EP0151364A2 - Packaging line for products with a film in a receptacle formed from a flat pre-cut blank - Google Patents

Abstract

The packaging line comprises a machine (4) for forming an open receptacle (1) from a grooved blank (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) over slideways (416), glued under nozzles (42) and positioned above a die (432) and below a deep-drawing punch (431). Suction jaws (4360) hold the ends of two films against suction faces (4311) of the punch. In the bottom position of the punch in the die, the films are cut by translatable cutters (4370) to obtain the sheets and are then unwound during the upward movement of the punch. The line also comprises means for sealing and thermally retracting the sheets above the products contained in the receptacle, and for covering the receptacle with a lid obtained from a grooved blank which is glued in a deep-drawn manner in a die in which the receptacle rises as a punch. <IMAGE>

Description

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 heat-shrinkable film contained in the receptacle.

The products thus conditioned and overwrapped can be boxes, flasks, documents or all grouped objects, or all products preconditioned or not, grouped or put individually in the receptacle. When several products are packaged in the same container, the batch of products can be homogeneous 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 means for forming the receptacle and means for gluing the sheets of film in 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 the shrinkable plastic film against the pre-glued bottom portion of the blank, possibly brought 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 disclose means for the implementation of this method.

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 object of the invention is 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 throughput very high.

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 end portions of said two sheets of film above the central panel of the first flat blank and for releasing said first end portions of the sheets after bonding of these inside the receptacle, and in that the packaging line 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 section external of the receptacle, and means for lowering into 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 for raising the punch above the upper 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 matrix, to unwind the films after cutting and to extract the receptacle formed from 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 having different heights in particular.

According to another aspect of the invention, the packaging line also comprises means which can be adapted as a function of the height of the receptacles to preferably heat seal and heat shrink the sheets of film above the products in the receptacles, but also means for close each receptacle with a cover formed from a second flat blank, precut, grooved and glued.

The means for closing each receptacle are also designed to impart a very high flow rate to the packaging line. 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 acting as a punch supported by the second plate and rising in the second die to support the central panel of the second blank and simultaneously stamp the second blank in the cover and glue said first panels of the second blank against said first sides of the receptacle.

• - la Fig. 1 est une vue de dessus d'un premier flan plat, prédécoupé et rainé pour former un réceptacle analogue à une barquette selon l'invention ;
• - la Fig. 2 est une vue de dessus d'un second flan plat, prédécoupé et rainé pour former un couvercle propre à fermer la barquette ;
• - la Fig. 3 est une vue de dessus en perspective du premier flan plat encollé ;
• - la Fig. 4 est une vue de dessus en perspective du premier flan encollé en cours de pliage et de collage à deux feuilles de film thermorétractable dans un avaloir d'une première matrice de formage de barquette ;
• - la Fig. 5 est une vue de dessus en perspective de la barquette formée prête à recevoir un lot de produits ;
• - la Fig. 6 est une vue de dessus en perspective de la barquette contenant un lot de produits entouré par des feuilles de film thermoscellées et thermorétractées, et du second flan plat encollé positionné au-dessus de la barquette et au-dessous d'une seconde matrice de formage de couvercle ;
• - la Fig. 7 est une vue en perspective de barquette fermée par le couvercle formé à partir du second flan plat encollé ;
• - les Figs. 8, 9 et 10 sont respectivement des vues schématiques longitudinale de côté, de dessus et de face avant d'une première machine d'une chaîne de conditionnement destinée à former en continu des barquettes et à coller deux feuilles de film thermorétractable à l'intérieur de la barquette ;
• - les Figs. 11 et 12 sont des vues schématiques longitudinale de côté et de face avant d'une seconde machine de la chaîne de conditionnement destinée à thermosceller et à thermorétracter en contnu les feuilles autour des lots de produits dans les barquettes ;
• - les Figs. 13 et 14 sont des vues schématiques de dessus et longitudinale de côté d'une troisième machine de la chaîne de conditionnement destinée à former en continu des couvercles et à fermer simultanément les barquettes par les couvercles ; et
• - la Fig. 15 est une vue schématique de dessus de moyens pour modifier l'écartement de deux glissières pour le transport de premiers flans plats ayant des dimensions différentes dans la première machine.

Other advantages and characteristics of the present invention will appear more clearly on reading the description with reference to the corresponding appended 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 perspective view from above of the formed tray ready 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-shrinked film, and of the second glued flat blank positioned above the tray and below a second forming die cover;
• - 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 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 ℓ 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 the bottom 10 in the longitudinal direction 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 made in the top face of the panel 10 in order to allow the upward folding of the panels 13 and 14. The longitudinal panels Il and 12 have a length L greater than the width ℓ of the transverse 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 a 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 FI, five panels, namely a central panel rectangular 20, two longitudinal rectangular panels 21 and 22 and two transverse panels in isosceles trapezoid 23 and 24, as well as four lateral portions called 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 tenons 132, 142 and mortises 200, 201 are eliminated.

As shown in Figs. 6 and 7, the height H of the transverse sides 13 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 words, 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 He and 12 from the tray. Such bonding prevents the passage of fingers between the tray and lid to steal 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 + ℓ) on 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 mono-oriented 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 leaves are thus fully 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 sized 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 extreme 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 1 containing the batch of products is transported to a third machine 6 in which the second pre-cut blank F2 is glued and the tray 1 is closed by the cover 2 simultaneously with the forming of the blank F2 in the 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 for 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 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 the posts 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 a output station 44 the trays formed in the 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 sheet metal walls 411. It receives a stack of flat blanks precut in cardboard F1 arranged longitudinally and horizontally and having crease lines oriented upwards. The stack of FI blanks 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 FI whose longitudinal edges 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 ℓ + 2h of a blank Fl.

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 pusher 417 is translatable back and forth between the slides under the action of a long cylinder without rod 418. The cylinder 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 FI 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 pusher 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 F1 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, 11 and 12 of the blank F1 under the gluing station. The glue ejections are preferably discontinuous in order to glue the grooved top side of the blank F1 by discontinuous glue lines 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 adhesive can be of the hot-melt adhesive type having an almost instantaneous setting time of the order of a few seconds or of the so-called wet liquid type. The nozzles are 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 II. 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 lines of discontinuous longitudinal glue 152, 153 over the entire length L of the panel central 10 of the F1 blank. 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 bond 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 matrix 432 in the station 43.

According to another variant, the stations 41 and 42 are arranged transversely, that is to say the direction of transport of the blank FI is parallel to the transverse panels 13 and 14 of the blank F1. In this case, two slides, such as 416, are spaced by L + 2H.

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 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 transverse traction springs 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 the lateral elements 4311 and 4312 of the 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 about ten millimeters less than the width 1 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 omitted and the vertical guiding of the punch is carried out by the jack 433. For the moment, the use of the auxiliary cylinder 434 is disregarded.

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 truncated quadrangular inverted pyramid, horizontally having chamfered edges pointed 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 drains extend between the slides 416 to the well 4321 while the longitudinal walls 4323 of the drains are less high and extend upwards from the well 4321 over a height substantially less than 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 includes means for taking and sticking two heat-shrinkable films 3 ₁ , 3 ₂ 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 435 and 435 ₂ . Each unwinding device 435 ₁ and 435 ₂ comprises, at the bottom, idle rolls for feeding film 4351, at the top, film drive means 4353 and film tensioning means 4354 to 4359, as well as idler intermediate cylinders 4352. The cylinders are horizontal and arranged laterally to the punch 431 and to the die 432. The direction of unwinding of mono-oriented films 3 ₁ and 3 ₂ is parallel to the direction of retraction of the films. A roll 4350 of heat-shrinkable film 3 ₁ , 3 ₂ rests by turning about its axis on two supply rolls 4351 at the level of the slides 416. The film 3 ₁ , 3 ₂ passes between the supply rolls and bypasses intermediate rolls 4352 to go up substantially vertically to the driving means 4353 substantially at the level of the jack 433. The driving means 4353 comprise a driving cylinder and an idle pressing cylinder between which the film 3 is clamped. The driving cylinder is rotated by a motor to unroll the film after cutting the corresponding sheet 31, 32 over a length L3 of sheet. The film 3 ₁ , 3 ₂ in each unwinding device 435 ₁ , 425 ₂ then passes over an upper intermediate cylinder 4352 at a level above the jack 433, below a first idler tension cylinder 4355 and above a second idler tensioner cylinder 4356, and descends vertically to below the punch 431 in the high position to be taken up by associated film gripping means 436 ₁ , 436 ₂ . The film tensioning means consist of a muffle. The 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 3 ₁ , 3 ₂ and supports at its ends the axes of the tension rolls 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 tends the film 3 ₁ , 3 ₂ between the engine cylinder 4353 and the associated film gripping means 436 ₁ , 43 ⁶ ₂ .

The film gripping means 436 ₁ and 436 ₂ associated with the unwinding devices 435 ₁ , and 435 ₂ 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 the high position, and below the second tensioning cylinders 4356.

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 to the width of the lateral elements 4311 and 4312 of the punch.

The vertical faces opposite the two jaws 4360 of the gripping means 436 ₁ , 436 ₂ , 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 3 ₁ and 3 ₂ coming from the unwinding devices -435 ₁ and 435 ₂ against the facing 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 pulled up and down respectively. The driving cylinders 4353 then unroll the films 3 ₁ and 3 ₂ 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 counterweights 4359, and consequently the descent of the cylinders 4355 and the rise 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 3 ₁ , and 3 ₂ 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 3 ₁ and 3 ₂ under the punch. The longitudinal bottom faces of the lateral elements 4311 and 4312 also include orifices 4318 which make it possible to aspirate said ends of the films 3 ₁ and 3 ₂ folded horizontally by the advance of the jaws 4360, intended to form the lower portions 310 and 320 of the sheets 31 and 32 cut later.

The central station comprises means 437 for cutting the films 3 ₁ and 3 _{2 in} order to obtain two sheets 31 and 32 when a tray 1 has just been formed in the well of the die 432. The means 437 for cutting the films comprise two knives 4370 fixed to 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 with respect to the upper longitudinal axis of transport of the blanks FI. The spacing of the knives 4370 is substantially equal to the width ℓ 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 3 ₁ and 32 after forming a tray in the well 4321 of the matrix.

• a) Au début du cycle de formation, le poussoir 417 est à l'avant des glissières 416, et les ventouses 413 dans le poste d'entrée 41 sont en position basse sous le flan inférieur en carton F1 dans la pile du magasin 410. Le poinçon 431 est en position haute. Les éléments latéraux 4311 et 4312 du poinçon sont maintenus à l'écartement minimum par les petits ressorts 4315 et 4316 et les petits vérins 4313 et 4314 sont désactivés. Les mâchoires 4360 sont écartées au maximum et aspirent par leurs orifices 4362 les "faces externes" des portions d'extrémité des films 3₁ et 3₂.
• b) La barre 414 avec les ventouses 413 est élevée par le vérin 415. Le flan inférieur F1 adhère par effet de succion sur les ventouses 413. Puis, sous l'action du vérin 415, la barre 414 supportant les ventouses 413 descend. Les ventouses 413 déposent le flan saisi F1 à l'arrière des glissières 416. La barre 414 demeure en position basse jusqu'à la fin du cycle de formation. Le long vérin longitudinal 418 est ensuite activé. Le poussoir 417 recule jusqu'à l'arrière du magasin 410, les butées 419 s'escamotant en passant sur le flan FI, puis le poussoir 417 avance et pousse le flan F1 sur les glissières 416 au moyen des butées escamotables 419. Le flan F1 glissant sur les glissières 416 passe sous les buses d'encollage 421 à 424 qui déposent les huit traits de colle discontinus 151 à 154 sur la face rainée de dessus du flan Fl.

The stages of the cycle for forming a tray 1 from a first precut and grooved blank in cardboard FI transported by the pusher 417, together with the laying of two sheets of film 31 and 32 in the tray in the 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 training 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 F1 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 3 ₁ and 3 ₂ .
• 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 in the low position until the end of the training cycle. The long longitudinal cylinder 418 is then activated. The pusher 417 moves back to the rear of the magazine 410, the stops 419 retracting passing over the blank FI, then the plunger 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 discontinuous lines of glue 151 to 154 on the grooved top face of the blank Fl.

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 3 ₁ and 3 ₂ . The suction through the orifices 4362 in the jaws 4360 ceases at the same time that a suction is created in the orifices 4317 and 4318 of the lateral elements 4311 and 4312. The jacks 4361 bring the jaws 4360 together under the suction lateral elements 4311 and 4312 of the punch 431. The approximation of the jaws 4360 contributes to pushing and bending the ends of the films 3 ₁ , 3 ₂ whose "internal faces" are pressed against the vertical longitudinal faces and the undersides of the lateral elements 4311 and 4312 of the punch by suction through the holes 4317 and 4318. Then the jaws 4360 are moved back as far as possible 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 is stationed 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.

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 the ends of the films 3 ₁ and 3 ₂ are bonded, underlying the elements 4311 and 4312, forming the lower end portions of the sheet 310 and 311.

During the volume setting of the tray by lowering the punch 431, the folded ends of the films 3 ₁ and 3 ₂ 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 3 ₁ and 3 ₂ , which quickly switches the muffle bars 4357 into the unwinding devices 435 ₁ and 435 ₂ . 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 3 ₁ and 3 ₂ under the undersides of the elements 4311 and 4312 are therefore glued to the panel 10 thanks to the four long lines of glue 152 and 153. However, the flaring of the walls 4322 and 4323 of the inlet 432 prevents the glue lines 151 and 154 on the longitudinal panels 11 and 12 coming into contact with the films 3 ₁ and 3 ₂ kept vertical before the extensions 131 and 141 are folded down towards the panel 10 in front of the lines of glue 151 and 154 by four suitably inclined corners of the drain 4320. These corners are formed by chamfered edges 4324 of the drain 4320, converging towards the 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 towards the punch by the high transverse walls 4322 of the hood. Simultaneously, the extensions 131 and 141 are gradually folded towards the panels 13 and 14 by the edges 4324 of the downstream. 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 of the longitudinal walls 4323 of the inlet, 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 11 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 square portions of the extensions 131 and 141 are pressed and glued against the longitudinal sides 11 and 12 by means of the four glue lines 151 and 154. The blank F1 is stamped in the tray 1 in well 4321 of the matrix . The bottom 10 is pressed substantially at the level of the lower base of the well 4321, between the bottom face of the punch 431 and the top face of the plate 440.

d) A suction is triggered through the orifices 4362 of the jaws 4360 so that the films 3 ₁ and 3 ₂ are attracted towards the opposite faces of the jaws and are always stretched during the following cutting operation.

Simultaneously, the suction cups 442 press the bottom 10 of the tray onto the 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 3 ₁ and 3 ₂ so that the remaining portions of film under the jaws 4360 in the matrix 432 constitute the sheets 31 and 32. When the knives retract 4370 towards the cylinders 4371, the upper portions of the sheets 31 and 32 fall into the tray 1.

f) After the films 3 ₁ and 3 _{2 have been} cut, the aspirations in the lateral elements 4311 and 4312 cease. The small cylinders 4313 and 4314 are deactivated, and the springs 4315 and 4316 recall the elements 4311 and 4312 towards the central element 4310 of the punch.

g) Then the punch 431 rises from the well 4321 to 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 up to the lower horizontal plane for extracting and transporting the tray, 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 435 ₁ and 435 ₂ are actuated to unwind the films 3 ₁ and 3 ₂ from the two rolls of film 4350 during the ascension 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 rocks the muffle bars 4357 in the opposite direction under the action of gravity of the counterweights 4359. The cylinders 4355 pivot down while cylinders 4356 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 motor means associated with the cylinders 4353 is preset so that it corresponds to a length L3 of sheet 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 low position of the plate 440 and above the lower transport plane. The upper face of the conveyor 445 constitutes the lower plane transport and extends the front of the upper face of the plate 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 to 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, a rear heat-sealing station 52 and a front heat-shrinking station 53 are provided.

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 inclined symmetrically relative 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 half-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 each of the stations 52 and 53 are provided with a vertical series of photoelectric cells 522, 532 arranged by side 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 51. The cells 522 and 532 detect the height H of the trays. The cells 523 and 533 detect the presence of a tray under the 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 at least one tray width 1 apart. The concealment of both cells 522 and 523 positions the nozzle 521 in the high position by means of the jack 520. The high position is greater than H relative to the conveyor 51. Then, after passage of the tray 1 in front of the cells 522, the concealment of the 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. The hot air softens the portions 311 and 321 applied one on 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 sealing or stapling.

A process analogous 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 shrink the two heat-sealed sheets 31 and 32. The 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 retraction of the sheets leads to pressing the batch of products P against the bottom 10 of the tray.

According to another variant, the heat-shrinking station 53 comprises, instead of the nozzles 531, a retraction 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 transporter 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 intermediate transport plane above the lower plane is intended for transporting the 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 which is capped with a cover 2 in a station for forming the cover and closing the tray 65 above the intermediate plane, and to extract each closed tray in a direction of transport. here perpendicular to the lower and intermediate directions of transport, from an outlet station 66. According to the illustrated embodiment, the conveyor 60 and the stations 63 and 64 are arranged on either side of the inlet station 64.

The orientation change station 62 comprises two rods 620 and 621 substantially perpendicular to the direction of transport of the trays on abutted 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 set back from the axis of transport of the trays leaving the machine -5 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, this 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 90 ° rotation 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 entry station 61 comprises a transverse jack 612, a pusher 613 fixed to the cylinder rods 612, a long vertical cylinder 614 underlying the lower transport plane, and a tray lifting tray 615 fixed to the cylinder rods 614. The entry station is intended to transfer the container from the carrier 60 to the plane intermediate 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 pusher 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 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 to slide on the plate 615. The pusher 613 then serves as the guide wall of the tray 1 during its vertical transfer to the intermediate plane. The rear side 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 the front of the conveyor 60. The pusher 613 does not return to the right side of the conveyor 60 until the end of the tray closing cycle.

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 plane of transport of a blank F2.

The stations 63 and 64 are substantially similar to the stations 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 made of sheet metal having internal width and length identical to those of an F2 blank. The magazine 630 contains a stack of flat blanks, pre-cut 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 60, 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 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 cylinder with parallel rods 635 moves the bar 634 vertically back and forth.

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 slides 636. The distance between the slides 636 is adjusted beforehand 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 the 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 F2 and stops just in 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 underlying 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 the rear of the magazine 630. A long rodless cylinder 638 is arranged 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 size 64 with respect 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 the plate 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. The glue ejections by the 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 front panel 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 plate 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 the station 65.

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 progressively 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 the well 651, which has dimensions equal to the dimensions of the horizontal external 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 de H. The walls of the drain seen from the outside are substantially 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 area 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 upper plate 660.

The drawing 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 products P 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 133 and 143 on the sides 13 and 14 of the tray reach the intermediate plane for transporting the blank F2, the pins 132 and 142 substantially penetrate 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 travel of the tray, the plate 615 is stopped coplanar to the top 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 the 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 transporter to other stations, such than a labeling station, a wrapping station or a. casing station. The jacks 614 and 662 are then activated in the opposite direction to lower the tray 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 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 4-5-6 packaging line. as described above may be provided for packaging products, for example of greater height, in other trays 1 ′ having bottom dimensions 10 ′ identical to the dimensions L x ℓ 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 the bonding of the latter against the longitudinal sides 11 'and 12' from the 1 'tray. In Figs. 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 I ′ 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 rate of forming.

Flat blanks, precut and grooved FI 'having dimensions (L + 2H') x (£ + 2h ') from which the second trays 1' are formed, are stacked in a second hollow parallelepipedal magazine 410 'adjacent to the first magazine 410, included in the entry station 41. The blanks F1 ′ are also arranged longitudinally and have crease lines oriented upwards.

Means for transversely translating all of the magazines 410 and 410 ′ and means 46 for moving apart and bringing the parallel slides 416 apart are provided under the slides 416 between the bar 414 and the gluing station 42.

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 the magazines are moved by the cylinder 450 along two transverse guide axes 451 or a transverse slide underlying the set of 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 FI, the magazine 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 ℓ + 2h of a blank FI. In this case, the actuation of the special button results in the activation of the jacks 450 and 460. The jack 450 transversely pushes all of the magazines 410 and 410 'so that the 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 blank FI '. The jack 460 pulls the rod 461 rearward and consequently the links parallel move 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 ℓ + 2h 'of a blank F1', as shown in short dashed lines in FIG. 15. The lower blank F1 'in the magazine 410' is then gripped by the suction cups 413, pushed by the pusher 417, glued in the station 42 and positioned above the matrix 432, as previously described for an F1 blank. Respective magnetic sensors fixed to the rodless cylinder 418 at suitable positions control glue ejections only during the passage of the panels 10 ', 11' and 12 'of the blank F1' under the gluing station. Depending on the width of the blank FI ', two additional lateral nozzles 420 and 425 are provided for depositing third lines of glue on the 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 be glued to 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 (ℓ + 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 1' in order to stamp into the matrix 432 both a large blank F1 'than a little F1 blank.

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 additional 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 somewhat modified compared to those described above.

For the formation of a small tray 1 from a blank F1, the films 3 ₁ and 3 ₂ 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 3 ₁ and 3 ₂ 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 cylinder 434 is activated to lower the punch from a height L3'-L3 against the support 440 where 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 l 'from a blank Fl', the cutting of the films 3 ₁ and 3 ₂ occurs after the actuation of the jack 434. After the descent of the punch 431 from a height L3 in the matrix 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 is pressed between the punch 431 and the support 440 at the end of the downward stroke L3' of the cylinders 433 and 434. The jaws 4360 grip the films 3 ₁ and 3 ₂ , and the knives 4370 cut films. 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 tray 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 unroll the films 3 ₁ and 3 ₂ 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 again activated.

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 stores containing first blanks having different dimensions.

According to other variants, when the different blanks FI, F1 'have identical dimensions L = L' and H = H ', which corresponds to film sheets having the same length L3 = L3', but have heights h and h 'of different longitudinal panels, the auxiliary cylinder 434 can be omitted.

It will be noted that the second machine 5 is capable of sealing and heat-shrinking pairs of sheets of film in trays having different heights thanks to the tray height detections by the series of photoelectric cells 522 and 532. The high position of the nozzles 521 and 531 corresponds to the height of the tallest 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 largest 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 be formed and sheets of film to be bonded. .

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 stations included in the machines and considered separately is included in the subject of this patent application.

Although the invention has been described according to preferred embodiments, those skilled in the art can make 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 receptacles and covers may be other than zectangular, par. prismatic or more generally polyhedral example. 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 a box.

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 as molded cellulose, or plastic.

Films 3 ₁ and 3 ₂ can be perforated, for example like 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. 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 approach by means of the cylinders 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 3 ₁ and 3 ₂ before the descent of the punch.

Claims (63)

1 - Product packaging line (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 (FI) 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 (1, 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 (FI) 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 (FI) and a lower section substantially equal to the external section of the receptacle (1), and means (433) for descending into the matrix (432 ) the punch (431) taking the first extreme portions (310; 320) sheets of film (31, 32) in order to simultaneously stick said first portions of film sheets against the flat blank (F1) and inside the receptacle (1) and to stamp the flat blank in the receptacle and to raise the punch (431) above the upper section of the die (432) after releasing 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) formed in two opposite faces of the punch (431) perpendicular to the flat blank (F1) for sucking 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 (F1) for sucking said first portions (310, 320) of the sheets of film during the descent of punch (431) in the die ( 432). 4 packaging line according to one of 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 ports (4317, 4318), and means (4313, 4314, 4315, 4316) for varying the spacing of the side elements of the punch so that the side elements (4311, 4312) descend into the matrix (432) with a maximum spacing equal to the distance (ℓ) between the first sides (11, 12) of the receptacle (1) and climb into the matrix (432) with a minimum spacing less than the distance (ℓ) between the first sides (11, 12) of the receptacle. 5 - Packaging chain 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 return springs (4315, 4316) to obtain the minimum spacing. 6 - Packaging line according to any one of claims 1 to 5, characterized in that the matrix (432) comprises an upper portion (4320) truncated pyramid having a cross section at least equal to the section of the first flat blank ( F1) and a lower part in the form of a well (4321) having internal dimensions substantially identical to the external dimensions of the receptacle (1). 7 - Packaging line according to claim 6, for which the first flat blank (FI) 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 folding the first and second panels (11, 12; 13, 14) respectively from the blank (F1) towards the central panel (10) during the descent of the punch (431) in the die (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) of the matrix (432). 9 - Packaging chain according to claim 7 or 8, for which the first blank (FI) 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 (FI) towards the central panel (10) and the interior of the receptacle (1) during the descent of the punch (431) into the die (432). 10 - packaging line according to one of claims 1 to 9, characterized in that it comprises on either side of the punch (431) means (435 _I , 435 ₂ ) for unwinding two films (3 ₁ , 3 ₂ ), preferably heat-shrinkable, second means (436 _I , 436 ₂ ) 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 (3 ₁ , 3 ₂ ) into the two sheets (31, 32). 11 - packaging line according to claim 10, characterized in that the second means for taking and releasing the films (436 ₁ ; 436 ₂ ) comprise two jaws (4360) on either side of the punch (431) comprising suction ports (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 unwound portions of the films (3 ₁ , 3 ₂ ) 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 of the films (3 ₁ , 3 ₂ ) against the first means for taking and releasing (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 (3 ₁ , 3 ₂ ) which are sucked through the first holes (4317) of the punch, then lowered with the punch (431) into the matrix (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 (3 ₁ ; 3 ₂ ) which are sucked in at least the second orifices (4318) of the punch, then lowered with the punch (431) into the die (432) to be glued to the bottom (10) and / or to the first sides (11, 12 ) of the receptacle (1). 14 - Packaging line according to 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 (436 ₁ , 436 ₂ ), under the latter and substantially above the first sides (11, 12) of the receptacle (1) when the punch (431) is substantially at the lower section of the die (432), in order to cut films (3 ₁ , 3 ₂ ) and obtain the two sheets of film (31, 32). 15 - A 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 according to any one of claims 10 to 15, characterized in that the means for unwinding the two films (435 ₁ , 435 ₂ ) successively comprise for each film (3 ₁ , 3 ₂ ); 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 permanently between the driving means (4353) and the means (4311, 4312; 436, 436 ₂ ) for taking and releasing portions (310, 320) of the film (3 ₁ , 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 (3 ₁ , 3) passes ), and a counterweight (4359), the bar (4357) pivoting under the pulling effect exerted on an extreme portion (310, 320) of the film (3 ₁ , 3 ₂ ) 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) unwind the film after the film has been cut and taking the cut end portion of the film by the second means to take and release (436 ₁ , 436 ₂ ). 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). 19 - Packaging line according to 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). 20 - packaging line according to claim 19, characterized in that the means for transferring a first flat blank (41) comprises a magazine (410) containing the stack of first flat blanks (F1), means (413, 414 , 415) to take a flat blank from the magazine 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 (F1). 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 lower blank (F1) of the stack when it is taken up by said means to take up a blank (413, 414, 415). 23 - Packaging line according to any one of claims 20 to 22, characterized in that the means for transporting the flat blank taken (416 to 419) comprise two parallel guide rails (416) preferably spaced apart from the width ( ℓ + 2h) of the first blanks (F1) for receiving the blank deposited by the means for taking a blank (413, 414, 415), a pusher (417), and means (418) for translating the pusher (417) into back and _- forth between the rails to slide received blank (F1) on the slides (416) from the magazine (410) to the upper section 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 (FI) deposited on the slides (416). 25 - Packaging line according to 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 (FI) to the upper section of the matrix (432) and means (46) for varying the spacing of the slides (416) preferably to the width (ℓ + 2h) of the first blanks (FI). 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 connecting 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 the slides (416) slide . 27 - Packaging line according to claim 25 or 26, characterized in that it comprises several magazines (410, 410 ') containing stacks of different first blanks (FI, FI') 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 ) preferably to the 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, Fl') are equal and in that the upper section of the matrix (432) has dimensions substantially equal to those (L + 2H ', £ + 2h') of the largest first blanks (F1 '). 29 - Packaging line according to claims 7, 10 and 27, characterized in that the heights (h; h ') of the first panels (11, 12; 11', 12 ') and the heights (H, H') of second panels (13, 14; 13 ', 14') of the different blanks (FI, F1 ') are different, in that the sheets of film (31, 32 31', 32 ') to be glued on the different blanks (FI , FI ') have different lengths (L3, L3'), in that the upper section of the matrix (432) has dimensions substantially equal to those (L + 2H ', ℓ + 2h') of the largest blanks ( FI '), in that for each blank (FI; FI') 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 sheets of film to be glued to the corresponding receptacle (1, 1 '), the films (3 ₁ ; 3 ₂ ) then being cut and then unrolled over the length of sheets, then the punch (431) goes down, the if applicable, at 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 '). 30 - Packaging line according to any one of claims 19 to 29, characterized in that it comprises means (42) above the transfer plane (416) of the first blanks (FI), between the stack ( 410) of the blanks (FI) and the upper section of the matrix (432), for gluing the grooved face from above of the first transferred blank (FI). 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 (FI), intended to bond 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 two lines of glue (151, 154) preferably discontinuous on the first panels (11, 12) of the transferred blank (FI), 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 - Compliant packaging chain. to claim 9 and any 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) of preferably discontinuous on the first panels (11, 12) of the transferred blank (FI), 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 chain according to any one of claims 1 to 33, characterized in that it comprises means (441) for mounting a plate (440) substantially to the lower section of the matrix (432) so to press with the punch (431) the bottom (10) of the receptacle (1), and to lower the tray (440) supporting the receptacle (1) with the glued sheets of film (31, 32) to a plane of lower transport (445). 35 - 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 its 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 to a conveyor (445). 37 - Packaging line according to any one of claims 1 to 36, comprising a second conveyor (51) of receptacles (1) each containing 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 upper sheets and means (531) above the second conveyor for heat shrinking the sealed sheets against the products, characterized in that it comprises for each of the means for sealing (521) and for heat shrinking (531), 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 line 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 include means for sealing (521) and for heat shrinking (531), a first photoelectric cell (523, 533) and second photoelectric cells (522, 532), and in that the simultaneous concealment of the first and second cells control the positioning of the means for sealing and for heat 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 lower position substantially greater than the height (H) of the receptacle (1) detected relative to the second conveyor (51). 39 - packaging line according to any one of claims 1 to 38, wherein each open receptacle (1) formed from a first blank (FI) 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 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 external section of the cover (2), intermediate means (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 for receiving an 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 plateau (615) and rising in the second m atrice (65) for supporting the central panel (20) of the second blank (F2) and for simultaneously stamping 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). 40 - 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 a part upper 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) has 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 folding down the first and second panels respectively (21, 22; 23, 24) of the second blank (F2) against the first and second sides (11, 12; 13, 14) of the receptacle during the rise of the second plate (615) supporting the receptacle (1) in the second matrix (65). 42 - Packaging line 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 glued against two second parallel sides. (13, 14-) of the receptacle (1) and in that the lower part (650) of the second matrix (65) has chamfered edges (6503) extending from the lower section of the second matrix 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 line according to any one of claims 39 to 42, characterized in that the intermediate means for transporting the second flat blank comprises means (63) for transferring the second flat blank (F2) from a stack of such blanks (630) toward the bottom of the lower section of the second die (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 towards the lower section of the second matrix (65), below it and above the receptacle (1) supported by the second plate (615). 45 - 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 comprise suction cups (633) translatable back and forth perpendicular to the direction of the intermediate means of transport to attract the lower or upper blank (F2) of the stack and to deposit it on two slides parallel (636) preferably spaced from the length of the second blanks (F2). 46 - Packaging line 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 taken by said means to take a second blank (633, 634, 635). 47 - Packaging line according to any one of claims 44 to 46, characterized in that the means for transporting the second taken blank (636 to 639) comprise two parallel guide slides (636) preferably spaced apart from the length of the second blanks (F2) for receiving 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 comes between the slides to slide the received blank (F2) on the slides (636) from the magazine (630) to the lower section of the second die, (432), below the latter 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 according to any one of claims 43 to 48, characterized in that the means for transferring a second blank (63) comprise two parallel slides (636) for slidingly guiding the second blank (F2) towards the lower section of the second die (65) and means for varying the spacing of the slides (636) preferably to the length of the second blanks (F2). 50 - Packaging line according to claim 49, characterized in that it comprises several stores (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 slides (636) preferably to the length of the second blanks contained in the transferred magazine. 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 line according to any one of 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 face grooved from below the second transported blank (F2). 53 - Packaging line 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 glue 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 line according to claim 41 and to 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 to glue 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). 55 - Packaging line according to claim 42 and to 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 glue (251, 254) preferably discontinuous under the extensions (211, 221) of the second blank (F2), intended to adhere said extensions against the external faces of the second sides (13, 14) of the receptacle (1). 56 - Packaging chain according to any one of claims 39 to 55, characterized in that it comprises means (60, 613) for pushing an open receptacle (1) from said receiving 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. Are constituted by a conveyor (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) from the front zone (610) onto the second plate (615). 59 - Packaging chain according to claim 58, characterized in that the conveyor (60) has a direction of transport perpendicular to the translation of the pusher (613). 60 - 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 conveyor (60). 61 - Packaging line according to one of claims 57 to 60, characterized in that it comprises means (62) above the conveyor (60) to rotate 90 ° each open receptacle (1). 62 - Packaging chain according to any one of 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 plate (615) onto a plate (660) and / or onto a conveyor . 63 - Packaging line according to 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 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 due to receptacle (1) or the central panel (20) of the cover (2).

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