EP2408674A1

EP2408674A1 - Tray, assembly of cardboard blanks, and device and method for forming such a tray

Info

Publication number: EP2408674A1
Application number: EP10712465A
Authority: EP
Inventors: Bernard Delause; Gérard Mathieu; Didier Desertot
Original assignee: Otor SA
Current assignee: Otor SA
Priority date: 2009-03-20
Filing date: 2010-03-22
Publication date: 2012-01-25
Anticipated expiration: 2030-03-22
Also published as: US20120111933A1; BRPI1009902A2; FR2943319B1; CN102421673B; BRPI1009902B1; WO2010106255A1; CN102421673A; CA2755525A1; FR2943319A1; EP2408674B1; US8939352B2; CL2011002327A1; MX2011009841A

Abstract

The invention relates to a cardboard tray made of three parts, to an assembly of blanks, and to a device and method for producing such a tray. The tray comprises a first part defining a bottom connected by first fold lines to two first opposite sidewalls and two second parts defining second opposite sidewalls, each comprising at least one longitudinal first flap connected to said second wall by a second fold line and glued on the bottom, and two sets of transverse flaps, each comprising at least one transverse flap glued to a first corresponding opposite side wall, respectively.

Description

PLATE, CARDBOARD FLANK ASSEMBLY, DEVICE AND METHOD FOR FORMING SUCH PLATE

The present invention relates to a tray made of cardboard sheet material formed of three separate pieces.

It also relates to a set of blanks for forming such a plate, a device for forming such a plate and a corresponding method. It finds a particularly important application although not exclusive in the field of stackable corrugated board trays, sufficiently resistant to contain products of various shapes such as fruit or semi-rigid pouches sachets type of soups, which can not themselves play a role in the compressive strength of the package.

We have known for a long time the trays of corrugated cardboard mono-blank. These trays do not naturally resist compression as much as the closed packages of the American box type.

To overcome this disadvantage, it has been proposed trays comprising returns or corner beams.

The latter have also made it possible to significantly reduce the grammages compared to traditional packaging.

Such single-blank packages, however, have disadvantages.

In particular they are not easily stackable. Indeed to allow their stacking securely and securely, the tray prior art provides stacking tenons.

But these are fragile and difficult to introduce accurately and repetitively in the corresponding mortises.

Another disadvantage of the known single-flan trays is due to the horizontal splines of two lateral faces which thus participates only very slightly in the compressive strength of the plate.

In addition, even if some trays can be made resistant enough to vertical compression thanks to sidewalks and / or corner beams, buckling tray bottoms continues to cause problems.

Finally, it has unfortunately been found that the slightest defect in the geometry of the trays of the prior art, generally formed by swaging in a cavity, has a significant impact on their resistance to

Vertical Compression (RCV).

The object of the present invention is to overcome these drawbacks by proposing a board made of cardboard sheet material, a set of blanks, a device and a method making it possible to manufacture such a board, which responds better than those previously known to the requirements of the practice. in particular in that it proposes an easily stackable tray, in three elements, two side elements of which form lateral beams, each provided with a glue flap on the bottom of the third element. Such a plate is tolerant to geometry defects, without this being detrimental to its RCV.

Each of the three elements will be able to be oriented and dimensioned, in grammage and groove thickness, so as to optimize its function, namely either the vertical compressive strength or the buckling resistance.

Advantageously, the invention makes it possible and in particular to provide vertical grooves for each of the side walls while allowing stacking trays, simple, effective and durable.

For this purpose, the present invention proposes in particular a plate made of cardboard sheet material, characterized in that it is formed of three separate pieces, namely a first piece forming a bottom connected by first fold lines to two first side walls. opposed and two second pieces forming two second opposite side walls each having at least one first longitudinal flap connected to the second wall by a second fold line and glued to the bottom and two sets of transverse flaps each comprising at least one transverse flap respectively glued on a corresponding first side wall opposite.

In particular embodiments, one and / or the other of the following provisions, alone or in combination: - the first two opposite walls have a free upper edge, devoid of longitudinal flap. Such an arrangement favors automatic manufacture; The bottom has four crushed end surfaces respectively at the four corners of the tray. Localized crushing at the ends of the bottom will thus give it an elasticity that will allow a slight bulge;

- Each first longitudinal flap is glued on the outer face of the bottom;

- Each first flap is glued on the inner face of the bottom; - The basis weight of the bottom carton and the first two side walls is different from that of the two second side walls; the grooves of the first walls and the second walls are perpendicular to the bottom of the plate;

- Each set of transverse flaps comprises a first transverse flap connected to the corresponding second side wall by a third fold line and adhered to the inner face of the first adjacent side wall. In other words the first two opposite walls are glued on the outer face of the transverse flaps opposite. Thus the side walls are straight without protrusion due to flaps overflow; each set comprises a second transverse flap connected by a fourth fold line to said first transverse flap to form an angled corner of the tray, said second transverse flaps being each themselves connected by a fifth fold line to a third cooperating transverse flap with the inner face of the second walls facing each other; a second wall comprises a longitudinal flap connected by an external fold line to form a lid for the tray;

- Each second wall further comprises at least one second longitudinal flap connected to said second wall by a sixth fold line on the opposite side to the first longitudinal flap;

- The second longitudinal flap itself has at least one folded end tongue; - Each second wall comprises a single second longitudinal flap provided on either side of an end tongue folded and glued to the outer face of the first flap or the first side wall opposite, said second sidewalk flap transversely on two opposite ends of said plate;

each second wall comprises two second longitudinal end flaps each provided with one of said folded end tongues, forming consolidation lugs at the four opposite ends of said plate; each first transversal flap further comprises at least one side tab folded and glued to the second longitudinal flap of a single piece forming a sidewalk;

each second flap comprises a recess at the level of the sixth folding line; the lateral ends of the first longitudinal flaps glued to the bottom of the plate are of complementary shape with the upper surface of the plate and / or the second longitudinal flap (s) and / or recesses, to allow the embedding of one into the other during the stacking of two trays one on the other;

each second wall comprises a central fold in an isosceles triangle and two first longitudinal flaps located on either side of said central fold;

- the tray has eight sides;

the third fold lines are oblique with respect to the perpendicular to the first fold lines, so as to give a frustoconical shape to said plate;

- At least a first side wall comprises fifth flaps connected on either side of the first wall by sixth fold lines adapted to cooperate with the outer face of an adjacent transverse flap;

the second walls are higher than the first adjacent lateral walls;

- The plate has a first side wall perforated partially or over its entire length or provided with a longitudinal tear strip.

The invention also provides a set of blanks for forming a sheetboard material tray as described above. Advantageously, it also proposes a set of blanks for forming a plate made of cardboard sheet material, characterized in that it comprises a first blank formed of a bottom connected by first fold lines to two opposite first side walls and a second flan adapted to form two opposite second side walls of said identical plate disposed on either side of a separation line, each second side wall comprising each at least a first longitudinal flap connected on one side to a corresponding second wall by a second fold line and on the other side by said separation line to the outer periphery of the other first longitudinal flap of the other second symmetrical side wall facing, said first longitudinal flaps being arranged to be bonded to the bottom and each second wall further comprising two sets of transverse flaps, said sets each comprising at least one transverse flap adapted to be respectively glued on a first side wall corresponding opposite when the tray is formed.

In advantageous embodiments, one and / or the other of the following provisions is also used:

the second opposite walls are symmetrical with respect to the separation line;

one of the opposite walls is connected by the external fold line to an upper shutter to form a lid for the plate;

the bottom comprises four crushed end surfaces located respectively at the four corners of the plate; - Each set of transverse flaps comprises a first transverse flap connected to the second side wall corresponding to a third fold line and adapted to be bonded to the inner face of the first adjacent side wall; each set comprises a second transverse flap connected by a fourth fold line to said first transverse flap to form an angled corner of the tray, said second flaps each transverse being themselves connected by a fifth fold line to a third transverse flap to cooperate with the inner face of the second walls facing; - Each second wall further comprises at least one second longitudinal flap connected to said second wall by a sixth fold line on the opposite side to the first longitudinal flap;

- The third fold lines are oblique to the perpendicular to the first fold lines, so as to give a frustoconical shape to said tray once formed.

The invention also proposes a device for forming a tray from two blanks of cardboard or corrugated cardboard material, namely a first blank formed of a bottom connected by first fold lines to two first side walls. opposed and a second blank adapted to form two opposite second side walls of said plate, identical and symmetrical with respect to a separation line, each second lateral wall each having at least one first longitudinal flap connected on one side to a corresponding second wall by a second fold line and on the other side by said separation line at the outer periphery of the other first longitudinal flap of the second symmetrical side wall opposite, and two sets of transverse flaps each comprising at least one flap transverse. characterized in that it comprises two storage magazines respectively first and second blanks, cutting means of the second blank at the separation line to form the two opposite second side walls, gripping means and transfer of the first blank from the store. storage at an assembly station, wedging means in abutment of the first blank to give it an exact reference position, means for gripping and laterally transferring by suction cups of the second walls to place them on the first cut thus indexed, means for gluing the first longitudinal flaps and the internal face of the second walls and / or sets of second flaps during their transfers, means for applying the first longitudinal flaps to the first blank, means for folding the sets of flaps; flaps to the second walls, means for transferring the set of blanks thus formed to a forming station and forming means at said forming station.

Advantageously, the forming means comprise a mandrel and means for winding the set of blanks around said mandrel to form the plate.

Also advantageously each set of transverse flaps comprising a first transverse flap connected to the corresponding second side wall by a third fold line and a second transverse flap connected by a fourth fold line said first transverse flap, said second transverse flaps being each themselves connected by a fifth fold line to a third transverse flap, the folding means of said sets comprise pins to form a wedge angle of the tray and pushing means for applying said third transverse flaps on the inner face of the second walls facing each other. In an advantageous embodiment, each second wall further comprising at least one second longitudinal flap connected to said second wall by a sixth fold line on the opposite side to the first longitudinal flap, the device further comprises means for folding said second longitudinal flap to form at least two lugs or two sidewalks on either side of the tray, and in that the mandrel is retractable between a tray forming position and an exhaust position of the ears or sidewalks.

Also advantageously each second wall comprising three central fold lines parallel to the third fold lines and two first longitudinal flaps located on either side of said central fold, the device comprises means for folding said three lines to form in the middle of said second walls a central fold in isosceles triangle.

The invention also proposes a method of forming a tray from two blanks of cardboard or corrugated cardboard material, namely a first blank formed of a bottom connected by first fold lines to two first walls. opposite sides and a second blank adapted to form two opposite second side walls of said plate, identical and symmetrical with respect to a separation line, each second lateral wall each having at least one first longitudinal flap connected on one side to a corresponding second wall; by a second fold line and on the other side by said separation line at the outer periphery of the other first longitudinal flap of the second symmetrical side wall opposite, and two sets of transverse flaps each comprising at least one transverse flap characterized in that, after cutting the second blank at the separation line to form the two opposite second side walls, transferring the first blank to an assembly station is wedged abutting the first blank to give it a exact reference position, the suction-side walls are laterally transferred by suction cups nt the first longitudinal flaps and the inner face of the second walls and / or sets of second flaps during their transfers, then they are placed on the first cut and indexed, we apply the first longitudinal flaps on the first blank, we fold the games flaps to the second walls, and the set of blanks thus formed is transferred to a forming station to form the tray. In an advantageous embodiment, the forming is done by winding around a mandrel.

Advantageously each set of transverse flaps comprising a first transverse flap connected to the second corresponding lateral wall by a third fold line and a second transverse flap connected by a fourth fold line to said first transverse flap, said second transverse flaps being each themselves connected by a fifth fold line to a third transverse flap, it folds said sets around pins to form a corner corner of the tray and said so-called third transverse flaps on the inner face of the second walls facing.

Also advantageously each second wall further comprising at least one second longitudinal flap connected to said second wall by a sixth fold line on the opposite side to the first longitudinal flap, folds said second longitudinal flap to form at least two ears or two sidewalks. on either side of the plate, and the mandrel is retracted between a plateau forming position and an exhaust position of the ears or sidewalks.

In an advantageous embodiment, each second wall comprising three central fold lines parallel to the third fold lines and two first longitudinal flaps located on either side of said central fold, said three folding lines are folded to form in the middle of the folds. say second walls a central fold in isosceles triangle. The invention will be better understood on reading the following description of embodiments given hereinafter by way of nonlimiting examples, with reference to the accompanying drawings in which:

- Figures 1, 2 and 3 are perspective views from below, from above and from the front of two stackable trays according to a first embodiment of the invention with reinforcing corners. FIGS. 4A, 5C and 6A, 7C show views, in perspective and flat respectively, of the three parts of the plate of FIG. 1.

- Figures 4B and 6B show another embodiment respectively in perspective and flat of a set of sidewall blanks 1 according to the invention.

- Figures 5A, 5B and 7A, 7B are views, respectively in perspective and flat, of blanks for obtaining a bottom piece according to two embodiments of the invention.

FIGS. 8A, 8B and 9A, 9B show other embodiments of trays and blanks for corresponding second lateral walls, according to two other embodiments of the invention on the one hand with sidewalks and on the other hand with corner angles.

- Figures 10A, 10B and 10C show in top view and from below, two trays obtained with the parts for second side walls of the blank of Figure 11, with sidewalks and corner angles.

- Figures 12 and 15 show in perspective two other embodiments of second parts according to the invention, combinable with the first bottom part in perspective of FIGS. 13 and 14.

- Figure 16 is a perspective view of a plate obtained by gluing together the blanks of Figures 14 and 15.

- Figures 17, 18 and 19 show flat blanks respectively corresponding to the shaped blanks of Figures 12, 13 and 14.

FIGS. 20A and 20B show blanks respectively for second part and first bottom piece making it possible to obtain the frustoconical trays during assembly and stacked represented in FIGS. 21 and 22.

FIGS. 23A, 23B, 24 and 25 show, in the form of flat blanks and in perspective, another embodiment of central folded plate, according to the invention.

- Figures 26A to 26G show in perspective and schematically the various operations performed during the implementation of the method according to the embodiment of the invention more particularly described here.

- Figures 27A and 27B illustrate an alternative embodiment of this method with retractable cylinder.

- Figures 28 and 29 show in side view and in top view of an embodiment of a device according to the invention, with mandrel.

- Figure 30 is a side view of the magazine- separation blanks to form the second parts of the device described with reference to Figures 28 and 29. - Figure 31 is a side view of Figure 29 according to section XXXI-XXXI.

- Figure 32 is a side view of the volume station around the mandrel. - Figure 33 is a partial perspective view of another embodiment of a tray according to the invention.

FIG. 34 shows sectional and perspective views of the bottom of the plate of FIG. 33. FIG. 35 is a perspective view of a bottom according to an embodiment of the invention similar to that of FIG. .

FIG. 36 is a perspective view of a half-tray being formed using the bottom of FIG. 35 and a blank half according to another embodiment.

- Figures 37 and 38 show in perspective the plateau obtained with the bottom and blank of Figures 35 and 36, in training and once completed. In the remainder of the description of the figures, the same reference numbers will be used to designate identical or similar elements.

FIGS. 1 to 3 show two parallelepipedal superposed platens 1, identical in cardboard sheet material, according to a first embodiment of the invention.

Each plate 1 is formed of three separate pieces 2, 3 and 4, namely a first piece 2 forming a bottom 5 connected by first fold lines 6 to two first side walls 7 and two second pieces 3 and 4 forming two second side walls. opposed 8 and 9 each having a first longitudinal flap 10, 11 connected to said second wall 8, 9 by a second fold line 12, 13 advantageously slightly offset to allow compensation of the cardboard thicknesses, at least in part, and bonded to the bottom face of the bottom 5.

Each second wall 8, 9 comprises two sets of transverse flaps 14, 15 each comprising at least one transverse flap 16 respectively bonded to the inner face of a first corresponding side wall 7 facing each other.

More specifically, on the plate shown in Figures 1 to 3 and also with reference to Figures 4A, 4B and 6A, 6B, each set of flaps 14, 15 comprises a first transverse flap 17 connected to the corresponding second side wall 8, 9 by a third fold line 18 and glued on the inner face of the first adjacent side wall.

Each set of flaps 14, 15 further comprises second rectangular transverse flaps 20 connected by a fourth fold line 21 to said first transverse flap (see FIGS. 3, 4A and 6A), said second transverse flaps being each themselves connected by a fifth fold line 23

(Parallel to the second fold line) to a third transverse flap 24 cooperating with the inner face 25 of the second walls facing to form a pillar 22 (see Figure 4A) corner corner of the plate.

As shown in Figure 3 it is also seen that the first flap 11 is arranged to fit between the upper portions 26 sets of transverse flaps 14, 15 forming corner pillar. This embedding is due in particular to the fact that the flaps 10 and 11 being glued to the bottom 3 of the top plate come into protrusion with respect to the bottom, which therefore allows an interlocking with the upper periphery of the pillars, while allowing self-centering and a lateral blocking of one tray on the other.

It is therefore understood that the existence of these flaps, glued to the lower outer face of the bottom allows an excellent stacking trays on each other.

More precisely and still with reference to FIGS. 4A and 6A, it will be noted that the two parts 3, 4 are obtained from the same cutout 27 (see FIG. 6A) symmetrical with respect to a cutting line 28.

The first longitudinal flaps 10, 11 are of substantially trapezoidal shape, the small base being formed by the second fold line 12, 13 and the large base itself being smaller than the total length of the second wall (8, 9 ) to which the first flap 10, 11 is attached, the respective lateral sides 28 of said first flap being for example nose-shaped to allow embedding by their complementary shape with the spacing between the pillars of the tray below.

A recess 29 between the two first flaps 10, 11 contiguous, symmetrical with respect to the cutting line 28 of oblong shape, is advantageously provided.

FIGS. 4B and 6B show an alternative embodiment of the second parts, which furthermore comprise on the outer peripheral edge 30 second walls, two triangular or trapezoidal tongues 31 directed outwards and respectively connected by fold lines 32 at each end of said periphery of the second walls. The tongues 31 are themselves laterally extended by a small rectangular tongue 34 located directly above the first transverse flap 17 and which allows (see FIG. 4B) when the second wall is formed with its corner pillars, to be covered by the outer face 35 of the first transverse flap 17 thus allowing consolidation of 1 set.

According to the embodiment of FIGS. 4B, 6A, 6B, there is furthermore shown substantially centered on each second wall 8, 9 an oblong hole 36 obtained by cutting allowing the plate to be grasped.

FIGS. 5A to 5C and 7A to 7C show three embodiments of first parts that can be used with the invention. FIGS. 5A and 7A show a blank 37 having a rectangular bottom 5 and two opposite first side walls connected to said bottom by the folding lines 6, namely a first vertical rectangular wall 38 of the height of the plate and a first wall 39 in the form of U, having a central recess 40.

In other embodiments (FIGS. 5B and 7B), the first bottom piece 41 comprises a first wall 42 of smaller height than the facing wall 38, which allows a lateral opening of the tray, or on the contrary two walls 7 of the same height (see Figures 1 to 3). Finally, in another embodiment of first parts 43 and with reference to FIGS. 5C and 7C, there is provided a first wall 44 provided with a tear-off tab 45 shown in broken lines in FIG. tray on one side to access for example its contents.

FIGS. 8A and 8B show two other embodiments of trays 46 and 47 according to the invention, and in FIGS. 9A and 9B the cutouts 48, 49 for second correspondence pieces.

More precisely, FIG. 8A shows a plate 46 whose first two lateral walls 50 are of smaller height than those of the second lateral walls 51.

These comprise on their upper periphery 52 second longitudinal flaps 53 capable of forming horizontal horizontal sidewalks, and having on each side two small lateral tabs 54 square, folded on the outer face of the first transverse flap 56 corresponding to the second wall concerned.

Figures 8B and 9B show for their part, a plate 47 with corner element 57 formed by two small tabs 58 of the type described with reference to Figure 6B. Small notches 59 in the upper periphery 60 of the first transverse flaps are provided to prevent overfalls.

These elements will notably allow the embedding with the first flaps in opposite protruding relative to the bottom of the plate. In the embodiment of FIGS. 8A and 8B, the top of the sidewalks 53 comprise a recess 62, where further spacing between corner elements 57, of complementary shape with the shape of the first protruding flaps, to allow embedding.

FIGS. 10A, 10B, 10C and 11 show another embodiment of a plate 63 according to the invention, which again comprises sidewalks 64 in the upper part formed by second longitudinal rectangular flaps 65 connected to the periphery 66 longitudinal upper second rectangular walls 67 and the first transverse flaps 68 having in turn small triangular tabs 69 closed and glued on top of the sidewalk flap described above.

The embedding is here possible between these two small triangular tabs 69 and the first flap of complementary shape. FIGS. 12 and 15 show in perspective and in plan two other embodiments of second walls 70 and 71 according to the invention, comprising two first transverse flaps 72 connected to two second transverse flaps 73, these embodiments permitting bonding to the second interior of a first piece 74 of the type of FIG. 13, rectangular, itself comprising two first rectangular walls 75 provided at each of their respective ends with a tongue 76 also rectangular, the second walls 71 of FIG. so arranged that their second flap 73 is glued on the inner faces 77 of the first walls of the package. In another embodiment (FIG. 14), the first part 78 has an octagonal bottom 79 and each first wall 80 comprises end tabs 81. The second walls 71 are then glued on this first part so that a first part is formed. eight-sided tray 82, the first transverse flaps 72 themselves being glued to the end tabs 81 of the first walls 80 of the first part. FIGS. 17 to 19 show the blanks for second pieces (FIG. 17) and first pieces (FIGS. 18 and 19) making it possible to produce the elements of FIGS. 12 and 15 and 13 and FIG. FIGS. 20A to 21 show other embodiments of first pieces 81 and second pieces 82 according to the invention, making it possible to form a frustoconical plate 83 with walls 84 inclined inwards, (or outside) favoring stacking.

More specifically, it is proposed a blank 85 formed of two second parts 82 symmetrical with respect to a central axis 86 comprising second rectangular walls 87 provided with the first longitudinal flap 10, 11 of the type described with reference to the preceding figures and from other two transverse flaps 88 trapezoidal shape, namely having a first side 89 formed by the fold line and connected to its second outer peripheral side 90 by two parallel sides 91 inclined outwardly, the opposite side to the first flap longitudinal 10, 11. The first piece, for its part, is then formed of a rectangular bottom 92 provided with the first two walls 93 which themselves have lateral sides 94 sloping inwards to form isosceles trapezes whose short side 95 and formed by the outer peripheral edge.

These upper edges 96 of the second walls 87 comprise notches 97 able to fit in the edges 98 of the longitudinal flaps 10 and 11 in the form of an escapement.

FIGS. 23 to 25 show another embodiment of the invention. The first piece

(Figure 23B) is itself formed by blanks similar to those described with reference to Figures 7A to 7C.

The second blank 99 making it possible to manufacture the second walls is itself formed symmetrically on either side of a dividing line 100, by a first rectangular flap 101 provided at its center with a fold line around which are located on either side and symmetrically, two parallel fold lines 103 and the third folding line 104 for attachment to the first transverse flaps 105, the outer upper periphery of this second wall further comprising tabs 106 of the type described with reference in Figure 9B or 6B.

The second walls, once separated from their connecting line (see Figure 24) are folded so that the central portion 107 comes to form an isosceles triangle, the dimension of the second wall, once gathered in the middle, being equal to the length of the first wall. The plate 108 is then formed similarly to the previous packages.

We will now describe more specifically with reference to Figures 26A to 26G, the method of manufacturing a tray according to one embodiment of the invention, of the type described with reference to Figures 1 to 3 and 4A and 5C.

From two blanks of corrugated sheet material, namely a first blank F formed of a bottom 5 connected by first fold lines 6 to two first and opposite side walls 7 and a second blank 27 to form two second walls 8, 9 opposite sides, identical and symmetrical with respect to the line of separation 28, each second lateral wall comprising at least one first flap 10, 11 longitudinal connected on one side to a second corresponding wall 8, 9 by a second line of folding 12 and on the other side by said dividing line 28 at the outer periphery of the other first longitudinal flap of the second symmetrical side wall opposite, and two sets of transverse flaps 14, 15 each having at least one transverse flap 24, the second blank is cut (step 110) at the separation line 28 to form the two second pieces.

Then transfer (arrow 111) the two second parts to an assembly station 112 by gluing the passage of the inner faces of the walls 8, 9 and the flaps 10, 11 and 24 with glue called "hot meIt" in a known manner in herself.

Then the first blank F of its vertical storage stack 115 is transferred (arrow 114) to a constant level, which is pressed onto the flaps 10 and 11 as shown in Figure 26B. Transfers are laterally by suction cup.

Then (arrow 116) is brought elements 117 which will allow the folding of the corner pillars and which will be described more precisely below with reference to the device.

Referring to FIGS. 26C and 26D, the sets of flaps 14 and 15 are folded (arrows 118 and 119) towards the second sized walls (see FIG. 26D) and then (FIG. 26E) after removal (arrow 120) of elements 117, the set of blanks thus constituted is transferred (arrow 121 of FIG. 26E) to a forming station 122 for winding it (arrow 123, see FIG. 26F) around an eight-sided mandrel 124 to form the plate 125 (FIG. see Figure 26G).

FIGS. 27A and 27B show the main steps of a different embodiment of the method according to the invention using a retractable mandrel 127 of the type known in itself, for example comprising four cleats 128 movable between a spaced apart position (FIG. 27A) and a retracted position (Figure 27B) for extraction (arrow 129) to escape the flanges 57 trays 47 of the type described with reference to Figure 8B and / or sidewalks with reference to Figure 8A.

A device 130 for forming a tray according to the embodiment of the invention more particularly described here is now shown with reference to FIGS. The device comprises two storage magazines 131 and 132 of the first blanks F and second blanks 27, said magazines being formed by forklifts on which the blanks are wedged and piled flat, the carriage rising as and when unfolding.

The storage magazine of the second blanks is also provided with a cutting blade (not shown) of the second blank symmetrically at the separation line 28 in two.

Two extraction arms 133 and 134 (see FIGS. 28 and 30) formed by pistons and provided with suction cups 135 enable the separation of one of the blanks relative to the other, their spacing and their transfer to the station. assembly 136 with gluing by means 137 known in themselves.

The first blank F is brought laterally via a carriage 138 to the assembly station comprising a transfer band 139.

More specifically, with reference to FIG. 28, the separating magazine for the second lateral walls comprises a carriage 140 brought to the assembly station, shown on a beam 140 'resting on either side on two tracks 140 ''.

It comprises the two arms 133, 134 of position in width. This feeder carriage is actuated by a drive belt 141 for transfer to the assembly station.

At the passage of the second blanks the sizing means 137 blanks for assembly are provided.

They are for example formed of glue guns known in themselves.

A transfer latch (not shown) at the various positions allows once the blank in position on the transfer band 139, taking the set and wedged to bring it to the next station.

The device 130 also includes a station

142 for forming the dihedrals or corner pillars, and more particularly a dihedron shaping and pressing system comprising pistons 143 and a descent trolley 144 of a workpiece comprising dihedra 145 shaped for pressurization.

A system 146 for folding the dihedrals with a pusher piston at 90 ° is also provided, the trolleys

148 provided triangular beams of triangular cross section for forming the dihedrons motorized being further provided below the training station. Slide-adjustable volume-sizing glue guns are conveniently positioned, and a vertical folding system (not shown) of the type described with reference to FIG. 32 is further provided. It thus comprises vertical arms 150 rounded at the top to facilitate docking and push the vertical flaps.

Once the beams are formed, the carriages 148 for feeding the dihedral forming beams 149 are removed and the assembly is pushed through the band 139 to the training station 151 around the mandrel 152.

Here again, sizing guns (not shown), before setting volume, are provided in a manner known per se, and a system 153 for folding and pressing the bottom adjustable in two directions by screw system. The system 153 is arranged to press the vertical walls of the plate on the lateral faces of the mandrel 152 brought from above.

Note that this one can be changed at the format level.

The system 153 comprises a crew 154 arranged to move between a low position 155 of exhaust of the vertical blades 156 with horizontal curved end 156 'and a high position 157 of blade plating on the walls 8 and 9 on the one hand and 7 on the other hand for bonding with the external faces of the corner pillars 14, 15.

We will now describe the operation of the device according to the embodiment of the invention more particularly specified here.

The second pieces or end cuttings are removed one by one from the constant level magazine 132.

The two peripheral edges of the first two longitudinal flaps 10 and 11 being linked by attachment points, unstacking is provided by the two systems shown in Figure 30 driven and equipped with suction cups, one end.

The top point of each unstacker is different which allows to release the attachment points and thereby separate the two second pieces or separate end cutouts.

These end cutouts are transferred to the junction station 136, and during this transfer the connecting panels are glued and placed in position in width by the two independent truck trolleys 140 driven by motor brains. The ends are then put in place at the junction station which comprises a conveyor belt 139.

During the same time, a bottom cut and / or first piece is extracted from the constant level magazine 131.

The transfer of the bottom cutout is done at the junction station via a carriage 138 also driven by motor brains. During this transfer an embedded gluing system deposits the glue necessary for the creation of the dihedrons of the extremities.

Then there is a pressurization of the bottom on the ends and a transfer of the assembly to the training station of the dihedrons.

The dihedral formation station 146 comprises the establishment of four counter-forms corresponding to the dimension of the dihedrons (two right and left systems powered by motor brains). Then there is placed vertically dihedrons around their raining (fold line) by a ramp and horizontal dihedrons around their complementary rainings by dynamic system and finally formatting and pressure of the dihedrons around the following grooves by a tool with pistons 143 and then a retreat against the forms.

Then the transfer to the volume setting station is performed. During this transfer the bottom is glued.

The volume is then made to volume by lowering the (internal) mandrel on the flat plate and placing the ends of the walls 8 and 9, then panels 7 of the bottom, before pressurizing the plate and ejection.

Note that in cases where the ends are equipped with total or partial sidewalks they are formed at the volume setting station, the inner mandrel then being retractable to allow its release.

Figures 33 and 34 show a tray portion 160 comprising a rectangular bottom 161 connected by the first fold lines 162 to two substantially rectangular first walls 163. The plate further comprises two second rectangular side walls 164 (one single is shown in the figure) comprising a rectangular longitudinal flap 165, connected to said second wall by a second fold line 166, centrally on a part of the length of the wall for example 2/3 or 4/5, and glued on the outer face 167 of the bottom, and two transverse flaps 168 bonded to the inner face 169 of the first walls 163 opposite.

As seen in the figures, the cardboard zone of the bottom at the level of the second folding line is divided into three parts, namely a central zone 170 facing the longitudinal flap 165 and two zones 171 located on the side and side. other between the edges of the flap and the first walls.

In order to minimize the extra thickness of the flap glued to the bottom of the bottom at the area 170 and formed so that the bottom deforms vertically to allow the edge of the flap to align with the fringes 172 of the areas 171 zones 173 are provided, substantially rectangular tab-shaped along or at the edge of a portion of the first fold line, for example of a width equal to half that of the area 171 and of sufficient length to obtain good elasticity, for example a few centimeters in function of the thickness of the carton.

This localized crushing of the cardboard at the ends of the bottom thus allows a slight bulge (see FIG. 35, arrow 174) so that the points of support of the vertical wall on the zones 171 are aligned with those of the zone 170. all the vertical walls formed by the first walls and the second walls participate similarly to the compression, significantly increasing the RCV.

FIGS. 35 to 39 show the partial elements, in perspective, in the process of being formed, or formed, of a plate 175 according to another embodiment of the invention. FIG. 35 shows a bottom 161 of the type of that described in FIG. 33.

FIG. 36 shows in perspective the bottom 161 and a half-blank 176. The half-blank 176 for obtaining the second side walls comprises a second rectangular wall 177, provided with the longitudinal flap 178, adapted to be glued on the bottom, in shape tongue, two lateral rectangular flaps 179 on either side, and the other side of an outer edge 180, forming a junction fold line 181, with a third rectangular flap 182 of length equal to that flaps 179, for example of length equal to 1/3 of the length of the first side walls 163, provided with two rectangular flaps 183, 184 adapted to be folded on the flaps 179 to form the sidewalk 185 (see Figure 38).

Recesses 186 at the fold lines 181, in the flap 182 of complementary shape to the tabs 178, to allow embedding, are provided.

In an embodiment shown in phantom in Figure 37, the flap 182 is replaced by a flap 187 to form the top of the plate and to close by a tab 188 on the second wall 189 facing.

It goes without saying and as it follows from the foregoing the present invention is not limited to the embodiments more particularly described. On the contrary, it embraces all the variants and in particular those in which the blanks of the first side walls and of the bottom are of heavy weight, for example 100 g / m ² , and that of the second walls and of low grammage, for example less than 50 g / m ² those where the forming station is different, the formation of the plate being done by pistons in a manner known per se, or in other ways not using a mandrel, those where the crushed lateral areas allowing bulging, are replaced by a central crushed area, the tongue 178 then being located for example inside the box, glued on the inner face of the bottom.

Claims

1. Tray (1) made of cardboard sheet material, characterized in that it is formed of three separate pieces, namely a first piece (2) forming a bottom (5) connected by first fold lines (6) with two opposite first side walls (7) and two second parts (3, 4) forming two opposite second side walls (8, 9) each having at least one first longitudinal flap (10) connected to said second wall by a second line of folding (12, 13) and glued on the bottom and two sets of transverse flaps (14, 15) each comprising at least one transverse flap (16) respectively bonded to a corresponding first side wall (7) facing.

2. Tray according to claim 1, characterized in that the first two opposite walls have a free upper edge devoid of longitudinal flap.

3. Tray according to any one of the preceding claims, characterized in that the first longitudinal flap is bonded to the outer face of the bottom.

4. Tray according to claim 3, characterized in that the bottom comprises four end surfaces (173) crushed respectively located at the four corners of the tray.

5. Tray according to any one of the preceding claims, characterized in that the basis weight of the bottom board and the first two side walls is different from that of the two second side walls.

6. Tray according to any one of the preceding claims, characterized in that the grooves of the first walls and second walls are perpendicular to the bottom of said tray.

7. Tray according to any one of the preceding claims, characterized in that each set of transverse flaps comprises a first transverse flap connected to the corresponding second side wall by a third fold line and adhered to the inner face of the first side wall adjacent.

8. Tray according to claim 7, characterized in that each set comprises a second transverse flap connected by a fourth fold line to said first transverse flap to form a wedge angle of the plate, said second transverse flaps being each themselves connected by a fifth fold line to a third transverse flap cooperating with the inner face of the second walls opposite.

9. Tray according to any one of the preceding claims, characterized in that a second wall comprises a longitudinal flap connected by an outer fold line to form a cover plate.

10. Tray according to any one of claims 1 to 8, characterized in that each second wall further comprises at least one second longitudinal flap connected to said second wall by a sixth fold line on the opposite side to the first longitudinal flap.

11. Tray according to claim 10, characterized in that said second flap longitudinally itself has at least one end tab folded.

12. Tray according to claim 11, characterized in that each second wall comprises a single second longitudinal flap provided on either side of an end tongue folded and glued to the outer face of the first flap or the first wall side opposite, said second transverse sidewalk flap on two opposite ends of said plate.

13. Tray according to claim 11, characterized in that each second wall comprises two second longitudinal end flaps each provided with one of said end tongues folded, forming consolidation ears at four opposite ends of said plate.

14. Tray according to claim 10, characterized in that each first transverse flap further comprises at least one side tongue folded and glued to the second longitudinal flap of a single piece forming a sidewalk.

15. Tray according to claim 14, characterized in that each second flap comprises a recess at the sixth fold line.

16. Tray according to any one of claims 10 to 15, characterized in that the lateral ends of the first longitudinal flaps glued to the bottom of the plate are of complementary shape with the upper surface of the plate and / or the second longitudinal flaps or and / or recesses, to allow the embedding of one in the other during the stacking of two trays one on the other.

17. Tray according to any one of the preceding claims, characterized in that each second wall comprises a central fold in isosceles triangle and two first longitudinal flaps located on either side of said central fold.

18. Tray according to any one of the preceding claims, characterized in that it comprises eight sides.

19. Tray according to any one of the preceding claims, characterized in that the third fold lines are at an angle to the perpendicular to the first fold lines, so as to give a frustoconical shape to said tray.

20. Tray according to any one of the preceding claims, characterized in that at least a first side wall comprises fifth flaps connected on either side of said first wall by sixth fold lines adapted to cooperate with the outer face. an adjacent transverse flap.

21. Tray according to any one of the preceding claims characterized in that the second walls are higher than the first adjacent side walls.

22. Tray according to any one of the preceding claims, characterized in that it comprises a first perforated side wall partially or over its entire length or provided with a longitudinal tear strip.

23. Set of blanks for forming a tray made of cardboard sheet material, characterized in that comprises a first blank formed by a bottom connected by first fold lines to two opposite first side walls and a second blank adapted to form two opposite second side walls of said identical plate and arranged on either side with respect to a line separating, each second lateral wall each having at least one first longitudinal flap connected on one side to a corresponding second wall by a second fold line and on the other side by said separation line to the outer periphery of the other first longitudinal flap of the other symmetrical second side wall opposite, said first longitudinal flaps being arranged to be glued to the bottom and each second wall further comprising two sets of transverse flaps, said sets each comprising at least one transverse flap adapted to be respectively glued on a first corresponding side wall screw to vi s when the tray is formed.

24. The assembly of claim 23, characterized in that the second opposite walls are symmetrical with respect to the line of separation.

25. An assembly according to any one of claims 23 to 24, characterized in that the bottom comprises four crushed end surfaces respectively located at the four corners of the tray.

Blank assembly according to any one of claims 23 to 25, characterized in that each set of transverse flaps comprises a first transverse flap connected to the corresponding second side wall by a third fold line and adapted to be adhered to the inner face of the first adjacent side wall.

27. Set of blanks according to claim 26, characterized in that each set comprises a second transverse flap connected by a fourth fold line to said first transverse flap to form a corner corner of the tray, said second transverse flaps each being themselves connected by a fifth fold line to a third transverse flap to cooperate with the inner face of the second walls facing.

28. Set of blanks according to any one of claims 23 to 27, characterized in that each second wall further comprises at least one second longitudinal flap connected to said second wall by a sixth fold line on the opposite side to the first flap. longitudinal.

29. An assembly according to any one of claims 23 to 27, characterized in that one of the second walls is connected by an outer fold line to an upper flap to form a lid to the tray.

30. Set of blanks according to any one of claims 23 to 29, characterized in that each second wall comprises a central fold in isosceles triangle and two first longitudinal flaps located on either side of said central fold.

31. Set of blanks according to any one of claims 23 to 30, characterized in that the third fold lines are at an angle to the perpendicular to the first fold lines, so as to give a frustoconical shape to said tray once formed.

32. Device for forming a tray from two blanks of cardboard sheet or corrugated cardboard material, namely a first blank formed of a bottom connected by first fold lines to two opposite first side walls and a second blank adapted to form two opposite second side walls of said plate, identical and symmetrical with respect to a dividing line, each second lateral wall each having at least one first longitudinal flap connected on one side to a second corresponding wall by a second line of folding and on the other side by said separation line at the outer periphery of the other first longitudinal flap of the second symmetrical lateral wall opposite, and two sets of transverse flaps each comprising at least one transverse flap characterized in that that it comprises two storage magazines respectively first and second blanks, cutting means of the second blank at the separation line to form the two opposite second side walls, means for gripping and transferring the first blank from the storage magazine to an assembly station, wedging means abutting the first blank to give it an exact reference position, means for gripping and laterally transferring suction cups of the second walls to place them on the first cut thus indexed, means for gluing the first longitudinal flaps and the inner face of the second walls and / or sets of second flaps during their transfers, means for applying the first longitudinal flaps to the first blank, means for folding the blanks; flaps to the second walls, means for transferring the set of blanks thus formed to a forming station, and forming means at said forming station.

33. Apparatus according to claim 32, characterized in that the forming means comprise a mandrel and means for winding the set of blanks around said mandrel to form the plate.

34. Device according to any one of claims 32 and 33, characterized in that each set of transverse flaps comprising a first transverse flap connected to the corresponding second side wall by a third fold line and a second transverse flap connected by a fourth folding line to said first transverse flap, said second transverse flaps being each themselves connected by a fifth fold line to a third transverse flap, the folding means of said sets comprise pins to form a corner corner of the tray and pusher means for applying said third transverse flaps on the inner face of the second walls opposite.

35. Device according to any one of claims 33 and 34 dependent on 33, characterized in that each second wall further comprising at least one second longitudinal flap connected to said second wall by a sixth fold line on the opposite side to the first longitudinal flap, it further comprises means for folding said second longitudinal flap to form at least two ears or two sidewalks on either side of the plate, and in that the mandrel is retractable between a plateau forming position and an exhaust position of the ears or sidewalks.

36. Device according to any one of claims 33 to 35, characterized in that each second wall comprising three central fold lines parallel to the third fold lines and two first longitudinal flaps located on either side of said central fold, it comprises means for folding said three lines to form in the middle of said second walls a central fold isosceles triangle.

37. A method of forming a tray from two blanks of cardboard sheet or corrugated cardboard material, namely a first blank formed of a bottom connected by first fold lines to two opposite first side walls and a second blank adapted to form two opposite second side walls of said plate, identical and symmetrical with respect to a dividing line, each second lateral wall each having at least one first longitudinal flap connected on one side to a second corresponding wall by a second line of folding and on the other side by said separation line at the outer periphery of the other first longitudinal flap of the second symmetrical side wall opposite, and two sets of transverse flaps each comprising at least one transverse flap, characterized in that, after cutting the second blank at the level of the separation line to form the two opposite second side walls, the first blank is transferred to an assembly station, it stops the first blank to give it an exact reference position, is transferred laterally by suction cups the second walls by gluing the first longitudinal flaps and the inner face of the second walls and / or sets of second flaps during their transfers, then they are placed on the first cut and indexed, the first longitudinal flaps are applied to the first blank, the flap sets are folded to the second walls, and the set of blanks thus constituted is transferred to a forming station to form the plateau.

38. The method of claim 37, characterized in that each set of transverse flaps comprising a first transverse flap connected to the corresponding second side wall by a third fold line and a second transverse flap connected by a fourth fold line to said first transverse flap, said second transverse flaps being each themselves connected by a fifth fold line to a third transverse flap, these folds are folded around pins to form a wedge angle of the plate and said third transverse flaps are applied to the inner face of the second walls facing each other.

39. Training method according to claim 38 characterized in that the tray is formed around a mandrel.

40. The method of claim 39, characterized in that, each second wall further comprising at least one second longitudinal flap connected to said second wall by a sixth fold line on the opposite side to the first longitudinal flap, folds said second flap. longitudinal to form at least two ears or two sidewalks on either side of the plate, and the mandrel is retracted between a plateau forming position and an exhaust position of the ears or sidewalks.

41. A method according to any one of claims 37 to 40, characterized in that each second wall comprising three central fold lines parallel to the third fold lines and two first longitudinal flaps located on either side of said central fold, folds said three fold lines to form in the middle of said second walls a central fold in isosceles triangle.