FR2640935A1 - Method of automatically setting the volume of trays (boat-shaped containers) having sealed corners and machine for implementing it - Google Patents

Abstract

The method and the machine relate to the volume-setting of a tray (boat-shaped container) of the type having sealed corners and provided with gussets 4. The volume-setting is effected by the deep-drawing, flat, of a precut, prefolded and pre-adhesive-coated tray (boat-shaped container). The deep-drawing is effected in a forming well 11, by means of a punch 13 which drives the bottom 1 of the tray (boat-shaped container) onto a table 10. During the movement of the tray (boat-shaped container), the gussets 4 are automatically folded over by means of a ramp 25 located beneath the starting plate 12 above a device 16 for holding the gussets 4 in the folded-down position, in order to allow, after removal from the forming well, installation of the flap 3e on the gussets 4 and the internal wall 3i of the tray (boat-shaped container). The fixing of the flap 3e is effected either by means of tabs situated laterally in the extension of the said flap 3e, which tabs are inserted into gussets produced at the ends of the large sides 2 of the tray (boat-shaped container) or by means of a tab 8 situated in the extension of the flap 3e, which tab is adhesively bonded beneath the bottom 1 of the tray (boat-shaped container).

Description

 The present invention relates to a method for automatically volume trays with sealed angles; it also relates to the machine allowing the implementation of the process.

 Trays or trays with sealed angles are generally used for packaging various food products. These trays have a waterproof character particularly appreciated for the packaging of meat.

 This type of waterproof tray is described in particular in document FR-A-2 502 587; it consists of a blank of corrugated cardboard coated with a sheet of impermeable paper to present a bottom from which stand four sides, parallel in pairs and symmetrical, obtained by folding in an angle; the tightness between two adjacent dimensions raised is obtained by means of bellows folded over the small dimensions, blocked by flaps arranged in the extension of these short sides and fixed under the bottom of the tray.

 Usually, the flaps are fixed by manual snap-fastening under the bottom of the tray by pinching the extreme fold of the flap between said bottom and the lateral extensions of the long sides glued under the bottom, as described in document FR-A-2 514 727.

 The present invention also allows the shaping of waterproof trays of the type described in patent application FR-A-87 15112. The tray described in this application is made, compared to the previous trays, with a significant saving in material. For this tray, in fact, the flaps on the short sides of the tray described in the aforementioned document FR-A-2 502 587 comprise, laterally, tabs which are inserted into gussets formed in the large dimensions at their ends. These gussets are obtained by the internal wall and by its external lining which is glued over the entire length, with the exception of a reserve at the ends constituting said gusset.

 The subject of the present invention is a process for automatic volume setting of these trays or trays with sealed angles by means of bellows, which tray is pre-cut, pre-folded flat and has two flaps for blocking the bellows as well as fixing means. of these flaps; this process consists - in positioning the tray flat in a reference angle, for example above a formation well, and under a stamping punch, - in forming the vertical sides by stamping the bottom of the tray in the well forming, simultaneously causing the bellows to close, - to press at least the bellows inside the flanks provided with locking flaps, to position them under these flaps, - to keep the bellows in this folded position on the outside of the flanks concerned , - to raise the training well before setting up the locking flaps on the bellows held in position, and fixing said flaps; - To release the tray by releasing it from the means for temporarily holding the bellows and raising the stamping punch.

 According to a first embodiment of the invention, and in particular for the volume of trays of the type comprising tabs arranged laterally on the bellows blocking flaps, which tabs are inserted in a gusset formed in the adjacent side , the process consists, after the lifting operation of the training well - to open the gussets - to place parallel to the bottom of the tray, the blocking flap; - to place the tabs in the plane of the opening of the corresponding gussets - to press the flap on the corresponding flank and the bellows while simultaneously engaging the tabs in the gussets.

 According to a second embodiment of the invention, for trays of the type comprising, in the extension of each bellows blocking flap, a fixing tongue or fold intended to be glued to the bottom, the method consists - simultaneously of lifting from the training well, to grasp the tray and to perform while maintaining the bellows, the establishment of the flaps on the sides and corresponding bellows; - to glue the tabs and / or the bottom - to fix the said tabs on the bottom.

 The invention also relates to a machine allowing the implementation of the method of automatic shaping of trays with sealed angles.

 This machine comprises - a table on which a training well is positioned and guided - a tray for receiving and positioning the flat tray, located at the upper part of the training well - a stamping punch arranged, in the rest position , at a level located above the receiving tray; this punch moving from its rest position located above the tray, up to the table, through the forming well - means for automatic installation of the bellows, in a position such that they are pressed outside sidewalls or lateral sides comprising the flaps, and means for holding these bellows in the pressed position - means for folding down and fixing the bellows blocking flaps.

 According to an essential arrangement of the invention, the machine comprises, fittings in the walls of the training well, ramps for automatic positioning of the bellows in a position such that they are plates on the sides provided with flaps; the upper part of these ramps being located, relative to the receiving tray, at a distance which corresponds substantially to the height of the tray.

 According to a first embodiment, for trays of the type comprising tabs arranged laterally on the blocking flaps, which tabs are inserted in gussets arranged on the adjacent sides, the stamping punch comprises means for handling the flaps of blocking to bring them from the position perpendicular to the bottom of the tray, in a position parallel to said bottom, facing outwards.

 The machine includes means for folding and then holding the lateral tabs of the flap in their plane of insertion into the gussets, and means which simultaneously cause: on the one hand, the pivoting of said flap in order to press it on the bellows, and, on the other hand, the insertion of the tabs in the gussets, locking said flap.

 Still according to the invention, the machine includes means for opening the gussets beforehand to allow the tabs to be inserted automatically; these means consist of lateral drawers moving under the bottom of the tray, perpendicular to the plane of the gussets, the end of each drawer has a catching finger.

of the external wall of the corresponding gusset.

 According to another arrangement of the invention, the machine comprises means making it possible to extract the tray after withdrawal of the stamping punch; these means consist of an ejector arranged on the table and arranged in the center, under the bottom of said tray.

 According to a second embodiment, for trays of the type comprising, in the extension of each flap, a fixing tongue intended to be glued to the bottom, the machine comprises, on the one hand, a carriage of the suction type provided with flaps lateral, which supports the tray simultaneously with the withdrawal of the formation well and the stamping punch, which carriage moves the tray parallel to the sides provided with locking flaps and, on the other hand, a guide structure of the carriage and the tray comprising means for holding the bellows in the pressed position on said sides, in the form of a guide, and means for folding the flaps on said bellows, in the form of a helix.

 Still according to the invention, the machine comprises a station for gluing the bottom of the tray and / or tongues which extend the locking flaps; it also includes means for plating said tabs on said bottom.

 According to another arrangement of the invention, the suction carriage is of the shuttle type; it transfers the tray from the stamping station to the gluing and finishing station of the tray.

 According to another arrangement of the invention, the machine comprises a supply station comprising on the one hand, a hopper in which the flat trays are routed vertically, placed on a large side, and, on the other hand, means supplying a tray under the stamping punch, which can be of the suction type.

The invention is further illustrated by the following description and the accompanying drawings, given by way of indication, and in which - FIG. 1 represents a tray obtained by the volume setting process according to the invention, - FIG. 2 represents a portion of blank of pre-cut and pre-folded cardboard, for a first type of tray, - Figure 3 partially shows, in perspective, the main phases of volume setting of the type of tray whose blank is shown in Figure 2, - Figure 4 shows a portion of pre-cut and pre-folded cardboard blank for a second type of tray
- Figure 5 shows in perspective, the main phases of shaping the tray whose blank is shown in Figure 4, - Figures 6 A to H show, schematically, the machine for carrying out the process according to the invention with the main phases of volume of the tray, the tray shown being that of the first type whose blank is shown in Figure 2, - Figure 7 illustrates schematically, in partial cutaway view, the main elements of the machine, for the volume of the tray, - Figures 8 A to G illustrate, schematically, the main steps of the volume of the tray of the second type, that is to say the one whose blank is shown in Figure 4, - Figure 9 schematically illustrates the last phases of the volume of trays of the second type, that is to say those whose side is shown in Figure 4.

 Figure 1 shows a tray produced by the volume setting process and the appropriate machine.

This tray consists of a square or rectangular bottom 1 bordered with longitudinal sides 2 and transverse sides 3. These long sides 2 and short sides 3 have a rectangular vertical section corresponding, as the case may be, to a double thickness of cardboard or alum in the shape of beam type which gives a special configuration to the tray and a more rigid character.

 This type of tray preferably consists of a cardboard side coated with plastic wrap or the like which allows it to be qualified as a sealed tray. This sealing is obtained, as shown in FIGS. 2 and 4, by means of bellows 4 which join the sides or internal walls 2i and 3 of the tray. The tray partially shown, Figure 3, and whose side is also partially shown in Figure 2, has long sides 2 made of a double thickness of cardboard the inner wall 2i and the outer wall 2e. The outer wall 2e is glued to the inner wall 2í, except at the ends, so as to form a gusset 5. This gusset 5 is found at the four corners of the tray, at each end of the long sides 2.

 The small internal side 3i is extended by a flap 3e, which flap comprises, FIGS. 2 and 3, laterally, tongues 6. These tongues 6 are intended to be inserted in the gussets 5 after having been folded square, by relative to the 3rd flap to be placed in the plane of the gussets 5. FIG. 3 is illustrated, the different operations leading to the volume of the tray of the first type, the side of which is shown in FIG. 2. By lifting the long sides 2 and short sides 3, the bellows 4 are formed; these bellows are then folded down on the external face of the small ribs 3i; the flap 3e is pressed against the bellows 4 and, simultaneously, the tongues 6 are inserted in the gussets 5. The tray set in volume is maintained in its shape by the pinching of the tongues 6 in the gussets 5.

 The same references have been kept for the parts common to the two types of trays. The sidewall partially represents, FIG. 4, corresponding to the tray of the second type, is constituted in the same way of a bottom 1, of an internal wall 2i corresponding to the large ribs 2, of an external wall 2e following the rib 21, and a strip 2b in succession, in the extension of the external wall 2e.

 We note that this external wall 2e comprises, laterally tabs 7 whose role will be illustrated in relation to FIG. 5.

 The small dimensions 3 consist of an internal wall 3i extended by a flap 3e which constitutes the external wall, which flap is extended by a tongue 8.

 FIG. 5 illustrates the various operations of volume setting of this second type of tray. The vertical lifting of the ribs 2 and 3 causes the formation of the bellows 4. These bellows 4 are folded against the external face of the internal walls 3i and, at the same time, they are covered by the legs 7 which complete the assembly of the angles from the tray. The flap 3e then comes to cover both the bellows -4 and the tab 7, and the tongue 8 is fixed to the bottom by means of a bonding for example.

 FIGS. 6A to H show, schematically, the machine in the different phases of volume setting of a tray. The tray shown in FIGS. 6A to H is a tray of the first type, that is to say as illustrated in FIGS. 2 and 3.

 The volume setting machine is made up of three main elements: a table 10, a training well 11 placed on the table and surmounted by a plate 12 and a stamping punch 13.

 Table 10 appears more particularly in FIG. 6H. It is in the form of a flat surface comprising centering studs 14 of the formation well 11. It also comprises, in its central part, an ejector device 15 in correspondence with the center of the bottom 1 of the tray. There are also devices 16 in the form of vertical plates located substantially in the plane of the short sides 2 of the tray, at the ends of these short sides. Note also FIG. 6E, behind the plates 16 an opening 17 whose width is greater than the width of the short sides 2 and which cooperates with a system 18 for shaping the small dimensions 2 and the tongues 6. This system 18 for placing in the form of the short sides is guided perpendicular to the table 10, FIG. 6G, by means of members 19 integral with the table; this system 18 is, on the side of the tray, in the form of a U open on the table, the central part 20 has a width which corresponds to the width of the short side 2 and whose lateral wings 21, perpendicular to the central portion 20 in the form of a ramp, have a height which corresponds to the length of the tongues 6 of the tray. The opening 17 arranged in the table 10, is intended to allow the passage of the lateral branches 21 and the central part 20 of the system 18 when the central part 20 is moved downwards towards the table to fold the flap 3e of said small side 3.

 The well 11 has two large panels 22 corresponding to the large dimensions 2 of the container and two small panels 23 corresponding to the short sides of the container. These panels 22 and 23 form the walls of the well 11 and are perpendicular to the table 10. They are fixed under the plate 12 by any suitable means.

 The small panels 23 comprise, laterally, means for automatically placing the bellows 4 of the tray. These means consist of an opening 24 arranged in the upper part of the panels 23, at the location of each of the bellows 4 of the tray. There are therefore four wells 24 on the well 11. These openings 24 also extend beyond the tray 12 for receiving the flat tray.

 Figure 7 shows, on a larger scale, all of the means used to volume a tray. Note the table 10 serving as a support for the well 11, a small panel 23 of which has been partially shown. This small panel 23 has the openings 24, the lower part of which is in the form of an inclined ramp 25. The purpose of the inclined ramp 25 is to pivot the bellows 4 around the edge of the container, to fold this bellows 4 onto the external face of the internal wall or side 3i of the container. The inclined ramp 25 is located clearly under the plate 12. The upper part of this ramp 25 is located at a distance from the upper plate 12, which corresponds substantially to the thickness of the tray. The opening 24 has a sufficient width to allow the passage of the bellows 4.On note, FIG. 6A, that the opening 24, - on the plate 12, is in the form of an arc of a circle whose center is located at the stop of the tray and whose radius is greater than the dimension of the bellows 4; this circular arc extends over an angle at the center of approximately 1200.

 Note also in FIGS. 6A and 7 in particular, openings 26 arranged in the tray 12, in the extension of the small panels 23. These openings are intended for the passage of the tongues 6 which laterally extend the flap 3e of the tray.

 Note also, in Figure 7, the opening 17 arranged for the passage of the system 18 for positioning the flap 3e and, in front of this opening, arranged in the lower corners of the small panel 23, the plates 16 serving to immobilize the bellows after their installation against the wall 3i. These plates 16 merge with the internal face of the panel 23, on the tray side.

 The plate 12 disposed at the upper part of the well 11 supports the panels 22 and 23. I1 has on the top a reference angle 27 intended to ensure the positioning and centering of the tray flat before it is placed in volume. Note, Figure 6A, above the plate 12, the stamping punch 13 which is movable vertically by means of a jack 28, which jack is fixed to its central part. This stamping punch 13 comprises two devices 30 each consisting of a tilting flap, 31, movable around an axis parallel to the stop 32 separating the internal wall 3i and the external wall or flap 3rd of the short side 3 of the tray. This device 30 also includes a jack 33, the body of which is integral with the jack 28 and whose rod is anchored on the pallet 31. This pallet 31 is intended to position the flap 3e in a horizontal position, parallel to the bottom 1 of the tray , before the system 18 for forming the tongues 6 is put into action.

 In Figure 7, we note the stamping punch 13 mounted at the end of a cylinder 28; this punch is parallel to the table 10 and to the plate 12, and its dimensions correspond substantially to the internal space of the tray. Note, on this punch 13, the device 30, shown partially, intended to act, by means of the pallet 31, on the flap 3e, to place it in a horizontal position, parallel to the bottom 1 of the tray.

 The process for setting the volume of the tray by means of the machine shown in FIGS. 6 and 7 is as follows. The tray presented flat in the reference angle 27 is a pre-folded and glued tray as appropriate. The volume setting process described below corresponds to a tray of the first type, that is to say a tray comprising a side as shown partially in FIG. 2. It is noted, for this type of tray, that the long sides are made up of two thicknesses of cardboard: an internal wall 2i and an external wall 2e glued in its central part only to the internal wall to allow the formation of gussets 5. This bonding is carried out prior to the volume of the tray.

 FIG. 6A shows the machine in the waiting position, ready to receive a flat container. FIG. 6B shows a flat tray placed in the reference angle 27 of the plate 12; this tray rests on the tray 12 and is surmounted by the stamping punch 13. As soon as this operation of introducing a tray flat on the tray 12, in the reference angle 27, is completed, the stamping punch 13 is animated by a movement in order to take by its bottom 1, the tray in the well 11 of training.

 FIG. 6C shows the start of the descent phase of the tray in the formation well 11.

As soon as the punch 13 presses on the bottom 1 of the tray, placing it below the upper level of the tray 12, the four sides of the tray are raised at an angle, which causes the immediate formation of the bellows 4 at each corner of the tray, which bellows are formed in the extension of the long sides 2. Note, in Figure 6C that the bellows 4 are formed and are positioned in the openings 24 formed in the tray 12 first.

As the punch 13 descends, see Figure 7 in particular, the bellows will come into contact with the ramp 25 responsible for rotating these bellows around each corner of the tray, to bring them against the external face of the internal wall or side 3i of the tray.

This phase also corresponds to FIG. 6D. Note, - in this figure 6D, that the tongues 6 which extend laterally the flap 3e, are located in the openings 26 arranged on the tray, which openings extend under the plate 12, between the panels 22 and 23 constituting the well 11.

 When the fqnd 1 of the tray arrives at the lower part of the ramps 25, the bellows 4 are plates on the wall 3i and the punch pushes the tray as far as the table 10, thus positioning the bellows 4 behind the plates 16 intended for retain these bellows. In this position, that is to say with the bottom 1 of the tray bearing on the table 10 and maintained by the punch 13, the well 11 is raised, FIG. 6E, completely releasing the tray, which remains trapped, in support on the table 10, by the pressure of the punch 13. We note in this figure, the position of the bellows 4, which are held by the vertical plates 16, pressing against the wall 3 of the tray.

 The next phase consists in placing and maintaining the flaps 3e in a position parallel to the bottom 1 of the tray. This movement of the flaps 3e is obtained by means of the system 30 by the tilting of the plates 31, under the effect of the jacks 33; each device acting on one of the flaps 3e of the short sides 3 of the tray. These flaps 3e are held in this position by a retractable pusher not shown, which is positioned in the opening 17, under said flap 3e.

 This flap 3e is kept horizontal during the folding phase of the tabs 6 arranged laterally.

This phase is shown in Figure 6G. It is obtained by means of the system 18 and in particular by the lateral wings 21 of this system. These tabs 6 are positioned in a plane which corresponds to the plane of the gussets 5 fitted at each end of the long sides 2 of the tray. Prior to the insertion of the tabs 6 into the gussets 5, the gussets 5 are slightly opened by means of drawers 35. These drawers appear in FIGS. 6E to 6H, and in particular, in FIG. 6E in a box which shows on the one hand , the retracted position of the drawer 35 and, on the other hand, its active position allowing the opening of the gusset 5. This drawer 35 is located on the table 10; it comprises, at its end normally located under the bottom 1 of the tray, a finger intended to grip the lower edge of the outer wall 2e of the large rib 2 of the tray. These drawers 35 are movable along an axis parallel to the short sides of the tray, from a position where the finger is retracted under the bottom of the tray, as it appears in the box in FIG. 6E, until a position where the finger has gripped the lower edge of the gusset 5. This operation of opening of the gussets is carried out prior to the withdrawal of the punch 13 from the tray and this withdrawal only occurs when the system 18 for placing the flaps 3e is in action to place these flaps against the wall 3i and, simultaneously, insert the tongues 6 in the gussets 5 open by the drawers 35. The positioning of the flaps 3e is carried out by the head 20 of the shaping system 18, during its movement towards the table 10, during which movement, the wings 21 penetrate into the opening 17 arranged in said table.

 This operation is illustrated in FIG. 6G, which figure shows the withdrawal of the punch 13 and, offset with respect to each other, the systems 18 which, on the one hand carry out the folding of the tongues 6 and the final shaping of the tray by the fold of the flap 3e on the internal wall 3i. The tray thus finished is ejected from the table 10 by the central ejector device 15; this ejection is carried out perpendicular to the table 10 to release the tray from the vertical plates 16 which held the bellows 4 in position.

 The shaping, or volume, of the second type of tray, as shown in FIGS. 4 and 5, is illustrated in FIGS. 8 and 9. This shaping takes place with the essentials of the machine shown in FIGS. 6A to D, which machine is completed by its own elements represented in FIG. 9 for particular phases illustrated in FIGS. 8D to G.

 In FIG. 8A, a stock of trays waiting in a hopper 40 is shown, for example. These trays are stored vertically, flat in this hopper, placed on their long side 2. They are pre-folded and pre-glued. This bonding concerns, for the long sides 2, the strip 2b situated in the extension of the flap 2e, which strip 2b is glued under the bottom 1 of the tray.

The first flat tray, at the outlet of the hopper 40, is apprehended by the punch 13. This punch can in this particular case as for the first type of tray, be a punch of the suction type. This punch 13 is positioned on the bottom 1 of the tray, on internal faces, and it brings this tray, above the tray 12, FIG. 6A, to stamp it in the well 11 thus causing it to be set up square. on the four sides, and at the same time, the formation of the bellows 4 at each angle of the tray, and in the extension of the long sides 2.The tray is shown in Figure 8B at the end of this first phase; the next phase consists in extending the descent of the tray into the well 11, to be folded down by means of the ramps 25, and this simultaneously, the bellows 4 and the tabs 7, on the external face of the internal wall 3i of the short sides 3. Note, Figure 9, side guides 41, arranged parallel to the short sides 3 of the tray; the purpose of these lateral guides is to maintain the bellows 4 and lugs 7 in the position pressed against the wall 3i. These lateral guides 41 intervene after the ramps 25; they replace the plates 16 mentioned above. When the punch 13 is at the end of the stroke, the tray and in particular its bottom 1 is located on a shuttle carriage 42 shown diagrammatically in FIG. 9, which replaces the table 10; it has flaps 43 intended to hold the long sides 2 of said tray. This carriage can also be a suction type carriage so as to maintain the tray by its bottom 1. When the tray is held by the shuttle carriage 42, the stamping phase is completed, the formation well is removed. ll and the punch 13. Under the effect of the carriage 42, the tray is moved between the lateral guides 41 which hold the bellows 4 and the tabs 7 and, during this movement, propellers 44 intervene to pivot the flaps 3e and the press against the guides 41 at first, then, at the end 45 of these guides, against the tabs 7 and the wall 3i. At the end of the guides 41, the tray reaches the gluing station.

 There is shown, Figures 8A, B, C, D and E, the different phases of the volume of the tray, as described above. At the end 45 of the guides 41, which corresponds to FIG. 8E, the tray reaches the gluing station 46. The lower part of the tray receives, laterally, two strips of glue on which the tabs 8 located will fold down at the end and in the extension of the flaps 3e. This positioning of the tongues 8 takes place at the end 47 of the propellers 44. FIGS. 8F and G show the positioning of the tongues 8 on the bottom 1 of the tray.

 The shuttle trolley 2 releases the tray as soon as the shaping is complete to return under the punch 13, and the well 11.

 The reference signs inserted after the technical characteristics mentioned in the claims are intended only to facilitate the understanding of the latter and in no way limit their scope.

Claims (12)

- CLAIMS  1.- Method for forming, or in volume, automatic trays with sealed angles by means of bellows (4), which tray is precut, pre-folded, flat and has two flaps (3e) for blocking said bellows (4 ), as well as means for fixing said flaps (3e), characterized in that it consists in - positioning the tray under a stamping punch (13), above a forming well (11) - at forming the vertical sides (2 and 3), by stamping the tray into the formation well (11), simultaneously causing the bellows (4) to close - pressing at least the bellows (4) on the external face of the sides ( 3i), under the blocking flaps (3e) - to keep the bellows (4) in this folded position on the outside of the sides (3i) concerned - to raise the formation well (11) before installing the flaps blocking (3e) on the bellows (4) held in position, and before fixing said flaps - to free the tray by releasing it from the temporary holding means for the bellows (4) and by raising the stamping punch (13)  2.- Method for automatically volume trays with tight angles, of the type comprising tabs (6) arranged laterally on the locking flaps (3e) of the bellows (4), which tabs are inserted in a gusset (5) formed in the adjacent side (2), characterized in that it consists, after the lifting operation of the formation well (11) - in opening the gussets (5) - in placing the locking flaps (3e) in a position parallel to the bottom (1) of the tray - to place the tabs (6) in the plane of the opening of the corresponding gussets - to press the flap (3e) on the corresponding side (3i), simultaneously engaging the tabs ( 6) in the gussets (5).  3.- A method of automatic volume according to claim 1, of trays of the type comprising, in the extension of each blocking flap (3e), a tongue or fold (8) for fixing, intended to be glued to the bottom ( 1), characterized in that it consists - simultaneously with raising the formation well (11), grasping the tray and carrying out, while maintaining the bellows (4), the positioning of the flaps (3e) on the corresponding sides (3i) - to glue the tabs (8) and / or the bottom (1) - to fix said tabs (8) on the bottom.  4. Machine for implementing the method of mounting trays according to claim 1, characterized in that it comprises - a table (10) on which is positioned and guided a formation well (11) - a tray ( 12) for receiving and positioning the flat tray, located at the top of the formation well (11) - a stamping punch (13) placed in the rest position, at a level located above the receiving tray (12) this punch (13) moving from its rest position, above the plate (12), as far as the table (10), through the training well (11) - means for automatically placing the bellows (4), in a position such that they are plates outside the internal walls (3i), and means for holding these bellows (4) in the pressed position; - Means for folding down and fixing the flaps (3e) for blocking the bellows (4).  5. Machine according to claim 4, characterized in that it includes, arranged in the panels (23) of the formation well, ramps (25) for automatic installation of the bellows (4) in a position such that they found pressed against the walls (3i) of the tray the upper part of these ramps (25) being located, relative to the receiving plate (12) at a distance which corresponds substantially to the height of the tray.  6.- Machine according to any one of claims 4 or 5, for the implementation of the method according to claim 2, characterized in that it comprises a stamping punch (13) provided with means (30) for taking charge flaps (3e), so as to bring them from the position perpendicular to the bottom (1) of the tray, to a position parallel to said bottom (1), facing outwards.  7.- Machine according to claim 6, characterized in that it comprises folding means (21) then holding, lateral tabs (6) of the flap (3e), in their plane of insertion in the gussets (5 ) and means (20), which simultaneously cause the pivoting of said flap (3e) to press it onto the bellows (4) and the insertion of the tongues (6) in the gussets (5), so as to lock said flap (3rd).  8.- Machine according to claim 7, characterized in that it comprises means for prior opening of the gussets (5) to allow the insertion of the tongues (6) automatically; these means consisting of lateral drawers (35) moving perpendicular to the plane of the gussets and comprising, at their end, under the bottom (1) of the tray, a finger intended to hang on the lower edge of the external wall ( 2e) of the corresponding gusset (5).  9.- Machine according to any one of claims 6 to 8, characterized in that it comprises means (15) for extracting the tray after removal of the stamping punch (13); these means consist of an ejector (15) arranged on the table (10) and arranged in the center, under the bottom (1) of said tray.  10.- Machine according to any one of claims 4 or 5, for the implementation of the method according to claim 3, characterized in that it comprises, on the one hand, a carriage (42), which supports the tray simultaneously with the withdrawal of the formation well (11) and the stamping punch (13), which carriage (42) moves the tray parallel to the side (2) and, on the other hand, a guide structure of the carriage (42) and of the tray, comprising means (41) which hold the bellows (4) and the legs (7), in the pressed position on the walls (3i), which means (41) are in the form of guides and in that it comprises means for folding the flaps (3e) on said bellows (4) and lugs (7), these means being in the form of propellers (44).  11.- Machine according to claim 10, characterized in that it comprises a station (46) for gluing the bottom (1) of the tray and / or tabs (8) which extend the locking flaps and, au- beyond the gluing station, means for plating said tabs (8) on said bottom.  12.- Machine according to any one of claims 10 or 11, characterized in that it comprises a carriage (42) of the suction type, which carriage is movable between the stamping station and the gluing station (46) and finishing the tray.