EP0328509A1 - Blank for a cardboard tray, particularly a corrugated cardboard one - Google Patents

Abstract

The blank for a cardboard tray, particularly a corrugated cardboard tray, has on its inside two folding grooves (36, 39), extending in the longitudinal direction, and two folding grooves (37, 38) extending perpendicular to the longitudinal direction, which folding grooves bound the bottom (31) of the tray and over which the side walls (32, 35) of the tray can be folded perpendicular to the bottom, approximately rectangular connection tabs (40-43) as extension of the side walls being formed at each corner of the bottom, by which connection tabs the side walls are connected to one another. It is proposed that, starting from the intersections (A') of the folding grooves bounding the bottom, the rectangular connection tabs have on their outside a diagonally outwardly extending folding groove (61) which divides the connection tabs in each case into two triangular regions (B', C'), the connection tabs being bonded on their one region (B') to the inside of the respective side wall and the bonded triangular regions being situated next to the respective unbonded region (C') and being connectable to the latter, e.g. by arresting straps (58) when the side walls of the tray are set up. <IMAGE>

Description

The invention relates to a sheet of cardboard, in particular corrugated cardboard, for a crate, which has two longitudinally extending folding grooves and two perpendicularly extending folding grooves which delimit the bottom of the crate and around which the side walls of the crate can be folded perpendicularly to the bottom, whereby protruding, approximately rectangular connecting tabs are provided on the side walls and hold the side walls connected to one another in the unfolded position.

In contrast to folding boxes with foldable bottom and lid flaps, there are so-called tray constructions for packaged goods for which no lid is required, which consist of a bottom part and / or side walls that can be folded up by 90 °. In order to be ready for use, the four side walls of such a tray must be connected with attached connecting parts at the corners (stapled, put together, glued, etc.) in order to remain at a right angle to the floor.

Especially when stacking "trays" there is the problem that the narrow side walls do not come into precise contact with one another. However, in order to prevent the "trays" from slipping into one another and thus damaging the packaged goods, it is customary to attach so-called stacking strips to at least two side parts of "trays", on which the stacked "trays" can be securely seated even with slight lateral displacements. As is customary in the industry, these packages are called crates, derived from the well-known wooden crates.

While normal "trays" with base and four side parts can be set up relatively easily manually or mechanically and locked at the corners, the attachment and fixation of stacking strips means a special effort. E.g. "Trays" machine-shaped and glued, this is usually done with a form stamp. If a stacking strip is formed at the same time, it is difficult to move the molding die out of the "tray". The technical effort and the loss of time therefore make the installation and bonding of trays considerably more expensive than the "trays" open at the top.

In the case of manually unfolded trays, the step-by-step unfolding of the side edges and the production of the corner connections plus the unfolding and fastening of the stacking strips results in a great deal of time. In addition, corner connections that are only made using slots and insert tabs are much more unstable than glued connections.

Machines that are designed as automatic machines are usually required to manufacture corner glued trays. Despite the advantages of machine-bonded crates, they cannot be used with all industrial or commercial packers, apart from the required machine investment. Space constraints, frequent format changes, a lack of specialist staff etc. are reasons for many packaging companies who, compared to wooden crates, have poorer quality, manually time-consuming folding corrugated cardboard crates for the transport of e.g. Do not use fruit, vegetables, meat, bread, etc.

The invention is now aimed at solving the problem that corner-glued crates can be produced by the manufacturer and brought to the user in the flat-folded state, which also saves transport costs compared to fully erected crates. This is achieved, starting from a cutting sheet of the type mentioned at the outset, that the rectangular connecting tabs, starting from the intersections of the folding grooves delimiting the base, have on their outside a diagonally extending folding groove which divides the connecting tabs into two triangular areas, wherein one of these areas is glued to the inside of each of the side walls, so that when the side walls of the tray are unfolded, the glued triangular area comes to lie next to the non-glued triangular area and can be connected to it. The packer can therefore pull up two side parts of the trays in a short amount of time, which at the same time brings the other two side parts into the vertical end position (90 ° to the floor) due to the corner gluing described. The stacking strips attached to the two opposite side walls then only need to be folded over and inserted in a conventional manner on the overlying side parts in order to stabilize the entire construction and make it ready for use.

For the user, time-consuming embossing and folding processes are thus eliminated before the filling process, and the crate according to the invention, like machine-glued crates, has maximum stability against dynamic side loads during transport.

Gluing the trays within the blank production process is much more economical than using individual gluing machines for each individual packer, since it is an integrated process and can be produced with one machine for the individual needs of many companies. In addition, it is possible to use corrugated cardboard materials that are more economical in terms of raw materials due to the strength gained in corner gluing and thus to compensate for the gluing costs.

Another advantage over crates, which are set up and glued in the individual packer with the help of a gluing machine, is that after using the packaging and after loosening the stacking tabs, the crates are brought back to their original flat shape without damage and space-saving for later reuse can be kept. The new type of packaging also offers the greatest production and supply security for its users. Due to the space-saving condition of the flat, internally glued crates, stocks can be kept available without storage space overloads, without having to fear bottlenecks in top-quality productions (e.g. in the harvest season due to the lack of personnel for manual crate erection or the limited machine capacity for gluing machines).

Exemplary embodiments of the blank sheet according to the invention or of the tray made from this blank sheet are explained in more detail with reference to the drawing. In the drawing, FIG. 1 shows a plan view of the blank sheet after a punching operation carried out by machine.

Fig. 2 illustrates the glued blank sheet ready for use. 3 and 4 show details of the blank sheet, namely a corner when unfolding.

5 shows a plan view of a further exemplary embodiment of the blank sheet according to the invention after a machine-operated punching or creasing process. FIG. 6 illustrates a corner of the blank sheet according to FIG. 5 on a somewhat larger scale. Fig. 7 shows a part of the blank sheet in the state ready for dispatch. 8 and 9 finally illustrate a corner of the set up and ready for filling tray in a perspective view or seen from the front.

1 consists of a bottom 1 and side walls 2, 3, 4, 5, which are divided from the bottom along folding grooves 6, 7, 8, 9. The side walls 2 - 5 are connected to one another via approximately rectangular connecting tabs 10, 11, 12, 13 in the corners of the rectangular part of the cut sheet consisting of the bottom and the side walls, which also run along folding grooves 14, 15, 16, 17 from the side walls are divided.

Stacking strips 18, 19 are formed on two opposite sides of the blank sheet, in the example shown following the side walls 3, 4, which extend from the adjacent side walls along folding grooves 20, 21 are divided. However, the stacking strips are separated from the respectively adjacent connecting tabs 10 - 13 along incisions 22.

The stacking strips 18, 19 also have folding grooves 23, approximately in the extension of the folding grooves 6, 14, 15 or 9, 16 and 17. Furthermore, folding grooves 24 are provided on the outer corner of the stacking strips, approximately at an angle of 45 ° run to the edges of the stacking strips.

All of the folding grooves mentioned so far enable the material to be folded over to the inside of the blank. On the other hand, folding flaps 25 to 13 are provided on the outside of the blank sheet on the connecting tabs, which extend from the intersection points A of the folding grooves 6, 7, 8, 9 delimiting the bottom 1 and extend diagonally at 45 ° to the outer corner of the connecting tab that they end approximately on the possibly rounded outer corner of the connecting tabs 10-13.

These folding grooves 25 thus subdivide the approximately rectangular connecting tabs 10 - 13 into two triangular areas B, C. At the same distance from the respective folding groove 25, slots 26, 27 are provided on both sides thereof, parallel to the folding groove. In the outer corners of the side walls further slots 27 'are formed, which are of approximately the same size as the slots 26, 27 and extend symmetrically with respect to the extensions of the folding grooves 7 and 8 to the slots 27.

The cutting sheet described above can be made in a first operation from a plate e.g. be punched out or corrugated from corrugated cardboard. In a second operation, the connecting tabs are provided with adhesive in their area B adjacent to the side wall 2 or 5 and folded around the folding grooves 7 and 8, so that the blank sheet assumes the state shown in FIG. 2. Here, the slots 27, 27 'coincide with each other. The cut sheet glued in this way can be stacked and delivered in order to be unfolded into a crate at the application site before being filled with packaging material.

The unfolding is illustrated in FIGS. 3 and 4 and is carried out by pulling apart and erecting the side walls in a position perpendicular to the floor 1. Then the stacking strips 18, 19 are bent around the folding line 20 and 21 and thus arrive in their final position parallel to the bottom 1. The end parts 18 ', 19' of the stacking strips are finally pulled down to the side walls 2 and 5 and their triangular tabs 28 as Lock in the now overlapping slots 26, 27, 27 'inserted. The tray is now ready to be filled with any packaging material and has sufficient stability to allow filled trays to be stacked. The production takes place in two work steps (punching and creasing or gluing), however, on only one machine and thereby results in a particularly economical manufacturing process, which eliminates the use of expensive machines.

Details deviating from the embodiment described above are conceivable. For example, the tab 28 can also be designed differently than triangular; it is crucial that it is plugged into the slots 26, 27, 27 'and acts as such. The slots 26, 27, 27 'can be shaped differently, e.g. circular perforations or punched through which a locking device can be inserted.

In certain cases, however, these insertion tabs have the disadvantage that the stretched-in elements protrude into the interior of the trays and can thus damage the contents or impair the filling volume. On the other hand, the corner connections of the stacking strips serve to stabilize the longitudinal walls. Since this is done by inserting the ends of the stacking strips at those points where the triangular connection tabs are located, it is possible, after another thought, to create a special locking and thus a stiffening of the corner connections of the tray. In this locking process, which is explained in more detail below, the work involved is less due to an almost non-targeted pressing of the parts to be connected than when inserting locking tabs into slots; Unintentional unlocking is no longer possible and the ends of the stacking strips no longer protrude into the interior of the packaging.

All this is achieved according to a development of the invention in that the locking tabs are provided with an undercut, preferably semicircular extension, and that the triangular, glued area of the connecting tabs and the area adjacent to this area of the adjoining side wall are each punched out , of which the punching in the triangularly glued area is larger in its contour than the punching in the adjacent area of the adjoining side wall with which it folds the side walls around the folded edge and glues the areas comes to lie on top of each other. In this case, the two punched-outs are designed in such a way that the preferably semicircular extension of the locking tab can be pushed through the punched-out side wall and can be locked like a push-button in the punched-outs which together form an undercut.

This measure allows a kind of barb or push button effect if the locking tab engages sufficiently deep in the punched out, with the result that the crate filled with packaging material can also be gripped and manipulated on the stacking strips so that the stacking strips perform a dual function.

This development of the invention is described in more detail below with reference to the exemplary embodiment from FIGS. 5-9.

5 consists of a base 31 and side walls 32, 33, 34, 35 which are divided from the base 31 along folding grooves 36, 37, 38 and 39. The side walls 33-35 are connected to one another via approximately rectangular connecting tabs 40, 41, 42, 43 in the corners of the rectangular part of the cut sheet which consists of the floor and the side walls and which also run along folding grooves 44, 45, 46, 47 from the side walls are divided.

On two opposite sides of the blank sheet in the example shown, adjacent to the side walls 33, 34, stacking strips 48, 49 are formed, which are separated from the adjacent side walls along folding grooves 50 51. However, the stacking strips 48, 49 are separated from the respectively adjacent connecting tabs 40-43 along incisions 52.

The stacking strips 48, 49 have folding grooves 53, approximately in the extension of the folding grooves 36, 44, 45 and 39, 46, 47.

The ends of the stacking strips separated by the incisions 52 from the connecting tabs are designed as locking tabs 58. They have an extension 60 which is provided with an undercut 59 and is approximately semicircular in the present case.

All of the folding grooves mentioned above allow the material to be folded over to the inside of the blank sheet. On the other hand, folding flaps 61 are provided on the connecting tabs 40, 41, 42, 43 on the outside of the blank sheet, which originate from the intersection points A 'of the bottom flaps 36, 37, 38, 39 and diagonally underneath Extend 45 ° to the outside corner of the connecting tabs. Preferably, a hole is punched out of the cut sheet at the respective point of the intersection points A 'mentioned and the folding groove 61 ends at the possibly rounded corners of the connecting tabs 40-43. The folding grooves 61 thus divide the approximately rectangular connecting tabs 40-43 into two triangular shapes Areas B ′ and C ′. Here, the triangular region B 'of the connecting tabs 40-43 and the regions D' adjacent to these regions of the side walls 32, 35 are each provided with a punching E, F, the punching E lying in the triangular areas B 'somewhat in its contour are larger than the punchings F in the adjacent areas D 'of the side walls 32, 35. The extension 60 of the locking tab 58 corresponds in the course of its contour (diameter, width) to the punched-out E and has somewhat larger dimensions than the contour of the punched-out F. When folding the cutting sheet around the folding grooves 37 and 38 by 180 ° to the state according to FIG. 7 and then gluing the triangular areas B 'to the respectively adjacent area D' of the side walls, the punched-out areas E and F (FIGS. 6, 7 ).

When the blank is set up, starting from the state according to FIG. 7 after folding around the folding groove 61, the regions B 'and D' which are glued to one another lie on the respective triangular region C 'of the connecting tabs, the crates thus set up being perpendicular to one another and to the floor has standing side walls. The stacking strips 48, 49 are then folded around the folded edges 50, 51 and the ends of the stacking strips, that is to say the locking tabs 58, are pulled down over the respective side wall, as shown in FIGS. 8 and 9. Thereupon it is possible to press the extensions 60 into the respective punched-out area F, whereupon the extensions 60 get caught by the corners 62 of the extended areas 60 coming to lie under corner-shaped extensions 63 of the punched-out area F (FIG. 9).

The extension 60 is somewhat larger in its dimensions than the punched-out F, through which it is pressed for hooking. On the other hand, the punched-out E is larger than the punched-out F and is approximately the same size as the extension 60, the indentation of the extensions being made possible by their slight deformation and the locking by Spring back into the undeformed position. After this locking, which is easy to carry out manually, the stacking strips are firmly connected to the side walls, so that the tray can also be raised on the stacking strips after filling.

It can be seen that the locking tabs do not protrude into the interior of the crate, thereby preventing possible damage to the packaged goods. The blank according to the invention also has the advantage that it can easily be set up on the spot to form a tray and this can be brought into a stable shape by locking the stacking strips.

As can be seen particularly from FIG. 8, the stacking strips 48, 49 are provided with vertically standing tabs 64 and the bottom 31 of the tray with perforations 65, which prevents the stacked trays from slipping sideways.

Claims (5)

1. Cutting sheet for a crate made of cardboard, in particular corrugated cardboard, which has on its inside two longitudinal fold grooves and two fold grooves running perpendicular to it, which delimit the bottom of the crate and around which the side walls of the crate can be folded perpendicular to the bottom, whereby Rectangular connecting tabs are formed as an extension of the side walls at each corner of the floor, from which the side walls are connected to one another, characterized in that the rectangular connecting tabs (10-13, 40-43), starting from the intersection points (A, A ′) of the folding grooves (6-9, 36-39) delimiting the bottom (1, 31), on their outside of the cut have a folding groove (25, 61) that extends diagonally outwards, each of the connecting tabs in two triangular areas (B, C, B ′, C ′), with the connecting tabs at one area (B, B ′) are glued to the inside (D, D ') of the respective side wall (2, 5, 32, 35) and when the side walls of the crate are set up, the glued triangular regions (B, B') next to the respective unglued region (C, C ') And are connected to them, for example by locking tabs (28, 58). 2. Cutting sheet according to claim 1, characterized in that the respective two triangular regions (B, C) of the connecting tabs (10-13) and the side walls (2, 3, 4, 5) have slots (26, 27, 27 ') , which overlap in the set-up position of the side walls and can be inserted as a lock through the tabs (28). 3. Cutting sheet according to claim 1 or 2, characterized in that on two opposite side walls (3, 4) of these along a folding groove (20, 21) divided stacking strips (18, 19) are formed, which are in the erected position of the side walls are parallel to the bottom (1) of the crates and have tabs (28) at both ends, which can be inserted as a lock through the overlapping slots (26, 27, 27 '). 4. Cutting sheet according to claim 1, characterized in that the locking tabs (58) are each provided with an undercut, preferably semicircular extension (60), and that the triangular glued areas (B ') of the connecting tabs (40, 41, 42, 43) and the respective areas (D ′) adjacent to these areas of the adjoining side walls (32, 35) are each provided with a punch-out tongue (E, F), the punched-out area (E) lying in the triangularly bonded area (B) being larger Has dimensions as the punched-out (F) in the adjacent area (D ') of the adjoining side wall with which it folds around the folded edges (37, 38) and the areas (B', D ') covers, and that both punched-out (E, F) are designed in such a way that the respective, preferably semicircular ending extension (60) of the locking tabs (58) by the associated punched (F) of the respective S. can be pushed through the side wall and can be locked like a push button in the cutouts (E, F) which together form an undercut. 5. Cutting sheet according to claim 4, characterized in that the extensions (60) of the locking tabs (58) are larger in their dimensions than the punched-out portions (F) located in the side walls (32, 35) and in the triangular regions (B ' ) cutouts (E) are larger than the cutouts (F) of the side walls (32, 35) and are approximately the same size as the extensions (60), the overlapping cutouts (E, F) in the triangular regions (B ′) form a common undercut with the side walls (32, 35) along one of their mutually assigned edges, in which the respective extension (60) can be hooked (FIG. 9).

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