FR2558792A1 - PACKAGING CHAIN OF FILM PRODUCTS IN A CONTAINER FORMED FROM A PRE-CUT FLAT BLANK - Google Patents

Abstract

THE PACKAGING CHAIN INCLUDES A MACHINE 4 FOR FORMING AN OPEN RECEPTACLE 1 FROM A FLAN RAINE F1 AND SIMULTANEOUSLY GLUING TWO SHEETS OF FILM 311, 321 INSIDE THE RECEPTACLE 1. THE FIRST BLANK IS TRANSPORTED FROM A STACK OF BLANKS 410 ON SLIDES 416, GLUED UNDER NOZZLES 42 AND POSITIONED ABOVE A DIE 432 AND BELOW A STAMP 431. 4360 SUCTION JAWS PLATE THE ENDS OF TWO FILMS AGAINST SUCTION FACES 4311 OF THE PUNCH. IN THE LOW POSITION OF THE PUNCH IN THE DIE, THE FILMS ARE CUT BY TRANSLATABLE KNIVES 4370 TO OBTAIN THE SHEETS, THEN ARE UNLOADED DURING THE ASCENSION OF THE PUNCH. THE CHAIN ALSO INCLUDES MEANS FOR SEALING AND THERMORETRACTING THE SHEETS ABOVE THE PRODUCTS CONTAINED IN THE RECEPTACLE, AND FOR STYLING THE RECEPTACLE WITH A LID OBTAINED FROM A RAIN BLANK AND GLUE PUNCHED IN A MATRIX RECEPTACLE IN WHICH AS A PUNCH.

Description

PACKAGING CHAIN OF FILM PRODUCTS IN A

  RECEPTACLE FORMED FROM A PRE-CUT FLAT BLANK

  The present invention relates to a product packaging line in an open receptacle against the bottom of which the products are held by means of two sheets of film

  heat shrinkable contained in the receptacle.

  The products thus packaged and overwrapped can be boxes, bottles, documents or all grouped objects, or all products, whether or not preconditioned, grouped or placed individually in the receptacle. When several products are packaged in the same container, the batch of products may be uniform or

heterogeneous.

  A packaging line as defined above is very succinctly described in French patent application FR-A-2426620. The chain entry station includes a conveyor carrying already formed receptacles containing products and two sheets of heat-shrinkable film glued inside the receptacle. The main purpose of the chain is to allow the upper extreme portions of the two sheets to be folded over the products, to heat-seal said upper portions of the sheets and to heat shrink the sheets around the products. The aforementioned patent application only describes the structure of the receptacle and not the means for forming the receptacle

  and means for sticking the film sheets into the receptacle.

  The structure of another packaging receptacle is described in French patent application FR-A-2506722. This other receptacle has the general form of a rectangular bottom tray on which a shrinkable plastic film, replacing the two sheets of film mentioned above, is glued and is folded around the objects in order to cover them and to enclose them tightly after shrinking. FR-A-2506722 also describes a method of manufacturing the container from a flat blank, precut and grooved. The method consists in applying against the pre-glued bottom part of the blank the shrinkable plastic film, 2 2- optionally fed continuously, by means of a punch of shape complementary to that of the tray. At a second stage of the process, the tray is shaped by folding panels, forming the sides of the tray, against the punch which is kept applied against the bottom by means of the film. Then the punch is moved away from the formed tray and the film is cut to leave a single film of film stuck to the bottom of the tray. After filling the tray with products, the tray can be capped by a cover obtained from a second flat blank, precut and grooved. Patent application FR-A-2506722 describes a method of manufacturing a tray but does not

  not disclose means for the implementation of this process.

  The present invention essentially aims to provide a packaging line for the manufacture of a packaging container in which are bonded two sheets of heat-shrinkable film suitable for surrounding the products contained in the receptacle. More particularly, the invention aims to provide an automated packaging line in which the gluing of the film sheets and the forming of the receptacle from a precut, grooved and glued blank are obtained practically.

  simultaneously, which gives a very high flow rate.

  To this end, a product packaging chain to be placed in an open receptacle having a bottom and at least two first parallel sides and to be covered with two parallel sheets of film, preferably heat-shrinkable, partly symmetrically bonded inside the receptacle , said receptacle being obtained from a first flat blank, precut, grooved and glued having a central panel and two first parallel panels to respectively form said bottom and said first sides of the receptacle by means of a movable punch having dimensions substantially identical to the internal dimensions of the receptacle, is characterized in that the punch comprises first means for taking first extreme portions of said two sheets of film above the central panel of the first flat blank and for releasing said first end portions of sheets after bonding of these inside the -3 - receptacle, and in that the conditioning chain nt comprises a forming die having an upper section at least equal to the section of the first flat blank to receive the first flat blank glued below the punch and a lower section substantially equal to the external section of the receptacle, and means for lowering in the die the punch taking the first extreme portions of the film sheets in order to simultaneously stick said first portions of film sheets against the flat blank and inside the receptacle and to stamp the flat blank in the receptacle and to reassemble the punch above the top section of the die after

  loosening of said first portions of the film sheets.

  The packaging line can include all the automatic means necessary to obtain a receptacle formed from a first flat blank and containing two sheets of heat-shrinkable film glued inside the receptacle. These means are suitable in particular for taking a first flat blank from a stack of such blanks, for transporting the flat blank taken towards the upper section of the matrix, for gluing the flat blank during the previous transport, for permanently stretching two films, to cut the films when the receptacle is still in the die, to unwind the films after cutting and to extract the formed receptacle

of the matrix.

  Preferably, the packaging line can form receptacles having identical bottoms but having different side heights. The formation of such different receptacles makes it possible to continuously package heterogeneous batches of products

  notably having different heights.

  According to another aspect of the invention, the packaging liner also comprises means adaptable as a function of the height of the receptacles for preferably thermally sealing and heat shrinking the sheets of film above the products in the receptacles, but also means for close each receptacle with a cover formed from a second blank

  flat, precut, grooved and glued.

  -4 - The means for closing each receptacle are also designed

  to give a very high flow rate to the packaging chain.

  To this end, a packaging line according to the invention in which each open receptacle formed from a first blank is to be closed by a cover obtained from a second flat blank, precut, grooved and glued having a central panel and two first parallel panels to respectively form an upper wall of the cover to be placed on upper edges of the receptacle and two first parallel sides of the cover to be bonded against the first sides of the receptacle, is characterized in that it comprises a second forming die having a lower section at least equal to the section of the second flat blank and an upper section substantially equal to the external section of the cover, intermediate means for transporting the second flat blank glued under the lower section of the second die, and means for up and down a second tray between on the one hand, an open receptacle receiving plane lower than the intermediate means to transport and on the other hand, the upper section of the second die, the receptacle playing the role of a punch supported by the second plate and rising in the second die to support the central panel of the second blank and simultaneously to stamp the second blank in the cover and glue said first panels of the second blank against said first

sides of the receptacle.

  Other advantages and characteristics of the present invention will appear more clearly on reading the

  description with reference to the corresponding attached drawings in

  which: - Fig. 1 is a top view of a first flat blank, precut and grooved to form a receptacle similar to a tray according to the invention; - Fig. 2 is a top view of a second flat blank, precut and grooved to form a clean lid to close the tray; - Fig. 3 is a perspective view from above of the first glued flat blank; - Fig. 4 is a perspective view from above of the first glued blank during folding and gluing to two sheets of heat-shrinkable film in a drain of a first tray forming matrix; - Fig. 5 is a top perspective view of the tray formed prate to receive a batch of products; - Fig. 6 is a perspective view from above of the tray containing a batch of products surrounded by sheets of heat-sealed and heat-shrunk film, and of the second glued flat blank positioned above the tray and below a second lid forming die ; - Fig. 7 is a perspective view of a tray closed by the cover formed from the second glued flat blank; - Figs. 8, 9 and 10 are respectively schematic longitudinal side, top and front side views of a first machine of a packaging line intended to continuously form trays and to glue two sheets of heat-shrinkable film inside. from the tray; - Figs. 11 and 12 are schematic longitudinal side and front views of a second machine of the packaging line intended to heat seal and heat shrink the sheets continuously around the batches of products in the trays; - Figs. 13 and 14 are schematic top and longitudinal side views of a third machine of the packaging chain intended to continuously form lids and to simultaneously close the trays by the lids; and - Fig. 15 is a schematic top view of means for modifying the spacing of two slides for the transport of first flat blanks having different dimensions in the

first machine.

  A packaging container according to the invention comprises a

  receptacle for receiving products to be packaged.

  The receptacle according to the embodiment described below and illustrated in the figures is a tray 1 shown in detail in FIG. 5. Tray 1 is obtained from a first blank -6 -

  single flat, pre-cut and grooved in cardboard F1 shown in Fig. 1.

  The blank has five panels and four lateral portions called extensions which are delimited between them by four creasing lines. A rectangular central panel 10 constitutes a bottom of the tray having a width ú and a length L. Two rectangular panels 11 and 12 extend the central panel 10 in transverse direction to form two longitudinal sides of the tray. The panels 11 and 12 are delimited with respect to the panel 10 by two longitudinal creasing lines 110 and 120 formed in the top face of the panel 10 in order to allow the upward folding of the panels 11 and 12. Two other rectangular panels 13 and 14 extend bottom 10 towards

  longitudinal to form two transverse sides of the tray.

  The panels 13 and 14 are delimited with respect to the panel 10 by two transverse creasing lines 130 and 140 formed in the top face of the panel 10 in order to allow the upward folding of the panels 13 and 14. The longitudinal panels 11 and 12 have a length L greater than the width L of the panels

13 and 14.

  Two opposite longitudinal edges of each longitudinal panel 13, 14 are extended in transverse direction on the side of the crease line 130, 140 by two L-shaped extensions 131, 141 which form, with the panels 11 and 12, two corners of the tray after gluing, folding and folding up at right angles up along the crease lines. Near the ends of the transverse edge 133, 143 of each transverse panel 13, 14 are provided two small rectangular tenons 132, 142. The tenons 132 and 142 are intended to pass through four rectangular mortises in an upper wall of the container formed by a

central panel with cover 2.

  A second element of the packaging container is constituted by the cover 2 shown in FIG. 7. The cover 2 is obtained from a second flat single blank, pre-cut and grooved in cardboard F2 shown in FIG. 2. The blank F2 has, like the tray blank F1, five panels, namely a central panel -7 - rectangular 20, two longitudinal rectangular panels 21 and 22 and two transverse panels in isosceles trapezium 23 and 24, as well as four lateral portions say extensions. The panels and extensions of the blank F2 are delimited between them by four creasing lines. The panels 21, 22, 23 and 24 are delimited with respect to the central panel 20 by respective creasing lines 210, 220, 230 and 240 formed in the underside of the panel 20 and defining the periphery of the panel 20. Two transverse edges opposite of each longitudinal panel 21, 22 are extended in longitudinal direction by two rectangular trapezoidal extensions 211, 221 whose oblique sides form with oblique sides of panels 23 and 24 two corners of the cover after gluing, folding and folding at right angles to the bottom along the crease lines. In the central panel 20, near the ends of the transverse creasing lines 230 and 240, four small rectangular mortises 200 and 201 are formed which are suitable for being crossed by the pins 132 and 142 of the tray respectively. According to another variant, the pins 132, 142 and

mortises 200, 201 are deleted.

  As shown in Figs. 6 and 7, the height H of the transverse sides i3 and 14 of the tray 1 is significantly greater than the height h of the longitudinal sides 11 and 12 of the tray 1 and is at least as great as the height of the products to be packaged P. The products P are here illustrated in the form of a heterogeneous batch of products such as boxes of different dimensions. The opening of the tray 1 is constituted by its upper face between the transverse edges 133 and 143 and by the longitudinal upper recessed parts above the longitudinal sides 11 and 12. The cover 2 completely covers the opening of the tray in view to form a completely closed box. In other colors, the height of the longitudinal sides 21 and 22 of the cover is at least equal to Hh, preferably equal to H, in order to allow bonding of the internal faces of the sides 21 and 22 of the cover against the external faces of the sides. 11 and 12 of the tray. Such bonding prevents the passage of fingers between the tray and the lid in order to steal the products and

  increases the stacking resistance of the tray.

  The extensions 131 and 141 are glued against the internal faces of the longitudinal sides 11 and 12 of the container in order to press the sides 21 and 22 of the cover on the external faces of the sides 11 and 12 of the container as shown in FIG. 7. The transverse sides 23 and 24 and the extensions 211 and 221 of the cover are glued against the external faces of the sides 13 and 14 of the tray. The third element of the packaging container consists of two sheets 31 and 32 of heat-shrinkable plastic film, preferably transparent. The sheets 31 and 32 are cut in a rectangular shape from two rolls of film. The sheets 31 and 32 have a width substantially equal to the length L of the bottom 10 of the tray 1 and a length L3 of the order of three quarters of the perimeter 2 (H + Z) of a transverse side 13, 14 of the tray so that the sheets cover at least the upper and longitudinal sides of the batch of products P, as shown in FIG. 6. In the following, "inner faces" of the sheets 31 and 32 are called the faces of the sheets intended to be in contact with the products, and "outer faces" of the sheets 31 and 32 the other faces of the sheets, including lower end portions. 310 and 311 are intended to be glued against the internal face of the bottom 10 of the tray 1, as shown in FIGS. 4 and 5. Upper end portions 311 and 321 of the sheets 31 and 32 cover the upper face of the batch of products P and overlap practically in the middle of this face. The overlapping portions 311 and 321 are joined together by heat sealing. The main direction of retraction of the sheets 31 and 32 of monooriented film is longitudinal to the sheets, that is to say parallel to the transverse sides 13 and 14 of the tray. As shown in Fig. 6, the sealed sheets 31 and 32 are heat-shrunk around and against the batch of products P, which presses the products against the bottom 10 of the tray. The products surrounded by the sheets are thus entirely contained in the tray 1 which can then be closed by the cover 2. The packaging container as shown in FIG. 7 is obtained at the outlet of a packaging line according to the invention from the two precut blanks F1 and F2 and from two rolls of heat-shrinkable plastic film. The packaging line essentially comprises three machines, linked together by intermediate conveyors if necessary, each comprising several work stations. A first machine 4 at the start of the packaging line glues the first precut blank F1, glues the lower end portions 310 and 320 of the sheets 31 and 32 to the glued blank and simultaneously forms the tray 1, then cuts the sheets 31 and 32. Following the first machine 4, the products P are deposited in the tray 1. Then the upper end portions 311 and 321 of the sheets 31 and 32 are heat sealed above the batch of products P and the sheets 31 and 32 are heat shrunk around the products in a second machine 5. The tray I containing the batch of products is transported to a third machine 6 in which the second precut blank F2 is glued and the tray 1 is closed by the cover 2 simultaneously with the

  blank F2 formed into cover 2.

  The various stationary elements included in the three machines 4, 5 and 6, such as jacks in particular, are fixed to uprights, beams, beams and the like of the frames of the machines not shown. The cylinders used are double-acting cylinders, with rod linked in rotation, fitted with magnetic sensors, unless otherwise stated. Machine control units are made in wired logic or are organized around programmable controllers or microprocessor based controllers. Various magnetic and photoelectric detection means trigger the different

  phases of the manufacturing cycle of a packaging container.

  Some of these detection means are mentioned below.

  The first machine 4 is shown schematically in Figs. 8, 9 and 10. Machine 4 has an upper horizontal plane for transporting the first precut blank from an entry station

- 10 -

  41 to store and take blanks F1, to a central station 43 to stick two sheets 31 and 32, form a tray 1 and cut the sheets 31 and 32. Between stations 41 and 43, a blank taken from station 41 is glued in an intermediate gluing station 42. The machine 4 also has a lower horizontal plane for transporting from an output station 44

  trays formed in station 43.

  The entry station 41 comprises a blank store 410 above the rear of the upper blank transport plane. The store 410 is substantially a hollow parallelepiped having four vertical walls 411 in t6le. It receives a stack of flat blanks precut in cardboard F1 arranged longitudinally and horizontally and having crease lines oriented upwards. The stack of blanks F1 rests on small studs 412 projecting from the internal periphery of the bottom of the magazine 410. Below the magazine are provided means for gripping the bottom blank of the stack. The gripping means comprise suction cups 413, for example three in number, aligned on a support bar 414 disposed under the longitudinal axis of the magazine 410. The bar 414 is a conduit connecting the suction cups to pressure and vacuum means d 'air. A cylinder with parallel rods 415 moves the bar 414 vertically back and forth. In the high position, the suction cups 413 draw the lower blank into the magazine 410 by suction effect, retained by the pins 412. When lowering the bar 414 under the action of the jack 415, the lower blank integral with the suction cups 413 crosses the pins 412 which then retain the next blank from the stack in the magazine. The suction cups 413 descend substantially below the upper transport plane which is defined by horizontal sides of two angled profiles playing the role of longitudinal slides 416. In the low position, the suction cups 413 release the gripped blank F1 whose longitudinal edges are formed by the longitudinal panels 11 and 12 and the extensions 131 and 141 rest on the horizontal sides of the slides 416. The distance between the vertical sides of the slides 416 is adjusted beforehand to the width

X + 2h of a Fl flan.

- il1-

  After the extraction of a blank F1 from the magazine 410, a pusher 417 passes under the magazine 410 between the slides 416 and stops just below the rear of the magazine 410. The pusher 417 is composed of a horizontal transverse plate which is substantially above the horizontal sides of the slides 416 and which supports at least two retractable stops 419 aligned transversely. The push-button 417 is translatable back and forth

  between the slides under the action of a long rodless cylinder 418.

  The jack 418 is arranged longitudinally by side and below the slides 416 and is intended to translate by means of the pusher 417, the blank F1 on the slides 416, from the rear of the magazine 410 to the rear of the central station 43. When the pusher 417 moves back towards the rear of the magazine 410, the stops 419 are retracted upwards by the blank F1 resting on the slides 416. The rear edge 143 and the rear tenons 142 of the blank F1 on

  the slides 416 are then in front of the two stops 419.

  According to another variant, the entry station can be arranged so that the gripping means 413, 414 and 415 take the upper blank of a stack of blanks F1 from a store

underlying the slides 416.

  Under the action of the jack 418, the blank F1 is pushed by the retractable stops 419 of the plunger 417 and slides on the slides 416. In the gluing station 42, glue ejections on the grooved top face of the blank F1 are triggered, when the front panel 13 of the blank FI crosses the gluing station 42. Magnetic sensors, for example, are suitably fixed on the rodless cylinder 418 and control the glue ejections during the passage of the panels 10, I1l and 12 F1 blank under the gluing station. The glue ejections are preferably discontinuous in order to glue the grooved top side of the blank F1 by lines of diseóOntinus glue as shown in FIG. 3. The gluing station has four nozzles 421 to 424 each having two orifices ejecting glue in a discontinuous manner onto the blank F1. The glue can be of the hot-melt glue type having an almost instantaneous setting time of the order of a few seconds or of the so-called wet liquid type. Nozzles are 2558r92

- 12 -

  transversely aligned and fixed to a stationary crossbar 429 above the slides 416. The orifices of two lateral nozzles 421 and 424 each deposit two small longitudinal glue lines 151, 154 on the front and rear ends of a respective longitudinal panel 11 , 12 of the FI blank, as shown in FIG. 3. The lines of glue 151 are intended to glue the square portions of two extensions 131 and 141 against the internal face of the panel 11. The lines of glue 154 are intended to glue the square portions of two extensions 131 and 141 against the internal face of the panel 12. Two central nozzles 422 and 423 each deposit two discontinuous lines of glue discontinuous

  152, 153 over the entire length L of the central panel 10 of the blank Fl.

  The two long lines of glue 152 are close to the crease line 110 and are intended to bond the lower portion 310 of a film sheet 31. The two long lines of glue 153 are close to the crease line 120 and are intended to stick the

  lower portion 320 of a film sheet 32.

  After gluing by passing under the nozzles 421 to 424, the glued blank F1 is transported to the central station 43. At the end of the advance of the pusher 417, the blank F1 still supported by the two slides 416 has its central panel 10 at below a movable punch 431 and above a first stationary die 432

in extension 43.

  According to another variant, the stations 41 and 42 are arranged transversely, that is to say the direction of transport of the blank F1 is parallel to the transverse panels 13 and 14 of the blank Fl.

  in this case, two slides, such as 416, are spaced L + 2H apart.

  The punch 431 is constituted by a central parallelepipedic element 4310 disposed along the longitudinal axis of transport of the blanks F1, and two lateral parallelepipedic elements 4311 and 4312 parallel to the central element 4310 and symmetrical with respect to the element 4310. The set of three elements 4310, 4311 and 4312 forming the punch 431 is a parallelepiped having a height substantially equal to the height H of the tray 1 and a length substantially less than the length L of the central panel 10 of the

- 13 -

  blank F1 suitable for forming the bottom of the tray. The width of the punch 431 is variable by means of two small single-acting transverse cylinders 4313 and 4314 and two springs

  transverse traction 4315 and 4316.

  The cylinders 4313 and 4314 are arranged in cavities in the center of the longitudinal vertical faces opposite the central element 4310 and the lateral elements 4311 and 4312. The bodies and the rods of the cylinders 4313 and 4314 are fixed respectively to the central element 4310 and to side elements 4311 and 4312 of

   0 punch. The stroke of cylinders 4313 and 4314 is of the order of 5 mm.

  The cylinders 4313 and 4314 move against the restoring forces of the springs 4315 and 4316 the elements 4311 and 4312 symmetrically with respect to the central element 4310 so that the punch 431 has a width substantially less than the width of the bottom 10 of the tray 1. In the separated state, the horizontal rectangular section of the punch 431 is thus practically equal to the internal horizontal rectangular section of the tray 1.

  The springs 4315 and 4316 are arranged at the rear and front ends of the upper faces of the lateral elements 4311 and 4312, respectively. The strands of each of the springs 4315 and 4316 are fixed respectively to the elements 4311 and 4312. The springs 4315 and 4316 recall the lateral elements 4311 and 4312 towards the central element 4310 when the jacks 4313 and 4314 are deactivated. The width of the punch 431 is then one

  ten millimeters to the width ú of the bottom of the tray 1.

  The central element 4310 of the punch is suspended from the rods of a large vertical cylinder 433 by means of a small auxiliary cylinder 434 having rods fixed to the center of the upper face of the element 4310. The stroke of the cylinder 433 is equal to the length L3 of the sheets 31 and 32. The vertical displacement of the punch under the action of the jack 433 is guided by means of vertical columns 4330 along which slide the perforated ends of horizontal bars 4331 fixed to the jack 434. However, according to another variant, the columns 4330 can be deleted.

  and the vertical guiding of the punch is carried out by the jack 433.

- 14 -

  For the moment, the use of the cylinder is disregarded

auxiliary 434.

  The matrix 432 has the shape of a vertical funnel with a substantially rectangular section composed of a drain 4320 flared upwards in the upper part and by a parallelepiped well 4321 in the lower part. The drain 4320 has the shape of a horizontally truncated quadrangular inverted pyramid having chamfered edges pointing downwards. The large internal horizontal base of the hood has an internal rectangular section at least as large as the outline of the blank F1 and is substantially below the slides 416. The small horizontal base of the hood has an internal rectangular section equal to the section of the well 4321, which has dimensions equal to the dimensions of an external horizontal section of the tray 1. The height of the drain 432 is of the order of 2 hours, while the height of the well 4321 is of the order de H. The walls of the drain are concave, seen from the outside. The transverse walls 4322 of the drain extend between the slides 416 to the well 4321 while the longitudinal walls 4323 of the drain are lower and extend upwards from the well 4321 over a substantially lower height at H. In addition to the means for forming a tray from a cardboard blank by stamping, constituted by the punch 431 and the die 432, the central station 43 comprises means for taking and sticking two heat-shrinkable films 31, 32 and cutting the two films in two sheets 31, 32 during the forming of the tray. As shown particularly in FIG. 10, the central station 43 comprises, on either side of the vertical plane of symmetry of the punch 431, two film unwinding devices 4351 and 4352 Each unwinding device 4351 and 4352 comprises, at the bottom, idle cylinders supplying film 4351 , in the upper part, film drive means 4353 and film tensioning means 4354 to 4359, as well as intermediate idler cylinders 4352. The cylinders are horizontal and arranged

  laterally to the punch 431 and to the die 432. The direction of-

- 15 -

  unwinding of the mono-oriented films 31 and 32 is parallel to the direction of retraction of the films. A roll 4350 of heat-shrinkable film 31 32 rests by turning around its axis on two supply rolls 4351 at the level of the slides 416. The film 31 32 passes between the supply rolls and bypasses intermediate rolls 4352 to go up substantially vertically to 'to the driving means 4353 substantially at the level of the jack 433. The driving means 4353 comprise a driving cylinder and a mad press cylinder between which the film is clamped 3. The driving cylinder is rotated by a motor to unwind the film after cutting of the corresponding sheet 31, 32 over a length L3 of sheet. The 31 "film 32 in each unwinding device 4351 4252 then passes over an upper intermediate cylinder 4352 at a level above the cylinder 433, below a first idler tension cylinder 4355 and above a second idler tensioner cylinder 4356, and descends vertically down below the punch 431 in the high position to be taken up by associated film gripping means 4361, 4362. The film tensioning means consist of a muffle. comprises a bar 4357 having a center 4358 pivoting about a horizontal axis fixed to the frame of the machine 4. The bar 4357 is arranged on one side of the film 31, 32 and supports at its ends the axes of the tensioning rollers 4355 and 4356 A counterweight 4359 is fixed on an arm of the bar 4357 near the first tension cylinder 4355 and thus recalls down the cylinder 4355 and upwards the second tension cylinder 4356, which permanently stretches the film 31 32 between the cylinder 4353 and the means of

  gripping associated film 4361, 4362.

  The film gripping means 436 and 436 associated with the unwinding devices 4351, and 4352 each comprise a longitudinal parallelepiped jaw 4360 moved back and forth by a transverse cylinder with parallel rods 4361. As shown in Figs. 8 and 10, the two jaws 4360 are lateral to the punch 451, at a level between the slides 416 and the punch in

  high position, and below the second tensioning cylinders 4356.

- 16 -

  The length of the jaws 4360 is equal to the length of the punch 431. The height of the jaws 4360 is equal to the height of a lower portion 310, 320 of a sheet 31, 32 and the width

  lateral elements 4311 and 4312 of the punch.

  The vertical facing faces of the two jaws 4360 of the gripping means 4361, 4362 comprise a very large number of regularly distributed suction orifices 4362. The orifices 4362 are connected through conduits made in the jaws 4360 to suitable air suction means. The orifices 4362 suck the lower ends of the films 31 and 32 from the unwinding devices 4351 and 4352 against the opposite faces of the jaws 4360 just before cutting the sheets 31 and 32 when a tray has just been formed in the well of the matrix 432. At this instant, the tensioning cylinders 4355 and 4356 are respectively pulled up and down. The driving cylinders 4353 then unroll the films 31 and 32 over a length of sheet, which releases the tension of the films and allows the tilting of the muffle bars 4357 under the action of the weights 4359, and consequently the descent of the cylinders 4355 and the

raising of cylinders 4356.

  As shown in Figs. 8 and 10, the opposite vertical longitudinal faces of the lateral elements 4311 and 4312 of the punch also have numerous regularly distributed suction orifices 4317. The orifices 4317 are connected through conduits made in the elements 4311 and 4312 to other suitable suction means. The orifices 4317 suck lower portions of the films 31 and 32 against the opposite faces of the elements 4311 and 4312 as soon as the two jaws 4360 come together in order to bend the ends of the films 31 and 32 under the punch. The longitudinal faces from below of the lateral elements 4311 and 4312 also include orifices 4318 which make it possible to aspirate said ends of the films 31 and 32 folded horizontally by the advance 7 of the jaws 4360, intended to form the lower portions 310 and 320 of the sheets.

  31 and 32 cut later.

- 17 -

  The central station includes means 437 for cutting the films 31 and 32 in order to obtain two sheets 31 and 32 when a

  tray 1 has just been formed in the well of the matrix 432.

  The means 437 for cutting the films comprise two knives 4370 fixed at the ends of the rods of two long longitudinal cylinders 4371. The cylinders 4371 are arranged horizontally above the lower transport plane of trays 1 and symmetrically by

  relative to the upper longitudinal axis of transport of the blanks Fl.

  The spacing of the knives 4370 is substantially equal to the width.

  of the central panel 10 of the blank F1 forming the bottom of the tray. The cylinders 4371 translate backwards then forwards the knives 4370 just below the film gripping jaws 4360 in order to cut the films 31 and 32 after forming a

  tray in well 4321 of the matrix.

  The stages of the cycle for forming a tray I from a first precut and grooved cardboard blank Fi transported by the pusher 417, together with the laying of two sheets of film 31

  and 32 in the tray in station 43 are now described.

  The auxiliary cylinder 434 is currently unused. The sheet length indications L3, L3 'in FIG. 10 are

  intended for variants described below.

  a) At the start of the formatinn cycle, the pusher 417 is at the front of the slides 416, and the suction cups 413 in the entry station 41 are in the low position under the lower cardboard blank FI in the stack of the magazine 410. The punch 431 is in the high position. The lateral elements 4311 and 4312 of the punch are kept at the minimum spacing by the small springs 4315 and 4316 and the small cylinders 4313 and 4314 are deactivated. The jaws 4360 are separated as far as possible and suck through their orifices 4362 the "external faces" of the end portions of the films 31 and 32 b) The bar 414 with the suction cups 413 is raised by the jack 415. The lower blank F1 adheres by suction effect on the suction cups 413. Then, under the action of the jack 415, the bar 414 supporting the suction cups 413 descends. The suction cups 413 deposit the blank F1 captured at the rear of the slides 416. The bar 414 remains

2558 7-92

- 18 -

  in the low position until the end of the training cycle. The long longitudinal cylinder 418 is then activated. The push-button 417 moves back to the rear of the magazine 410, the stops 419 retracting passing over the blank F1, then the push-button 417 advances and pushes the blank F1 on the slides 416 by means of the retractable stops 419. The blank F1 sliding on the slides 416 passes under the glue nozzles 421 to 424 which deposit the eight lines of glue

  discontinuous 151 to 154 on the grooved top face of the blank FI.

  The small cylinders 4313 and 4314 are activated to separate the lateral elements 4311 and 4312 from the punch. The vertical longitudinal faces of the punch 431 are thus in the immediate vicinity of the films 31 and 32. The suction through the orifices 4362 in the jaws 4360 ceases at the same time as a suction is created in the orifices 4317 and 4318 of the lateral elements 4311 and 4312. The cylinders 4361 bring the jaws 4360 together under the suction side elements 4311 and 4312 of the punch 431. The approximation of the jaws 4360 contributes to pushing and bending the ends of the films 31, 32 whose "internal faces" are pressed against the faces vertical longitudinal and bottom faces of the lateral elements 4311 and 4312 of the punch by suction through the orifices 4317 and 4318. Then the jaws 4360 are moved back to the

  maximum away from the punch by the transverse cylinders 4361.

  c) When the jaw spacing 4360 is again maximum, the glued blank F1 is positioned on the front of the slides 416, above the hood 4320. The central panel 10 of the blank F1 is just below the punch 431 and above the well 4321 of the first die, at the end of the advancement of the pusher 417. The pusher 417 parks behind the dumper 4320 until

the end of the training cycle.

  At this instant, the jack 433 rapidly descends the punch 431 into the die 432. The small jacks 4313 and 4314 remain activated throughout the descent of the punch 431. Simultaneously, a horizontal rectangular support 440 is raised under the action of a jack vertical with rods 441. The stroke of each of the cylinders 433 and

  441 is equal to the length L3 of sheets 31 and 32.

- 19 -

  As shown in Figs. 8 and 10, the tray 440 is disposed axially under the well 4321 of the matrix, in the outlet station 44. The dimensions of the tray 440 are identical or substantially smaller than the bottom 10 of a tray 1. The upper face of the support 440 comprises four suction cups 442 suitably distributed on the longitudinal and transverse axes of the plate, as shown in Figs. 8 and 9. The jack 441 raises the plate 440 substantially to the lower base of the well 4321 of the matrix so that at the end of the elevation of the plate 440 and the descent of the punch 431, the plate 440 and the punch 431 press the bottom 10 on which are glued the ends of the films 31 and 32 underlying the elements 4311 and 4312, forming

  the lower end portions of sheet 310 and 311.

  During the volume setting of the tray by lowering the punch 431, the folded ends of the films 31 and 32 are held by the suction through the orifices 4317 and 4318 of the spaced apart elements 4311 and 4312 of the punch. The punch thus pulls down the films 31 and 32 'which quickly switches the muffle bars 4357 in the unwinding devices 435 and 4352 The cylinders 4355 are pulled up and the cylinders 4356 are pulled down. During the descent of the punch, the "external faces" of the ends of the films 31 and 32 under the undersides of the elements 4311 and 4312 are therefore glued to the panel 1G0 by means of the four long lines of glue 152 and 153. However, the flaring walls 4322 and 4323 of the outlet 432 prevents the lines of glue 151 and 154 on the longitudinal panels 11 and 12 from coming into contact with the films 31 and 32 kept vertical before the extensions 131 and 141 are folded down towards the panel 10 in front the lines of glue 151 and 154 by four suitably inclined corners of the hood 4320. These corners are formed by chamfered edges 4324 of the hood

  4320, converging on well 4321.

  At the start of the descent of the glued blank F1 in the hood 4320 under the thrust exerted by the punch, the transverse panels 13 and 14 are gradually folded down towards the punch by the high transverse walls 4322 of the hood. Simultaneously, the

- 20 -

  extensions 131 and 141 are gradually folded towards the panels 13 and 14 by the edges 4324 of the drain. On the other hand, the longitudinal panels 11 and 12 are still horizontal until the central panel 10 is at the level of the upper edges. longitudinal walls 4323 of the outlet, as shown in FIG. 4. The smaller height of the walls 4323 thus makes it possible to fold the longitudinal panels 11 and 12 only after the extensions 131 and 141. The edges of the extensions 131 and 141 initially aligned with the crease lines 130 and 140 do not scrape therefore not the glue lines 151 and 154 at the ends of the

longitudinal panels 11 and 12.

  After the central panel 10 has passed between the longitudinal walls 4323 of the drain, the glued longitudinal panels II and 12 are folded down substantially vertically against the extensions 131 and 141, and the transverse panels 13 and 14 are also folded down vertically in well 4321. The v square portions of the extensions 131 and 141 are pressed and glued against the longitudinal sides 11 and 12 thanks to the four lines of glue 151 and 154. The blank FI is stamped in the tray 1 in well 4321 of the matrix. The bottom 10 is pressed substantially at the lower base of the well 4321, between the bottom face of the punch 431 and the top face of the plate 440. d) Aspiration is triggered through the orifices 4362 of the jaws 4360 so that the films 31 and 32 are drawn towards the opposite faces of the jaws and are always stretched

  during the next cutting operation.

  Simultaneously, the suction cups 442 press the bottom 10 of the

tray on tray 440.

  e) The two cylinders 4371 are briefly activated back and forth. The knives 4370 advance under the suction faces opposite the jaws 4360 and cut the stretched films 31 and 32 so that the remaining portions of film under the jaws 4360 in the matrix 432 constitute the sheets 31 and 32. When the knives 4370 move back towards cylinders 4371, portions

  upper sheets 31 and 32 fall into tray 1.

- 21 -

  f) After the films 31 and 32t have been cut, the aspirations in the lateral elements 4311 and 4312 cease. Small cylinders 4313 and 4314 are deactivated, and springs 4315 and 4316 recall

  elements 4311 and 4312 to the central element 4310 of the punch.

  g) Then the punch 431 rises from the well 4321 towards its high position above the jaws 4360 under the action of the upper jack 433. Simultaneously, the plate 440 with the tray 1 attracted by the suction cups 442 is lowered from the well 4321 until on the lower horizontal plane of the tray extraction and transport,

  under the action of the lower jack 441.

  As soon as the knives 4370 retreat by the jacks 4371 after the films have been cut, the driving cylinders 4353 in the unwinding devices 4351 and 4352 are actuated to unwind the films 31 and 32 from the two film rolls 4350 during the ascent of the punch 431. The unwinding of the films attenuates the tension of the films between the driving cylinders 4353 and the gripping jaws 4360, which turns the muffle bars 4357 in the opposite direction under the action of gravity of the counterweights 4359. The cylinders 4355 pivot towards down while the 4356 cylinders pivot up. The stopping of the driving cylinders 4353 is triggered by the concealment of a photoelectric cell 4354, for example arranged at the low position of one of the weights 4359. The amplitude of the tilting of the bars 4356 during the operating phase drive means associated with cylinders 4353 is preset so that it corresponds to a

sheet length L3 31, 32.

  The output station 44 also comprises means for extracting the tray 1 formed from the machine 4. The means for extracting comprise a transverse pusher 443 fixed to the end of the rods of a longitudinal cylinder 444, as well as a receiving plane trays, preferably in the form of a horizontal conveyor 445 with rollers or endless belt. The jack 444 is arranged longitudinally behind the position

  bottom of platform 440 and above the lower transport plane.

  The upper face of the conveyor 445 constitutes the lower plane

- 22 -

  transport and extends the front of the upper face of the tray

440 in the low position.

  As soon as the tray 440 reaches the low position, the attraction of the tray 1 by the suction cups 442 ceases and the jack 444 is activated back and forth so that the pusher 443 pushes the tray 1 on the conveyor 445 which drives the tray towards the second

machine 5.

  During transport between the output station 44 of the first machine 4 and the second machine 5, possibly by intermediate conveyor belts or rollers, the upper portions of the sheets 31 and 32 are raised and separated, a batch of products is placed on the bottom 10 of the tray, and one of the upper portions 311 and 321 of sheet is covered by the other above the batch of products. These latter operations are carried out either manually or by mechanical, automatic or semi-automatic means, such as a case-packing machine, adapted to the shapes and dimensions of the products or to the batch of products. Such means do not belong to the scope of the invention. The second machine 5 is constituted by a tunnel 50 through which passes a horizontal conveyor belt or roller 51, as shown in Figs. 11 and 12. Inside the tunnel 50 are provided a rear heat-sealing station 52 and a front station for

heat shrink 53.

  The heat-sealing station 52 comprises a vertical cylinder 520 and a hot air blowing nozzle 521 with a vertical end fixed to the rods of the cylinder 520. The orifice of the nozzle 521 is oblong and disposed parallel to the longitudinal axis of the conveyor 51 and above it. The heat-shrinking station 53 comprises another vertical cylinder 530 and two hot air blowing nozzles 531 fixed to the rods of the cylinder 530 above the conveyor 51. The ends of the nozzles 531 are symmetrically inclined with respect to

  to the longitudinal axis of the conveyor 51 and converge towards this axis.

  The spacing of the ends of the nozzles 531 is greater than the semi-width of a tray 1. The nozzles 521 and 531 inject jets of hot air as long as the second machine 5 is in service. In

- 23 -

  each of the stations 52 and 53 is provided with a vertical series of photoelectric cells 522, 532 arranged by cSte and behind the nozzles 521, 531 at a distance substantially equal to L, as well as a photoelectric cell 523, 533 disposed by side substantially under the nozzles 521, 531 and substantially above the conveyor 5i. Cells 522 and 532 detect the height H of the trays. Cells 523 and 533 detect the presence of a

  tray under nozzles 521 and 531 respectively.

  When a tray 1 filled with a batch of products P covered by the sheets 31 and 32 enters the tunnel 50, the tray 1 is guided between two longitudinal rods 54 distant at least one width ú of tray. The concealment of both the cells, 522 and 523 positions the nozzle 521 in the high position not through the jack 520. The high position is greater than BO relative to the conveyor 51. Then, after passage of the tray 1 in front of the cells 522, the concealment of cell 523 alone positions the nozzle 521 in the low position by means of the jack 520. The low position is substantially greater than H relative to the conveyor 51. The jet of hot air blown in through the nozzle 521 seal the upper portions 311 and 321 of the film sheets 31 and 32 substantially along the longitudinal axis of the tray. Hot air softens the portions 311 and 321 applied

  one over the other and bind them intimately.

  According to other variants, the nozzle 521 is replaced by infrared radiation devices or by any other known means for securing the sheets, such as by heat-bonding or stapling, a process similar to the previous one is also accomplished in the heat-shrinking station 53. The simultaneous concealment of cells 532 and 533 positions the nozzles 531 in the high position by means of the jack 530. The high position is greater than H relative to the conveyor 51. Then in response to the concealment of the cell 533 alone, the jack 530 positions the nozzles 531 in the low position which is substantially greater than H relative to the conveyor 51. The two jets of hot air blown in by the two nozzles 531 retract the two heat-sealed sheets 31 and 32. The

- 24 -

  main direction of retraction of the sheets of mono-oriented film being parallel to the front 13 and rear 14 sides of the tray, the sheets 31 and 32 are heat shrunk against the batch of products between the upper junction of the sheets and the lower portions 310 and 320 under products. The shrinking of the sheets leads to pressing the batch of products P against the bottom

from the tray.

  According to another variant, the heat-shrinking station 53 includes, instead of the nozzles 531, a shrink tunnel with

infrared radiation.

  The tray 1 containing the batch of products P surrounded by the heat-sealed and heat-shrunk sheets 31 and 32, as shown in FIG. 6, is then transported from station 53 to the third machine 6, by the transporter 51 and by a transporter 60

  extending the conveyor 51 to the inlet of the machine 6.

  With reference to Figs. 13 and 14, the third machine 6 has three horizontal transport planes. A lower transport plane is defined by the entry conveyor 60 which introduces each tray 1 into an entry station 61 after a 90 rotation in a change of orientation station 62 at the front of the conveyor 60. A plan of intermediate transport above the lower plane is intended for the transport of second blank of cover F2 parallel to the conveyor 60. Each second blank F2 is gripped from a storage and gripping station 63, then glued in a station d 'sizing 64 and finally superimposed on a tray rising from the lower plane. An upper transport plan is intended to receive each tray 1 which is capped with a cover 2 in a cover forming station and tray closure 65 above the intermediate plane, and to extract each closed tray in a direction of transport here perpendicular to the lower and intermediate transport directions, from an exit station 66. According to the illustrated embodiment, the transporter 60 and the stations 63 and 64

  are arranged on either side of the entrance station 64.

  The orientation change station 62 comprises two rods 620 and 621 substantially perpendicular to the direction of

- 25 -

  transport of trays on butted conveyors 51 and 60.

  The rods 620 and 621 are arranged on one of the sides of the rear of the conveyor 60. The rear rod 620 is shorter than the front rod 621. The end of the rear rod is substantially S withdrawn from the axis for transporting the trays leaving the machine between the guide rods 54. A tray 1 leaving the heat-shrinking station 53 abuts by its front side 13 against the rear rod 620, which gradually turns the tray. The front side 13 then abuts against the longer front rod 621, substantially at the corner of the sides 12 and 13, which ends the rotation of 90 of the tray 1. The tray is now transported substantially transversely on the conveyor 60 between two guide rods 623 converging towards the entry station 61. In the entry station 61, the longitudinal side 12 of the tray 1 abuts against a transverse guide rod 611 in front of the front zone 610 of the conveyor 60. The station inlet 61 comprises a transverse cylinder 612, a pusher 613 fixed to the rods of the cylinder 612, a long vertical cylinder 614 underlying the lower transport plane, and a tray lifting tray 615 fixed to the rods of the cylinder 614. The station entry is intended to transfer the tray from the transporter 60 to the intermediate plane of

transport of second blanks F2.

  As shown in Figs. 13 and 14, the plate 615 in the low position extends the front zone 610 of the conveyor 60 transversely to the left relative to the direction of advance of the conveyor 60. The plate 615 is located vertically of the cover forming station and closing the tray 65. The presence of the tray in the zone 610 is detected by a photoelectric cell 616 which initiates the process of closing the tray in the machine 6.

  The plunger 613 extends the guide rod 623 on the right side of the conveyor 60 before receiving the tray 1. As soon as the tray 1 is detected by the cell 616, the jack 612 which is housed substantially under the gluing station 64, on each side of the conveyor 60, pulls the pusher 613 over a length substantially

- 26 -

  less than the width of the conveyor 60, in the zone 610. The tray 1 thus pushed by the pusher 613 slides over the reception zone 610, then is guided between the front guide rod 611

  and a rear guide rod 617 for sliding on the plate 615.

  The pusher 613 then serves as a guide wall of the tray 1 during its vertical transfer to the intermediate plane. The rear catcher of the pusher 613 is extended by a vertical plate 618 perpendicular to the conveyor 60. The plate 618 retains a second tray 1 waiting on the conveyor 60 and allows the trays to be introduced one by one into the reception area 610 to 1 front of the conveyor 60. The pusher 613 does not return to the right side of the conveyor 60 until the end of the closing cycle

tray.

  The vertical jack 614 is activated to raise the tray 615 supporting the tray 1 with a batch of products P to the upper extraction plane via the intermediate transport plane of a

blank F2.

  Posts 63 and 64 are substantially similar to posts 41

and 42 in the first machine 4.

  The blank storage and gripping station 63 comprises a magazine 630 of second blanks F2 above the intermediate plane and at the front of the machine 6. The magazine 630 is substantially a hollow parallelepiped having four vertical walls 631 in shape having internal width and length identical to those of an F2 blank. The magazine 630 contains a stack of flat blanks, precut and grooved in cardboard F2 which are arranged transversely to the direction of transport on the intermediate plane. In other words, the longitudinal panels 21 and 22 of each blank F2 are arranged at the front and at the rear in the direction of transport on the intermediate plane opposite to the direction of transport of the tray on the lower conveyor, and the transverse panels 23 and 24 and the extensions 211 and 221 of each blank F2 are parallel to the direction of transport on the intermediate plane. In the magazine 630, the stack of blanks F2 rests on small pins 632 at the internal periphery of the bottom of the magazine. The creasing lines 210 to 240 of the blank F2

- 27 -

  suitable for forming the internal corners of a cover are turned downwards. Below the magazine 630 are provided means for gripping the lower blank of the stack. The gripping means are in the form of suction cups 633, for example three in number, aligned on a carrying bar 634 disposed under the longitudinal axis of the magazine 630. The bar 634 constitutes a conduit connecting the suction cups 633 to pressure means and air depression. A 635 parallel rod cylinder moves

  vertically back and forth the bar 634.

  In response to the detection of a tray 1 in the reception area 610 by the photoelectric cell 616 in the entry station 61, the jack 635 raises the bar 634 from the intermediate transport plane. In the high position, the suction cups 633 attract by suction the lower blank F2 in the magazine 630. The jack 635 then lowers the lower blank gripped F2 towards the two longitudinal slides 636 with an L-shaped section. In the low position, the suction cups 633 release the blank captured F2. The panels 23 and 24 and the extensions 211 and 221 of the blank F2 rest on the horizontal sides of two L-shaped profiles forming longitudinal rails 636. The distance between the rails 636 is adjusted

  prior to the length of a blank F2.

  According to another variant, the second blank storage and gripping station 63 can be arranged so that the gripping means 633, 634 and 635 take the upper blank of a stack of blanks F2 from a sub-store next to

slides 636.

  After the installation of a blank F2 on the slides 636 by the suction cups 633, a pusher 637 coming from the gluing station 64 passes under the magazine 630 and above the suction cups 633 and the blank installed U2 and stops just at rear of store 630 relative to the intermediate transport direction. The pusher 637 is composed of a horizontal transverse plate above the slides 636 and at least two retractable stops 639 which are adjacent to the plate. The stops 639 are erased while the pusher 637 moves back on the blank F2 placed on the slides 636 and appear again when the pusher 637 is stopped at

- 28 -

  the rear of the magazine 630. A long rodless cylinder 638 is disposed along the left side of the intermediate transport plane and translates back and forth the pusher 637 between the rear of the magazine 630 and the front of the station. sizing 64 relative to the intermediate transport direction. The jack 638 is activated so that the stops 639 of the pusher 637 push the longitudinal edge of the panel 22 of the blank F2 towards the gluing station 64, when a tray 1

is present on tray 615.

  The gluing station 64 has four nozzles 641 to 644 projecting glue in a discontinuous manner under the blank F2. The glue can be of the same type as that used in the gluing station 42 of the first machine 4. The nozzles 641 to 644 are fixed to a stationary cross bar 645 below the slides 636. Two lateral nozzles 641 and 644 deposit two discontinuous glue lines 251 and 254 along the cross panel 23 and extensions 211 and 221 on either side of the panel 23 and along the cross panel 24 and extensions 211 and 221 on either side of the panel 24 respectively, as shown in FIG. 6. Two central nozzles 642 and 643 deposit under the panels 21 and 22 two discontinuous lines of glue 252 and 253 symmetrical with respect to the transverse axis of the blank F2. Glue ejections by nozzles 641 to 644 are triggered by magnetic sensors fixed on the rodless cylinder 638 and detecting the arrival of the longitudinal edge of the panel

  before 21 of the blank F2 in the gluing station 64.

  - After gluing by passing over the nozzles 641 to 644, the glued blank F2 is pushed by the retractable stops 639 of the pusher 637 to the other end portions of the slides 636, above the tray 615 supporting the tray 1. Then the pusher 637 returns to the rear of the magazine 630 after extraction of a new blank F2 from the magazine 630. At the end of the thrust of the blank F2, the creasing lines 210 to 240 of the central panel 20 of the blank F2 intended to form the upper wall of a cover 2 are exactly vertical to the sides 11 to 14 of the tray 1 on the tray 615 and also vertical to the four walls of a

  well 651 of a second matrix in station 65.

- 29 -

  In the lid forming and tray closing station 65, the lid stamping die is in the form of a vertical funnel with a substantially rectangular section composed at the bottom, by a gully 650 flared downwards and, in upper part, by the well 651. The downstream 650 has the shape of a horizontally truncated quadrangular pyramid having gradually chamfered edges, pointed downwards. The large horizontal base of the hood 650 has an internal rectangular section at least as large as the outline of the blank F2 and is substantially above the slides 636. The small horizontal base of the hood 650 has a rectangular internal section equal to the section of well 651, which has equal dimensions

  the dimensions of the horizontal outer section of a cover 2.

  The height of the drain 650 is of the order of 2 hours while the height of the well 651 is of the order of H. The walls of the drain

  views from the outside are noticeably concave.

  In the outlet station 66, the upper base of the well 651 is just below the upper transport plane defined by a horizontal plate 660 extending in the transverse direction beyond the plate 615, towards the outside of the machine 6 The outlet station 66 comprises means for extracting each tray 1 closed by a cover 2 from the tray 615 at the upper base of the well 651. The means for extracting the closed tray include a longitudinal pusher 661 fixed to the end of the rods of a horizontal transverse actuator 662. The actuator 662 is above the receiving zone 610. The pusher 661 is translatable back and forth by the actuator 662 above the upper base of the well 651 and, if necessary, above the plate

higher 660.

  The stamping process of the glued blank F2 left by the pusher 637 on the slides 636 above the tray 615 in the low position supporting the tray 1 containing a batch of

P products is as follows.

  The vertical jack 614 quickly lifts the tray 615 from the low position at the lower tray transport plane, as shown in FIG. 6. When the upper chants

- 30 -

  133 and 143 from sides 13 and 14 of the tray reach the intermediate plane of blank transport F2, the pins 132 and 142 penetrate substantially into the mortises 200 and 201 of the blank F2. The blank F2 is detached from the slides 636 and carried by the sides 13 and 14 of the tray. The blank F2 is set in volume by then mounting in the hood 650. The large transverse walls 6501, the small longitudinal walls 6502 and the chamfered edges 6503 of the hood 650 gradually fold the glued panels 21 and 22 vertically, the glued panels 23 and 24 and the glued extensions 211 and 221 to the corresponding sides 11 and 12, 13 and 14 of the tray 1. When the blank F2 enters the well 651, the large transverse walls 6510 and the small longitudinal walls 6511 of the wells press the panels 21 and 22 on the one hand, and the panels 23 and 24 and the extensions 211 and 221 on the other hand, against the sides 11 and 12, 13 and 14 of the tray 1 acting as a real punch in the matrix 65. The bonding of the cover 2 constituted by the blank F1 on the tray 1 is carried out in the well 651 by means of the glue lines 251 to 254. At the end of the upward stroke of the tray, the

* plate 615 is stopped coplanarly with the upper plate 660.

  The upper jack 662 is then activated so that the pusher 661 pushes the tray 1 completely closed by the cover 2 towards the plate 660, which releases the tray 615. The bottom of the tray 1 slides on the plate 660 until the end of stroke of pusher 662. At this instant, the tray 1 can be removed manually or by automatic means in order to stack it on a stack of trays full of products, or can be transported by another conveyor to other stations, such than a labeling station, a wrapping station or a packing station. The jacks 614 and 662 are then activated in the opposite direction to lower the plate 615 to the level of the lower tray transport plane and to pull the pusher 661 substantially set back from the well 651 in order to form another

  cover and close another tray.

  As shown in Figs. 13 and 14, the third machine 6 is particularly compact. However, according to others

- 31 -

  variants, the station 62 and the conveyor 60 can be omitted so that the conveyor 51 in the machine 5 extends the plate 615, either transversely or longitudinally. The stations 63 and 64 on the one hand, and the station 66 on the other hand can be arranged in another way relative to the entry station 61. A packaging chain 4-5-6 as described above can be provided for packaging products, for example of greater height, in other trays 1 'having bottom dimensions 10' identical to the dimensions L x ú of the bottom 10 of the trays 1 but having a height h 'of longitudinal sides 11 'and 12' and a height H 'of transverse sides 13' and 14 'greater than h and H respectively. The same covers 2 can be used to close the trays 1 ', by choosing a difference (H'-h') smaller than the height of the longitudinal sides 21 and 22 of the cover in order to allow them to be glued against the longitudinal ribs. it 'and 12' from the tray 1 '. In the Pigs. 8 and 9, it has been assumed that the first machine 4 forms two types of tray, although the

  number of types of tray is not limited to two.

  The selection of the forming of one of the trays 1 or 1 ′ is controlled automatically by means of a special button on the control console of the machine 4 at the end of a tray forming cycle. This selection of formats does not affect the

forming rate.

  Flat blanks, precut and grooved Fi 'having dimensions (L + 2H') x (at + 2h ') from which the second trays 1' are formed, are stacked in a second hollow parelepipedic store 410 'adjacent to the first store 410 , included in entrance station 41! The blanks Fl 'are also arranged longitudinally and have oriented crease lines

to the top.

  Means for transversely translating all of the magazines 410 and 410 ′ and means 46 for spreading and bringing together the parallel slides 416 are provided under the slides 416

  eiter the bar 414 and the gluing station 42.

- 32 -

  The means for translating the magazines are in the form of a transverse cylinder 450 arranged opposite the longitudinal cylinder 418 relative to the slides 416, having rods fixed under all the magazines 410 and 410 '. All of the magazines are moved by the cylinder 450 along two transverse guide axes 451 or of a transverse slide underlying all the magazines 410 and 410 ′ and above the slides.

  416, as shown in Figs. 8 and 9.

  The means 46 are shown diagrammatically in FIG. 15. They comprise a longitudinal cylinder 460 with a through rod 461, two pairs of parallel rods 462 and two guide pins 463 perpendicular to the slides 416 and below them. The cylinder 460 is disposed under the center of the rectangle formed by the axes 463 and the slides 416. The parallel rods of a pair have first ends articulated at the ends of the through rod 461 of the cylinder 460 and second ends articulated under the one of the slides 416. The slides 416 are

  mounted to slide transversely on the guide pins 463.

  When a tray 1 is to be formed from a blank F1, the tray 143 is above the slides 416, as shown in FIG. 9, and the rod 461 is at the end of the front stroke so that the rod 462 pulls the slides 416 at a minimum spacing corresponding to the width ú + 2h of a blank Fl. In this case, the actuation of the special button results by activating cylinders 450 and 460. Cylinder 450 transversely pushes all magazines 410 and 410 'so that magazine 410' is positioned above the slides 416 and focused on the bar 414 which is provided with four suction cups 413 to take a flan Fi '. The jack 460 pulls the rod 461 backwards and consequently the links parallel separate the slides 416 which slide along the guide pins 463 until the slides 416 are spaced apart by a maximum spacing corresponding to the width ú + 2h 'of a blank Fi', as shown in short dashed lines in FIG. 15. The lower blank Fi 'in the magazine 410' is then grasped by the suction cups 413, pushed by the pusher 417, glued in the station-42 and positioned above the matrix 432, as

- 33 -

  described above for a blank Fl. Respective magnetic sensors fixed on the rodless cylinder 418 at suitable positions control glue ejections only during the passage of the panels 10 ', 11' and 12 'of the blank FI' under the post gluing. Depending on the width of the blank Fi ', two additional lateral nozzles 420 and 425 are provided for depositing third

  glue lines on panels 11 'and 12'.

  When the machine 4 is designed to form trays 1 and 1 ', the forming operation in the station 43 is substantially different from that described above, mainly due to the length L3' of sheets of heat-shrinkable film 31 'and 32' to stick on the bottom of a tray 1 'larger than the length L3 of the sheets 31 and 32. The large base of the drain 4320 has width and length substantially equal to those (i + 2h') and (L + 2H ') of a large blank FI' and the heights of the outlet 4320 and of the well 4321 are chosen as a function of the height H 'of the large trays i' in order to stamp into the matrix 432 as well a

large flan FI 'than a small flan Fl.

  According to the embodiment illustrated in Figs. 8 and 10, the jacks 433 and 441 have a stroke equal to the length L3 of the sheets 31 and 32 for small tray 1. Knowing that the high position of the tray 440 is always the same regardless of the type of blanks to be stamped, the punch 431 must descend from a height equal to the longest length L3 'of film sheet. The supplement of

  stroke L3'-L3 of the punch is obtained by the auxiliary cylinder 434.

  Steps d) to g) of forming a tray 1 or 1 'are some

  little modified compared to those described previously.

  For forming a small tray 1 from a blank F1, the films 31 and 32 are cut before the actuation of the jack 434. When the jack 433 has lowered the punch 434 from a height L3 in the matrix 432, portions of the films 31 and 32 are attracted by the jaws 4360 in order to cut the films by the knives 4370. The aspirations in the elements 4311 and 4312 of the punch cease, the small jacks 4313 and 4314 are deactivated and the auxiliary jack 434 is activated to lower the punch from a height L3'-L3 against the support 440 o

- 34 -

  the tray 1 is gripped by the suction cups 442. Then the jacks 434 and 433 raise the punch 431 above the jaws 4360, the jack 441 descends the tray 440 with the tray 1, the driving cylinders 4353 are rotated, and the small cylinders 4313 and 4314 are activated again. For the forming of a large tray 1 'from a blank FI', the cutting of the films 31 and 32 occurs after the actuation of the jack 434. After the descent of the punch 431 from a height L3 in the die 432 by the jack 433, or during the activation of the jack 433, the auxiliary jack 434 is activated. The bottom 10 'of the tray 1' is pressed between the punch 431 and the support 440 at the end of the downward stroke L3 'of the jacks 433 and 434. The jaws 4360 grip the films 31 and 32' and the knives 4370 cut the movies. Then, the aspirations in the elements 4311 and 4312 of the punch cease, the small cylinders 4313 and 4314 are deactivated and the elements 4311 and 4312 are brought together by the springs 4315 and 4316, and the cylinder 441 descends the plate 440 supporting the tray 1 ' with glued sheets 31 'and 32' while the punch goes up. The rotation of the driving cylinders 4353 after the previous cut lasts longer after the formation of a small tray 1 ', in order to unwind the films 31 and 32 over a length L3'. Indeed, the descent of the punch 431 for the forming of the large tray 1 'has resulted in a longer film run, that is to say by lower positions of the cylinders 4356 and higher positions of the cylinders 4355. On the other hand, the concealment of the photoelectric cell 4354 by the counterweight 4359 of one of the muffle bars 4357 controls the stopping of the rotation of the driving cylinders 4353 whatever the type of tray formed. When the punch 431 is in the high position, the

  small cylinders 4313 and 4314 are activated again.

  Instead of the cylinders 433 and 434, a single cylinder with variable means for locking the rod can be used. Such a jack makes it possible to stop the punch 431 at an intermediate level, then at the low level against the plate 440, as a function of the length of film sheets required for the tray to be formed. The previous cylinder can be used when the entry station 42 includes many

- 35 -

  stores containing first blanks having different dimensions. According to other variants, when the different blanks F1, Fl 'have identical dimensions L = L' and H = Il ', which corresponds to film sheets having the same length L3 = L3', but have heights h and h 'of different longitudinal panels, the cylinder

  auxiliary 434 can be deleted.

  It will be noted that the second machine 5 is capable of sealing and heat shrinking pairs of film sheets in trays having different heights thanks to the height detections of

  tray by the series of photocells 522 and 532.

  The high position of the nozzles 521 and 531 corresponds to the height of the

higher trays.

  The station for storing and gripping cover blanks 63 in the third machine 6 can also contain other magazines 630 'to receive other cover blanks F2' having the same dimensions of central panel, as shown in FIGS. 13 and 14. Means for transversely translating all of the magazines 630 and 630 'similar to the means 450-451 and means for moving apart and bringing the parallel slides 636 similar to the means 46 are then provided under the slides 636. In this case , the dimensions of the second matrix 65 for forming the covers are determined as a function of the width and length of the

larger blanks F2 '.

  The packaging line is delivered with different cylinders and different elements constituting the dies, trays and plates as well as with the corresponding tools in order to adapt these organs according to the dimensions of the trays and lids to

  form and sheets of film to stick.

  Of course, the machines 3, 4 and 5 can be used separately or be included in a more complex packaging chain. Each of these three machines considered separately also falls within the subject of this patent application. Likewise, each of the positions included in the machines and considered separately

  falls within the subject of this patent application.

- 36 -

  Although the invention has been described according to preferred embodiments, a person skilled in the art can bring to it some

  modifications while remaining in the field of protection requested.

  The product or products contained in the container can be polyhedral blocks or any shape. The horizontal section of the receptacles and covers may be other than rectangular, for example prismatic or more generally polyhedral. The receptacle can be U-shaped, that is to say having only one bottom and two sides. In this case, the container without lid thus formed can be turned over and packed in

the cash register.

  The cover can be partially openable to form a display of products P protected by the film sheets and visible to consumers. Such a display will thus be advantageously used in the field of distribution to the general public. To this end, the central part 20 of the cover can be pre-perforated along a rectangle 202 and / or two crossed lines 203, as shown in FIGS. 2, 6 and 7, or according to strips in order to form one or more parts which can be pivoted upwards or

tear off.

  The material constituting the receptacle and / or the cover may be partially or totally based on cardboard, fibers such

  than molded cellulose, or plastic.

  Films 3 and 3 can be perforated, for example as

I 2

  a plastic net. The "external faces" of the portions of the sheets 31 and 32 above the lower end portions 310 and 320 can be glued to the internal walls of the extensions 131 and 141 of the tray, and if necessary, to the internal walls of the longitudinal sides 10 and 11; in this case, the nozzles 421, 422, 427 and 428 in the gluing station 42 also glue the extensions 131 and 141 and the panels 10 and 11 over their entire length. According to another variant, the "external faces" of the lower end portions 310, 320 of the sheets 31, 32 are glued only against the internal faces of the extensions 131 and 141 of the tray and, if necessary, to the internal walls of the sides.

- 37 -

  longitudinal 10 and 11, above the bottom 10. The gluing station 42 is modified as above but no longer has central nozzles 423 to 426. In the high position of the punch 431, the underside of the punch are then coplanar with those of the jaws 4360 which are brought together by means of the jacks 4361 against the elements 4311 and 4312 of the punch so that only the vertical suction faces of the latter grip the ends of the

  films 31 and 32 before the punch is lowered.

2558792 '

- 38 -

Claims (49)

R E V E N D I C A T I 0 N S   1 - Product packaging chain (P) to be placed in an open receptacle (1) having a bottom (10) and at least two first parallel sides (11, 12) and to be covered with two parallel sheets of film, preferably heat-shrinkable , (31, 32) partly glued symmetrically inside the receptacle (1), said receptacle (1) being obtained from a first flat blank, precut, grooved and glued (F1) having a central panel (10 ) and two first parallel panels (11, 12) to respectively form said bottom and said first sides of the receptacle by means of a movable punch (431) having dimensions substantially identical to the internal dimensions (Q, L) of the receptacle (1) , characterized in that the punch (431) comprises first means (4311, 4312) for taking first end portions (310, 320) of said two sheets of film (31, 32) above the central panel (10) of the first flat blank (F1) and to release said first extreme portions (310, 320) of the sheets after they have been bonded inside the receptacle (1), and in that the packaging line comprises a forming die (432) having a cross section greater than at least equal to the cross section of the first flat blank (F1) below the punch (431) to receive the first glued flat blank (F1) and a lower section substantially equal to the outer section of the receptacle (1), and means (433) for descending into the matrix (432 ) the punch (431) taking the first end portions (310, 320) of the film sheets (31, 32) in order to simultaneously stick said first portions of film sheets against the flat blank (F1) and inside the receptacle (1) and stamp the flat blank into the receptacle and to raise the punch (431) above the upper section of the die (432) after loosening of said   first portions (310, 320) of the film sheets (31, 32).   2 - Packaging line according to claim 1, characterized in that the first means (4311, 4312) for taking and releasing said first portions (310, 320) of the two sheets of film (31, 32) comprise first orifices ( 4317) - 39 -   formed in two opposite faces of the punch (431) perpendicular to the flat blank (FI) to suck said first portions (310, 320) of the film sheets during the descent of the   punch (431) in the die (432).   3 - packaging line according to claim 1 or 2, characterized in that the first means (4311, 4312) for taking and releasing said first portions (310, 320) of the two sheets of film (31, 32) comprise second orifices (4318) formed in a face underlying the punch (431), parallel to the flat blank fFl) for sucking said first portions (310, 320) of. sheets of film during the lowering of the punch (431) in the matrix (432).   4 - Cha -ae of conditioning conforms to one of the   claims 2 or 3, characterized in that the punch (431)   comprises two symmetrical lateral elements (4311, 4312) parallel to said first sides (11, 12) of the receptacle (1) and to said sheets of film (31, 32) including said suction orifices (4317, 4318) t, t means (4313, 4314, 4315, 4316) to vary the distance between the lateral elements of the punch so that the lateral elements (4311, 4312) descend into the die (432) with a maximum deviation equal to the distance (g) between the first sides (11il, 12) of the receptacle (1) and rise in the matrix (432) with a minimum spacing less than the distance (M) between the first sides (11, 12) of the receptacle.   5 - Packaging chalne according to claim 4, characterized in that the means for varying the spacing of the lateral elements (4311, 4312) of the punch (431) comprise jacks (4313, 4314) to obtain the maximum spacing and of   return springs (4315, 4316) to obtain the minimum spacing.   6 - Packaging chain in accordance with any one of   Claims I to 5, characterized in that the matrix (432)   comprises a truncated pyramidal upper part (4320) having:. ectinca greater at least equal to the section of the first flat blank (F1) and a lower part in the form of a well (4321) having 3 internal dimensions substantially identical to the dimensions external of the receptacle (1). - 40 -   7 - Packaging chain according to claim 6, for which the first flat blank (F1) comprises two second parallel panels (13, 14) to form two second parallel sides of the receptacle (1), characterized in that the upper part ( 4320) of the matrix (432) comprises first and second sides (4323; 4322) for respectively folding the first and second panels (11, 12; 13, 14) from the blank (F1) towards the central panel (10) during the lowering the punch (431) into the matrix (432).   8 - Packaging line according to claim 7, for which the height (h) of the first sides (11, 12) of the receptacle (1) is less than the height (H) of the second sides (13, 14) of the receptacle, characterized in that the first sides (4323) of the upper part (4320) of the matrix (432) extend from the well (4321) over a height less than the height of the second sides (4322) of the upper part (4320) from the matrix (432).   9 - packaging line according to claim 7 or 8, for which the first blank (F1) has foldable extensions (131, 141) extending the second panels (13, 14) to form corners of the receptacle (1), characterized in that the upper part (4320) of the matrix (432) has chamfered edges (4324) extending from the upper section of the matrix and converging towards the well (4321) of the matrix to fold down the extensions ( 131, 141) from the blank (F1) towards the central panel (10) and the interior of the receptacle (1) during the descent   of the punch (431) in the matrix (432).   - Packaging line conforming to one of the   Claims 1 to 9, characterized in that it includes   and on the other side of the punch (431) means (4351 4352) for unwinding two films (31, 32)? preferably heat shrinkable, second means (4361, 4362) above the matrix (432) for taking and releasing portions of the unwound films, and means (437) above the matrix (432) for cutting the two   films (31, 32) in the two sheets (31, 32). - 41 -   11 - Packaging line according to claim 10, characterized in that the second means for taking and releasing the films (4361, 4362) comprise two jaws (4360) on either side of the punch (431) having orifices d suction (4362) opposite the punch (431) and means (4361) for translating the jaws (4360) back and forth above the upper section of the die (432), said jaws sucking portions unwinding of the films (31 32) when the punch (431) is at the lower section of the die (432) and during the cutting of the films and the raising of the punch, and said jaws releasing and transferring cut end portions 310, 320 films (31, 3 2) against the first means to take and release (4311, 4312) when the punch (431) is   above the upper section of the die (432).   12 - Packaging line according to claims 2   and 11, characterized in that the jaws (4360) are brought together against said opposite faces of the punch (431) to press the end portions (310, 320) of the films (31 32) which are sucked through the first orifices (4317) of the punch, then down with the punch (431) into the die (432) to be   glued to the first sides (11, 12) of the receptacle (1).   13 - Packaging line according to claims 3   and 11, characterized in that the jaws (4360) are brought together under the underlying face of the punch (431) to fold the end portions (310, 320) of the films (31, 32) which are sucked in by at least the second holes (4318) of the punch, then lowered with the punch (431) into the die (432) to be glued to the bottom   (10) and / or at the first sides (11, 12) of the receptacle (1).   14 - Packaging line in accordance with any one of   claims 10 to 13, characterized in that the means for   cutting the two films (437) comprise two knives (4370) and means (4371) for translating the knives (4370) back and forth along the second means for taking and releasing (4361, 4362), under the latter and substantially above the first sides (11, 12) of the receptacle (1) when the punch (431) is substantially at the level of the lower section of the die (432), in order to cut - 42 -   the films (31, 32) and obtain the two sheets of film (31, 32).   - Packaging line according to claims 4   and 14, characterized in that the knives (4370) are moved back and forth when the spacing of the lateral elements (4311,   4312) of the punch (431) is maximum.   16 - Packaging line in accordance with any one of   claims 10 to 15, characterized in that the means for   unwinding the two films (4351, 4352) comprise successively for each film (31 32); a film feed roller (4350) rotating on itself, rotating motor means (4353) for unwinding the film from the feed roller over a length (L3) of film sheet (31, 32) after cutting the film, and means (4357) for stretching the film continuously between the driving means (4353) and the means (4311, 4312; 4361, 4362) for taking and releasing portions (310, 320) of the film ( 31 32). 17 - Packaging line according to claim 16, characterized in that the means for stretching the film comprise a pivoting bar (4357) having ends supporting idler cylinders (4355, 4356) between which the film (31 32) passes, and a counterweight (4359), the bar (4357) pivoting under the pulling effect exerted on an extreme portion (310, 320) of the film (31, 32) by the first means to take and release (4311, 4312) when the punch (431) descends into the die (432), and pivoting in the opposite direction under the effect of gravity exerted by the counterweight (4359) when the driving means (4353) unroll the film after the film has been cut and the the extreme cut portion of the film by the second means for taking and release (4361, 4362).   18 - Packaging line according to claim 17, characterized in that the stopping of the motor means (4353) for unwinding the film is triggered by occultation of a photoelectric cell (4354) by an arm of the bar (4357) supporting the flyweight (4359). - 43 -   19 - Packaging line in accordance with any one of   Claims 1 to 18, characterized in that it comprises   means (41) for transferring a first flat blank (F1) from a stack of such blanks (410) above the upper section of the die (432) and below the punch (431). - Packaging chain according to claim 19, characterized in that the means for transferring a first flat blank (41) comprise a magazine (410) containing the stack of the first flat blanks (F1), means (413, 414, 415 ) to take a flat blank from the store stack, and means (416 to 419) for transporting the flat blank taken to the upper section of the   die (432) and below the punch (431).   21 - packaging line according to claim 20, characterized in that the means (413, 414, 415) for taking a flat blank from the stack in the store are underlying or overlying the store (410) and comprise suction cups (413) translatable back and forth perpendicular to the blank transport direction to attract the upper or lower blank (F1) of the stack and to deposit it on two parallel slides (416) preferably spaced apart from the width (L + 2h) of the first blanks (FI). 22 - Packaging line according to claim 20 or 21, characterized in that the lower internal periphery of the magazine (410) comprises pins (412) on which rest the stack of first blanks * F1) and which are crossed by edges of the bottom blank (FI) of the stack when taken by said means   to take a blank (413, 414, 415).   23 - Packaging line conforming to any one of the   claims 20 to 22, characterized in that the means for   transport the taken flat blank (416 to 419) comprise two parallel guide rails (416) preferably spaced from the width (9, + 2h) of the first blanks (F1) to receive the blank deposited by the means for taking a blank ( 413, 414, 415), a pusher (417), and means (418) for translating the pusher (417) back and forth between the slides to slide the received blank (F1) onto - 44 -   the slides (416) from the magazine (410) to the section   upper part of the die (432) and below the punch (431).   24 - Packaging chain according to claim 23, characterized in that the pusher (417) supports retractable stops (419) which are retracted when the pusher crosses   the blank (F1) deposited on the slides (416).   - Packaging line in accordance with any one of   claims 19 to 24, characterized in that the means for   transferring a first flat blank include two parallel slides (416) for sliding guide the first blank (F1) to the upper section of the die (432) and means (46) for varying the spacing of the slides (416) preferably to the   width (Q + 2h) of the first blanks (F1).   26 - Packaging chain according to claim 25, characterized in that the means (46) for varying the spacing of the slides comprise a jack (460) parallel to the slides (416) having a through rod (461), at least two rods (462) each articulated at one end of the through rod (461) and at one of the slides (416) and two axes (463) which are perpendicular to the slides and along which slide the slides (416).   27 - Packaging line according to claim 25 or 26, characterized in that it comprises several magazines (410, 410 ') containing stacks of different first blanks (F1, Fl') but having identical central panels (10, 10 '), and means (450, 451) for transferring one of the magazines (410, 410') above or below the slides (416), simultaneously with the variation of the spacing of the slides (416 ) in preference to   width of the first blanks contained in the transferred store.   28 - Packaging line according to claims 7   and 27, characterized in that the heights (h; h ') of the first panels (11, 12; 11', 12 ') of the different blanks (F1; Fi') are different and the heights (H; H ') of the second panels (13, 14; 13 ', 14') of the different blanks (F1, Fi ') are equal and in that the upper section of the matrix (432) has dimensions; 8792 - 45 -   substantially equal to those (L + 2H ', ú + 2h') of the largest first blanks (FI ').   29 - Packaging line according to claims 7,   and 27, characterized in that the heights (h; h ') of the first panels (11, 12; 11', 12 ') and the heights (H, H') of the second panels (13, 14; 13 ', 14 ') different blanks (F1, F1') are different, in that the sheets of film (31, 32; 31 ', 32') to be glued on the different blanks (F1, FP ') have different lengths (L3 , L3 '), in that the upper section of the matrix (432) has dimensions substantially equal to those (L + 2H', ú + 2h ') of the largest blanks (FI'), in that for each blank (F1; F1 ') to be stamped in the die (432), the punch (431) automatically descends in the die (432) first by a height (L3; L3') equal to the length of the sheets of film to be stick to the corresponding receptacle (1, 1 '), the films (31; 32) then being cut and then unwound over the length of the sheets, then the punch (431) descends, if necessary, to a lower level which is the same for all receptacles and which preferably corresponds to a total descent height equal to the length   (L3 ') of the longest sheets of film (31', 32 ').   - Packaging chain conforming to any one of the   Claims 19 to 29, characterized in that it comprises   means (42) above the transfer plane (416) of the first blanks (F1), between the stack (410) of the blanks (F1) and the upper section of the matrix (432), for gluing the grooved face from above of first blank transferred (F1).   31 - Packaging line according to claim 30, characterized in that the means for gluing (42) comprise at least two nozzles (422, 423) for depositing at least two lines of glue (152, 153) preferably discontinuous on the central panel (10) of the transferred blank (F1), intended to glue the first end portions (310, 320) of the film sheets (31, 32) on the   bottom of the receptacle (1) formed from said blank.   32 - Packaging line according to claim 30 or 31, characterized in that the means for gluing (42) comprise at least two nozzles (421, 424) for depositing at least - 46 -   two lines of glue (151, 154) preferably discontinuous on the first panels (11, 12) of the transferred blank (F1), intended to glue the first end portions (310, 320) of the film sheets (31, 32) against the internal faces of the first sides (11, 12) of the receptacle (1) formed from said blank. 33 - Packaging line according to claim 9   and to any one of claims 30 to 32, characterized in   that the means for gluing (42) comprise at least two nozzles (421, 424) for depositing at least two lines of glue (151, 154) preferably discontinuous on the first panels (11, 12) of the transferred blank (F1) , intended to glue said foldable extensions (131, 141) against the internal faces of the first sides   (11, 12) of the receptacle (1) formed from said blank.   34 - Packaging line conforming to any of the   Claims 1 to 33, characterized in that it comprises   means (441) for mounting a plate (440) substantially up to the lower section of the matrix (432) in order to press with the punch (431) the bottom (10) of the receptacle (1), and for lowering the plate ( 440) supporting the receptacle (1) with the sheets of   glued film (31, 32) to a lower transport plane (445).   - Packaging chain according to claim 33, characterized in that the plate (440) comprises suction cups (440) for pressing the bottom (10) of the receptacle (1) on the plate during his descent.   36 - Packaging chain according to claim 34 or 35, characterized in that it comprises a pusher (443) and means (444) for translating the pusher (443) back and forth to push the receptacle (1 ) on the plate (440) preferably towards a transporter (445).   37 - Packaging line in accordance with any one of   Claims 1 to 36, comprising a second transporter (51) of   receptacles (1) containing each of the products (P) covered by two sheets of heat-shrinkable film (31, 32) having upper end portions (311, 321) overlapping above the products, means (521) above the second conveyor for preferably thermally sealing the end portions - 47 -   upper sheets and means (531) above the second conveyor to heat-shrink the sealed sheets against the products, characterized in that it comprises for each of the means for sealing (521) and for heat shrinking (531), the first means (523, 533) for detecting the arrival of each receptacle (1) on the second conveyor (51) at the level of the means for sealing and heat-shrinking respectively, means (520, 530) for lowering and mounting said means for sealing and heat shrink respectively, and means (522, 532) preceding said means for sealing and heat shrink for detecting the height of each receptacle (1) on the second conveyor (51) so that the means for descending and ascending descend and ascending said means for sealing or heat shrink substantially above the receptacle (1) as soon as the first means for detecting (523, 533) detect the receptacle (1) under the means for sealing or heat shrinking respectively. ement   38 - Packaging cable according to claims 27   and 37, characterized in that the first means for detecting (523, 533) and the second means for detecting (522, 532) each comprise means for sealing (521) and for heat shrinking (531), a first photoelectric cell ( 523, 533) and second photocells (522, 532), and in that the simultaneous concealment of the first and second cells control the positioning of the means for sealing and for shrinking at a high position substantially greater than the height ( H ') of the highest receptacles (1') relative to the second conveyor (51), and the concealment of the first cell alone controls the positioning of the means for sealing and for heat shrinking at a low position substantially greater than the height (11 ) of the receptacle (1) detected relative to the second transporter (51).   39 - Packaging line in accordance with any one of   claims 1 to 38, wherein each open receptacle (I)   formed from a first blank (F1) is to be closed by a cover (2) obtained from a second flat blank, precut, grooved and glued (F2) having a central panel (20) and two first - 48 -   parallel panels (21, 22) to respectively form an upper wall of the cover to be placed on upper edges of the receptacle (1) and two first parallel sides of the cover to be bonded against the first sides (11, 12) of the receptacle (1), characterized in that it comprises a second forming die (65) having a lower section at least equal to the section of the second flat blank (F2) and an upper section substantially equal to the outer section of the cover (2), means intermediates (63) for transporting the second glued flat blank (F2) under the lower section of the second die (65), and means (614) for raising and lowering a second plate (615) between on the one hand a plane of reception of open receptacle (610, 60) lower than the intermediate means for transporting (63) and on the other hand, the upper section of the second die (65), the receptacle (1) playing the role of a punch supported by the second stage (615) and amount in the second mast rice (65) for supporting the central panel (20) of the second blank (F2) and for simultaneously pressing the second blank (F2) into the cover (2) and gluing said first panels (21, 22) of the second blank (F2) against said first sides (11, 12) of the receptacle (1).   - Packaging line according to claim 39, characterized in that the second matrix (65) comprises a lower part (650) truncated pyramid having a lower section at least equal to the section of the second flat blank (F2) and an upper part in the form of a well (651) having dimensions   substantially identical to the external dimensions of the cover (2).   41 - Packaging line according to claim 40, characterized in that the second flat blank (F2) comprises two second parallel panels (23, 24) to form two second sides of the cover (2) to be bonded against two second parallel sides ( 13, 14) of the receptacle (1) and in that the lower part (650) of the second matrix (65) comprises first and second sides (6501, 6502) for retracting the first and second panels (21, 22; 23 respectively) , 24) of the second blank (F2) against the first and second sides (11, 12; 13, 14) of the receptacle during the rise of the - 49 -   second plate (615) supporting the receptacle (1) in the second matrix (65).   42 - Packaging cable according to claim 40 or 41, characterized in that the second flat blank (F2) has foldable extensions (211, 221) extending the first panels (21, 22) of the second blank, to be bonded against two second parallel sides (13, 14) of the receptacle (1) and in that the lower part (650) of the second die (65) has chamfered edges (6503) extending from the lower section of the second die and converging towards the well (651) to fold the extensions (211, 221) of the second blank (F2) against the second sides (13, 14) of the receptacle during the rise of the second plate   (615) supporting the receptacle (1) in the second matrix (65).   43 - Packaging cable conforming to any one of the   claims 39 to 42, characterized in that the means   intermediates for transporting the second flat blank include means (63) for transferring the second flat blank (F2) from a stack of such blanks (630) to the bottom of the lower section of the second matrix (65).   44 - Packaging line according to claim 43, characterized in that the means for transferring a first blank (63) comprise a magazine (630) containing the stack of second flat blanks (F2) having grooved faces oriented downwards, means (633, 634, 635) for taking a second flat plane in the stack of the magazine, and means (636 to 639) for transporting the second flat blank taken to the lower section of the second die (65), below of the latter and above the receptacle (1)   supported by the second plate (615).   - A packaging line according to claim 44, characterized in that the means (633, 634, 635) for taking a second blank from the stack in the store are underlying or overlying the store (630) and include suction cups (633)   translatable back and forth perpendicular to the direction of.   intermediate means of transport to attract the lower or upper blank (F2) of the stack and to deposit it on two slides - 50 -   parallel (636) preferably spaced from the length of the second blanks (F2).   46 - Packaging chain according to claim 44 or 45, characterized in that the lower internal periphery of the magazine (630) comprises pins (632) on which rest the stack of second blanks (F2) and which are crossed by edges of the lower blank (F2) of the stack when it is taken up by said means   to take a second blank (633, 634, 635).   47 - Packaging line in accordance with any one of   claims 44 to 46, characterized in that the means for   transport the second blank taken (636 to 639) comprise two parallel guide rails (636) preferably spaced apart from the length of the second blanks (F2) to receive the blank deposited by the means for taking a second blank (633, 634, 635) , a pusher (637), and means (638) for translating the pusher (637) back and forth between the slides to slide the received blank (F2) onto the slides (636) from the magazine (630) towards the lower section of the second matrix (432), below it and   above the receptacle (1) supported by the second plate (615).   48 - Packaging chain according to claim 47, characterized in that the pusher (637) supports retractable stops (639) which are retracted when the pusher crosses   the blank (F2) deposited on the slides (636).   49 - Packaging line in accordance with any one of   Claims 43 to 48, characterized in that the means   for transferring a second blank (63) comprise two parallel slides (636) for sliding guide the second blank (F2) towards the lower section of the second die (65) and means for varying the spacing of the slides (636) from preference to length of the second blanks (F2).   - Packaging chalne according to claim 49, characterized in that it comprises several magazines (630, 630 ') containing stacks of second blanks (F2, F2') different but having identical central panels (20, 20 ') , and means for transferring one of the magazines (630, 630 ') above or below the slides (636), simultaneously with the variation of the spacing - 51 -   slides (636) preferably at the length of the second blanks   contained in the transferred store.   51 - Packaging line according to claim 50, characterized in that the lower section of the second die (65) has dimensions substantially equal to those of the largest second flat blanks (F2 ').   52 - Packaging chalne conforming to any one of the   claims 39 to 51, characterized in that it comprises   second means (64) below the intermediate means for transporting the second blank (63, 636) for gluing the grooved face   from below the second transported blank (F2).   53 - packaging chain according to claim 50, characterized in that the second means for gluing (64) comprise at least two nozzles (642, 643) for depositing at least two lines of glue (252, 253) preferably discontinuous under the first panels (21, 22) of the second blank (F2), intended to bond the first sides (21, 22) of the cover (2) formed from the second blank against the external faces of the first sides (11, 12) of the receptacle (1).   54 - Packaging chalne according to claim 41   and one of claims 52 and 53, characterized in that the   second means for gluing (64) comprise at least two nozzles (641, 644) for depositing at least two lines of glue (251, 254) preferably discontinuous under the second panels (23, 24) of the second blank (F2), intended gluing the second sides (23, 24) of the cover (2) formed from the second blank against the faces   external of the second sides (13, 14) of the receptacle (1).   - Packaging line according to claim 42   and any one of claims 52 to 54, characterized in   that the second means for gluing (64) comprise at least two nozzles (641, 644) for depositing at least two lines of glue (251, 254) preferably discontinuous under the extensions (211, 221) of the second blank (F2) , intended to bond said extensions against the external faces of the second sides (13, 14) of the receptacle (1). - 52 -   56 - Packaging line conforming to any one of   claims 39 to 55, characterized in that it comprises   means (60, 613) for pushing an open receptacle (1) from   of said reception plane (610, 60) on the second plate (615).   57 - A packaging chain according to claim 56, characterized in that said open receptacle receiving plane and the means for pushing consist of a transporter (60).   58 - Packaging chain according to claim 56, characterized in that said open receptacle receiving plane is constituted by a front zone (610) and a conveyor (60) and in that said means for pushing comprise a pusher (613) translatable back and forth to push an open receptacle (1)   of the front zone (610) on the second plate (615).   59 - Packaging line according to claim 58, characterized in that the conveyor (60) has a direction of   transport perpendicular to the translation of the pusher (613).   - Packaging chain according to claim 59, characterized in that the pusher (613) is provided with a rear plate (618) perpendicular to the direction of transport of the conveyor (60) for retaining receptacles (1) waiting on the transporter (60).   61 - Packaging chalne conforming to one of the   claims 57 to 60, characterized in that it comprises   means (62) above the conveyor (60) for turning 90 each open receptacle (1).   62 - Packaging box conforming to any one of the   claims 39 to 61, characterized in that it comprises a   third pusher (661) and means (662) for translating the third pusher (661) back and forth above the level of the upper section of the second die (65) to push each receptacle (1) closed by a cover (2) from the second   tray (615) on a plate (660) and / or on a conveyor.   63 - Packaging line in accordance with any one of   claims 39 to 62, characterized in that the central panel   (20) of each second blank (F2) is pre-perforated so that the - 53 -   cover (2) formed from the second blank and closing a receptacle (1) has a part (221, 22; or 21, 22, 23, 24, 211, 221) fixed to the receptacle (1) and another part (20 , 21, 23, 24, 211; or 202, 203) detachable from the receptacle (1) or from the central panel (20) of the cover (2).