DE69430319T2 - CARDBOARD BOX WITH DEVICE FOR LOCKING THE LID AND CUT TO PREPARE IT - Google Patents

Description

The present invention relates to a box made of corrugated cardboard or an equivalent material with a polygonal section, which box has side surfaces, a bottom and a lid, comprising two mutually opposite upper flaps and two mutually opposite lower flaps arranged above said upper flaps, said flaps being connected to the side surfaces by fold lines, and wherein the lid comprises:

- two slots formed in the upper flaps on both sides of the cover, parallel to and at a distance d from the fold lines of the lower flaps, and

- two tabs, each cut out of the lower flaps on one side and hinged on the other side, parallel to the fold lines of the said lower flaps, each covering the said upper flaps and arranged so that their ends each engage in corresponding slots in the lid.

It also relates to a cutting device for making such a box. It is particularly, but not exclusively, applicable to polygonal boxes with more than four sides, for example those with eight sides, four of which are cut off, which, if not completely filled, may deform in the event of lateral stresses.

Locking systems are already known that allow the blocking of a box lid, which subsequently leads to disadvantageous deformations can be prevented. In particular, this involves sealing with adhesive tape.

However, such systems have disadvantages. In fact, they require an additional box element, namely the adhesive tape, and therefore entail additional costs and work processes during production.

A box of the type described above is also known (US-A-3,302,853), but it has other disadvantages. In fact, the flaps are closed by engaging their enlarged ends in the corresponding slots, which allows the lid to be effectively locked in the closed state, but makes it difficult to reopen the box, for example to affix a label to identify the contents or to add items to the contents of the box that was previously closed for the first time.

Also known (FR-A-1 083 621; US-A-2 167 917) are closure systems with tabs that are blocked by lateral or transverse protrusions under the opposite edge of slots. Such systems also have the disadvantage of making it difficult or even impossible to open the box again once it has been closed.

The invention relates to the manufacture of a box and a blank which meet the requirements imposed in practice better than the previous ones, in particular by proposing a system for closing the lid which allows good angularity of the box when closed, is simple and easy to use, does not entail additional costs and allows the successive closing and opening of the lid in a simple, reliable and reproducible manner.

To this end, the invention proposes in particular a box made of corrugated cardboard or equivalent material with a polygonal section of the type described above, characterized in that the end of each flap is in the shape of a point and is designed to abut below, over a distance h of the order of 5 mm or less, against the peripheral edge of the corresponding slot arranged on the side opposite the fold line of said flap.

In advantageous embodiments, use is also made of one and/or the other of the following arrangements:

- h is of the order of 2 mm or less;

- each slot consists of two half-slots provided opposite one another in the peripheral edges of the upper flaps, the tabs being laterally centred in relation to the corresponding lower flaps;

- each half-slit is continued in its end part located on the opposite side of the other opposite half-slit by a line which can be divided or cut out in the corresponding upper flap, said divisible or cut out line facing the fold line of the lower flap of the flap which corresponds to said half-slit over a certain distance and is located at the level of the corresponding edge of said flap.

Such an arrangement allows the system to function properly during successive closing and opening operations and at the same time allows greater elasticity of the hinge formed by the fold line of the tab.

- Each tab is essentially in the shape of a T, the crossbar of which is connected to the fold line of the tab in relation to the corresponding surface.

- Each tab has the shape of a rectangle or isosceles trapezoid, which ends in a triangular end section with an obtuse tip angle.

- The base consists of flaps connected to the side surfaces by fold lines, namely two opposing inner flaps and two opposing outer flaps, and comprises two recesses in the said outer flaps, the shape of which matches that of the tab.

The invention also relates to a blank made of corrugated cardboard film or an equivalent material, which is intended to form a box with a polygonal section and comprises:

- side covers connected to each other by first, parallel fold lines,

- a first arrangement of flaps suitable for forming the bottom of the box, which are connected to one side of the said lateral flaps by second folding lines extending orthogonally to the said first folding lines, and

- a second arrangement of flaps suitable for forming the box lid, which is connected to the other side of the said th side flaps are connected by third lines orthogonal to said first fold lines, said arrangement consisting of two side flaps referred to as upper flaps which are nested with two side flaps referred to as lower flaps,

the lower flaps each having a tab cut out of said flap on one side and connected to the adjacent cover on the other side by a fold line substantially coinciding with the third fold line of said flap,

the peripheral edges of the upper flaps opposite the third fold lines each having two slit parts arranged on either side of said upper flaps at a certain distance d from the lateral edges of said corresponding flaps,

characterized in that the end of the tabs forms a point and that the length d' of said tabs between the end of the point and the fold line of the tab with the envelope to which it is attached is slightly greater than said distance d.

Further essential features and advantages of the invention will become apparent from the following description, in which exemplary embodiments are explained with reference to the drawings. In the drawings:

- Fig. 1 is a plan view of a blank according to an embodiment of the invention;

- Figures 2 to 5 show steps in the formation and closing process of the lid of a box formed from a blank of the type described with reference to Figure 1;

- Fig. 6 is a plan view of another embodiment of a blank according to the invention;

- Fig. 7 is a plan view of a blank according to another embodiment of the invention; .

- Fig. 8 two perspective partial views of the closure flap of the lid made with the blank from Fig. 7 in the closure position and during elastic opening of the same by simply pressing on the lid;

Fig. 1 shows a blank 1 with a series of eight side envelopes, namely four main envelopes, including the two large envelopes 2 and 3, which are nested with two small envelopes 4 and 5, and four intermediate envelopes 6, which are suitable for forming the cut-off corners of the box, said intermediate envelopes being located between a large and a small envelope when the box is formed.

In the embodiment described here in particular, the row of envelopes ends on the one hand in a flap 7, which can be attached to the intermediate envelope 6, which is attached in relation to the said flap to the main envelope 2 arranged on the other side of the row of envelopes. The envelopes are connected to one another by the first, parallel folding lines 8.

The blank comprises a first arrangement of flaps 9, which is arranged on one side of the envelopes and is intended to form the box bottom, and a second arrangement 10 of envelopes, which is arranged on the other side of the Envelopes are arranged and intended to form the box lid.

In detail, the first arrangement 9 comprises four substantially rectangular flaps connected to the side surfaces of the four main envelopes by fold lines 11 which are perpendicular to the first fold lines, namely two large flaps 12 and 13 connected to the large envelopes 2 and 3 and two small flaps 14 and 15 connected to the small envelopes 4 and 5.

The intermediate envelopes 6 do not have any flaps.

In the embodiment specifically described here, the two large flaps 12 and 13 have a width in the transverse direction that is equal to or substantially equal to half the width of the box formed.

The large flaps 12 and 13 are identical. Each large flap comprises three sides 12.1, 12.2 and 12.3 (13.1, 13.2 and 13.3), namely two side surfaces 12.1 and 12.3 (13.1 and 13.3) located on either side of said flap and one side 12.2 (13.2) located parallel to and opposite the second fold line 11 of the flap with the corresponding cover.

Each side surface of the large flap comprises a first part which, starting from the two fold lines, is bevelled at 45º towards the inside of the flap and is designed to contact the adjacent intermediate envelope when the box is formed, the first part continuing in a second part perpendicular to said second fold lines, while said side surface is formed at an angle with the peripheral edge in a crescent-shaped recess 16 with a first shoulder 17 towards the inside of the flap, which may be rounded, for example, and a second shoulder 18, which is also directed towards the inside of the flap, for example at a right angle, the length of the peripheral edge 12.2, 13.2 of the parallel side between the upper ends 16' of the crescent-shaped recesses being L.

The small flaps 14 and 15 are identical and rectangular in the embodiment specifically described here. Their sides are also at a distance from the sides of the corresponding large envelopes, for example at a distance of a few millimetres.

The second arrangement 10 of flaps is connected to the four main envelopes by third fold lines 19, 20 and 21 running perpendicular to the first fold lines 8. The second arrangement has in detail two large flaps 22 and 23, which are each connected to the large envelopes by the fold lines 19, and two small flaps 24 and 25, which are each connected to the small envelopes by the fold lines 20 and 21, as will be described in more detail below.

The large flaps 22 and 23 each have three sides 22.1, 22.2 and 22.3 or 23.1, 23.2 and 23.3, namely two sides [22.1 and 22.3; 23.1 and 23.3] and one side arranged parallel to and opposite the third fold lines [22.2 and 23.2].

Each side comprises a first part which, starting from the third fold lines, extends obliquely outwards at an angle of 45º and is designed to come into contact with the corresponding intermediate covers when the box is opened. a second part arranged perpendicular to the third lines and an end part 26 bevelled towards the inside of the flap.

The peripheral edges of the sides 22.2 and 23.2 each comprise two identical, rectangular or substantially rectangular slots 27 and 28, which run perpendicular to the said edges and are located on both sides of the flap at a certain distance d, for example 3 to 5 mm, from the side edges 22.1 and 22.3 on the one hand and 23.1 and 23.3 on the other hand and have a length of x/2 and a width of 3.

The width l of the flaps 22 and 23 between the fold lines 19 and the peripheral edges 22.2 and 23.2 is equal to half the width of the box lid, so that when the box is formed, said edges abut one another, the slots 27 and 28 of the flap 22 being opposite the corresponding slots 27 and 28 of the flap 23 to form two identical, parallel slots lying on the junction between the flaps.

The small flaps 24 and 25 are themselves rectangular and have, for example, the same width 1 as the large flaps 22 and 23. They each have a tab 29 which, on the one hand, is cut out of the flap and, on the other hand, is connected to the cover 4 or 5 by a fold line 21 which is slightly offset towards the inside of the flap, for example by 1 or 2 mm in relation to the fold line 20, and which is located on either side of the said tab which is centred opposite the flap.

The tab has an end 30 in the form of a tip, which for example has an obtuse tip angle in the order of sion of 160 or 170º, the distance between the fold line 21 and the end of the tip 30 being d' and d' being slightly larger than d, for example two to three millimetres larger than d.

The tab also has a T-shape that matches the shape of the two symmetrical crescent-shaped recesses 16.

Figures 2 to 5 show the formation of a box 31 with cut corners 32, made with a blank of the type shown in Figure 1.

The box 31 has main side surfaces 33, a bottom 34 and a lid 35 comprising two identical, opposite upper flaps 36 and two identical, opposite lower flaps 37, which are connected to the side surfaces by fold lines 38 and 39, respectively.

Figures 4 and 5 show in detail the lid of the box, which has two slots 40 formed in the respective upper flaps on either side of the lid, parallel to the fold lines 39 of the lower flaps 37 and at a distance d from them to the surfaces to which they are connected.

The cover also comprises two tabs 41 which are cut out of said lower flaps 37 on one side and are arranged on the other side so as to be pivotable in relation to the side surface corresponding to said flap 37 about the fold lines 42 which run parallel to the fold lines 39 of the lower flaps 37 and slightly above them.

The tabs cover the upper flaps, which in turn cover the corresponding part of the cutout from the tabs of the lower flap, the end 43 of said tabs engaging in the slots 40.

The box base, in turn, has two small inner flaps 44 and two large outer flaps 45, which are each connected to the corresponding side surfaces by fold lines 46 and 47.

The base has two recesses 48, the shape of which matches that of the tabs, so that when the boxes are stacked on top of one another, the tabs engage in the recesses of a box above them, which enables the boxes to be blocked laterally in relation to one another.

Fig. 6 shows another embodiment of a blank 50 according to the invention.

The blank 50 here has only four covers 51 and an end-gluing tab 52 to form a parallel-flat box.

The flaps 53 forming the lid here have the same width, two of said flaps having tabs 54 of substantially rectangular shape, the ends of which are suitable for cooperating with the half-slots 55 which, once assembled, form the lid slots as described above.

For example, the flaps 56 forming the bottom of the box do not have any crescent-shaped recesses and are of the classic type for American boxes.

The design of the base and the lid of a box according to the invention will now be described with reference to Figs. 2 to 5.

The side walls of the box are formed by winding them around a mandrel, with the inner flaps being folded over first. The outer flaps are then folded over the inner flaps, as shown schematically in Fig. 2.

The box is then filled from the top. The lower flaps of the lid are then folded. Due to the offset arrangement between the fold lines 20 and 21, whereby the lines 20 are also more pronounced than the fold lines 21, the flaps remain straight or vertical (see Fig. 3).

Then the upper flaps of the lid are folded, with the perimeter edges of said flaps abutting each other (see Fig. 4).

Finally, the tabs are folded and their ends snap into the slots.

Fig. 7 shows a blank 60 made of double-sided corrugated cardboard, for example in a thick version (over 5 mm), according to another embodiment of the invention, which has four rectangular side covers 61, 62, 63 and 64, which are each connected in pairs by folding lines 65 running parallel to one another.

The blank ends on the one hand in a bonding flap 66 and has on one side in the transverse direction a first arrangement 67 of four flaps, each connected to one side of each lateral cover by second folding lines 68 running perpendicular to the first, and with which the box bottom is to be formed, and on the other hand a second arrangement 69 of four flaps, connected on the side opposite said covers by three folding lines 70, and with which the box bottom is to be formed.

The arrangement 69 consists of two rectangular side flaps 71 and 72, referred to as upper flaps, which are nested with two side flaps 73 and 74, referred to as lower flaps.

The lower flaps, for example, are isosceles trapezoids with a base angle α, which is in the order of magnitude between 88º and 70º.

They have, for example, the same height as the upper flaps and each have a tab 75 which is cut out of the flap and connected to the corresponding cover (62 or 64), as can be seen, for example, in Fig. 1.

Each flap has a lower part in the shape of an isosceles trapezoid, advantageously with a height d0 and a base angle β (long side of the trapezoid), said base coinciding or substantially coinciding with the fold line 70. The angle β is, for example, of the order of between 85º and 60º and is, for example, 80º.

The tab ends in a triangular end portion 76 with an obtuse tip angle, for example in the order of of 160º, and low height i, for example a height of 2 mm.

For example, the height of the tab (distance d' = d0 + i) is equal to half the width H of the flap.

The upper flaps 71 and 72 in turn have on both sides of their peripheral edge 77 opposite the fold lines 70 and extending from this a rectangular half-slit 78, which runs perpendicular to said peripheral edge 77 and the inner edge 79 (which faces the center of the flap) has a distance of or substantially of d0 from the next adjacent side edge 79 located perpendicular to the peripheral edge 77 of said flap.

Each half-slit 78 ends in a cut-out or divisible line 80 which is aligned over a certain length 1, for example in the order of 1 to 2 cm, obliquely to the edge 79 adjacent to the fold line 70.

The arrangement 67 intended for forming the box bottom has two essentially rectangular flaps 81 and 82, which are each nested in pairs with two flaps in the form of an isosceles trapezoid 83 and 84.

The flaps 81 and 82 each have an outer peripheral edge 85 which consists of two, for example, identical parts running parallel to the second fold lines 68, said edge being provided with a step between its two parts.

Each end of the flaps 81 and 82 also has a recess 87 or 88, the shape of which matches that of a half-flap, as already seen.

The operation of the closing/opening process of the lid will now be described in more detail with reference to Fig. 8.

In addition, the presence of the cut-out lines 80 facilitates the successive opening and closing operations of the box 89.

The flap 75 is opened by exerting pressure on the upper flaps 71 and 72 adjacent to the flap or by pressing the centre of the box lid, which allows the flap, the end of which is only slightly clamped under the upper flaps beyond the slot 90 formed by the two half-slits 78, to be released automatically with good elasticity, the inner part 91 of the upper flaps delimited by the lines 80 acting as a return spring.

Claims (12)

1. Box (31, 89) made of corrugated cardboard film or an equivalent material with a polygonal section, which has side surfaces (33), a bottom (34) and a lid (35), comprising two opposing upper flaps (36) and two opposing lower flaps (37) arranged above said upper flaps, said flaps being connected to the side surfaces by fold lines (38, 39) and wherein the lid (35) has: - two slots (40, 90) which are formed in the upper flaps (36, 71, 72) on both sides of the cover parallel to and at a distance (d, do) from the fold lines (39) of the lower flaps (37), and - two tabs (41, 75) each cut out of the lower flaps on one side and hinged on the other side, each parallel to the fold lines (39) of said lower flaps, covering said upper flaps each and each having an end (43) which engages in a corresponding slot in the cover, characterized in that the end (43) of each of the tabs forms a point and that the length d' of said tabs between the end of the point and the fold line of the tab with the cover to which it is attached is slightly greater than said distance (d, d0), said ends coming to abut below each of the peripheral edge of the corresponding slot located on the opposite side of the fold line of the tab over a distance h which is of the order of 5 mm or less. 2. Box according to claim 1, characterized in that h is in the order of 2 mm or less. 3. Box according to one of the preceding claims, characterized in that each slot (40) consists of two half-slots provided opposite one another in the peripheral edges of the upper flaps (36), the tabs (41) being laterally centered in relation to the corresponding lower flaps (37). 4. Box according to claim 3, characterized in that each half-slit is extended with its end part located on the opposite side of the other half-slit by a divisible or cut-out line (80) in the corresponding upper flap, said line extending over a certain distance from the fold line of the lower flap of the flap (75) corresponding to said half-slits and being located at the level of the corresponding edge of said flap. 5. Box according to one of the preceding claims, characterized in that each tab (41) has substantially the shape of a T, the crossbar of which is connected to the fold line (39) of the tab in relation to the corresponding surface. 6. Box according to one of claims 1 to 4, characterized in that each tab (75) has substantially the shape of a rectangle or an isosceles trapezoid which ends in a triangular part with an obtuse apex angle. 7. Box according to one of the preceding claims, characterized in that the bottom (34) consists of flaps (44, 45) which are each connected to the side surfaces by fold lines (46, 47), namely two opposing inner flaps (44) and two opposing outer flaps (45), said base comprising two recesses (48) in said outer flaps, the shape of which matches that of the tabs (41). 8. Blank (1, 50, 60) made of corrugated cardboard film or an equivalent material, intended for forming a box with a polygonal cross-section, comprising: - side covers (2, 3, 4, 5, 6; 51; 61, 62, 63, 64) which are connected to one another by first, parallel fold lines, - a first arrangement (9, 56, 67) of flaps connected to one side of said side flaps by second fold lines orthogonal to said first fold lines and adapted to form the bottom of the box, and - a second arrangement (10, 53, 69) of flaps connected to the other side of said lateral envelopes by third fold lines orthogonal to said first fold lines and suitable for forming the lid of the box, said arrangement consisting of two side flaps (22, 23; 71, 72) called upper flaps, between which there are two side flaps (24, 25; 73, 74) called lower flaps, said lower flaps each having a tab (29, 54, 75) cut out of said flap on one side and connected to the adjacent envelope on the other side by a fold line substantially converging with the third fold line of said flap, the peripheral edges (22.2, 23.2; 77) of the upper flaps opposite the third fold lines each having two slot parts (27, 28; 55; 78) on either side of the said upper flaps are at a certain distance (d, d₀) from the side edges of said corresponding flaps, characterized in that the end of the flaps has the shape of a point and the length of said flaps d' between the end of the point and the fold line of the flap with the envelope to which it is attached is slightly greater than said distance (d, do), by a distance h which is of the order of 5 mm or less. 9. Blank according to claim 8, characterized in that each half-slit (78) is extended at its end part opposite the outer peripheral edge (77) of the corresponding upper flap (71, 72) by a line which can be divided or cut out in said upper flap over a certain distance, said divisible or cut out line being oblique to the fold line (70) of the upper flap and to the lateral peripheral edge (79) of said upper flap which is closest to said half-slit and being arranged so that, after the formation of the box, it is at the level of the corresponding edge of the flap. 10. Blank according to one of claims 8 and 9, characterized in that each tab (29) has substantially the shape of a T, the crossbar of which is aligned with the central part of the corresponding third fold lines (20), parallel thereto and slightly offset from the inside of the flap in relation to these. 11. Blank according to one of claims 8 and 9, characterized in that each tab (54, 75) has essentially the shape of a rectangle or isosceles trapezoid, which ends in a triangular part with an obtuse apex angle. 12. Blank according to one of claims 8 to 11, characterized in that the sides of the bottom flaps, which correspond to the side surfaces provided with the upper flaps on the other side, have crescent-shaped recesses (16; 87, 88) whose shape matches that of a half-flap.