CARDBOARD PACKAGING WITH A CLOSURE AND RETENTION SYSTEM FOR ONE LID

Abstract

A cardboard container with a retention system for a closing lid, the container comprising a bottom (3), a closing lid (2), and side walls attached to the bottom (3) of the box; wherein upper edges of the side walls define an opening (8) that is closed by the lid (2) in a folded position of said lid (2), which is joined, by means of a fold line (9), to an upper edge of a rear side wall (4) opposite a front side wall (5); wherein the retention system (1) comprises a locking section (12) located in the front side wall (5) and a flap (10) that is an extension of a front edge (11) that forms part of the perimeter of the lid (2); and wherein said front edge (11) is parallel to the fold line (9) joining the lid (2); characterized in that: - the flap (10) comprises two aligned tabs (101, 102), where each tab (101, 102) includes an end extension (101a, 102a); where said end extensions (101a, 102a) generate respective open recesses (101b, 102b) delimited by the end extensions (101a, 102a) of each tab (101, 102) and by a portion of the front edge (11) of the lid (2); - where the fitting section (12) comprises two front slots (121, 122) where each front slot (121, 122) comprises an upper section (121a, 122a) and a lower section (121b, 122b) located under the upper section (121a, 122a); where the upper section (121a, 122a) has a first width (B1) that is of lesser extent than a second width (B2) of the lower section (121b, 122b); where each front slot (121, 122) is adjustable to a corresponding tab (101, 102) each of said tabs (101, 102) being dimensioned to be inserted and extracted through the corresponding lower section (121b, 122b) of the front slot (121, 122), and to fit with retention into the upper section (121a, 122a) of said front slot (121, 122), where, with the cover (2) in the folded position, the extreme extensions (101a, 102a) of each tab (101, 102) are in contact with portions of the outer face of the front side wall (5) of the box.

Description

CARDBOARD PACKAGING WITH A CLOSURE AND RETENTION SYSTEM FOR ONE LID Object and field of the invention The present invention relates to a cardboard container with a retention system for a closure lid that forms an integral part of the cardboard container itself; where the closure lid is configured to be able to close an opening of said container in a very particular way, maintaining a certain tension on the closure lid, thus enhancing the security of the closure of the cardboard container. To achieve this, the closure lid incorporates a flap comprising two aligned tabs, each tab designed to engage with a corresponding slot located on the front side wall of the container. Thus, in the closed position, with the tabs engaged in their respective slots, these tabs provide a characteristic double locking mechanism that prevents the lid from accidentally opening. This double-locking system using two independent tabs provides greater security and stability in the closure of the container compared to systems with a single central flap, distributing the retention forces more evenly along the front edge of the lid and minimizing the risk of deformation or accidental release of the closure, even when the container is completely full or subjected to rough handling. The present invention falls within the technical field of cardboard packaging, and more specifically within that of cardboard packaging provided with an integrated closing lid that incorporates a retention system configured to keep said lid securely in a closed position. The retention system of the invention is particularly applicable to cardboard packaging intended for the storage and transport of various products, especially those that require a secure and reliable closure that prevents accidental opening during handling, transport or display at points of sale. Background of the invention Currently, there are many types of cardboard packaging, among which it is worth highlighting those packaging whose opening is closed by means of a lid that includes a flap that is configured to be inserted through a front slot located on one of the side walls of the packaging; all of this as disclosed, for example, in document IT201900003575U1. In this case, the lid retention system is a weak latch, unable to provide security in maintaining the container's closure when the container is subjected to rough handling by a user. In such cases, the lid latch usually comes loose, releasing the container's opening. This can cause the contents to spill out, damaging them or even resulting in their loss if they are fragile, such as when the contents are tableware or glass items. Another limitation of the container described in the aforementioned document is that when the container is completely filled with the corresponding product, reaching contact with the lid itself, it may happen that, during handling of the container, and even without handling it, the product load itself can push the lid upwards, towards the opening position and easily release the mouth of the container, leaving the product inside exposed to the outside unprotected. Additionally, there are prior art cardboard containers that incorporate closure systems with a single continuous central flap that fits into a central groove. While these systems can provide a functional closure, they have significant limitations regarding the distribution of retention forces. A single central flap concentrates all the closing stress on a small area of ​​the front edge of the lid, which can cause localized deformation of the cardboard material, especially when the container is fully filled or subjected to repeated handling. Furthermore, single-flap locking systems are more susceptible to material fatigue failure, as the area of ​​repeated folding and unfolding is concentrated in a limited space. This can result in a gradual weakening of the locking mechanism, reducing its effectiveness with continued use and compromising the safety of the closure in the medium term. Therefore, there is a need in the state of the art to develop an improved retention system that distributes the closing forces more evenly, minimizes the risk of deformation of the cardboard material, and provides greater security against accidental openings, even when the package is completely full or subjected to rough or repeated handling. Description of the invention In order to achieve the objectives and avoid the drawbacks mentioned in the previous sections, the invention proposes a cardboard container with a system for retaining a closing lid. The cardboard box comprises a bottom, a lid, and side walls attached to the bottom. It also includes front walls. The upper edges of the walls define an opening that is closed when the lid is folded. The lid is joined, by a fold line, to the upper edge of a rear side wall opposite a front side wall. The retention system comprises a locking section located on the front side wall and a flap that extends from a front edge forming part of the lid's perimeter. This front edge is parallel to the fold line joining the lid to the rear side wall. The flap comprises two aligned tabs, each with an end extension. These end extensions create open recesses defined by the extensions themselves and a portion of the front edge of the lid. This configuration of two independent tabs, instead of a continuous central flap, allows for a balanced distribution of retention forces along the front edge of the lid. Each tab acts as an independent anchor point, minimizing the risk of localized deformation of the cardboard that could occur with a single central flap. The recesses created between the end extensions and the front edge of the lid serve a technical function by allowing each tab to have two sections of different widths, facilitating attachment by the latching and retention mechanism. The locking section comprises two front slots, each consisting of an upper section and a lower section located beneath the upper section. The upper section has a first width that is narrower than the second width of the lower section. This staggered configuration of each front slot is crucial for the retention system's operation, as the wider lower section allows for loose insertion and removal of the tabs, preventing the user from having to force the cardboard material during opening and closing operations. Conversely, the narrower upper section provides the precise fit necessary to keep the tabs securely retained. Each front slot is adjustable to a corresponding tab, each tab being sized to be inserted and removed through the corresponding lower section of the front slot and to fit securely into the upper section of that front slot. When the lid is in the folded position, the outermost extensions of each tab are in contact with portions of the outer face of the front side wall of the case. This contact of the outermost extensions against the outer face of the front side wall is the key element of the retention system, as it physically prevents the tabs from being forced out through the front slots when the lid tends to open. The double-flange retention system provides a balanced distribution of forces by having two independent anchor points, preferably positioned symmetrically, so that the retention forces are distributed evenly along the front edge of the lid. This contrasts with single-flange systems, where all the stress is concentrated in a small area, causing localized deformation and progressive weakening of the material. Furthermore, the double-locking mechanism provides redundant safety, so that even if one of the tabs suffers damage or partial deformation, the second tab will continue to provide retention, keeping the container securely closed. When the lid is folded in the closed position, regardless of whether the container is full, upward pressure is exerted on the lid by the fold line. The double-flap system distributes this pressure between two anchor points, significantly reducing the risk of the contents releasing the closure—a common problem with single-flap systems. The configuration of the front slots allows the tabs to be inserted and removed loosely through the wider lower section, facilitating opening and closing without forcing the material. Once inserted, the tabs snap into the narrower upper section, providing a precise fit that ensures retention.By preventing stress concentration in a single area, the system reduces fatigue of the cardboard material, allowing for multiple opening and closing cycles without significant deterioration of the retention mechanism. The extended tabs, visible against the outer face of the front side wall, provide a clear visual indication that the package is properly closed, which is especially useful in fast-paced environments such as retail outlets or warehouses. In a particular configuration, each tab comprises a first section attached to the front edge of the lid, having a first width that is delimited between the recess and an outer side edge of each tab, and a second section having a second width that is greater than the first width, where said second width comprises the first width of the first section plus a width equal to the extreme extension of each tab. The lower section of each front slot has a second width adjustable to the second width of the second section of each tab, while the upper section of each front slot has a width adjustable to the first width of the first section of each tab.This specific geometric configuration ensures a precise dimensional fit between the tabs and the front slots. The wider second section of each tab can easily pass through the wider lower section of the slot during insertion. The narrower first section fits snugly into the narrower upper section of the slot, providing the necessary retention. The outermost extensions, being wider than the first section, automatically align with the outer face of the front side wall once insertion is complete. This precise dimensional fit eliminates excessive play that could allow unwanted movement of the lid, while also preventing overly tight fits that would hinder opening and closing or damage the cardboard. Preferably, the two front slots are identical and arranged on the front side wall, symmetrically with respect to a median plane of symmetry perpendicular to the front side wall, the bottom, and the lid of the carton. The symmetrical arrangement of the front slots ensures that the retention forces are distributed evenly on both sides of the carton's median plane, preventing torsional moments that could deform the lid or side walls. Furthermore, the identical front slots simplify the die-cutting process during carton manufacturing, as the same cutting geometry can be used for both slots, reducing production costs and minimizing manufacturing errors. The symmetrical arrangement also gives the carton a balanced and professional appearance, which is important in commercial applications where product presentation is key. Additionally, the two tabs are identical and arranged symmetrically with respect to a median plane of symmetry, perpendicular to the front side wall, the bottom, and the closing lid of the cardboard container. The symmetry of the tabs, in combination with the symmetry of the front slots, provides a perfectly balanced retention system that ensures that the retention forces are identical on both sides of the container, that the closing process is intuitive for the user as both tabs are inserted identically into their respective slots, and that the wear of the cardboard material is uniform on both sides, maximizing the lifespan of the retention system. Advantageously, the locking section comprises a central element that forms part of the front side wall, located between the two front slots. In the folded position of the lid, this central element sits between the two flap tabs, abutting the two end extensions. The central element serves an important technical function as a reinforcing and positioning element, providing additional rigidity to the front side wall in the area where the slots are located. This prevents the wall from deforming or buckling under the pressure exerted by the tabs. By abutting the two end extensions of the tabs, the central element acts as a centering element, ensuring that both tabs are correctly positioned in their respective slots and preventing lateral displacement that could compromise the effectiveness of the closure.In addition, the central element helps to distribute the loads exerted by the tabs towards the lateral areas of the front side wall, preventing stress concentrations that could weaken the material. In a practical configuration, the end extensions of the tabs comprise curved and / or angled edges for inserting the tabs through the lower section of the front slots. These curved and / or angled edges significantly facilitate the tab insertion process, as they act as guiding surfaces that direct the tabs into the front slots, reducing the precision required by the user during the closing operation. The curved or angled geometries allow the tabs to slide smoothly through the lower sections of the slots, minimizing the effort required to complete insertion and reducing the risk of damaging the cardboard material. The ease of insertion provided by these curved or angled edges makes closing the package a quick and intuitive operation, enhancing the end-user experience. Additionally, the recesses feature curved and / or angled edges. These curved and / or angled edges complement the function of the curved edges on the end extensions, providing a smooth transition between the narrower first section and the wider second section of each tab. This smoothed geometry reduces stress concentrations in the transition zones, minimizing the risk of breakage or tearing of the cardboard material during repeated opening and closing cycles. In a specific configuration, the recesses of the flaps collectively form a rectangular trapezoid shape. This trapezoidal shape provides an optimal geometry that can be achieved through simple die-cutting operations, with straight cuts and a single angled cut, thus simplifying the manufacturing process and reducing costs. The trapezoidal geometry gradually distributes stress from the narrowest section to the wider section, avoiding sharp corners that could act as stress concentrators and points of origin for breakage. Furthermore, the trapezoidal shape gives the flap a clean and professional appearance. Functionally, the fold line between the lid and the rear side wall creates tension that tends to keep the lid in the open position. This tension is an important element of the retention system, as the lid's natural tendency to return to its open position generates a constant force that keeps the tabs pressed against the upper sections of the front grooves. This active force ensures that the retention system remains engaged even when the container is subjected to vibrations or sudden movements. The resistance the lid offers when folded provides tactile feedback to the user, indicating that they are overcoming the material's natural tension and are therefore correctly closing the lid.Furthermore, the constant tension exerted by the fold line compensates for any slight play that might exist between the tabs and the front slots, ensuring a firm closure without unwanted movement. Each front groove comprises an upper edge against which the corresponding tab abuts in the folded position of the lid, these tabs being inserted into the front grooves. The upper edge of each front groove acts as a stop element that limits the insertion travel, precisely defining the final position of each tab and ensuring that the lid always remains in the same closed position, thus providing consistency and repeatability in the container closure. When the lid tends to open due to its natural tension or the pressure of the contents, the tabs abut against the upper edges of the grooves, transferring these vertical forces to the front sidewall structure. This load transfer is essential to maintain a secure closure. The front slots are typically located near the top edge of the front side wall. This placement maximizes the available space within the package, and it is important to ensure sufficient cardboard material is present along the edge to maintain the closure's structural integrity. The upper sections of the front slots are tall enough to fully accommodate the first section of the tabs in the folded position of the lid. This complete enclosure of the first section of the tabs within the upper slot sections protects them from impacts or accidental snagging that could damage them or cause them to release unintentionally. Because they are fully housed within the upper sections, the tabs do not protrude above the top edge of the front side wall, giving the closed container a cleaner, more professional appearance. Furthermore, being fully inserted allows the tabs to utilize the full height of the upper sections, maximizing the contact surface and thus the maximum possible retention force. Brief description of the figures Figure 1 shows a perspective view of the cardboard container with the closure lid retention system, the subject of the invention, where the closure lid is in an extended position with the container opening released. A detail of the second front slot is included. Figure 2 shows a perspective view of the closed cardboard box, where the closing flap is in a folded position, closing the opening of the box. An enlarged detail is included showing how the second tab of the flap is inserted into the second front slot, housed in the upper section of said second slot. Figure 3 shows a top view of the retention system in an unlatched position. This figure illustrates the dimensions of the flap tabs, particularly the widths A1 and A2 that define the tab sections, as well as the recesses defined by the end extensions. Figure 4.- Shows a front view of the retention system in an engaged position, where you can see how the second tab of the flap is inserted into the second front slot, with the extreme extensions in contact with the outer face of the front side wall. List of references shown in the figures: 1 - Retention system 2 - Closing lid 3 - Fund 4 - Rear side wall 5 - Front side wall 5.- Upper edge of the front side wall 6 - First front wall 7 - Second front wall 8 - Mouthpiece 9 - Fold line 1.- Flap 10.- First tab 101.- Extreme extension of the first eyelash 101.- Hollow of the first eyelash 10.- Second tab 102.- Extreme extension of the second eyelash 102.- Hollow of the second eyelash 1.- Front edge 1. Lace section 12.- First front slot 121.- Upper section of the first front slot 121.- Lower section of the first front slot 12.- Second front slot 122.- Upper section of the second front slot 122.- Lower section of the second front slot 1.- Upper edge of the slot 1.- Central element A1 - First tab width A2 - Second tab width B1 - First slot width B2 - Second slot width Description of an example of embodiment of the invention Considering the numbering adopted in the figures, the cardboard container with a retention system (1) for a closing lid (2) comprises a bottom (3), the closing lid (2), and walls attached to the bottom (3) of the box. Between the side walls are a rear side wall (4) and a front side wall (5) opposite said rear side wall (4), as well as a first front wall (6) and a second front wall (7) opposite each other, all the walls forming a prismatic cavity. The upper edges of the side walls define an opening (8) that allows the container to be filled and emptied, where said opening (8) can be closed by means of the lid (2), ensuring its closure by means of the retention system (1) of the invention. As shown in Figure 1, the lid (2) is attached to the upper edge of the rear side wall (4) by means of a fold line (9) that tends to keep the lid (2) in an unfolded position. This tendency is due to the inherent tension of the cardboard material of the container, which is an important element of the retention system (1) since it generates a constant force that keeps the tabs (101, 102) pressed against the upper sections (121a, 122a) of the front slots (121, 122) when the container is closed. The retention system (1) of the invention comprises a flap (10) that is an extension of a front edge (11) forming part of the perimeter of the lid (2), wherein said front edge (11) is parallel to the fold line (9) joining the lid (2) to the rear side wall (4) of the container. The flap (10) of the retention system (1) is complemented by a snap-on section (12) located on the front side wall (5) in close proximity to its upper edge (5a), such that the retention system (1) comprises the combination of the flap (10) and the snap-on section (12). As shown in detail in Figure 3, the flap (10) comprises two aligned, identical, symmetrically arranged tabs (101, 102), where each tab (101, 102) includes an extreme extension (101a, 102a). These extreme extensions (101a, 102a) generate two open cavities (101b, 102b) delimited by the extreme extensions (101a, 102a) of each tab (101, 102) and by a portion of the front edge (11) of the lid (2). These hollows (101b, 102b) delimit a first width (A1) of a first section of each tab (101, 102) which is complemented by a second width (A2) of a second section comprising the first width (A1) plus the widths of the extreme extensions (101a, 102a) of each tab (101, 102). In the embodiment shown in the figures, the two tabs (101, 102) are identical and arranged symmetrically with respect to a median plane of symmetry perpendicular to the front side wall (5), the bottom (3), and the lid (2) of the cardboard container. This symmetrical arrangement ensures that the retention forces are distributed in a perfectly balanced manner on both sides of the median plane of the container, preventing torsional moments that could deform the lid (2) or the side walls. As shown in Figure 1, the fitting section (12) comprises two front slots (121, 122), each of which comprises an upper section (121a, 122a) and a lower section (121b, 122b) located below the upper section (121a, 122a), as can be seen in the detail of Figure 1. The upper section (121a, 122a) has a first width (B1) that is smaller than a second width (B2) of the lower section (121b, 122b). This stepped configuration of each front slot (121, 122) is essential for the correct operation of the retention system (1). The two front slots (121, 122) are identical and arranged on the front side wall (5), symmetrically with respect to the same median plane of symmetry mentioned above. The lower section (121b, 122b) of each front slot (121, 122) has a second width (B2) adjustable to the second width (A2) of the second segment of each tab (101, 102), while the upper section (121a, 122a) of each front slot (121, 122) has a width adjustable to the first width (A1) of the first segment of each tab (101, 102). As shown in Figure 3, the fitting section (12) comprises a central element (15) that forms part of the front side wall (5) located between the two front slots (121, 122). This central element (15) provides additional rigidity to the front side wall (5) in the area where the front slots (121, 122) are located, preventing said wall from deforming or buckling under the pressure exerted by the tabs (101, 102). In the embodiment shown, the extreme extensions (101a, 102a) of the tabs (101, 102) comprise curved edges to facilitate the insertion of the tabs (101, 102) through the lower section (121b, 122b) of the front slots (121, 122). Complementarily, the recesses (101b, 102b) comprise curved edges that provide a smooth transition between the first, narrower section and the second, wider section of each tab (101, 102). Collectively, the recesses (101b, 102b) of the tabs (101, 102) comprise a rectangular trapezoidal shape, as clearly shown in Figure 3. The container closure process is carried out as follows. Once the container has been filled with the corresponding product through its opening (8), it is closed by folding the lid (2) downwards against some resistance offered by the lid (2) to its folding due to the structure of the cardboard material of the container. During the folding process of the lid (2) downwards, the flap (10) is positioned close to the upper edge (5a) of the front side wall (5) where the locking section (12) is located. Next, the tabs (101, 102) are inserted into the box through the lower sections (121b, 122b) of the front slots (121, 122). Because the second width (B2) of the lower sections (121b, 122b) is adjustable to the second width (A2) of the second section of the tabs (101, 102), this insertion is done loosely without forcing the cardboard material. Subsequently, the narrower portion (A1) of each tab (101, 102) is fitted into the upper section (121a, 122a) of the corresponding front slot (121, 122). As shown in detail in Figure 2, in this closed position, each tab (101, 102) is substantially fitted into the upper section (121a, 122a) of its corresponding front slot (121, 122), with the tendency of the lid (2) to fold upwards towards the unfolded position maintained by the tension of the cardboard material at the fold line (9) that joins the lid (2) to the rear side wall (4) of the box. As shown in Figure 4, each front slot (121, 122) comprises an upper edge (14) against which the corresponding tab (101, 102) abuts in the folded position of the lid (2), said tabs (101, 102) being inserted into the front slots (121, 122). In this way, the closure of the container is completely ensured, with the tabs (101, 102) securely engaged against the front side wall (5). In the closed position shown in Figure 2, the outermost extensions (101a, 102a) of each tab (101, 102) are in contact with the central element (15) of the front side wall (5) of the box. This contact of the outermost extensions (101a, 102a) with the central element (15) is the key element of the retention system (1), as it physically prevents the tabs (101, 102) from being pushed out through the front slots (121, 122) when the lid (2) tends to open. The central element (15), located between the two front slots (121, 122), is positioned between the two tabs (101, 102) of the flap (10), abutting the two outermost extensions (101a, 102a). The upper sections (121a, 122a) of the front slots (121, 122) are tall enough to fully accommodate the first section of the tabs (101, 102) in the folded position of the lid (2). Being fully housed within the upper sections (121a, 122a), the tabs (101, 102) do not protrude above the upper edge (5a) of the front side wall (5), providing a clean and professional appearance to the closed container. The retention system (1) of the invention provides effective closure of the container, the main advantage of which is minimizing accidental opening of the container when closed with its lid (2) in the folded position, even when the container is completely full. The balanced distribution of retention forces between two independent anchor points significantly reduces the risk of the contents' pressure releasing the closure, a common problem in single-flap systems. Furthermore, the double-locking mechanism provides redundant safety, so that even if one of the tabs (101, 102) were to suffer any damage or partial deformation, the second tab would continue to provide retention, keeping the container securely closed. It should also be noted that the retention system (1) of the invention substantially facilitates the attachment and detachment of the tabs (101, 102), while preventing parts of the tabs (101, 102) from being deformed or bent, especially their extreme extensions (101a, 102a), all thanks to the fact that their fitting and detachment in the front slots (121, 122) is done loosely through the lower sections (121b, 122b) of the slots (121, 122).

Claims

1. A cardboard container with a retention system for a closing lid, the container comprising a bottom (3), a closing lid (2), and side walls attached to the bottom (3) of the box; wherein upper edges of the side walls define an opening (8) that is closed by the lid (2) in a folded position of said lid (2), which is joined, by means of a fold line (9), to an upper edge of a rear side wall (4) opposite a front side wall (5); wherein the retention system (1) comprises a locking section (12) located in the front side wall (5) and a flap (10) that is an extension of a front edge (11) that forms part of the perimeter of the lid (2); and wherein said front edge (11) is parallel to the fold line (9) joining the lid (2); characterized in that: - the flap (10) comprises two aligned tabs (101, 102), where each tab (101, 102) includes an extreme extension (101a,102a); wherein said extreme extensions (101a, 102a) generate respective open cavities (101b, 102b) delimited by the extreme extensions (101a, 102a) of each tab (101, 102) and by a portion of the front edge (11) of the lid (2); - wherein the fitting section (12) comprises two front grooves (121, 122) wherein each front groove (121, 122) comprises an upper section (121a, 122a) and a lower section (121b, 122b) located below the upper section (121a, 122a); wherein the upper section (121a, 122a) has a first width (B1) which is of lesser extent than a second width (B2) of the lower section (121b, 122b); where each front slot (121, 122) is adjustable to a corresponding tab (101, 102) each of said tabs (101, 102) being dimensioned to be inserted and extracted through the corresponding lower section (121b, 122b) of the front slot (121, 122), and to fit securely into the upper section (121a, 122a),of said front groove (121, 122), where, with the lid (2) in the folded position, the extreme extensions (101a, 102a) of each tab (101, 102) are in contact with portions of the outer face of the front side wall (5) of the box.

2. Cardboard container with a lid retention system, according to claim 1, characterized in that each tab (101, 102) comprises: - a first section attached to the front edge (11) of the lid (2) having a first width (A1) that is delimited between the recess (101b, 102b) and an outer side edge of each tab (101, 102); and - a second section having a second width (A2) of greater extent than the first width (A1), wherein said second width (A2) comprises the first width (A1) of the first section plus a width of the extreme extension (101a, 102a) of each flange (101, 102); wherein the lower section (121b, 122b) of each front slot (121,122) has the second width (B2) adjustable to the second width (A2) of the second section of each tab (101, 102), while the upper section (121a, 122a) of each front slot (121, 122) has a width adjustable to the first width (A1) of the first section of each tab (101, 102).

3. Cardboard container with a retention system for a closure lid, according to any of the preceding claims, characterized in that the two front slots (121, 122) are equal and are arranged in the front side wall (5), symmetrically with respect to a median plane of symmetry, perpendicular to the front side wall (5), the bottom (3), and the closure lid (2) of the cardboard container.

4. Cardboard container with a retention system for a closing lid, according to any of the preceding claims, characterized in that the two tabs (101, 102) are equal and are arranged symmetrically with respect to a median plane of symmetry,perpendicular to the front side wall (5), to the bottom (3), and to the closing lid (2) of the cardboard container.

5. Cardboard container with a closing lid retention system, according to claim 3, characterized in that the locking section (12) comprises a central element (15) that forms part of the front side wall (5) located between the two front slots (121, 122), wherein said central element (15) is located between the two tabs (101, 102) of the flap (10) in the folded position of the lid (2), abutting the two end extensions (101a, 102a).

6. Cardboard container with a retention system for a closure lid, according to any of the preceding claims, characterized in that the extreme extensions (101a, 102a) of the tabs (101, 102) comprise curved and / or inclined edges for the insertion of the tabs (101, 102) through the lower section (121b, 122b) of the front slots (121,122).

7. A cardboard container with a lid retention system, according to claim 6, characterized in that the recesses (101b, 102b) comprise curved and / or inclined edges.

8. A cardboard container with a lid retention system, according to claim 6 or 7, characterized in that the recesses (101b, 102b) of the tabs (101, 102) collectively comprise a rectangular trapezoidal shape.

9. A cardboard container with a lid retention system, according to any of the preceding claims, characterized in that the fold line (9) located between the lid (2) and the rear side wall (4) generates a tension that tends to maintain the lid (2) in an unfolded position.

10. A cardboard container with a lid retention system, according to any of the preceding claims, characterized in that each front slot (121,122) comprises an upper edge (14) against which the corresponding tab (101, 102) abuts in the folded position of the lid (2), said tabs being inserted into the front slots (121, 122).

11. A cardboard container with a lid retention system, according to any of the preceding claims, characterized in that the front slots (121, 122) are located in close proximity to an upper edge (5a) of the front side wall (5).

12. A cardboard container with a lid retention system, according to any of the preceding claims, characterized in that the upper sections (121a, 122a) of the front slots (121, 122) are of sufficient height to fully accommodate the first section of the tabs (101, 102) in the folded position of the lid (2).