Technical field

The present invention relates to reusable containers. In embodiments, the reusable container can be used in the takeaway food industry. In embodiments, the container comprises a single unit which is combinable and interlockable with a second substantially identical unit, forming a substantially closed composite container.

Background

Containers are useful for storing items until they are required for use. The takeaway food service industry has a need for containers for the transportation of food off-premises. Historically, the industry has predominantly relied on single-use, disposable containers to fulfil this need. Single-use containers are often made from plastic or plastic-lined cardboard, both of which offer detrimental effects to the environment of our planet.

In light of these sustainability concerns, there is a growing demand for reusable containers in the provisioning of takeaway food. That is to say a container product which is used by a consumer, subsequently washed and then used again multiple times over. This growing market of reusable packaging solutions is a notable element of the emerging global movement widely termed the ‘circular economy’.

Traditional single-use container solutions often utilise ‘living hinges’ in order to create an enclosed volume. One problem that arises when moving to a reusable container solution is the durability of such hinge constructions. An alternative approach to take is to create separate container and lid items; yet this approach requires further monetary investment in additional Stock Keeping Units (SKUs).

The largest sector in terms of product demand for such reusable container solutions lies in the Quick Service Restaurant industry (widely known in the field as the QSR industry). Perhaps the leading functional requirement for such reusable container solutions in the QSR industry is expeditious assembly. That is to say it is deemed critical that food items may be packaged quickly and intuitively, allowing a large quantity of food items to be processed into packaging in the shortest possible amount of time.

Other key requirements for reusable container solutions lie in efficient stacking to optimise storage, strong durability for commercial washing and an appropriate product cost in line with the product’s expected lifespan.

US Pat. 5,273,174 to Fisher provides a takeaway food container. In Fisher, there is described a container comprising two substantially identical tray members that cooperate to define an enclosed space for pizza. In order to form the pizza container, there are protrusions positioned inside the boundary of the unit’s peripheral rim, with associated cut-away portions. It should be noted that the requirement for the user to form the container by aligning the protrusions with the opposing cut-away portions in Fisher’s invention is not conducive to expeditious assembly. Furthermore, each tray member of US Pat. 5,273,174 comprises a groove (female) 26 and a rib (male) 28 which in use are intended to interlock with one another. However, the described invention of Fisher would thereby only assembly in a single orientation, presenting a potential clash of male-male geometry in the opposing orientation. In the QSR industry, this package is unlikely to allow a large quantity of food items to be processed into packaging in the shortest possible amount of time.

Accordingly, there exists a need for an improved container that can be used as a reusable food container in the takeaway food service industry. Preferably the container would overcome or at least ameliorate some of the problems of the prior art containers currently available.

Summary of invention

In a first aspect of the present invention there is provided a container unit comprising: a base, a side wall around the base, the side wall comprising: - a rim having an outer peripheral edge and an upper face, and

- at least two protruding flanges spaced from one another, each protruding flange configured to extend laterally from the side wall and upward relative to the upper face of the rim to define an edge receiving portion; wherein the container unit is configured to interlock with a substantially similar or substantially identical container unit to thereby define an enclosed container; the enclosed container being assemblable by bringing the upper faces of the rims of two container units into contact with one another, the outer peripheral edge of each rim being received into the edge receiving portion of a respective protruding flange, whereupon by rotation of one of the container units relative to the other of the container units:

- the pairs of protruding flanges align and mate and optionally interlock with one another to substantially prevent separation of the two bowl shaped units forming the enclosed container; the enclosed container being dissassemblable by reversing the rotation of one of the container units relative to other of the container units thereby causing the container units to be separated.

The container unit can interlock with another container unit to form a substantially enclosed container. The enclosed container can contain any substance or material. In an embodiment, the enclosed container is a reusable takeaway food container.

In this embodiment, the substance or material intended to be contained in the enclosed container is food. The reusable takeaway container system can be utilised in a modular fashion.

This container unit has an interlocking closure system that interlocks with the closure system of a substantially identical or substantially similar container unit in order to form an enclosed volume to contain the food content. The container units can be identical. The container units can be substantially identical and vary in only incidental ways that do not affect their ability to mate with one another. The container units can be substantially similar and may vary in size and proportion relative to one another but utilise the same interlocking closure features. The container unit of embodiments of the present invention removes the requirement for additional lid components which in turn reduces SKU count, simplifies operations and reduces monetary investment. The modular approach can, in embodiments, remove the need for hinges which are not substantially durable over multiple reuses. An aim of the invention is to provide a modular, interlocking, reusable container solution which presents expeditious assembly, strong durability and efficient stacking.

In a preferred embodiment, the container unit is constructed from a durable plastic. In another embodiment the container unit is constructed in steel or similar durable metal. As material science develops, other future viable embodiments may be constructed in bio-based polymers. Each material presents a different manufacturing approach, the creation of which are well known in the art. The preferred material presently contemplated for forming such a container unit is a durable plastic such as polypropylene or other injection-mouldable thermoplastic. The preferred production method for the container unit is injection moulding, although it is also feasible the container unit may be created in plastic through compression moulding; a viable approach for products manufactured in thermosetting plastics such as melamine. Both of these moulding techniques create well-defined and highly detailed, accurate geometry which enables effective interlocking and consistency when manufacturing at scale.

In embodiments, the overall sizing of the container units, by way of the general diameter (or length and width) and height, may be varied to accommodate various types and volumes of food content. Some exemplar sizing will be provided herein, but it should be noted that these examples are provided to give relative context to the invention, and do not encompass the entirety of the invention’s possible embodiments. Embodiments which are designed to house food items such as pizzas or flatbreads may be shallow in height and proportionately large in diameter (or length and width, implied without further mention hereafter). These embodiments may present as around 15mm-40mm in single unit height, and 200mm-400mm in diameter. Embodiments which are designed to house salads or rice dishes may present as around 40mm-100mm in single unit height, and 150mm-200mm in diameter. Embodiments which are designed to house burgers and sandwiches may present as around 25mm-40mm in single unit height and around 130mm-170mm in diameter. The latter sizing proposal is particularly appealing to the inventor, as it presents in a fashion whereby a single container unit fits within the hand, and therefore is particularly conducive to expeditious assembly.

In embodiments, the container unit is predominantly circular-shaped since this is most suited to a rotary locking operation. Alternate embodiments of the invention may present in different overall shape configurations, such as substantially rectangular, substantially square or substantially ovular. In an embodiment, the upper part of the container unit defining the rim is the same shape as the base of the container. In an embodiment, the upper part of the container defining the rim has a different shape to the base of the container.

The container unit comprises a base. The base is the flat part of the bottom of the container unit that can be placed on a surface during use. The base can have an outer surface that is the outside of the container unit and an inner surface that is the surface onto which food can be placed inside the container. In the disclosed embodiments herein, the base presents as both circular and square. In further embodiments, the base may present in other shapes as aesthetically desired. When assembled, a first container unit will have a base that can be placed on a surface i.e. for filling the container with a food product. A secondary mated container unit interlocked with the primary container unit will also have a base, only now the base will be inverted and thereby forms the top of the enclosed container.

In an embodiment, the base can be created as a separate component to the main container body. It is proposed that in this embodiment, there would be a substantially permanent assembly created between the two components (base and body), most effectively achieved via a double-shot injection moulding process or an insert injection moulding process, but also viable through adhesive. The purpose of this assembly variation is twofold. Firstly, it is a means of achieving a notable and permanent colour differentiation within the container unit product. Secondly, it offers the opportunity to entrap an NFC (Near Field Communication) chip or RFID (Radio Frequency Identification) chip, or other advanced technological means, which may facilitate the tracking of each independent unit within a widespread reuse system.

The base has a side wall around its periphery. If the base is circular there can be one peripheral side wall. If the base is e.g. square there can be four side walls, one along each edge of the squared-base. The side wall can extend upwardly in a straight or sloped configuration. The slope of the or each side wall can be generally outwards to create a bowl-shape. In an embodiment, a sloped angular nature of the side wall can be a desirable feature in facilitating and optimising stacking. The angle of side walls may be adjusted to enable either closer stacking or more distanced stacking, depending upon the product requirements. There can be an optional step feature towards the top of the side wall to facilitate stacking. The step feature can prevent the container unit from moving too far into another container unit during stacking. The step feature may also provide a convenient location between the stacked container units so that the individual units can be prised apart from one another once stacked.

The side wall terminates in what can be broadly termed a rim. The rim comprises an upper substantially flat surface that is the upper face. The upper face can define a level top surface of the container unit. The rim also comprises an outer peripheral edge which runs around the outside edge of the container. The outer peripheral edge can be any edge or vertex at the upper part of the rim taking any shape or configuration. The upper face can be the thickness, or visible width, of the side wall. Alternatively, the upper face can have an increased thickness, or visible width, relative to the side wall. The increased thickness can be provided by a widening at the top surface in the form of a ledge (may also be referred to as a flange or a lip) at the upper end of the side wall.

The side wall of the container unit comprises at least two protruding flanges. A single protruding flange will provide only one location for interlocking with another container unit and would not be as effective as two locations for interlocking. While two locations of interlocking should suffice and may be the most cost effective in terms of material and manufacturing, there can be more than two protruding flanges to provide more than two locations for interlocking. In embodiments, there are two, three or four (or more) protruding flanges per container unit. In the case of two protruding flanges, preferably the two flanges are spaced from one another around the container unit. The spacing between protruding flanges can be equidistant. In an embodiment, the protruding flanges are diametrically opposed to one another around the container unit. Where there are more than two protruding flanges, the flanges can be equidistant from one another around the side wall of the container unit.

Upon assembly with a substantially identical or substantially similar container unit, the secondary container unit must be inverted (rim downwards) with respect to the primary container unit and positioned rim-to-rim against the primary unit. By rim-to- rim it is meant that the upper faces of each container unit are in contact such that the rims are concentrically aligned. A rotary twisting motion between these two units will induce the interlocking of the protruding flange features, creating an enclosed volume in a physically secure arrangement. Once assembled, the interlocking of the protruding flanges can prevent or at least reduce separation of the two container units. Although it should be understood that the decreased tendency for the container units to separate is related to unintended separation, since once the container units need to be separated, the user can disassemble the container units. Furthermore, under the application of excessive force, the container units may be separable from one another despite the locking arrangement.

In order to facilitate interlocking, each protruding flange extends outwardly in a lateral direction from the side wall of the container unit. The protruding flange can extend from any part of the side wall, although in preferred embodiments, the flange protrudes from the outer peripheral edge of the rim of the side wall. In further alternate embodiments, protruding flanges are not directly adjoined to the outer peripheral edge of the rim, but instead may protrude via a stem or flange which originates from a lower positioning on the side wall. In terms of the distance that each protruding flange extends, the distance is about a finger-grip’s distance from the side wall. This means that when the user assembles the enclosed container, they can use their fingers to grip and manipulate the protruding flanges into mating alignment, if desired. Furthermore, when the user picks up the enclosed container (formed from two container units interlocked together), they are able to grab and hold the protruding flanges with their fingers.

The protruding flanges also extend upwardly in a direction away from the container unit base. The protruding flanges are therefore in an elevated position above the level top surface or the upper face of the container. The protruding flanges themselves have a further laterally extended feature which is distanced from the rim of the container, creating an area that sits outside the main perimeter of the container where interlocking may occur. The geometry of each protruding flange extending laterally and upward defines an edge receiving portion. The edge receiving portion of a protruding flange of the primary container receives the rim edge of the secondary container. The edge receiving portion of a protruding flange of the secondary container receives the rim edge of the primary container. The amount of upward extension of the protruding flange must be sufficient to receive the edge of the rim, or specifically the outer peripheral edge of said rim, of an opposing container, engaging that container in concentric alignment and preventing (or at least reducing) against lateral slippage. Additionally, the amount of upward extension of the protruding flange must be sufficient that upon assembly with a substantially identical unit, the opposing protruding flanges may pass both under and over one another, facilitating interlocking. For such a relationship to occur, it is necessary that the underside of the elevated protruding flange aligns in a planar fashion at roughly at the same height as the upper face of the container. Considering this, the amount of extension of the protruding flange may be deemed to be the result of the chosen material thickness, combined with any additional design element, which elevates beyond the height of the upper face.

The lateral/upward extension of the protruding flange to define the edge receiving portion means that when the secondary container unit is brought into contact with the primary unit, the positioning rim-to-rim concentrically is more easily effected. This improvement in concentric rim-to-rim positioning is due to the fact that each protruding flange must engage over the edge of the other container in order for the upper faces to contact in the rim-to-rim orientation. Thus, in embodiments, the arrangement of geometry at the protruding flanges, positioned outside and elevated above the peripheral rim of the container is notable, and critical to the functionality of the invention.

The preferred embodiment comprises a container unit which is predominantly circular at the rim, and which allows for concentric alignment of two containers upon inverted assembly. Upon assembly of two units in this case, the protruding flanges facilitate concentric alignment due to their positioning outside the peripheral rim of the container. Upon assembly, the inner edges of the protruding flanges, deemed the edge receiving portion, form a contact relationship with the outer peripheral edge of the rim on the opposing container, facilitating concentric alignment. In the preferred 2-flange embodiment, contact relationships are formed at 4 points to facilitate concentric alignment, which is satisfactory. On alternate 3- flange and 4-flange embodiments, concentric alignment is further enhanced with 6 contact points and 8 contact points formed respectively.

The protruding flanges are each a rotational repeat of substantially identical geometry. On the underside of each protruding flange there can be an integrated locking feature that holds the two aligned and mated protruding flanges into contact with one another once the enclosed container is formed. In an embodiment, the integrated locking feature comprises a head part with male and female features directly adjacent to one another on each protruding flange, which pass over, and nest with one another upon rotation to form the enclosed container. In an embodiment, the male and female features can take the form of semi-lozenge shapes (one upward and one downward).

The present arrangement is an improvement over prior art arrangements in which the peripheral locking tabs are positioned inside the boundary of the unit’s peripheral edge with associated cut-away portions. Such an arrangement offers no benefit of concentric alignment upon assembly, moreover the protruding locking tab geometry in such a prior arrangement would hinder concentric alignment. It should also be noted that the requirement for the user to align the locking tabs with opposing cut-away portions is not conducive to expeditious assembly. The present invention on the other hand is likely to increase the user’s ability to form the composite container and is conducive to expeditious assembly. An optional but highly preferable feature of the invention which is most useful in the preferred circular-shaped, 2-flange embodiment is the addition of inter-connecting arcuate fins which appear at the peripheral upper face of the container unit. This arrangement of geometry may facilitate a secure nesting configuration at the rim area upon inverted assembly, whereby multiple male-female geometry interactions occur simultaneously between the two units. Upon assembly of two substantially identical container units the nesting configuration may create robust concentric alignment of the two container units, preventing lateral slippage which can cause the independent disconnection of the protruding flanges. It should be noted that 2- flange embodiments of the invention which present without the described arcuate fins are deemed to be functional, but not optimal, due to the increased likelihood of lateral slippage.

Also described is a container unit comprising a base, a side wall around the base, the side wall comprising at least two protruding flanges equally spaced from one another; and a rim comprising: an inner rim portion having female features in the form of inner arcuate locking fin(s); and an outer rim portion having male features in the form of outer arcuate locking fin(s); wherein the inner arcuate locking (fins) and the outer arcuate locking fin(s) are arranged around a central point, the container unit being configured to interlock with a substantially identical or substantially similar container unit to thereby define an enclosed container; the enclosed container being assemblable by bringing the rims of two container units into contact with one another, whereupon by rotation of one of the container units relative to the other of the container units: the inner arcuate locking fins and outer arcuate locking fins slide around one another and overlap to thereby substantially prevent lateral movement between the two container units; and the pairs of protruding flanges align and mate and optionally interlock with one another to substantially prevent separation of the two container units forming the enclosed container; the enclosed container being dissassemblable by reversing the rotation of one of the container units relative to other of the container units thereby causing the container units to be separated.

In embodiments, the arrangement of arcuate fins achieves optimal product functionality in terms of expeditious assembly. To appreciate the ingenuity of this geometry, the alternative possibilities should be considered.

In order to achieve a male-female relationship on any identical product which has been inverted, it is imperative that male and female geometry appear on opposing sides of a product respectively, equidistant from a central point or plane. With this consideration, an arrangement of geometry that has only 1 male feature and 1 female feature will inherently display a male side and a female side. Upon inverted assembly, the nesting of the male-female geometry will satisfy in one orientation, yet in the opposing orientation (a rotation of 180 degrees) there will be an unavoidable clash of male-male geometry, inhibiting assembly. Therefore, it can be considered that such arrangements are suboptimal, particularly in consideration of expeditious assembly.

In order to achieve dual-orientation male-female mating relationships on a substantially identical product which has been inverted, which is to say an effective assembly of units may occur in two orientations, the breakdown of the necessary geometry must be arranged around a central point in a roughly quarterly fashion. In the preferred embodiment of the disclosed invention this presents in the arrangement of arcuate fin protrusions or arcuate locking fins. The arcuate fins present as differing protrusions. Preferably there are 2 of each protrusion. In an embodiment, 2 may be considered outer arcuate locking fins, and 2 may be considered inner arcuate locking fins. For the sake of clarity, this specification document will consider the outer arcuate locking fins to be male features, with the inner arcuate locking fins considered to be female features. For effective dualorientation assembly functionality, the arrangement of the arcuate locking fins must present in alternation, in a clockwise fashion: male, female, male, female, or female, male, female, male.

In order to allow the fins to overlap once the container units are assembled, the inner arcuate locking fin or fins are located at an inner rim portion of the upper rim. The outer arcuate locking fins are located at an outer rim portion of the upper rim. When assembling the enclosed container, the faces of the rims of two container units are brought into contact with one another and rotated. Upon rotation, the locations of the inner arcuate locking fins is such that the outer arcuate locking fins are able to pass by them and overlap.

It should be noted that the quarterly arrangement of male-female geometry (a division of the upper rim area into 4 distinct regions) is the minimum execution to allow dual-orientation assembly functionality, and for that reason the inventor considers this to be the optimal execution of the principle. It is recognised, however, that the same functionality may be achieved through a more complex execution of the principle. That is to say, a division of the rim area into 8, 12 or 16 distinct regions may yield the same functional result with geometry arranged in a male-female alternating fashion. An execution of such nature is not viewed to be a departure from the principle. Similarly, an execution which replaces the arcuate fins with tongue and groove geometry will also be similarly functional and is not viewed to be a departure from the principle. Tongue and groove geometry is widely understood to be a standard arrangement of male and female features, whereby the female comprises two outer fin protrusions presenting a central recessed cavity, and the male comprises a singular central fin protrusion which may be received into the female’s central recessed cavity.

A true quarterly arrangement of 90-degrees for the arcuate fin features would create an entirely closed volume but would not allow for rotary movement between the two units because the fin features would abut one another. The rotary movement is required to create the secure assembly (enclosed container). Therefore, the staggering of the arcuate fins is created with a necessary gap between fin features to allow and facilitate the rotary movement. The size of the gaps between these features directly relates to limiting the degree of rotary movement between assembled units. This can be customised to each product requirement. In addition, creating a differential length between the male and female features, making them unequal, allows for the effective overlapping of the features during assembly, which in turn can create an entirely closed-off internal cavity. Additionally, the arcuate fins may be spaced in such a way that upon assembly of two substantially identical units, there remains intentional through-gaps into the internal cavity, positioned at opposing sides of the assembly, which are functionally useful as steam outlets for heated food content. The general thickness of each fin in the preferred arrangement equates to roughly half of the thickness (or width or breadth) of the level top surface or upper face of the rim, with consideration of an allowed tolerance gap for the desired rotary interaction, the allowance for which is well known in the art, varying 0.1 mm - 0.5mm. With consideration of general plastic moulding thicknesses, general durability requirements and assumed cost targets, it is proposed likely that the arcuate locking fins will present in a thickness range of 0.5mm - 5mm. Upon variation of product requirements, the thicknesses of the arcuate fins may sit outside this range.

The length of each fin may relate to the overall size (or diameter in a round embodiment) of the container unit. That is to say that container units of a larger overall size may display arcuate fins of increased length, proportionate to overall container sizing. Conversely, in embodiments where it is not desirable to entirely close off the internal cavity, arcuate fins may be reduced in length, creating increased through-gaps into the internal cavity upon assembly of two substantially identical units. Such is to say that arcuate locking fins may present in varying lengths independent of and unrelated to overall container size. Arcuate locking fins may also present with significant length differentiation between male and female features, which is to say that male features may present in greater length than female features, and vice-versa. It is recognised that any addition of arcuate locking fins (or other male-female geometry), of any length, will enhance concentric alignment and prevent lateral slippage. Moreover, it is recognised that the greater the length of the male-female features in relation to the overall product sizing, the more robust the resultant concentric alignment.

The size of the gaps between the arcuate locking fins is directly related to the degree of movement between two assembled container units. Specifically, the gap between the endpoint of an arcuate fin and what may be considered a vertical or horizontal centreline of the divided level top surface, is the defining dimension which limits the rotational movement. It is proposed that gap spacing at an angle of between 10-degrees and 30-degrees is desirable. In the disclosed embodiment, gap spacing, from endpoint of arcuate fin to centreline, is presented at an angle of 15-degrees. It should be noted that an execution of a 15-degree gap spacing in this way results in a 30-degree rotational limitation upon assembly of two container units. In each case, the limited rotary movement will be double the value of the specified gap spacing.

In embodiments, the disclosed reusable container unit can be used for the safe transit of food content. The preferred embodiment is a substantially round vessel comprising of a base and side walls to create a void into which food items can be placed. The container unit has at least two protruding flanges which are equally spaced around the rim of the container unit, and which extend beyond the height of the upper face of the rim. The protruding flanges are a rotary repeat of substantially identical geometry, including integrated adjacent male and female features on the underside of the flanges. The container unit may be assembled in an interlocking fashion with a substantially identical container unit by inverting the secondary unit and placing it rim-to-rim against the primary unit. The assembly of two container units can be secured in an assembled state via a rotary motion which causes the interlocking of opposing protruding flanges on the two respective units, including the integrated contact between any male and female elements on the protruding flanges of the two respective units. The preferred embodiment of the container unit utilises a staggered arrangement of arcuate locking fins having a male and female geometry at the rim. Upon assembly with a second identical or substantially similar container unit, this arrangement of male and female locking fin geometry may create a nested relationship between the container units which may assist concentric alignment, prevent or reduce lateral slippage and in embodiments ensure a secure assembly. An assembly of two identical or substantially similar container units in this fashion may create a substantially enclosed volume for the safe transit of food content.

In an embodiment of operation, a stack of easily accessible container units will exist within the food provisioning area in a restaurant or food-providing establishment. There can be multiple stacks of container units. There may be different stacks of different sized container units, which are substantially similar in their defining characteristics and diameter, and are interlockable, but present different overall product heights. In a food provisioning scenario, the assembler will remove a primary container unit from the stack, placing it upon a surface with the base in contact with the surface, and the open void of the container unit upwardly facing. Food may be prepared separately before being placed into the primary container unit. In this scenario, a ready-made food item will be placed into the open void of the primary container unit. In an alternate scenario, food items may be prepared directly within a primary container unit that is positioned with its open void upwardly facing. For example, an item such as a sandwich or burger may be created directly in the primary container unit by the orderly placing of the elements in a sequential fashion into the open void of the unit; beginning with the lower bread component, followed by the filling elements, and topped with the upper bread component.

In both scenarios, once the food content is complete and located within the void of the primary container unit, a secondary substantially identical or substantially similar container unit is removed from a stack and is inverted and positioned atop, rim-to-rim against the primary, lower container unit. That is to say the base of the secondary container unit will be facing upwardly, and the rim downwardly. The edge receiving portions created by the elevated protruding flanges will facilitate easy concentric alignment between the two units. A swift, intuitive twisting action is performed by the assembler, whereby the upper secondary unit is rotated against the lower primary unit. This rotary motion, which in the preferred embodiment is a clockwise motion (but may be configured as an anti-clockwise motion) engages the protruding flanges and interlocks the units to form a substantially enclosed composite container, substantially covering the food item and protecting it for transit.

Additional steps such as labelling the container with a disposable sticker, or scanning the container via a unique identification system, are optional, and may be performed before delivering the composite container to the customer.

Brief Description of the Figures

Embodiments of the invention will now be described with reference to the accompanying drawings which are not drawn to scale and which are exemplary only and in which:

Figure 1 is a top aerial view of the elementary, 2-flange embodiment.

Figure 2 is a side elevational view of the elementary, 2-flange embodiment.

Figure 3 is a front elevational view of the elementary, 2-flange embodiment.

Figure 4 is a central sectional view as indicated at points C-C on Figure 3.

Figure 5 is an underside view of the elementary, 2-flange embodiment.

Figure 6 is a close-up sectional view of the protruding flange, as indicated at points B-B on Figure 5.

Figure 7 is an isometric % view of the elementary, 2-flange embodiment.

Figure 8 is an isometric % view of an assembly of two identical elementary, 2-flange embodiments arranged in a closed, interlocked state.

Figure 9 is an isometric % view of a 3-flange embodiment.

Figure 10 is a top aerial view of an assembly of two identical 3-flange embodiments arranged in an unlocked state.

Figure 11 is an isometric % view of an assembly of two identical 3-flange embodiments arranged in a closed, interlocked state.

Figure 12 is a top aerial view of an assembly of two identical 3-flange embodiments arranged in a closed, interlocked state.

Figure 13 is an isometric % view of a 4-flange embodiment.

Figure 14 is a top aerial view of an assembly of two identical 4-flange embodiments arranged in an unlocked state.

Figure 15 is an isometric % view of an assembly of two identical 4-flange embodiments arranged in a closed, interlocked state.

Figure 16 is a top aerial view of an assembly of two identical 4-flange embodiments arranged in a closed, interlocked state.

Figure 17 is a top aerial view of the preferred, 2-flange embodiment.

Figure 18 is a side elevational view of the preferred, 2-flange embodiment.

Figure 19 is a front elevational view of the preferred, 2-flange embodiment.

Figure 20 is a central sectional view as indicated at points G-G on Figure 19.

Figure 21 is an isometric underside view of the preferred, 2-flange embodiment.

Figure 22 is an isometric % view of the preferred, 2-flange embodiment.

Figure 23 is an isometric % view of an assembly of two identical preferred, 2-flange embodiments arranged in a closed, interlocked state.

Figure 24 is a top aerial view of an assembly of two identical preferred, 2- flange embodiments arranged in a closed, interlocked state.

Figure 25 is a close-up sectional view of two interlocking flanges, as indicated at points E-E on Figure 24.

Figure 26 is a side elevational view of an assembly of two identical preferred, 2-flange embodiments arranged in a closed, interlocked state. Figure 27 is a front elevational view of an assembly of two identical preferred, 2-flange embodiments arranged in a closed, interlocked state.

Figure 28 is a central sectional view as indicated at points A-A on Figure 27.

Figure 29 is an isometric % view of an assembly of two identical preferred, 2-flange embodiments arranged in an unlocked state.

Figure 30 is a top aerial view of an assembly of two identical preferred, 2- flange embodiments arranged in an unlocked state.

Figure 31 is a detailed sectional view of the flange and rim interaction between two units, as indicated at points F-F on Figure 30.

Figure 32 is a side elevational view of a stack of ten preferred, 2-flange embodiments, nested into one another in a vertical direction.

Figure 33 is a central sectional view as indicated at points D-D on Figure 32.

Figure 34 is an isometric % view of an assembly of two unidentical preferred, 2-flange embodiments arranged in a closed, interlocked state.

Figure 35 is a front elevational view of an assembly of two unidentical preferred, 2-flange embodiments arranged in a closed, interlocked state.

Figure 36 is a side elevational view of an assembly of two unidentical preferred, 2-flange embodiments arranged in a closed, interlocked state.

Figure 37 is a detailed side elevational view of a protruding flange.

Figure 38 is a top aerial view of the preferred 2-flange embodiment, featuring additional reference indicators.

Figure 39 is an isometric % view of an alternate 2-flange embodiment with recessed regions.

Figure 40 is an isometric % view of an assembly of two identical alternate 2- flange embodiments with recessed regions arranged in a closed, interlocked state.

Figure 41 is an isometric % view of an alternate 2-flange embodiment with a substantially square base.

Figure 42 is an isometric % view of an assembly of two identical alternate 2- flange embodiments with a substantially square base, arranged in a closed, interlocked state.

Figure 43 is an isometric % view of a substantially square, 2-flange embodiment.

Figure 44 is an isometric % view of an assembly of two identical substantially square, 2-flange embodiments, arranged in a closed, interlocked state.

Figure 45 is an isometric % view of a substantially square, 4-flange embodiment.

Figure 46 is an isometric % view of an assembly of two identical substantially square, 4-flange embodiments, arranged in a closed, interlocked state.

Figure 47 is an isometric % view of an alternate 2-flange embodiment with tongue and groove features.

Figure 48 is an isometric % view of the preferred, 2-flange embodiment, with a hamburger placed inside.

Figure 49 is a detailed section view conveying the anatomy of the rim. Detailed Description of Embodiments of the Invention

The general construction of the container unit is comprised of a base 28, side wall 27 and an open top to create a void 30 into which food content may be placed. The sloped angular nature of the side walls 27 is a desirable feature in facilitating and optimising stacking, as depicted in Figure 32 and Figure 33. The angle of side walls 27 may be adjusted to enable either closer stacking or more distanced stacking, depending upon the product requirements.

Side wall 27 terminates in a rim 18, comprising outer peripheral edge 24 and upper face 23. Beneath the outer peripheral edge 24 is an optional step feature 32. In the disclosed embodiments, step feature 32 assists in creating secure stacking. In alternate embodiments of the invention there is no requirement for step feature 32. In a further embodiment step feature 32 appears in a lower positioning on side wall 27. In alternate embodiments of the invention the side walls 27 are not angled and are vertical. In further embodiments of the invention, side walls 27 have a curved or fully rounded profile.

Figures 1 -8 (inclusively) depict what is considered the elementary embodiment of the container unit. The elementary embodiment comprises the minimum essential features of the invention. The elementary embodiment comprises two protruding flanges 20. Each protruding flange 20 extends outwardly in a lateral direction from the side wall 27 of the container unit. The protruding flange 20 also extends upwardly beyond the planar height of upper face 23. The outward and upward arrangement of the protruding flange 20 is clearly shown in Figure 37.

The two protruding flanges 20 of Figures 1 -8 are positioned at opposing sides of the container units’s rim 18, a separation of 180-degrees, and which are integral to creating the interlocking of two assembled units. The geometrical positioning of protruding flanges 20, elevated above the height of upper face 23 and outside rim 18, define an edge receiving portion 34. The location of the protruding flanges 20 is clearly depicted in Figures 1 , 2, 5 and 7. In alternate embodiments of the invention, the protruding flanges 20 may vary in size, shape and appearance. In further alternate embodiments, protruding flanges are not directly adjoined to outer peripheral edge 24 of rim 18, but instead may protrude via a stem or flange which originates from side wall 27.

On the underside of the protruding flanges 20 is provided an integrated locking feature 25/26. The integrated locking feature is in the form of a moulded features male 25 and female 26, which are positioned adjacent to one another. In the disclosed embodiments of the invention, the features male 25 and female 26 take the form of semi-lozenge shapes. In other embodiments of this invention the shape and proportions of these features may vary. The location of these moulded details 25 and 26 is clearly depicted in Figure 5 and the sectional view B-B which is illustrated in Figure 6.

The concentric alignment of the rims 18 (and the outer peripheral edges 24 of the rims) between the two container units is assisted by each protruding flange 20 having an edge receiving portion 34. The height of edge receiving portion 34 need only be sufficient for the rim 18 of the opposing container unit to be received into it, preventing lateral slippage. That said, the defining requirement of protruding flanges 20 is that their underside 19 aligns roughly in a planar fashion with upper peripheral face 23. Therefore, in the disclosed embodiments it can be understood that the height of receiving portion 34 is defined somewhat by the material thickness of protruding flanges 20.

Upper face 23 is considered the upper face of rim 18 of the container unit. In the elementary embodiment, upon inverted assembly of two substantially identical container units, a contact relationship is achieved between the upper face 23 on the lower unit and the upper face 23 on the upper unit, as depicted in Figure 8. Upon such assembly, concentric alignment of the units is achieved through multiple mating relationships, which occur simultaneously at the regions where edge receiving portions 34 mate with the outer peripheral edge 24 of the rim of the opposing container. In an assembly of 2-flange embodiments, these mating relationships of edge/edge receiving portion 24/34 will occur at four regions simultaneously, creating concentric alignment between the units. These mating relationships 35 are indicated in the associated figures. A 2-flange embodiment displays four mating relationships 35 in Figure 30. In the 3-flange embodiment of the invention depicted in Figures 9,10,11 ,12, container units present with three protruding flanges 20 which are positioned at equal 120-degree increments around rim 18. In the 4-flange embodiment of the invention depicted in Figures 13,14,15,16, container units present with four protruding flanges 20 which are positioned at equal 90-degree increments around rim 18. In both of these embodiments, concentric alignment between two assembled substantially identical units is further enhanced by the increased number of aforementioned mating relationships 35, achieved by the increased number of edge receiving portions 34 on the corresponding flanges 20. In the 3- flange embodiment, the described mating relationships 35 occur in 6 regions, depicted in Figure 10. In the 4-flange embodiment, the described mating relationships 35 occur in 8 regions depicted in Figure 14. An example of the described mating relationship 35 is depicted in Figure 31 , which is a sectional view of an unlocked assembly of the preferred 2-flange embodiment.

Figure 8 depicts an inverted assembly of two identical container units of the elementary embodiment. This illustration depicts the relationship between the opposing protruding flanges 20 upon assembly. In this illustration 20A depicts a protruding flange of the lower unit, with 20B depicting a protruding flange of the upper, inverted unit. Upon assembly in this fashion, protruding flange 20B passes underneath protruding flange 20A, creating an interlocked relationship between the container units. In this embodiment of the invention, a substantially identical interlocking relationship occurs simultaneously at the opposing side of the assembly. That is to say it occurs simultaneously in two locations around rim 18. In further disclosed embodiments of the invention, the interlocking relationships between opposing protruding flanges 20 occur in additional locations around rim 18 simultaneously. In the disclosed 3-flange embodiment, interlocking relationships occur in three locations simultaneously. In the disclosed 4-flange embodiment, interlocking relationships occur in four locations simultaneously.

Upon the assembled contact relationship between opposing protruding flanges 20A and 20B, there is a further nesting relationship which occurs between integrated locking features that are male 25 on the primary container unit and female 26 on the secondary container unit. There is a simultaneous nesting relationship created between female 26 on the primary container unit and male 25 on the secondary container unit. These nesting relationships are depicted in Figure 25, which is a sectional view of interlocking protruding flanges 20A and 20B, as indicated at points E-E on Figure 24.

The disclosed embodiments of the invention propose that surface 29 is an appropriate positioning for brand placement, should it be required. In alternative embodiments of this invention surface 29 may vary in size and shape. This is an optional but preferred feature of the invention.

Figures 17-33 (inclusively) depict the preferred 2-flange embodiment of the invention. The notable differentiator from the elementary 2-flange embodiment is the additional inclusion of arcuate locking fins at the rim 18, positioned atop of upper face 23.

Figure 22 is an isometric % view of the preferred 2-flange embodiment. In this illustration the arrangement of the arcuate fins 21 and 22 is depicted. For the purpose of clarity, this specification shall consider inner arcuate fin 21 to be the female and outer arcuate fin 22 to be the male. Upon the inverted assembly of two substantially identical units, there is a nesting relationship created between the male 22 fins of the primary container and the female 21 fins of the secondary container; as well as a simultaneous nesting relationship created between the female 21 fins of the primary container and the male 22 fins of the secondary container. These nesting relationships provide enhanced concentric alignment, which is particularly valuable in a 2-flange embodiment. The enhanced concentric alignment can prevent or at least reduce lateral slippage between the two container units upon assembly and disassembly, ensuring that the interlocking and disengaging of the protruding flanges occurs simultaneously on both sides of the assembly.

Concerning the preferred 2-flange embodiment, upon the inverted assembly of two substantially identical units, upper face 23 creates a contact relationship with the top surfaces of both male fin 22 and female fin 21 of the opposing container unit. These contact points combined with the aforementioned nesting relationships of arcuate fins 22 and 21 and the appropriate positioning of protruding flanges 20 creates a substantially enclosed volume between two assembled container units.

In a less preferred embodiment of the invention depicted in Figures 39 and 40, there is no requirement for outer arcuate fins 22, whereby they are replaced with recessed regions 41 . Recessed regions 41 become the female features in embodiments of this style, with inner arcuate fins 21 A becoming the male features. In the depicted embodiments of Figures 39 and 40, the arcuate fins 21 A extend to an increased height, beyond the height of the protruding flanges 20, making them the highest point of the container unit’s geometry. This is not a requirement of embodiments in this style, it is viable that protruding flanges 20 remain the highest point of geometry, but it is a notable, optional differentiator. In this same embodiment, upper face 23 becomes disrupted where recessed regions 41 are evident. Embodiments of this style are functional but are not preferred, due to the required thickening of material, and the required straightening of side walls 27, to accommodate recessed regions 41 , which result in increased unit cost and inefficient stacking respectively.

In the preferred 2-flange embodiment illustrated in Figures 17 and 38, the notable gaps 33 between arcuate fins 22 and 21 , where face 23 is at its maximum width, dictates the amount of rotational movement between two assembled container units. The size of gaps 33 can be varied for the desired embodiment of the invention. Upon the inclusion of arcuate fins 21 and 22, the inclusion of gaps 33 is necessary to allow for sufficient rotational movement between two assembled substantially identical container units in order to engage and disengage the interlocking mechanism, which occurs at the protruding flanges 20. Specifically, the critical spacing gap is defined as angle 36 on Figure 38. Angle 36 is the amount of space created between the endpoint of an arcuate locking fin (in this case male fin 22) and what is deemed the vertical (or horizontal) centreline 37 of the rim. This gap is the critical dimension which defines the amount of rotary movement between two assembled container units. By increasing and decreasing the size of this angle, it is possible to increase and decrease the amount of rotary movement respectively. In the embodiment depicted in Figure 38, angle 36 is 15-degrees. In this case, the resultant rotary movement will be limited to 30-degrees. Similarly, if the value of angle 36 were to be increased to 25-degrees, the resultant rotary movement would be limited to 50-degrees, and so forth. It is suggested that an appropriate value for angle 36 is in the range of 10-degrees to 30-degrees.

There will be embodiments of the invention that will require steam outlets, that is to say to create a substantially enclosed volume in the enclosed container that is not entirely closed. In such cases, the length and positioning of male fin 22 and female fin 21 , to create gaps 33, may be adjusted to create an intentional gap of a desired size upon assembly of two substantially identical container units. The preferred 2- flange embodiment presents this feature, as depicted at outlet 38 in Figure 23. The size of outlet 38 is customisable and variable by the amending of gap 40, as depicted in Figure 38. Gap 40 is the spacing between the endpoint of male arcuate fin 22 and centreline 39. In the depicted embodiment this is an angular dimension of around 4-degrees, resulting in a dimensional gap (in the proposed sizing) of around 5mm. Upon assembly with a secondary container unit, the resultant size of outlet 38 in this case would be 10mm in width (double the value of gap 40). Steam outlets may be customised in this way, with the resultant width of outlet 38 always being double the value of gap 40.

Figure 29 depicts an assembly between substantially identical container units of the preferred 2-flange embodiment. In this assembly the container units are arranged in an unlocked state. That is to say that the interlocking features are disengaged.

An additional variation of construction, displayed in the disclosed preferred 2-flange embodiment, is the creation of surface 29A as a separate component to the main container unit body. It is proposed that there would be a substantially permanent assembly created between the two components, most effectively achieved via a double-shot injection moulding process or an insert injection moulding process, but also viable through adhesive. This variation in construction is displayed in Figure 20. The purpose of this assembly variation is twofold. Firstly, it is a means of achieving a notable and permanent colour differentiation within the product. Secondly, it offers the opportunity to entrap an NFC (Near Field Communication) chip or RFID (Radio Frequency Identification) chip, or other advanced technological means, which may facilitate the tracking of each independent unit within a widespread reuse system.

Figures 34, 35, 36, depict a securely locked assembly comprising two unidentical but substantially similar container units. That is to say the upper secondary container unit 31 is of reduced height and volume capacity, but of the same diameter and with the same defining characteristics of the primary lower container unit. In other embodiments of the container unit size and proportions may be varied in this fashion, allowing multiple size configurations for the resulting enclosed volume.

Figures 41 and 42 depict an embodiment of the invention which is substantially circular at the upper peripheral rim 18, yet is substantially square at the base. The resultant shape of void 30, at its internal base 42, is therefore substantially square. Upon assembly of two such embodiments, shown in Figure 42, the upwardly facing base of the secondary, upper container unit is visible, and is shown to be substantially square. Surface 29B is in this case the proposed surface for brand placement, and presents as substantially square. Transitions of a similar nature, whereby embodiments with a substantially circular rim 18 transition into other shapes at internal base 42 are possible. Embodiments of this nature, whereby rim 18 remains substantially circular, are deemed optimally functional, and may present with arcuate locking fins as shown in Figure 41 .

Figures 43 and 44 depict a 2-flanged, substantially square embodiment. In such embodiments, the upper peripheral rim area indicated at rim 18A presents as substantially square, with moderately rounded character. In the disclosed embodiment, the substantially square profile continues downwardly to present a substantially square internal base 42. Figure 44 depicts an assembly of two such 2- flanged embodiments depicted in Figure 43. In this assembly, the upwardly facing base of the secondary, upper container unit is visible, and is shown to be substantially square. Surface 29B remains the proposed surface for brand placement, and again presents as substantially square, in keeping with the embodiment’s overall form. Such 2-flange, substantially square embodiments are functional but not optimal, due to the inherent exclusion of arcuate locking fins and the increased likelihood of lateral slippage.

Figures 45 and 46 depict a 4-flanged, substantially square embodiment. In such embodiments, the upper peripheral rim area indicated at rim 18A presents as substantially square, with moderately rounded character. In the disclosed embodiment, the substantially square profile continues downwardly to present a substantially square internal base 42. Figure 46 depicts an assembly of two such 4- flanged embodiments depicted in Figure 45. In this assembly, the upwardly facing base of the secondary, upper container unit is visible, and is shown to be substantially square. Surface 29B remains the proposed surface for brand placement, and again presents as substantially square, in keeping with the embodiment’s overall form. Such 4-flange, substantially square embodiments are deemed to be superior to their 2-flange, substantially square counterparts due to the increased number of edge receiving portions, which in turn reduce the likelihood of lateral slippage between assembled units.

In substantially square embodiments, such as those depicted in Figures 43-46, it is not feasible to create true concentric alignment of edge receiving portions with opposing rims, or outer peripheral edges, due to the inherent lack of a shared central axis. However, functionality may be achieved via considerate moderate curvature at upper peripheral rim 18A, which may allow sufficient rotary movement to interlock and disengage the protruding flanges.

Figure 47 depicts a variation of the preferred 2-flange embodiment, whereby the arcuate locking fins are replaced with tongue and groove geometry. In the disclosed embodiment, inner arcuate fins 21 are replaced with tongue 43, and outer arcuate fins 22 are replaced with groove 44. Such embodiments are similarly functional to the preferred 2-flange embodiment with arcuate fins. This variation is less preferred due to the requirement for increased width of upper peripheral face 23, resulting in increased material usage and increased product cost.

Figure 48 is an isometric view of the preferred 2-flange embodiment of a container unit with a hamburger placed inside. A secondary container unit can be placed over the primary container unit shown to enclose the hamburger into a substantially closed container for use/delivery.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Any promises made in the present description should be understood to relate to some embodiments of the invention and are not intended to be promises made about the invention as a whole. Where there are promises that are deemed to apply to all embodiments of the invention, the applicant/patentee reserves the right to later delete them from the description and does not rely on these promises for the acceptance or subsequent grant of a patent in any country.