WO2013056336A1

WO2013056336A1 - A cardboard sheet provided with one or more folding lines for the formation of a box and method for obtaining said sheet

Info

Publication number: WO2013056336A1
Application number: PCT/CA2011/001171
Authority: WO
Inventors: Bilal MADWAR
Original assignee: Madwar Bilal
Priority date: 2011-10-18
Filing date: 2011-10-18
Publication date: 2013-04-25

Abstract

The present invention concerns a cardboard sheet (1), preferably of the pass pour tout type, comprising one or more folding lines (2) for the formation of a box (4). The folding lines (2) are formed by a groove (2) that penetrates partially inside the thickness of the cardboard sheet (1). The groove is trapezoid-shaped and is such a way it terminates into the thickness of the cardboard with a flat edge (5) of a pre-determined width.

Description

TITLE

A CARDBOARD SHEET PROVIDED WITH ONE OR MORE FOLDING LINES FOR THE FORMATION OF A BOX AND METHOD FOR OBTAINING SAID SHEET

Technical field

The present invention refers to the technical field relative to the production of cardboard boxes .

In particular, the invention refers to an innovative cardboard sheet provided with folding lines made in such a way that the sheet results easily foldable at angles also superior to a right angle for the formation of a box and also in case of use of very rigid cardboard. The invention also discusses the box obtained starting from said sheet, the method of realization of said folding lines and the machinery for obtaining folding lines.

Background art

Cardboard boxes of various shapes and sizes which are used for very diverse purposes have long been known. For example, boxes of any size and shape are made for containing food products such as sweets and biscuits or boxes for containing non-food products such as shoes, jewels, pens, etc.

There also exist boxes which are commercialised in the shape of a pre-formed flat sheet and which, through a pressure on the sides, acquire the final shape of a box. In this case, there is the possibility of economizing significantly on waste.

In all said cases, either if the box is sold already finished or if it is to compose, it includes folding lines which can be obtained in different ways on the basis of the thickness of the cardboard.

In the case of minor thicknesses, a knurl is enough. On the other hand, in the case of major thicknesses, therefore superior to one millimetre, it is necessary to realize said folding lines by practising a groove on the cardboard sheet that penetrates partially into the thickness of the cardboard itself, creating a track line. However, the groove must have a pre-determined shape to allow to fold between them, one towards the other, the two edges at 90° and even at angles major than said right angle .

To that aim, the background art includes the realization of a V groove that consequently takes away an equivalent form of material. The V groove generates two walls which terminate inside the thickness of the sheet with an apex. Therefore, starting from the apex, such walls become progressively apart through the thickness. In this way, precisely thanks to the distance that increases progressively between said two walls, it is possible to fold the two edges one towards the other up to when said walls become in contact one with the other.

On the basis of the angle of the walls, the sides fold between them at different angles.

There exist in the background art various examples of production of boxes as described, such as the patent with publication number GB839580.

However, such a type of groove presents various technical inconveniences.

The first one concerns the fact that it is necessary · to increase significantly the inclination of the groove walls (angles of penetration with respect to the cut surface superior to 45°), that is increase the distance between the two legs forming the V, in order to be able to easily fold between them two edges at 90° or even at superior angles. This creates an important realization problem of the groove itself. Further, if the distance between the legs of the V is not enough, when the sheet is folded the two walls enter into contact with high pressure, creating strong states of tension that can cause tears, no matter the yield of soft cardboard.

The apex of the groove is also, in any case, a point of strong concentration of tension and this can cause the initiation of breakages also in the case of legs of V sufficiently separated.

Disclosure of invention

It is therefore the aim of the present invention to provide a new type of groove practised on a cardboard sheet for the formation of a box that solves at least in part said technical inconveniences.

In particular, it is the aim of the present invention to provide a cardboard sheet wherein the grooves, which generate the folding lines, are such as to allow the folding of two subsequent edges of the cardboard sheet also at angles superior to the right angle and without triggering any tension phenomena that may cause tears.

These and other aims are therefore obtained with the present cardboard sheet (1) comprising one or more folding lines (2) for the formation of a box (4) in accordance with claim 1.

The cardboard sheet includes one or more folding lines (2) of which at least one or all of them are formed by a groove that penetrates partially in the thickness of the cardboard .

In accordance with the invention, the groove is now trapezoid-shaped in such a way as to terminate into the thickness of the cardboard with a flat edge (5) of a pre- determined width.

In accordance with the invention, all the technical problems formulated are thus solved. The trapezoidal shape allows to substitute the apex of the V groove with a flat edge 5. In this way, all the tension states induced are significantly reduced precisely because of the presence of a pointed apex. Therefore, the risk of breakage or tear is significantly reduced along the folding line.

Moreover, the flat edge 5 distances the two inclined walls (7, 8) of the groove. In this way, it is possible to operate grooves at inferior inclinations being anyway able to easily fold between them two subsequent edges of the cardboard sheet at angles even superior to 90°.

The edge, by distancing the two walls, in some cases completely avoids the direct contact between the walls and in other cases anyway reduces the pressure of contact, thus allowing a folding of the cardboard also in case of cardboards that are very rigid and at high angles.

The flat edge is now physically a rotation pin (10) somewhat round between the two subsequent edges of sheet to fold, thus rendering the folding of the cardboard more functional.

The presence of a flat edge facilitates the operation of application of the eventual glue in the groove made.

Further advantages and characteristics can be deduced from the dependent claims .

Brief description of drawings

Further characteristics and advantages of the present invention will result clearer with the description that follows of some embodiments, made to illustrate but not limiting, with reference to the annexed drawings, wherein:

- Figure 1 describes, in an orthogonal section of the development direction in length of the folding line 2 on a cardboard sheet, the trapezoidal shape of the groove or track formed for the formation of a box;

- Figure 2 shows in a perspective view a cardboard sheet 1 on which said folding lines are practised that form said tracks at trapezoidal sections;

- Figure 3 shows as a way of example a box obtained starting from a sheet as per figure 2;

- Figure 4 and figure 5 show the folding of the cardboard sheet obtainable through said folding lines in accordance with the invention;

- Figure 6 and figure 7 show an axonometric view of the machinery used for the realization of such tracks;

- Figures from 8 to 14 show a possible embodiment of a box in accordance with the invention and preferably, but not necessarily, made in a cardboard of the pass par tout type.

- Figures from 15 to 17 show a second box shape in accordance with the invention and preferably, but not necessarily, made in a cardboard of the pass par tout type.

Description of some preferred embodiments

Figure 1 shows in section a cardboard sheet 1 which can be folded for the formation of a box 4 through one or more folding lines 2.

The sheet, as also schematically shown in figure 2 and in figure 3, can be of various shapes and sizes. Just for clarity purposes, figure 2 shows, in a non limiting way, a rectangular sheet with four folding lines 2 and folded to form a box 4.

In accordance with the invention, figure 1 shows the groove 2 that forms the folding line. The groove is therefore trapezoid-shaped, that is it allows the take away of material in such a way as to form a track whose transversal section, in other words the section orthogonal to the development direction of the groove line 2 on the sheet, is trapezoid-shaped .

The groove presents two inclined walls (7, 8) which penetrate inside the thickness of the cardboard.

The inclination of penetration, with respect to the surface 1' of the cardboard, can be variable, for example 45° with respect to the surface 1' .

Naturally, nothing would impede different inclinations with angles inferior or superior to said angle of 45°, for example 30°, 35°, 40° or 50°.

The two walls (7, 8) penetrate starting from the surface 1' and are distanced between them in such a way that, on the basis of the inclination of penetration, terminate into the thickness, delimiting a flat edge 5 of a pre-determined width.

Such a groove is particularly idoneous for sheets of major thickness in which the knurl is not feasible. In general, such sheets have a thickness superior to one millimetre. This invention allows the use even of cardboard of the "pass par tout" type which is very rigid since it is of pure compacted cellulose. In fact, it is known that such cardboard is used, in virtue of its rigidity comparable to a plastic plate, for the realization of frames and therefore considered not usable up to now for the formation of boxes. In fact, the background art of the V groove required the use of soft cardboard since, when the two walls of the groove touch one another, these present anyway a certain yield that allows to reach the pre-chosen angle. In case of very rigid cardboard, almost like a plastic-coated plate (in fact we talk about the "pass par tout" cardboard) the groove must be very precise because there is no yield of the material. Moreover, the apex of the V groove in this case certainly causes a tear because the rigidity of the material is too much. The present invention overcomes these limits, rendering usable also cardboard of the "pass par tout" type, generally known as "useless" for the formation of the boxes and thus allowing to realize boxes which present a major rigidity and therefore a major resistance to wear.

The edge 5 avoids the direct contact between the two walls (7, 8) also with folding angles superior to 90° or, in case of contact, reduces the pressure between the walls, allowing the formation of the box also with extremely rigid cardboard.

Figure 4 shows the effect of such a type of groove with an inclination of the walls (7, 8) of about 45° with respect to the surface 1' . Figure 4 shows how such a type of groove allows to fold perfectly the two parts of the sheet 1 around the edge 5 which serves as rotation pin. Thanks to the presence of the edge 5 that distances the two walls (7, 8), they do not enter into contact with an inclination at 90° around the edge 5 itself (see axes 110 and 100) . Figure 4 in fact shows with d the distance between the walls 7 and 8 when the sheet is folded at 90°.

Figure 5 shows how, in accordance with the invention, it is possible to continue folding the sheet around the groove in such a way as to obtain an inclination also superior to 90° (see angle OL) . In substance, the walls, on the basis of the width of the edge and of the inclination of the walls, will touch one another by rotations that allow even to lay down an edge on the other.

It is therefore clear how, in accordance with the invention, it is absolutely possible to realize a groove with walls (7, 8) at an inclination also inferior to 45°, being still able to fold the sheet on itself at 90° and avoiding the contact between the walls or anyway reducing the pressure of contact between the walls. Both figure 4 and figure 5 show how the edge 5 is somewhat round and this reduces significantly the state of tension in the folding point (unlike a V-shaped apex) , thus allowing also the use of cardboard of the pass par tout type.

Going back to figure 1, the groove, in a non limiting way, presents some sizes applicable to a preferred embodiment of the invention.

Generally, the flat edge 5 is realized in a size of width at least equal or superior to the millimetre. This optimises the technical effects described above.

In particular, an example, non limiting, of a high thickness of cardboard is shown in figure 1, for example of the pass par tout type, in the order of 1,3mm. In this case, a trapezoidal groove can be applied, for example, in such a way that the longer base of the trapezoid (distance between the walls 7 and 8 in the point of penetration in the surface 1' ) is of 3mm. With an inclination of penetration of the walls (7, 8) of about 45° at a depth of 1 mm an edge of width of 1 mm and a residual thickness of 0,3 mm are obtained.

This configuration is particularly advantageous for the following reasons:

The thickness of penetration of 1mm leaves a residue of about 0,3 mm which serves as a rotation pin. Such thickness guarantees a good mechanical resistance.

The relation between the width of 3 mm and that of a 1 mm between the superior and inferior bases of the groove allows to obtain a folding at 90°, impeding that the walls (7, 8) touch one another. Not only does this reduce the effect of tension but, above all, it allows to spread and maintain better in position the eventual layer of adhesive that wants to be applied.

Moreover, such a relation between the longer and the shorter bases of the trapezoid allows an easy and precise removal of the tapes of material delimited by the two walls (7, 8) for the formation of the trapezoidal track (as better explained below) .

Naturally, nothing would impede anyway to obtain grooves with relations of size different and/or on cardboard of any nature and of different thickness.

The figures that follow refer to the machinery used for operating such a groove.

In particular, figure 6 shows a head 50 rotatable around a central axis 200 and mounted on a sliding trolley (not visible just for descriptive simplicity purposes) . The head 50 moves with respect to a working plan on which the sheet 500 to be grooved is positioned for obtaining folding lines 2 of the box.

Once the sheet is fixed on the working plan, through a computerized control system, the depth of the groove is adjusted and the coordinates for the marking of the lines 2 are determined.

The rotatable head mounts a blade 51 with a predetermined inclination (see figure 7, for example) , which naturally determines the inclination of the walls 7 and 8.

Figure 7 therefore shows the formation of a first groove line that generates, for example, the first wall 7. At this point, being the groove line completed, the head rotates of 180° around its axis 200 to change the angle of the blade that thus becomes completely complementary to the preceding one. Figure 7 in fact shows the same head in a first position for the formation of the wall 7 and in the rotated position for the formation of the wall 8. Figure 7, for simplicity purposes and in a non limiting way, represents the two grooves that intersect, creating a groove that is V-shaped and not trapezoidal as described in the present invention. For obtaining the trapezoidal track, it is therefore necessary and sufficient that, following the rotation of the head, it contextually translates of such a pre-defined quantity as to realize a groove 8 that forms a second wall 8 sufficiently distanced and parallel to the wall 7 in such a way as to terminate in the thickness without intersecting the wall 7 (thus delimiting the edge 5) .

At this point, it is enough to operate the removal of the tape of material delimited by the two walls (7, 8) to obtain a trapezoidal track.

The operation of removal of the tapes can be made manually or through a mechanical element that lifts the tape, causing its detachment, or even through an aspirator .

This type of groove allows to obtain boxes in a very rigid material, such as the pass par tout. These boxes can be arranged in such a way as to fold in a flat manner as shown in figure 11. the user can purchase them to assemble them later in the shape of a box quickly, pressing them on the sides (see figures 9 and 10) . In this way, a significant economizing of waste is obtained.

The box, as shown in detail in figure 8, is presented as a flat sheet 20 in which all the folding lines 21 are present of which one or more of these can be realized, for example in the shape of a trapezoid as described as far.

Figure 8 shows two sides 22 and 23 which are glued both on a flank of the sheet through a foldable edge 28. The foldable edge 28 includes, preferably, the trapezoidal groove to allow to fold the edge itself on the cardboard sheet to which it is connected.

As shown in figure 8, each side (22, 23) includes two angles 24 at its ends. The angle 24 is subdivided in a first part 25 and in a second part 26 through a trapezoidal groove 30 as described. The angle 25 is connected to the part 50 of the sheet 1 through glue, while on the part 26 the application of an adhesive tape is included, whose removal allows to glue said part to the part 50, realizing the finite box shape (see figures 10 and 13 in succession) .

In accordance with the invention, the box can be entirely realized in pass pour tout material, realizing at least the trapezoidal groove 30 and allowing to flatten completely the box as shown in figure 11, even using a material as rigid as that.

In this way, as shown in figure 9, until the removal of the adhesive or bi-adhesive tape arranged on the parts 26 does not take place, it is not possible to fix the shape of the box.

The box can include also a magnet-metal coupling (250; 250' ) for the closure and a window 300 for allowing to visualize the content and eventually closed by a transparent material.

The window can be aesthetically enhanced by making an inclined bevel 350 which results particularly evident precisely with the use of the pass par tout.

This aesthetic effect allows to close the window also with a layer of non transparent material. In this way, the inside of the box is not visible but a nice frame effect is anyway obtained.

A second preferred embodiment of the box is identical to the preceding one, except for that fact that the angles 424 are not subdivided into two halves, but instead it is a single angle that is foldable with respect to the side 422 to which it is connected, always thanks to a groove as described.

The back angles 424 are provided with a detachable adhesive, while the front ones include the magnet 430. When the box is folded, as per figure 16 and 17, the angles can be fixed to the remaining part of the box after the removal of the adhesive, thus allowing the formation of the box. As shown in figure 17, the front side 450 includes two holes for the passage of the magnets, which couple to a relative metal 430' for the closure (or vice versa, naturally) .

Claims

A cardboard sheet (1) for the formation of a box (4) and comprising one or more folding lines (2) in the shape of a groove (2) that penetrate partially inside the thickness of the cardboard sheet (1) and characterized in that said groove is trapezoid-shaped in such a way as to terminate into the thickness of the cardboard with a flat edge (5) of a pre-determined width .

A cardboard sheet (1), according to claim 1, wherein the shape of the groove, in an orthogonal section of the development direction in length of the folding line (2), is trapezoidal.

A cardboard sheet (1), according to claim 1 or 2, wherein the groove is such as to remove a predetermined trapezoidal area of material in the thickness of the cardboard.

A cardboard sheet (1), according to one or more of the preceding claims from 1 to 3, wherein said groove generates a first (7) and a second wall (8), inclined with respect to the surface (1') of the cardboard sheet (1) and separated from each other with such a distance as to form said edge (5) to the final depth in which they penetrate in the thickness.

A cardboard sheet (1), according to claim 4, wherein the walls (7, 8) are included at 45° with respect to the surface ( 1' ) .

A cardboard sheet (1), according to one or more of the preceding claims, wherein the flat edge (5) has a width at least equal or superior to 1 mm.

A cardboard sheet (1), according to one or more of the preceding claims, wherein the longer base of the trapezoidal groove has a width of 3 mm and the shorter base forming the flat edge (5) has a width of 1mm.

8. A cardboard sheet (1), according to one or more of the preceding claims, wherein the groove is such as to form an isosceles trapezoid.

9. A cardboard sheet (1), according to one or more of the preceding claims, wherein the thickness of the sheet is at least equal or superior to 1mm, preferably equal to 1.3mm.

10. A cardboard sheet (1), according to one or more of the preceding claims, wherein said cardboard is of the pass pour tout type.

11. A box characterized in that it comprises a cardboard sheet (20; 400) as per one or more of the preceding claims from 1 to 10 appropriately folded.

12. A box, according to claim 11, wherein to the cardboard sheet (20; 400) are further connected two sides (22, 23) , said sides (22, 23) being provided with one or more folding lines (30) in the shape of a trapezoidal groove so as to be able to fold, extending entirely on the cardboard sheet (1) to which they result connected .

13. A box, according to claim 12, wherein said sides (22, 23) present, each one at its ends, an angle (24) foldable in two parts (25, 26) through a trapezoidal groove (30) and of which a first part (25) of the angle is connected to the base sheet (20) and the second part (26) is free and provided with an adhesive material in such a way that the box results compoundable by gluing said second part (26) to the sheet (20) .

14. A box, according to claim 12, wherein said sides (422) present, each one at its ends, an angle (424) that is foldable by means of a trapezoidal groove and is provided with an adhesive material in such a way that the box results compoundable by gluing the angle to the sheet (400) .

A box, according to one or more of the preceding claims from 11 to 14, wherein the cardboard sheet (20; 400) includes an opening (300).

A box, according to claim 15, wherein said opening (300) is delimited by an inclined bevel (350).

A box, according to one or more of the preceding claims from 11 to 16, wherein a magnet-metal coupling (250; 250'; 430, 430') is included for the closure of the box.

A method for obtaining a cardboard sheet (1) provided with one or more of the folding lines (2) for the formation of a box (4) and comprising the operations of:

- Arrangement of the sheet (1) below a mobile blade (51), the blade being arranged in such a way as to penetrate partially in the thickness of the sheet with a pre-determined first angle with respect to the surface (1') of the sheet;

- Realization of a first groove line (2) of a predetermined length;

- Extraction of the blade and arrangement of the blade in such a way that it results at an angle of penetration complementary to the first angle;

- Generation of a second groove line parallel to the first line and that penetrates at the same depth of the first groove line;

- And wherein the distance between said first and said second groove line is selected in such a way as to form an edge (5) in correspondence of the depth of penetration of said two lines in the thickness of the cardboard in such a way that the removal of the tape determines the formation of a trapezoid-shaped track.

A box characterized in that it is realized in accordance with the method of claim 18 starting from a cardboard sheet of the pass par tout type.

A machine for the formation of one or more folding lines (2) in a cardboard sheet (500) for the formation of a box (4) and comprising:

- A blade-holder (50) provided with a groove blade (51), the blade-holder being translatable along one or more groove direction parallel to a support plane for the sheet (500) and the blade being arranged according to a pre-determined angle of penetration with respect to the sheet, the blade-holder being further rotatable around a rotation axis (200) orthogonal to the support plane of the sheet and;

- Control means for controlling the movement of the blade-holder in such a way that at the end of the realization of a first groove line (7) that penetrates partially in the thickness of the sheet, said control means cause the rotation of the blade-holder of 180° around its rotation axis (200) in such a way as to realize a second groove line (8) parallel to the first groove line and distanced apart from the first groove line, the second groove line (8) penetrating in the thickness to the same depth of the first groove line (7) in a such manner that the removal of the tape delimited by said two grooves (7, 8) causes the formation of a trapezoid-shaped track.

A machine, according to claim 20, wherein means for removing the tape delimited by said two grooves (7, 8) are further included.