are intended to be folded and a folded position in which the plate is away from the mandrel and in that the mandrel is itself movable between a first forming position in which its outer cross section corresponds to the inner cross section of the box or part of box and a second retracted position in which its outer cross section is less than the internal cross-section of the box or part of a box.

 By face of the mandrel means a plane delimited by its end edges, for example formed by angles, without the said face being necessarily full and / or formed by a surface plate equal to that of said face.

 Similarly plate (comprising gripping means) means a surface element extending on a surface equal to at least a portion of the surface of a side flap to form the bottom of the box or portion of box.

 Part of a box is in particular the lid or the bottom of a box.

 In advantageous embodiments, one or more of the following provisions are also and / or in addition:

 - The device comprises a system of articulated arms capable of being deployed in a direction substantially perpendicular to said end face of the mandrel and a first end is secured to the frame of the device and a second end supports said plate;

 said plate is movable in rotation between a flattened position in which it is substantially parallel to the application face of the mandrel and a rectified position in which it is substantially parallel to said end face;

- The first gripping means comprise suction means; when the mandrel is in its first retracted position, the distance between the upper face and the application face of the mandrel is arranged to be smaller than the width of the box or part of a box;

 - The articulated arm system is rotatable about a vertical axis passing through its first end secured to the frame.

 The invention also relates to a method of extracting a box or portion of polygonal section box from a mandrel, the box or part of box resulting from the shaping around said mandrel of a blank comprising a sequence of at least three flaps, namely two end flaps on either side of at least one intermediate flap, said flaps being connected to each other by parallel fold lines and provided with side flaps, respectively connected to said flaps by lines bending perpendicular to the fold lines connecting said flaps, said blank having been pre-glued at least at two lateral flaps and brought under the mandrel, which is in a first forming position in which the flaps have been wound around the mandrel, characterized in that it comprises the following steps:

applying a pressing force on an end face of the mandrel on which side flaps have been previously folded, to fix the flaps together and form the bottom of the box or box part whose inner surface is in contact with the mandrel,

 - grabbing by suction the bottom of the box or part of the box thus formed,

- reduce the outer section of the mandrel and

 - Exert on the outer surface of the bottom pulling force perpendicular to the end face, releasing the pressure on the bottom of the box or part of the box, to extract said box or box part of the mandrel.

 Advantageously, it is also and / or moreover recourse to one and / or the other of the following provisions:

 - After extraction of the box or part of the mandrel box, said box or part of box is raised vertically and transferred to an evacuation station;

 the box or part of the box is extracted and rectified by the same means;

 said means also contribute to the transfer of the box or part of a box to an evacuation station;

 said means also make it possible to fold down at least one of said flaps on said lateral face of the mandrel.

The invention also relates to a machine for forming a box or part of box with a polygonal section from a blank comprising a sequence of at least three parts, namely two end flaps on each side of at at least two intermediate flaps, said flaps being connected together to the others by parallel fold lines and provided with lateral flaps, respectively connected to said flaps by fold lines perpendicular to the fold lines connecting said flaps, comprising:

 a sizing station in which an adhesive is deposited on at least two lateral flaps,

 a forming station in which the flaps are wound around the mandrel and flaps on the same side of said flaps are folded and

 an extraction station comprising a device as described above.

 Advantageously, it is also and / or moreover recourse to one and / or the other of the following provisions:

 - The machine also includes a transfer station to at least one evacuation station;

the transfer station comprises second gripping means for the box or part of the box present at the extraction station, these second means being rotatable between a first position in which they are opposite the extraction station and a second position in which they are facing the evacuation station, these second gripping means being also movable in translation between an extended position in which they are intended to be in contact with the box or part of a box and a retracted position of rest; - The evacuation station comprises gripping means movable in translation between a retracted position and an extended position;

 the second gripping means comprise suction means.

 The invention also relates to a method of forming a box or portion of box with a polygonal section, from a blank having a set of flaps connected to each other by parallel fold lines and provided with side flaps, connected respectively to said flaps by fold lines perpendicular to the fold lines connecting said flaps, wherein:

 the blank is glued at least at the level of two lateral flaps and brought under a mandrel,

 the blank is then shaped around the mandrel to obtain a box or part of a box,

 said box or part of a box is extracted from the mandrel by implementing the method as described above,

 said box or part of box being then transferred to an evacuation station.

 The invention will be better understood and its advantages will appear more clearly on reading the following description of embodiments given as non-limiting examples. The description refers to the accompanying drawings in which:

FIG. 1 shows in plan view an embodiment of a blank that can be used with the method and the sizing device according to the invention. Figure 2 is a perspective view of a polygonal section box forming machine, from the blank shown in Figure 1, including a sizing device according to the invention.

 Figure 3 is a side view in longitudinal section of the machine shown in Figure 2, more precisely on the right side of the machine in the direction of routing of the blanks.

 Figures 4 and 5 are top views of the machine shown in Figure 2, Figure 5 differing from Figure 4 in that it also shows blanks being processed on the machine.

 Figure 6 is a rear perspective view of an exemplary extraction device according to the invention in the retracted position.

 Figure 7 is a view similar to Figure 6, wherein the extraction device is in the deployed position.

 Figures 8A to 8F are side views illustrating the different steps of extracting a box from the mandrel.

 Figure 9 is a perspective view illustrating the extraction device in the deployed position and with a box, corresponding to Figures 7 and 8C.

 Figure 10 is a perspective view illustrating the extraction device in the folded position and with a box, corresponding to Figures 6 and 8F.

Figures 11A to 11G are top views illustrating the different stages of transfer and evacuation of the box, after its extraction. The elements common to the different figures will be designated by the same references.

 FIG. 1 shows a blank 1 of double-sided corrugated cardboard, for example of low grammage (<250 g / m 2) for example of thickness 3 mm intended to form a box.

 It comprises a series 2 of four rectangular main shutters 3, 4, 5, 6 terminated by a gluing tab 7 and interconnected by first fold lines parallel to each other, namely a first central or reference fold line. 8, two first lateral fold lines 9 and 10, and a first end fold line 11, junction with the tongue 7.

 The shutters 3 and 6 are called extreme shutters and the shutters 4 and 5, intermediate shutters.

 The blank comprises, in a manner known per se, a first set 12 of rectangular or substantially rectangular flaps 13 connected to the main flaps by second fold lines 14 perpendicular to the first and adapted to form the top of the box after filling and a second set 15 flaps 16a to 16d rectangular or substantially rectangular also connected to the main flaps by second fold lines 14 and fit to form the bottom of the box.

The method and the device according to the invention can also use variants of the blank shown in FIG. 1 and in particular a blank comprising rectangular main shutters. interconnected by rectangular intermediate flaps.

 In known manner, these intermediate flaps form, on the final box, the beveled corners of the latter.

 They can also use blanks comprising an intermediate flap and two extreme flaps to obtain a box portion.

 FIGS. 2 to 5 are first of all described to describe a machine for forming a box or part of box with a polygonal section from the blank shown in FIG. 1, this machine comprising a sizing device according to FIG. embodiment of the invention more particularly described here, in particular with reference to the other figures.

 This machine 20 comprises a frame or structure 21 forming a platform carrying subsets or independent modules, assembled to ensure the formation of a box from the blank shown in Figure 1.

 This is the blank storage-unstacking module 30, the module 40 for gluing the blanks, the forming module 50, and the extraction module 60.

 These modules can be manufactured independently and then mounted on the frame 22.

 Thus, the frame 21 provides the connection between the two end modules, namely the storage-unstacking module 30 and the extraction module 60.

In the posts 22 of the frame, can be provided an electrical cabinet that includes an automaton Programmable control of the machine, known in itself.

 The first storage-unstacking module 30 comprises a storage magazine 31 in the semi-vertical position of the blanks 1 to be formed.

 This comprises two modular chains 32 driven by a system 33, comprising for example an asynchronous motor.

 The chains 32 are for example coupled to a freewheel 34 and allow to maintain a blank ready to be fed in front portion 36.

 In the storage magazine 31, the blanks are stored with the printed side facing the outside of the machine and the tab of the blank located on the right side of the machine in the direction of scrolling blanks.

 This module 30 also comprises means 35 (see FIG. 3) for unstacking the blanks 1 from the magazine 31.

 The gluing module 40 comprises a sizing device with a flat support 41, such as a table, intended to receive a blank 1. On the longitudinal edges of this table 41, there are provided lugs 410 fixed with respect to the table, to ensure the positioning of the blank.

 The gluing device also comprises a system of articulated arms 42 supporting a nozzle 420 positioned above the support.

The forming module 50 comprises a mandrel 51, that is to say a form tool, around which the blank previously glued by the gluing device will be formed.

 In order to move the blank 1 from the gluing device to the mandrel 51, there are provided transfer means 43 comprising a system of articulated arms situated under the table 41 and capable of grasping a blank from below by means of FIG. aspiration.

 The forming module 50 (see FIG. 4) comprises two pods 52, 53, integral with the frame 21 and arranged on either side of the mandrel 51, transversely and symmetrically with respect to the direction of delivery. flan from the gluing station.

 These nacelles comprise, in the example illustrated in Figures 2 to 5, the winding means of the flaps and the tongue of the fixing means.

 The extraction module 60 comprises an extraction station for extracting a box or portion of polygonal section box from the mandrel 51 where it has been formed, by means of an extraction device 61, an evacuation station comprising the two conveyors 62, 63 and a transfer station from the extraction station to the evacuation station.

 The extraction device will now be described in more detail with reference to FIGS. 6 to 9.

 This extraction device is shown in the folded position in FIG. 6 and in the deployed position in FIG.

It is of the nacelle type and comprises a system of articulated arms 63 and a plate 64. The system 63 is, at one of its ends 630, secured to the frame 21 of the machine by appropriate means 631.

 Moreover, at its other end 632, the system 63 is secured to support means 640 for the plate 64.

 In the example illustrated in the figures, these support means comprise two parallel pieces 6400 fixed by one of their ends 6401 to the end 632 of the system 63.

 The other ends 6402 of the support means 640 are connected by a common axis 6403, around which the plate 64 is mounted to rotate. The actuation of the plate is carried out by means of the set of rods 643.

 The system 63 comprises two sets 633 and 634 of arms articulated together which can be suitably controlled so that the extraction device 61 takes the folded position illustrated in Figure 6 or the extended position illustrated in Figure 7.

 The plate 64 is shown in a flattened position in FIG. 6 and in a rectified position in FIG. 7.

Furthermore, the plate 64 is provided with gripping means 641. These gripping means comprise suction means. It may especially be gripping cups (illustrated in Figures 6 and 7) connected to a vacuum system in a manner known per se. These means are intended to be active on the upper face 642 of the plate 64, that is to say the opposite side to the system 63 articulated arms, in Figure 6.

 Reference is now made to FIGS. 8A to 8F to explain the different operating steps of the extraction device illustrated in FIGS. 6 and 7.

 In practice, the device 61 is designed to complete the realization of the bottom of the box or part of box, previously formed on the mandrel 51. This is illustrated in Figures 8A to 8C.

 Thus, FIG. 8A schematically illustrates the forming station 50, with the mandrel 51.

 By comparing on the one hand Figures 8A to 8C and on the other hand Figures 8D to 8F, it is understood that the mandrel 51 is movable between a forming position, illustrated in Figures 8A and 8C and a retracted position, illustrated in Figures 8D and 8F.

 In the forming position illustrated in FIGS. 8A to 8C, the outer cross section of the mandrel corresponds to the inner cross section of the box that will be obtained from the blank 1.

 In the retracted position illustrated in FIGS. 8D to 8F, the distance between the application face 510 of the mandrel and the opposite upper face 511 is smaller than the width of the box that will be obtained from the blank 1.

 FIG. 8A illustrates the blank 1 at the end of its forming at the forming station 50.

Thus, the flap 5 is pressed against the application face 510, the flap 3, against the opposite face 511 and the flaps 4 and 6 on the side faces. Only the side face 512 is illustrated in the figures.

 Furthermore, the flap 3 is fixed on the tongue 7, the side flaps 16b and 16d are folded against the end face 514 of the mandrel, and the flap 16a.

 At the end of the operations performed at the forming station, the blank is in the configuration illustrated in FIG. 8A, while the extraction device 61 is in the position illustrated in FIG. 6. The plate 64 is therefore at the spacing of the mandrel 51 and is in its flattened position. FIG. 8A also shows that the plate 64 is then substantially parallel to the application face 510 of the mandrel, its upper face 642 being situated at a level lower than that of the application face 510.

 In the next step illustrated in FIG. 8B, the articulated arm system 63 has been actuated so as to be deployed in the longitudinal direction of the machine or in a direction substantially perpendicular to the end face 514 of the mandrel, in the opposite direction to the movement of the blanks in the machine 21.

 The extraction device 61 and the mandrel 51 are positioned relative to each other, so that the plate 64 is under the flap 16c in the deployed position of the extraction device 6.

In the next step illustrated in FIG. 8C, the articulated arm system 63 remains in its position deployed and the plate 64 is actuated to move to its upright position (illustrated in Figure 7).

 This actuation is achieved by means of the set of rods 643.

 The rotational movement of the plate 64 in the clockwise direction makes it possible to fold the flap 16c around the fold line 14 against the end face 514 of the mandrel, and more specifically on the flaps 16b and 16d previously folded on this face of the mandrel. 'end.

 In this movement, the plate 64 also supports the flap 16a previously folded against the flaps 16b and 16d.

 Thus, it is the two flaps 16a and 16c that the plate 64 applies against the flaps 16b and 16d, exerting a pressure force, to ensure the attachment of the flaps, thanks to the adhesive lines present on the upper face of the blank, at the flaps 16a and 16c.

 Thus, at the end of the step illustrated in the figure

8C, the flaps 16a to 16d are fixed together.

 The gripping means 641 provided on the face 642 of the plate 64 are then activated to engage the bottom of the box thus formed, grasping it by suction.

Figure 8D illustrates the next step in which the mandrel 1 is placed in a second retracted position, wherein its outer cross section is smaller than the inner cross section of the box. The pressure exerted by the plate 24 on the end face 514 is released and the articulated arm system 63 is actuated to initiate its folding, still in a substantially longitudinal direction but, this time, in the direction of movement of the blanks. inside the machine 21.

 In the next step illustrated in FIG. 8E, the articulated arm system 63 is substantially in the folded position and the plate 24 rotates counterclockwise about the axis 6403.

 Due to the activation of the gripping means, the box remains in good contact with the plate 24.

 FIG. 8F illustrates the position of the box and the extraction device at the end of the extraction process. Thus, the articulated arm system 63 and the plate 64 are in the position shown in Figure 6, the system 63 being in the folded position and the plate 64 in the flattened position.

 The box thus extracted from the mandrel may be deposited on one or other of the conveyors 62 or 63.

 Figures 9 and 10 illustrate the positioning of the extraction device 61, with respect to the conveyors 62 and 63.

 As illustrated in Figures 2 to 5, these two conveyors extend longitudinally, that is to say, in the direction of movement of the blanks in the machine.

The extraction device is positioned at the front of the conveyors 62 or 63, or between these conveyors and mandrel 51, and between the two conveyors.

 FIG. 9 illustrates the extraction device 61 and the two conveyors 62, 63 while the extraction device 61 is in the position illustrated in FIGS. 7 and 8C, a box in the prone position being engaged with the plate 24 .

 Figure 10 illustrates the extraction device in the position shown in Figures 6 and 8F, a box being present standing on the plate 24 in the flattened position.

 Reference is now made to FIGS. 11A to 11G to describe an example of implementation of the transfer on a conveyor of a box extracted from the mandrel 51 and present on the extraction device 61, in the position illustrated in FIG. 10.

 This transfer is here carried out by means of a device 65 comprising an arm 550 movable in rotation about an axis 651 fixed relative to the frame 21 and substantially vertical, that is to say substantially perpendicular to the table 41 or at the application face 510 of the mandrel.

 This axis of rotation 651 extends between the two conveyors 62 and 63, only the latter being illustrated in FIGS. 11A to 11G.

 The device 65 supports, at the end of the arm 650 opposite the axis 651, a plate 652 provided with gripping means 653.

As shown in FIGS. 11A and 11E to 11G on the one hand and FIGS. 11B to 11D on the other hand, this plate 652 is movable between a position retracted, illustrated for example in Figure 11A and an extended position, illustrated for example in Figure 11B.

 Figure 11A thus illustrates the box on the extraction device 61. The box is open and rests at its bottom on the plate 64 of the extraction device.

 The plate 652 of the extraction device 65 is then facing a lateral face of the box.

 Fig. 11B illustrates the next step in which the device 65 has moved into its deployed position. The gripping means 652 are then in contact with the lateral face of the box 1a. They are operated to seize the box.

 In the next step illustrated in FIG. 11C, the device 65 initiates a rotational movement about the axis 651 and in the clockwise direction.

 In its position shown in FIG. 11D, the device 65 has completed its rotational movement by 90 ° and the box 1 is then in contact with or slightly above the conveyor 63. The gripping means 652 are then deactivated.

 In the next step illustrated in FIG. 11E, the device 65 has passed into its folded position and the box is evacuated by the conveyor 63.

As shown in FIG. 11F, while the box 1 'continues to move on the conveyor 63, the device 65 rotates about the axis 651 and counter-clockwise. At this time, a new box 1 'has been extracted from mandrel 51 by the device extraction 61 and is on the latter in the position shown in Figure 10.

 FIG. 11G illustrates the end of the 90 ° rotational movement of the device 65, which returns to the position shown in FIG. 11A, to carry out a new transfer cycle of a box 1a on the conveyor 63.

 The invention is however not limited to this mode of implementation. In particular, the extraction device 61 could be designed so that the articulated arm system 63 is rotatable about a vertical axis passing through its first end 630.

 Thus, at the end of the step illustrated in FIG. 8F, the extraction device being in the folded position, it could rotate 90 ° about this vertical axis. The box there would then be opposite one end of the conveyor 63. Additional means would then be provided for carrying out its transfer on the conveyor 63.

 It follows from the foregoing description that the extraction device according to the invention makes it possible to move the box from a supine position to a standing position, the still open face of the box then being directed upwards. The box is in a stable position when standing since it is permanently held by the extraction device during its tilting.

Furthermore, the cooperation of this extraction device 61 with transfer means, such as the device 65, makes it possible to deposit the box on a conveyor, always stable way. Indeed, these transfer means, such as the extraction device 61, comprise gripping means, in particular by suction.

 Thus, the invention avoids the disadvantages of the devices and methods known in the state of the art by maintaining a permanent contact between the box and gripping means, until the removal of the box on the conveyor. This contributes to increasing the rates that can be achieved with the machine 20.

 We will now describe the operation of the machine for forming a box with reference to the figures.

 From the blank storage magazine 31, a first blank 1 is extracted and tilted horizontally.

 It is then dropped on the table 41 and positioned precisely on the table 41.

 The blank being stationary, adhesive lines are deposited on at least two side flaps 16c and 16a, on the upper face of the blank, the lower face constituting the printed face of the blank.

 The blank is then transferred from the sizing station to the forming station and is carried out, during this transfer, the deposition of a line of adhesive near the free edge of the flap 3 or on the tongue 7.

The blank 1 being positioned under the mandrel, it is wound around the mandrel, here by means of two nacelles 52 and 53. However, this forming can be achieved by any means. At the end of the forming step, the flap 3 is glued to the tongue 7 and the side flaps 16a and 16c are glued to the flaps 16b and 16d to form the bottom of the box on the end face 510 of the mandrel. The latter is turned on the side of the extraction module 60.

 In a variant, at the end of the forming step, the flaps are not fixed to each other, only the flaps 16a, 16b and 16d being folded.

 It is then the extraction device that proceeds to fold the flap 16c and the fastening of the flaps together, as shown in Figures 8A to 8C.

 The device 61 then extracts the box thus formed from the mandrel 51, as has been described with reference to FIGS. 8D to 8F, the box then being deposited on one or the other of the conveyors 62 or 63, for example as illustrated on FIG. Figures 11A-11G.

 The above description also applies to the formation and extraction of a can portion.

 Of course, this method is implemented in the context of a successive and automatic forming of boxes or box parts, so that blank is glued during forming of the blank n-1.

 As is obvious and as also follows from the above, the present invention is not limited to the embodiments more particularly described. On the contrary, it embraces all the variants and in particular those in which the mandrel has eight sides and / or those where the flaps forming the bottom are folded over the mandrel by complementary means.

Claims

1. Device for extracting a box or part of polygonal section box from a mandrel (51) having an upper face (511), an application face (510) connected by side faces and an end face (514), mandrel on which it was previously formed from a blank (1) comprising a sequence of at least three flaps (3 to 6), namely two flaps (3, 6) on the left and right. other of at least one intermediate flap (4, 5), said flaps being connected to each other by parallel fold lines (8 to 10) and provided with side flaps (13, 16a to 16d), respectively connected to said flaps by fold lines (14) perpendicular to the fold lines (8 to 10) connecting said flaps, characterized in that it comprises a plate (64) having first gripping means (641) and movable in translation between a deployed position in which the plate is close to the end face (514) of the mandr in which side flaps (16a to 16d) are intended to be folded and a folded position in which the plate (64) is away from the mandrel (51) and in that the mandrel (51) is itself movable between a first forming position in which its outer cross section corresponds to the inner cross section of the box or box portion and a second retracted position in which its outer cross section is less than the internal cross-section of the box or part of a box.  2. Device according to claim 1, characterized in that it comprises a system of articulated arms (63) capable of being deployed in a direction substantially perpendicular to said end face (514) of the mandrel and a first end (630 ) is integral with the frame (21) of the device and a second end (632) supports said plate (64).  3. Device according to claim 1 or 2, characterized in that said plate (24) is rotatable between a flattened position in which it is substantially parallel to the application face (510) of the mandrel and a rectified position in which it is substantially parallel to said end face (514).  4. Device according to one of claims 1 to 3, characterized in that the first gripping means (642) comprise suction means.  5. Device according to one of claims 1 to 4, characterized in that, when the mandrel (51) is in its first retracted position, the distance between the upper face (511) and the application face (510) of the mandrel is arranged to be smaller than the width of the mandrel box or part of box.  6. Device according to one of claims 1 to 5, characterized in that the system of articulated arms (63) is rotatable about a vertical axis passing through its first end secured to the frame. 7. A method of extracting a box or portion of polygonal section box from a mandrel, the box or part of the box resulting from the shaping around said mandrel (51) of a blank (1) comprising a sequence of at least three flaps (3 to 6), namely two end flaps (3, 6) on either side of at least one intermediate flap (4, 5), said flaps being connected to each other by means of fold lines (8 to 10) parallel and provided with lateral flaps (13, 16a to 16d), respectively connected to said shutters by fold lines (14) perpendicular to the fold lines (8 to 10) connecting said shutters, said blank (1) having been previously glued at least at two lateral flaps (16a, 16d) and brought under the mandrel (51), which is in a first forming position in which the flaps have been wrapped around the mandrel, the outer cross-section corresponds to the inner cross section of the box or box part, characterized in that it comprises the following steps:  applying a pressing force on an end face (514) of the mandrel on which side flaps (16a to 16d) have been previously folded, to fix the flaps together and form the bottom of the box or part of a box whose inner surface is in contact with the mandrel, - grabbing by suction the bottom of the box or part of the box thus formed, - reduce the outer section of the mandrel so that it is in a second retracted position, and  - Exert on the outer surface of the bottom pulling force perpendicular to the end face, releasing the pressure on the bottom of the box or part of the box, to extract said box or box part of the mandrel.  8. A method according to claim 7, characterized in that after extraction of the box or part of the box of the mandrel, it rectifies said box or portion of box vertically and is transferred to an evacuation station (62, 63).  9. The method of claim 7 or 8, characterized in that one extracts and rectifies the box or portion of box by the same means (61).  10. The method of claim 9, characterized in that said means (61) also contribute to the transfer of the box or part of a box to an evacuation station (62, 63).  11. The method of claim 9 or 10, characterized in that said means (61) also allow to fold at least one of said flaps on said side face of the mandrel. 12. Machine for forming a box or part of box with polygonal section from a blank (1) comprising a sequence of at least three flaps (3 to 6), namely two extreme flaps (3, 6) on either side of at least one intermediate flap (4, 5), said flaps being connected to each other by parallel fold lines (8 to 10) and provided with lateral flaps (13, 16a and 16d) , connected respectively to said flaps by fold lines (14) perpendicular to the fold lines connecting said flaps, comprising:  a gluing station (40) in which an adhesive is deposited on at least two lateral flaps (16a, 16c),  - a forming station (50) in which the flaps (3 to 6) are wound around the mandrel (51) and flaps on the same side of said flaps are folded and  - An extraction station comprising a device (61) according to one of claims 1 to 6.  13. Machine according to claim 12, characterized in that it also comprises a transfer station (65) to at least one evacuation station (62, 63). 14. Machine according to claim 13, characterized in that the transfer station (65) comprises second gripping means (652) of the box or portion of box present at the extraction station, these second means being rotatable between a first position in which they are opposite the extraction station (61) and a second position in which they are facing the evacuation station (62, 63), these second gripping means (652) being also movable in translation between an extended position in which they are intended to be in contact with the box (1 ') or part of a box and a retracted position of rest. 15. Machine according to claim 12 with a device according to claim 6, characterized in that the extraction station comprises gripping means (64) movable in translation between a retracted position and an extended position.  16. Machine according to claim 14, characterized in that the second gripping means (652) comprise suction means.  17. A method of forming a box or part of box polygonal section, from a blank (1) having a set of flaps 3 to 6) connected to each other by fold lines (8 to 10) parallel and provided with side flaps (13, 16a to 16d), respectively connected to said flaps by fold lines (14) perpendicular to the fold lines (8 to 10) connecting said flaps, wherein: the blank (1) is glued at least at the level of two lateral flaps (16a, 16c) and brought under a mandrel (51), the blank (1) is then shaped around the mandrel (51) to obtain a box or part of a box,  said box or part of a box is extracted from the mandrel (51) by implementing the method according to one of claims 7 to 11,  said box or box portion being subsequently transferred to an evacuation station (62, 63).