RU237734U1 - Closed box of flattened shape - Google Patents

Abstract

The utility model relates to cardboard packaging. A closed, flattened box, characterized by its composition consisting of a corrugated cardboard sheet box, open at the top, and a flat-folding lid, attached to the box, with the side walls equal in height to the box's side walls. The lid and the box are each made from a sheet blank by bending its parts along fold lines, having a rectangular bottom, from which the first two oppositely located side walls are bent along the fold lines, each made of two parts successively located through the fold line, the first of which has a slot for gripping by hand, at the end sections of the second part of the side wall, fold lines directed at an angle are made, the starting point of each of which is located at the extreme angular point on the fold line of the second part of the side wall from the bottom, and the end point is on the free edge of the second part of the side wall to divide the end section by this fold line into two fragments of a triangular shape in plan, the second two oppositely located side walls are made with the possibility of bending from the bottom and are connected at the end sections by fold lines with the end sections of adjacent second parts of the side walls, during assembly, the second side walls are bent towards the bottom, laid on its surface and on the surface of the second part of the side wall with by gluing a fragment of the end section of the second part to the second part of the adjacent side wall, and the first part of the side wall is folded inward along the fold line toward the bottom and placed on the inside of the second part with the tabs inserted into the slots along the fold line of the side wall to form a double wall. When placing the lid on the box, the double side walls of the lid are located along the perimeter of the box between the double side walls of the box, the direction of the corrugation of the corrugated cardboard of the lid, the side walls of which are brought into contact with the side walls of the box, is perpendicular to the direction of the corrugation of the corrugated cardboard of the box. 12 fig.

Description

The utility model relates to cardboard packaging, specifically closed, flattened cardboard boxes made of corrugated cardboard, and can be used as shipping containers for food products. The claimed tray design is intended for assembly on an automatic assembly line or assembly machine, but can also be assembled manually.

Boxes or crates consisting of a box body closed with a separate lid are convenient because the packaging retains its marketable appearance and, in most cases, can be reused. Currently, two methods are used to assemble such boxes: manual assembly and assembly on an automated line. Each assembly method utilizes a specific tray design. Manual assembly involves joining the walls together by inserting fold-down flaps between the sheets of double sides, or by inserting the flap tabs into special slots in the side walls. Such assembled boxes are a bulky structure that must be stored in a warehouse and delivered in batches to the assembly station. This is inconvenient and costly. This leads to overstocking of the warehouse with bulky containers, which are difficult not only to store but also to transport. In this case, pre-assembled folding boxes offer an advantage, as they are convenient to store in stacks and are easy to transport to the consumer. The peculiarity of such packaging is that it is stored in a sheet form (assembled flat) and straightens out when one of the parts of the box is grasped.

An example of such a design is the tray described in CN 211108482, B65D5/24, B65D5/36, published on July 28, 2020, which is assembled from a sheet blank by bending its parts using gluing.

A cardboard sheet blank comprises a bottom, from which first sidewalls extend along two opposite fold lines on two opposite sides. Each sidewall is made of two parts, the second of which is folded inward along the fold line and secured by inserting a tab into a slot in the bottom. Second sidewalls are connected to the other sides of the bottom along the fold lines. Their end flaps are folded away from the sides and have a fold line on each, extending from the corner of the bottom to the middle of the free edge of the flap. During automatic assembly, the manipulator glues the corner sections of each end flap facing the first part of the first sidewalls and folds the second sidewalls, placing them on the bottom and on the first parts of the first sidewalls. The result is a flat assembly in which the second sidewalls rest on the bottom and on part of the first sidewalls. Next, fold the second sections of the first side walls over and place them on top of the flat assembly. This creates a compact tray assembly. When opening the assembly to form the tray, unfold the second sections of the first side walls and straighten all the walls, as they are glued together. Only after the side walls have straightened are the second sections of the first side walls folded inward and their tabs inserted into the slots in the bottom. These second sections, by inserting the tabs, prevent the tray walls from folding again along the fold lines of the end flaps of the first side walls.

A design flaw with this tray is that the final assembly step, straightening it, is performed manually by the operator, who must insert the second sections of the first walls into the tray and insert the tabs of these sections into the slots in the bottom. Therefore, it cannot be assumed that this tray can be assembled from start to finish on an automatic assembly line or machine.

Another drawback is the difficulty of assembly. The second side walls are made with longitudinal flaps, which, after straightening the tray, must also be folded inward toward the bottom and secured with tongues in the slots in the bottom. Only then will the tray maintain its shape, the walls remain flat, and the tray retain its original form.

Thus, the familiar tray is partially assembled on an automatic assembly line to form a flat assembly that can be stacked and transported. At the tray packaging site, the assembly must be straightened to the tray shape and the additional flaps folded inward, which is done manually by the operator.

This deficiency was corrected in the decision on RU 211128, B65D5/36, published. 23.05.2022), which describes a folding tray made from a sheet cardboard blank by folding its parts along fold lines, having a rectangular bottom, from which the first two oppositely located side walls are bent along the fold lines, each of two parts sequentially located through the fold line, wherein the first part is made with bendable end flaps, and at the end sections of the second part, fold lines directed at an angle are made, the starting point of each of which is located at the apex of the corner of the first part of the side wall, and the end point is on the free edge of the second side wall, the second two oppositely located side walls are made with the possibility of bending and are made at the end sections located next to the bendable end flaps of the first side walls, at an angle by directed fold lines, the starting point of each of which is located at the apex of the corner of the bottom, and the end point is on the free edge of the second side wall, wherein during assembly the second the side walls are bent towards the bottom and laid on its surface with the end parts being bent back and laid on top of these side walls, the end sections of the second part of the first side walls are bent back along the fold lines, laid on top of the surface of the second parts, and glue is applied on top of them, the foldable end flaps of the first parts of the first side walls are bent back along the fold lines, laid on top of the adhesive surface of the end sections of the second part of the first side walls, and glue is applied on top of them, and the first side walls are bent back from the bottom and laid on top of the adhesive sections of the foldable end flaps of the first parts of the first side walls.

This solution is adopted as a prototype.

A drawback of this tray is its insufficient strength in maintaining its spatial shape. To increase strength and maintain its shape, shelves are used, blocking access to the tray cavity on the shorter sides. These trays are not designed for automatic product stacking; they can be used on automated lines with manual product stacking. Strength is also reduced because all tray walls are made of single-sheet cardboard, the load-bearing capacity of which directly depends on maintaining the cardboard's flatness and the absence of transverse (lateral) loads. This folding tray uses a gluing technique, the quality of which depends on the quality of the adhesive itself and the dosage of the adhesive dispensed from the nozzle. If the adhesive contact area is insufficient, a piece of the adhesive may break off when the tray is straightened. This can also occur if the tray wall is loaded during product stacking. In this type of tray, the gluing zones are unprotected, so any load will cause the bond to break. And since only the surface layers of the corrugated cardboard are glued together, the bond is essentially held together by two thin sheets of paper glued together.

Despite the simplicity of manufacturing, tray-type boxes have a drawback: the product placed inside (such as sour cream cups or cottage cheese) must be protected, meaning the box must be closed at the top. This creates a problem: such boxes cannot be stacked due to the risk of the trays sagging under the weight of the product or the deformation of the walls, which can lead to the product losing its marketability. Only a small number of boxes can be stacked, provided that the walls are equipped with stops to prevent the box being stacked from shifting from above. Double-walled boxes somewhat increase the load-bearing capacity of the packaging, but sealing an open box still poses a challenge.

Interest has recently grown in flattened boxes with sidewalls no taller than a single sour cream cup (for example). There are many products that cannot be stacked in two or more rows in a single box, and they require flattened boxes. However, flattened boxes are best used for transporting lighter goods/products, as this type of box, especially tray-shaped ones, is highly susceptible to bending and loss of sidewall flatness. Double sidewalls and reinforced corners lead to increased cardboard consumption, which is impractical for single-use boxes.

The lid used to cover a tray-type box relieves the side walls of the box during stacking by distributing the top load across the lid. However, the lid does not maintain the shape of the side walls of the box, as the load distributed across the lid is transferred to the side walls of the box. If boxes are stacked incorrectly (for example, offset), one of the side walls becomes overloaded, causing it to lose its flatness and subsequently collapse (see, for example, RU 183069).

Thus, the present utility model is aimed at achieving a technical result consisting in increasing the strength properties of a flattened box closed with a lid by placing oppositely located double walls of the lid between the double walls of the box.

The said technical result is achieved in that a closed flattened box characterized by the fact that it consists of a box made of sheet corrugated cardboard, unfolding from a flat assembly position, open at the top, and a lid placed on this box, unfolding from a flat assembly position, the height of the side walls of which is equal to the height of the side walls of the box, wherein the unfolding lid and the unfolding box are each made from a sheet blank by bending its parts along fold lines, having a rectangular bottom, from which the first two oppositely located side walls are bent along the fold lines, each made from two parts successively located across the fold line, the first of which has a slot for gripping by hand, at the end sections of the second part of the side wall, fold lines directed at an angle are made, the starting point of each of which is located at the extreme angular point on the fold line of the second part of the side wall from the bottom, and the end point is on the free edge of the second part of the side wall to divide the end section by this fold line into two triangular in shape in the plan of the fragment, the second two oppositely located side walls are made with the possibility of bending away from the bottom and are connected at the end sections by fold lines with the end sections of adjacently located second parts of the side walls, during assembly the second side walls are bent towards the bottom, laid on its surface and on the surface of the second part of the side wall with gluing a fragment of the end section of the second part to the second part of the adjacently located side wall, and the first part of the side wall along the fold line is folded inward towards the bottom and laid on the inner side of the second part with the introduction of tongues into the slots along the fold line of the side wall to form a double wall, wherein when placing the lid on the box, the double side walls of the lid are located along the perimeter of the box between the double side walls of the box, the direction of the corrugation of the corrugated cardboard of the lid, the side walls of which are brought into contact with the side walls of the box, is perpendicular to the direction of the corrugation of the corrugated cardboard of the box.

These features form a stable set of essential features sufficient to obtain the required technical result.

This utility model is illustrated by a specific example of implementation, which, however, is not the only possible one, but clearly demonstrates the possibility of achieving the required technical result.

Fig. 1 - a cardboard sheet blank for a folding box;

Fig. 2 - cardboard sheet blank for folding lid;

Fig. 3 - the box according to Fig. 1 in the form of a sheet (flat) assembly;

Fig. 4 - the cover according to Fig. 2 in the form of a sheet (flat) assembly;

Fig. 5 - shows the first straightening of the flat assembly of the box according to Fig. 3

Fig. 6 - shows the straightening of all the walls of the box according to Fig. 3 and the formation of double opposite walls;

Fig. 7 - general view of the assembled box;

Fig. 8 - shows the first straightening of the flat assembly of the cover according to Fig. 4

Fig. 9 - shows the straightening of all the walls of the lid according to Fig. 4 and the formation of double opposite walls;

Fig. 10 - general view of the assembled cover;

Fig. 11 - assembly of the box;

Fig. 12 - external view of the assembled box.

This utility model addresses new product packaging featuring a flat, closed-type box consisting of a box that folds out from a flat assembly position and is open at the top, and a tray-type lid that folds out from a flat assembly position and fits over the box, with the sides of the lid abutting the sides of the box. The box can be used as a storage container, a display container, or a shipping container. The lid not only serves as a closing element to protect the stored product, but also as a structural member to maintain the box's shape and increase its load-bearing capacity by reducing the effects of bending deformations.

A characteristic feature of flattened boxes, even those with a top-flap lid and regardless of the lid type or construction method, is that the height of the side walls is significantly smaller than the length and width of the bottom. The shape retention of open-type or four-flap boxes depends on maintaining the flatness of the side walls and the strict geometry of the corner areas. The larger the side wall area, the more elastically it resists deformation, that is, external loads on the surface. By decreasing the side wall area by reducing its height, the elasticity is sharply reduced, and the box is maintained in shape solely by the stiffening ribs, which are the fold lines of the side walls from the bottom. However, when the bottom is loaded with the weight of the stored goods, the bottom itself loses its flatness, leading to deformation of the stiffening ribs along the fold lines. As a result, the box can twist diagonally along the bottom, meaning it cannot withstand bending loads. To increase bending resistance, they try to reduce the bottom area, but this leads to the use of this type of box only for small, non-weighted, piece goods.

Currently, there is a need to use boxes with larger bottoms and shallower sidewalls, for example, for storing sour cream or yogurt cups. However, this significantly increases the weight load on the bottom of the box, leading to distortion and product damage. Therefore, manufacturers are moving away from this type of box and toward open trays, which feature reinforced sidewalls and transverse reinforcements in the form of bars or crossbars to prevent the tray from buckling. However, these trays require increased cardboard consumption and are difficult to assemble, which is inconsistent with the single-use nature of this packaging.

The proposed box differs from existing solutions for transporting low-height goods that require careful handling by its simple design, ease of assembly, and high load-bearing capacity with a developed bottom surface area due to the formation of a power belt along the perimeter of the joined side walls of the box and lid, while in the corner areas the walls become four-layered.

Although the claimed box consists of a box body and a lid, these elements of the overall design are not only functionally interconnected but also structurally integrated, as the box's structure is directly linked to the lid's structure and is determined by the latter's design. The achievable technical result is achieved only when the box is closed and because the lid bears the box's load due to the contact arrangement of its side walls, the specific direction of the cardboard corrugations, and the height of the side walls.

The terms "box" and "lid" are used loosely. Essentially, a box consists of a lower section and a top section placed over it, which form a structural unit due to the friction between the walls of the sections, cardboard on cardboard. Therefore, when assembled, the lid does not separate, like the lid on a shoebox. However, for the sake of clarity in describing the claimed utility model, it is convenient to use the terms "box" and "lid" for the structural parts of the box.

The box and lid are made of corrugated cardboard by folding sections of a sheet blank (Figs. 1 and 2) to form a bottom and side walls folded away from it. The design algorithm for both the box and lid is identical and is as follows:

Each element of the box is made from a sheet blank (Fig. 1 and 2) by bending its parts along fold lines, having a rectangular bottom, from which the first two oppositely located side walls are bent along the fold lines, each made of two parts sequentially located across the fold line, the first of which has a slot for gripping by hand, at the end sections of the second part of the side wall, fold lines directed at an angle are made, the starting point of each of which is located at the extreme angular point on the fold line of the second part of the side wall from the bottom, and the end point is on the free edge of the second part of the side wall to divide the end section by this fold line into two fragments of a triangular shape in plan, the second two oppositely located side walls are made with the possibility of bending from the bottom and are connected at the end sections by fold lines with the end sections of adjacent second parts of the side walls, during assembly the second side walls are bent towards the bottom, laid on its surface and onto the surface of the second part of the side wall with gluing a fragment of the end section of the second part to the second part of the adjacent side wall, and the first part of the side wall is folded inward along the fold line towards the bottom and laid on the inside of the second part with the insertion of tongues into the slots along the fold line of the side wall to form a double wall.

A special feature of the box and lid under consideration is that the design of the sheet blank is made in such a way that the box and lid can be assembled into a flat assembly (Figs. 3 and 4) using four gluing points for each assembly.

Below is an example of a specific design of the box with reference to Fig. 1, 3 and Fig. 5-7.

The box is made from a sheet of corrugated cardboard (corrugated) blank 1 (Fig. 1) by folding its sections along the fold lines. Blank 1 includes a rectangular base 2, to which side panels 4 of shorter length and 5 of longer length are connected along all sides along fold lines 3. Each pair of opposite side panels is of identical shape and construction.

Bend back from the bottom along fold lines 3 are the first two oppositely positioned side walls 4 of shorter length, each formed by two successive sections 6 and 7, positioned across the fold line. A longitudinal cutout 8 is made in the central area of section 6, essentially also serving as a handle, allowing the box to be carried with the hand grip. This cutout 8 replicates the cutout in section 7. On the free edge of section 7 are projections 9, which, when this section is folded, fit into slots 10 at fold line 3.

Side wall 5 is made with folding end flaps 11, rectangular in plan. After folding, these end flaps are laid on the surface of part 6 and glued to it. The length of these flaps is shorter than the distance from cutout 8 to fold line 3 at side wall 5.

The valves 11 are made with fold lines 12 directed at an angle, the starting point of each of which is located at the extreme angular point on the fold line of the second part 7 of the side wall from the bottom, and the end point is on the free edge of the second part of the side wall of shorter length to divide the end section 11 by this fold line 11 into two fragments 13 and 14 of a triangular shape in plan. Fragments 14 are glued to the surface of part 6 of the first wall 4.

The flat assembly of the box (Fig. 3) is obtained as follows. The side walls 5 are folded and placed on the surface of the bottom so that the end flaps 11 are on the surface of part 6 of the side wall 4. Then, the fragments 14 are glued to the surface of the first part 6. In this position, the flat assembly of the box is fed to the press conveyor, where, under the pressure of the punch, the assembly is compacted and given a flat, non-opening shape.

The layout of the flat assembly of the box is as follows (Fig. 5-7).

The flat assembly of the box, which has arrived at the goods packaging station, is opened. For this purpose, the longer side walls 5 are lifted to a vertical position (Fig. 5), which leads to the formation of a fold between fragments 13 and 14 (along the fold line 12). At the same time, the side wall 4 comes to a vertical position (Fig. 6). After the side walls 4 and 5 have taken a vertical position, the second part 7 of the side wall is folded inside the box (Fig. 6), placed on the surface of the first part 6 and the tongues and projections 9 (made on the free edge of part 7) are inserted into the slots 10 in the bottom, which leads to the second part 7 pressing the glued fragments 14 and does not allow them to come off even if the gluing was incomplete or of poor quality (Fig. 7). In this way, a box 15 assembled from a flat cardboard blank is obtained (Fig. 7).

Lid 16 has a similar design (Figs. 2, 4, and 8-10) and is assembled using the same algorithm as box 15. Its distinctive feature is that side wall 4 with parts 6 and 7 is formed on the longer side (Figs. 2 and 4). That is, in the box, the formation of the double side wall 4 is performed along the shorter wall, and in the lid, the double side wall is formed on the longer wall. When assembling the box, the double side walls of the lid are located along the perimeter of the box between the double side walls of the box. Moreover, all walls of the box and lid have mutual contact along the mating surfaces. This allows the box to have a force belt along the perimeter of all side walls, which is formed by a combination of three-layer walls adjacent to each other on each side of the box. Essentially, these three-layer walls are a prefabricated composite structure in which friction is created between the layers, allowing the load of one layer to be supported by the remaining layers, which act as support. This allows, for example, the use of standard Category B corrugated cardboard to be replaced by Category E corrugated cardboard (thinner), reducing the weight of the box while maintaining high load-bearing capacity, which is not dependent on the cardboard thickness but is determined by the design of the side walls and corner areas.

Corrugated cardboard has a unique structure, with a corrugated paper layer sandwiched between flat paper layers, all of which are parallel to each other. Due to this structure, the stiffness of the corrugated sheet along the corrugation direction is always higher than the stiffness perpendicular to the corrugation. Given this, the proposed solution utilizes a technique to create equal strength between the load-bearing belt and the box as a whole by aligning the corrugation of the lid's corrugated cardboard, whose sidewalls are in contact with the box's sidewalls, perpendicular to the corrugation of the box's corrugated cardboard.

Furthermore, the corner areas feature four-layer reinforcement, preventing corner deformation when the box is loaded with goods. These reinforcements act as stiffening ribs for both the box and lid sides, preventing box warping, sidewall flatness, and preventing diagonal bending of the entire box.

The declared closed-type box, due to the elimination of shape loss, moves from the category of single use to the category of repeated use.

When stacking boxes, shifting the top boxes relative to the boxes below does not cause them to lose their shape, as all boxes in the stack are supported by the load-bearing belt. Even when offset, the top box rests on at least three sidewalls of the bottom box, which is sufficient to support the stack and prevent deformation of the boxes below.

Thus, the utility model allows for increasing the strength properties of a flattened box by forming a power belt around the perimeter of the mating side walls of the box and its lid.

Claims (1)

A closed box of a flattened shape, characterized in that it consists of a box made of sheet corrugated cardboard, unfolding from a flat assembly position, open at the top, and a lid placed on this box, unfolding from a flat assembly position, the height of the side walls of which is equal to the height of the side walls of the box, wherein the unfolding lid and the unfolding box are each made from a sheet blank by bending its parts along fold lines, having a rectangular bottom, from which the first two oppositely located side walls are bent along the fold lines, each made from two parts successively located through the fold line, the first of which has a slot for gripping by hand, on the end sections of the second part of the side wall, directed fold lines are made at an angle, the starting point of each of which is located at the extreme angular point on the fold line of the second part of the side wall from the bottom, and the end point is on the free edge of the second part of the side wall to divide the end section by this fold line into two fragments of a triangular shape in plan, the second two oppositely located side walls are made with the possibility of bending away from the bottom and are connected at the end sections by fold lines to the end sections of adjacently located second parts of the side walls, during assembly the second side walls are bent towards the bottom, laid on its surface and on the surface of the second part of the side wall with gluing a fragment of the end section of the second part to the second part of the adjacently located side wall, and the first part of the side wall is bent inward along the fold line towards the bottom and laid on the inner side of the second part with the insertion of tongues into the slots along the fold line of the side wall to form a double wall, wherein when placing the lid on the box, the double side walls of the lid are located along the perimeter of the box between the double side walls of the box, the direction of the corrugation of the corrugated cardboard of the lid, the side walls of which are brought into contact with the side walls of the box, is perpendicular to the direction of the corrugation of the corrugated cardboard of the box.