CA2881590A1 - Collapsible container and blank therefor - Google Patents

Abstract

A container having a generally triangular shape and an opening for receiving an article is provided, along with a blank and method for making same.
The container is formed by joining first and second flaps along a single face, preferably at a single point of attachment. A lid is provided along an end panel which can be securely sealed to close the container. The container can be transitioned from a first flat configuration for storage to a second three dimensional configuration for use.

Description

. .

COLLAPSIBLE CONTAINER AND BLANK THEREFOR
TECHNICAL FIELD
[0001] The present invention relates to the field of containers such as disposable paperboard cartons that may be shipped and stored in a flattened, collapsed configuration and then opened into an uncollapsed, open configuration for use. More specifically, the present invention relates to a generally prism-shaped container having a sealable opening for receiving food or other articles.
BACKGROUND

[0002] In the food industry, disposable paperboard cartons are often used in connection with prepared foods such as sandwiches, microwaveable foods and the like. Food and other perishable items can be safely shipped and displayed in rigid containers that also provide an attractive display to the consumer. For example, single-serve items such as sandwiches are often packaged in individual containers and stored in refrigerated displays. The container is typically configured to closely fit the article, such a prism-shaped container with triangular sidewalls to closely fit a triangular sandwich. The container typically includes a panel or lid that can open for access to the interior and which can be sealed shut. The panel or lid may include a window covered with a transparent material to display the contents.

[0003] Disposable containers are often manufactured from blanks which are cut out from a sheet of material and folded to assemble the finished container. The material used to form the blank, along with the construction of the container, is selected to provide sufficient strength and resistance to leakage.

[0004] Efficient and cost-effective shipping, handling and storage of empty containers prior to filling can be a challenge. In some cases, unfilled containers = , can nest to reduce space. In other cases, the container is stored in a flat configuration and opened up into a three dimensional configuration prior to filling. In such cases, the container may be partially assembled by adhering together certain of the panels, with assembly being completed by transitioning the container to its three-dimensional shape, which in some cases includes additional adherence steps.

[0005] For food use, the container should have a sealable lid. This prevents leakage or contamination and for some applications permits the atmosphere within the container to be replaced with an inert gas such as nitrogen to slow spoilage. As well, the joints of the container where panels meet should be substantially sealed to prevent leakage and contamination.
Within the interior of the container, it is desirable to minimize locations where food can be trapped, such as glued layers of material.

[0006] Disposable containers are often shaped to match the shape of the articles contained within. In the case of diagonally cut sandwiches, this often requires a triangular prism shape. Examples are disclosed in WO 2007/012880 Al by Goldman, U.S. Patent No. 6,695,202 by Miess, GB 2,425,524 A by Rokov, and U.S. Patent Nos. 7,597,238 and 6,431,365 by Money et al.

[0007] The triangular prism shape of such containers can pose difficulties in terms of providing a blank that can be efficiently and easily fabricated into an assembled container in the folded configuration, and then easily converted into the unfolded open configuration. The container should also include a lid which can be securely sealed whereby the fully assembled and filled container is substantially sealed. It is also desirable to provide a container design that can be easily modified to fit different sizes of articles, for example a relatively thin container to hold thin sandwiches and a wider container for wider sandwiches, all with the same basic configuration of cardboard blank. It is desirable to provide a blank that can be easily fabricated using a minimum amount of material and cuts and folds. It is further desireable to provide a blank which can be assembled into a container with a minimum number of steps, gluing, or fastening of parts.

[0008] It is further desirable to provide a container in which the assembled blank may be folded into a compact flat configuration prior to use, for storage, transport and the like. Preferably, the design of the blank should allow the container to be easily transitioned from a flat configuration for storage to a three dimensional configuration for use as a container. In some cases it is desirable for the container to be able to fold into the compact, flat configuration by folding sidewalls either inwardly or outwardly depending on the requirements of the user and other factors.
SUMMARY OF THE INVENTION:

[0009] The present invention relates to a blank as well as a folded partially assembled container and an assembled container formed from said blank. The invention also relates to a method of assembling a container from a blank.

[0010] According to one broad aspect, the invention provides a blank for forming a container in a generally triangular prism shape having an opening for receiving an article. The blank includes a quadrilateral end panel having first and second opposing sides, third and fourth opposing sides, and a longitudinal axis extending from the third side to the fourth side; a generally triangular first side panel having first, second and third sides, said first and third sides meeting at an apex, said first side panel joined by a hinge along its first side to the first side of the end panel and comprising a central fold extending from the apex to an intermediate point on the second side of the first side panel whereby said first side panel is subdivided into two essentially equal triangular portions that can be folded either inwardly or outwardly; a second side panel comprising a mirror image of the first side panel about the longitudinal axis, the second side panel joined by a hinge to the second side of the end panel; first and second flaps joined by a hinge to the third side of the first and second side panels, respectively, said flaps being aligned whereby when said side panels are . .

inwardly folded along their respective hinges to be parallel to each other, said flaps overlie each other to form an end wall which opposes the quadrilateral end panel when the blank is formed into the container; and a lid connected by a hinge to the third side of the quadrilateral end panel for closing the opening when the blank is formed into the container. The end panel and lid are aligned along the longitudinal axis and the first and second side panels extend laterally outwardly from said axis. The assembled, container is formed in flattened configuration by fastening the flaps together in overlying relationship and folding the triangular portions of said side panels together in overlying relationship by folding said first and second side panels inwardly or outwardly along the central fold lines thereof.

[0011] According to another broad aspect, the invention provides a blank for forming a container in a generally triangular prism shape having an opening for receiving an article. The blank includes a quadrilateral end panel, the quadrilateral end panel having first and second opposing sides and third and fourth opposing sides; a generally triangular first side panel having first, second, and third sides, the first side panel hinged along its first side to the first side of the quadrilateral end panel and comprising a first central fold line extending from a vertex of the first and fourth sides of the quadrilateral end panel to an intermediate point on the second side of the first side panel; a generally triangular second side panel having first, second, and third sides, the second side panel hinged at the first side of the second side panel to the second side of the quadrilateral end panel and comprising a second central fold line extending from a vertex of the second and fourth sides of the quadrilateral end panel to an intermediate point on the second side of the second side panel; a first flap hinged to the third side of the first side panel and a second flap hinged to the third side of the second side panel, wherein the first and second flaps form a panel that opposes the quadrilateral end panel when the blank is formed into the container; and a lid hinged to the third side of the quadrilateral end panel for closing the opening when the blank is formed into the container.

=

[0012] According to another broad aspect, the invention provides a container having a generally triangular prism shape and an opening for receiving an article. The container includes a quadrilateral end panel having first and second opposing sides, third and fourth opposing sides, and a longitudinal plane substantially normal to the quadrilateral end panel; a generally triangular first side panel having first, second and third sides, said first and third sides meeting at an apex, said first side panel joined by a hinge along its first side to the first side of the end panel and comprising a central fold extending from the apex to an intermediate point on the second side of the first side panel which substantially bisects said second side whereby said first side panel is subdivided into two essentially equal triangular portions that can be folded inwardly or outwardly; a second side panel comprising a mirror image of the first side panel about the longitudinal plane, the second side panel joined by a hinge to the second side of the end panel; first and second flaps joined by a hinge to the third side of the first and second side panels, respectively, said flaps being aligned whereby when said side panels are inwardly folded along their respective hinges to be parallel to each other, said flaps overlie each other to form an end wall which opposes the quadrilateral end panel; and a lid connected by a hinge to the third side of the quadrilateral end panel for closing the opening of the container. The container is formed by fastening said flaps together in overlying relationship and folding the triangular portions of said side panels together in overlying relationship by folding said first and second side panels inwardly or outwardly along the central fold lines thereof.

[0013] According to yet another broad aspect, the invention provides a container having a generally triangular prism shape and an opening for receiving an article. The container includes a quadrilateral end panel, the quadrilateral end panel having first and second opposing sides and third and fourth opposing sides; a generally triangular first side panel having first, second, and third sides, the first side panel hinged along its first side to the first side of the quadrilateral end panel and comprising an first central fold line extending from a vertex of the first and fourth sides of the quadrilateral end panel to an intermediate point on the second side of the first side panel; a generally = =

triangular second side panel having first, second, and third sides, the second side panel hinged at the first side of the second side panel to the second side of the quadrilateral end panel and comprising a second central fold line extending from a vertex of the second and fourth sides of the quadrilateral end panel to an intermediate point on the second side of the second side panel; a first flap hinged to the third side of the first side panel and a second flap hinged to the third side of the second side panel, wherein the first and second flaps form a panel that opposes the quadrilateral end panel; and a lid hinged to the third side of the quadrilateral end panel for closing the opening of the container.

[0014] In some embodiments, the container or blank further includes a third flap hinged to the fourth side of the quadrilateral end panel for covering the apex of the quadrilateral end panel and the opposing panel formed by the first and second flaps. In some embodiments, the third flap is sandwiched between the first and second flaps when the container is assembled.

[0015] In some embodiments, the first and second flaps can be secured to one another on a single face of the container, preferably at a single point of attachment using an adhesive or by heat sealing.

[0016] In another broad aspect of the invention, there is provided a method of forming a generally triangular prism-shaped container having an opening for receiving an article. The method includes providing a blank as described above; folding said first and second side panels inwardly or outwardly along the central fold thereof; and securing the first and second flaps to one another in overlying relationship, preferably at a single point of attachment.

[0017] Directional terms such as "front" and "rear", "top" and "bottom", "first" and "second", "right" and "left" are used herein purely for convenience of description. Such terms are used for illustration purposes and are not intended to limit the present disclosure. As well, and dimensions herein are not intended to limit the scope of the invention unless specifically stated. Furthermore, geometric terms such as "straight", "flat", "point" and the like are not intended =

to limit the invention to the level of geometric precision, but should instead be understood in the context of the invention which includes such departures from geometric position as the relatively high manufacturing tolerances that are normal and/or acceptable in the field of this invention, as well as the functional requirements of products in the field of the invention wherein a high level of precision may not be required.
BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG 1 is a plan view of a blank according to a first embodiment of the present invention.

[0019] FIG 2A is a plan view of a container formed from the blank of FIG
1, which has been folded into a first flat configuration wherein the sidewalls are folded outwardly.

[0020] FIG 2B is a plan view of a container formed from the blank of FIG
1, which has been folded into a second flat configuration wherein the sidewalls are folded inwardly.

[0021] FIG 3 is a perspective view of a container formed from the blank of FIG 1, in an unfolded configuration for filling and sealing.

[0022] FIGS 4A-D are plan views of blanks according to further embodiments of the present invention, showing various alternative window designs and other alternative aspects.

[0023] FIGS 5A-D are plan views of blanks according to still further embodiments of the present invention.

, =

DETAILED DESCRIPTION

[0024] Referring to FIG 1, a blank 100 is provided which can be assembled into a container 101, as seen in Figure 3. Figures 2A and 2B show an assembled container 101 in a folded, flattened configuration.

[0025] Blank 100 typically consists of a flat sheet of cardboard or similar rigid or semi-rigid material. The material should have sufficient rigidity whereby when formed into an assembled container 101, it provides a suitable level of protection and crush-resistance for the intended use of the container. Blank 100 may be cut or stamped from a continuous roll or large sheet of material using conventional techniques. Blank 100 may also be formed from a food-grade material and may comprise a coating on at least one side (which ultimately may form the inside of the container 101) to prevent leakage from the container 101 or contamination from entering the container 101. The coating may also permit components of the blank 100 to be heat-sealed together, as discussed below.

[0026] Blank 100 comprises in general terms an array of panels that are connected together by fold lines, usually referred to herein as "hinges". When assembled, the panels form walls of the container101, as discussed below.
When blank 100 comprises a single continuous sheet, as illustrated herein, then the hinges will comprise fold lines within the blank 100. However, it will be understood that blank 100 may comprise separate panels, in which case the hinges may comprise separate hinge members that join together the individual panels.

[0027] Blank 100 comprises in general terms a generally rectangular end panel 105, two triangular side panels 110 and 115 that oppose each other, a generally rectangular lid panel 140, generally rectangular bottom flaps 120, 130 that protrude from the side panels 110, 115, and a central flap 125 which protrudes from end panel 105. Lid 140 panel has an exposed end edge 143.
For purposes of reference, blank 100 has an elongate axis "a" that extends =

between end edge 143 and central flap 125. Lid panel 140, end panel 105, and central flap 125 are longitudinally aligned along axis a.

[0028] As described below, the blank 100 may be assembled into a container 101 which can transition from a flattened configuration, shown in Figures 2A and 2B to an open position for filing, as seen in Figure 3. When container 101 is unfolded into the open configuration, lid 140 can be closed to retain an article within the container 101 and sealed shut. Since blank 100 is normally formed from a continuous sheet of material, the respective panels are normally continuous with each other and are defined by fold lines within blank 100.

[0029] End panel 105 connects to opposing side panels 110 and 115 along fold lines 106 and 107 located along opposing sides of end panel 105 and protrudes laterally therefrom. Fold lines 106 and 107 permit side panels 110 and 115 to fold inwardly via valley folds. Each opposing side panel 110 and 115 is joined to a corresponding bottom flap, 120 and 130 respectively, at fold lines 117 and 112, respectively.

[0030] A central flap 125 extends from the end panel 105 at a fold line 109. Central flap 125 seals the exposed edge of end panel 105 to reduce the likelihood of leakage. Central flap 125 is located between bottom flaps 120 and 130, whereby the respective flaps 120, 125 and 130 may be sandwiched together and secured to form a bottom wall of the container, as described below.

[0031] End panel 105 is generally rectangular in shape, and in some cases may be trapezoidal to improve stacking of the container 101 once assembled.
The width of end panel 105 may be selected to vary the dimensions of container 101 to accommodate a selected article. For example, in the blanks 100, 200 shown in FIGS 1 and 4, the end panel 105, 205 is dimensioned to provide a relatively wide container. In the blank 300 shown in FIG. 5, a narrower end panel 305 is provided for a narrower container. Further = -variations can be also made to provide a container 101 having a triangular prism shape of desired side to side depth to accommodate, for example, sandwiches of differing thicknesses.

[0032] Side panels 110 and 115 are generally triangular in shape and are essentially mirror images of each other so as to provide the finished container 101 with a triangular prism shape. Side panels 110 and 115 consist of right angle triangles in the present embodiment. Each side panel 110, 115 is defined by an apex 121, a first side defined by fold lines 107,106 at the junction with the end panel 105, a second side defined by fold lines 112, 117 at the junction with the bottom flaps 120, 130, and a hypotenuse 129.

[0033] In other embodiments, side panels 110 and 115 may be isosceles or equilateral triangles. Scalene triangles may also be used for side panels and 115, so long as the end panel 105, the opposing bottom wall formed by the flaps 120 and 130 and the lid 140 are of differing lengths.

[0034] Side panels 110 and 115 are each substantially bisected by an apical fold 111, 116 which extends from apex 121 to an intermediate point on the hypotenuse 129. Apex 121 is located at the junction between the end panel 105, the central flap 125, and a respective side flap 120, 130. Where the intermediate point is the midpoint of the hypotenuse 129, these folds 111 and 116 bisect side panels 110 and 115, respectively, creating two equal triangular sub-panels 110a/110b and 115a/115b.

[0035] Folds 111 and 116 act as hinges to permit container 101 to be unfolded from an essentially flat, semi-assembled (flattened) configuration (FIG
2A-2B) into a fully open configuration (FIG 3) wherein the container can receive a food article or other contents. Fold lines 111 and 116 are substantially perpendicular to the periphery of their respective side panels 110 and 115.
Folds 111 and 116 may fold outwardly as seen in Figure 2A or inwardly as seen in Figure 2B. This allows the same container 101 to be folded in two different =
=

ways depending on requirements such as storage limitations, equipment and other factors.

[0036] Bottom flaps 120 and 130 form a bottom wall of container 101 when secured together in overlying fashion, as seen in FIG 3. In the blank 100 seen in FIG 1, flap 130 is continuous with side panel 110 and extends from fold line 112 thereof.

[0037] Flanges 131, 113 and 118 extend from the opposing side panels 110, 115 and one or more cooperating end panels 120 and 130 to provide an outwardly-protruding shelf around the open mouth of container 101 to which lid 140 can be sealed.

[0038] In FIG 1, flange 131 protrudes laterally from a side edge of bottom flap 130 and is continuous with flange 113 of side panel 110. In blank 100, bottom flap 120 is not provided with a similar flange, since when container is assembled, the corresponding side edge flap 120 is unexposed. In FIGS 4-5, the flange 231/331 is divided into two portions 231a/331a and 231b/331b provided on bottom flaps 220/230 and 320/330, respectively.

[0039] Lid 140 is substantially rectangular, but may be provided with rounded corners. Lid 140 is joined to the end panel 105 opposite central flap 125, at fold line 108. The exposed edge regions of lid 140 contact flanges 113, 118, 131 when the lid 140 is closed. When a container 101 is assembled from the blank 100, the flanges 113, 118, 131 are positioned along the opening of the container 101 and serve as a surface upon which the lid 140 can be sealed.

[0040] Lid 140 and flanges 113, 118 and 131 may be sealed together with a heat sealable material such as a film or coating laminated to one side of blank 100. Alternatively, lid 140 may be secured to the flanges 113, 118, 131 with a suitable adhesive or mechanical closure.

. -

[0041] Where heat sealing is used to seal the lid 140, the heat seal is conventionally formed by the application of heat and pressure to the lid 140 and flanges 113, 118, 131. A heat sealable film may be limited to areas that are to be heat sealed or alternatively the blank may comprise a continuous layer of heat sealable film, which may also provide gas and/or liquid impermeability to the material. Other materials for manufacturing a blank 100, such as plastics, may also be suitable for heat sealing without requiring the application of an additional heat sealable film.

[0042] Lid 140 includes a window 150 to permit the contents of the container 101 to be viewed. Window 150 is normally covered with a clear film.
In the blanks 100, 200 and 300 shown in FIGS 1, 4A and 5A, windows 150, 250 and 350 are generally rectangular in shape. Other sizes and configuration for windows 150, 250 and 350 are depicted in FIGS 4B-4D and 5B-5D. It will be seen that lid 140 may be provided with a large variety of window configurations. As well, similar windows may be provided as appropriate in other panels such as side or end panels 105, 110 and/or 115.

[0043] As seen in figures 2A and 2B, blank 100 is initially assembled into container 101 by fastening bottom flaps 120 and 130 together in overlying relationship, preferably using an adhesive. Other means of attachment are also contemplated, including heat sealing in embodiments where the blank is formed from a heat sealable material such as plastic or a paperboard material having a heat sealable film or layer. Central flap 125 may be sandwiched between bottom flaps 120 and 130.

[0044] In FIG 2-3, the larger bottom flap 130 overlies central flap 125 and bottom flap 120 such that the larger bottom flap 130 is exposed on the inside of container 101 when unfolded. This arrangement provides a generally continuous inner surface to the container 101 and sandwiches central flap 125 between flaps 120 and 130 for added structural integrity. The sequence of layering can be varied from the above.

= =

[0045] Blank 100 is configured such that the assembled container 101 may be formed by securing bottom flaps 120 and 130. Where a central flap 125 is provided on the blank 100, it can also be secured to the bottom flaps 120 and 130 for added structural integrity. By gluing these flaps together, blank 100 may be assembled into a container 101 in a three dimensional container ready for filing with a food article or a flattened configuration for transport and storage.

[0046] This simplicity of assembly can reduce the complexity of the machinery and materials required for fabrication of the container. For example, container 101 can be fabricated from the blank 100 in FIG 1 by fastening flaps 120, 125 and 130 together. No further fastening steps are required until the lid is sealed to the filled container.

[0047] Depending on the configuration and dimensions thereof, container 101 may be folded into one of two flat configurations. FIG 2A depicts a first flat configuration in which the side panels 110 and 115 are folded outwardly along fold lines 111 and 116. FIG 2B depicts a second flat configuration in which the side panels 110, 115 are folded inwardly along apical fold lines 111 and 116 by interweaving subpanels 110a/110b with 115a/115b or vice versa.

[0048] The first flat configuration shown in FIG 2A may be preferable in applications where it is desirable to minimize the number and complexity of folding actions when preparing the container 101. The second flat configuration shown in FIG 2B may be preferable in applications where it is desirable to minimize the size of the container 101 when stored in the flat configuration.

[0049] When the container 101 is ready for use, it may be transitioned to a three-dimensional open configuration, an example of which is depicted in FIG

3. If the container 101 is in the first flat configuration (i.e. side panels 110, 115 folded outwards as in Figure 2A), this may be achieved by applying an inward force at fold lines 111, 116, which in turn causes the container 101 to open into the three-dimensional configuration. If the container is in the second . , flat configuration (i.e. side panels 110, 115 folded inwards as in Figure 2B), this may be achieved by applying an outward force at the end panel 105 and the bottom panel formed by bottom flaps 120, 130. In either case, the force applied to transition the container may be applied manually or by automated means.

[0050] After filling the container 101, the lid 140 is secured to the flanges 113, 118, 131 as described above. Closure of the lid 140 thereby provides structural stability to the container 101, so as to resist transition back to a flat configuration. In embodiments where a sealing closure is used, closure of the lid 140 may also provide a barrier against the escape of small particles, liquids, or gasses from the container 101.

[0051] Blank 100 may be fabricated by known techniques such as cutting, stamping or the like from a roll or sheet of material. Various suitable materials may be used to form the blank 100, depending on the application. For example, paperboard materials such as heavy papers, card stock, or corrugated cardboard may be used. Other suitable materials include plastics, such as polyethylene terephthalate (PET), high density polyethylene (HDPE), polyvinyl chloride (PVC), Low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), or a combination thereof.

[0052] The manufacturing process may begin by cutting or stamping the chosen material into the outline of a blank 100 in accordance with the present invention. In the blank 100 depicted in FIG 1, this process is simplified by the fact that no internal cuts are required in the blank 100 unless a window 150 is provided. The generally triangular shape of the blank 100 also aids in arranging a series of blanks 100 along a single sheet of starting material, so as to minimize the amount of waste left behind after cutting. If the blank 100 includes a window 150, it may be cut out at this time and a transparent window material, such as a plastic film may be applied either immediately after cutting or as the final step in assembly of the blank 100. Fold lines 106, 107, 108, 109, 111, 112, 116 and 117 are then imparted onto the cut material to create the blank 100, often by pre-scoring or perforating the material.

[0053] Assembly of the container 101 from the blank 100 is achieved by folding the blank 100 along fold lines 106, 107, 108, 109, 111, 112, 116 and 117 and securing the bottom flaps 120 and 130 to one another (and if present, to the central flap 125) in the manner described above. If present, flanges 113, 118, 131 may also be folded outwards in preparation for securing the lid 140. Inward folding of flanges 113, 118 and 131 may also be used, depending on the application.

[0054] In general, folds are either of a 'hill type' or 'valley type'. The particular folds applied to each fold line 106, 107, 108, 109, 111, 112, 116 and 117 when assembling the container 101 depend on the desired configuration of the container 101 and would be apparent to the person of skill in view of the present specification.

[0055] For example, in the preferred embodiment depicted in FIG 2A, fold lines 106, 107, 108, 109, 111, 112, 116 and 117 are all valley folds, which may simplify the assembly process for this blank 100. In contrast, the embodiment depicted in FIG 2B uses hill folds for the apical fold lines 111 and 116, so as to permit the side panels 110, 115 to fold inwards when in the second flat configuration. If flanges 113, 118 and 131 are to face outward, they are subjected to hill folds. If flanges 113, 118 and 131 art to face inward, they are subjected to valley folds.

[0056] In applications involving high throughput assembly of the container 101, it may be preferable to use automated means for folding the blank 100 and securing the bottom flaps 120, 130 (and if present, to the central flap 125). Suitable equipment for the application in question would be apparent to the person of skill in view of the present specification.

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[0057] Figures 4 and 5 depict alternative embodiments of the invention.
FIGS 4A-4D show blanks 200 according to the invention in which the lid 240 has one or more windows 250 therein. As seen in Figures 4A through 4D, windows 250 may be consist of an elongated rectangle, a trapezoid, an oval or a pair of semicircles. It will be evident that many other window configurations may be provided. Windows 150, 250, 350 are covered with a transparent material such as cellophane or plastic film.

[0058] The blanks 200 are depicted in FIGS 4A to 4D using similar , reference numerals in the '200' series to denote structures which serve analogous functions to those described above for blank 100.

[0059] Briefly, each blank 200 comprises an end panel 205 hinged to side panels 210, 215 at fold lines 206 and 207. A lid 240 and central flap 225 are also hinged to the end panel 205 at fold lines 208 and 209. The lid 240 may include a window 250. Apical fold lines 211, 216 which begin at an apex 221 and end at a hypotenuse 229 divide the side panels 210, 215 into subpanels 210a/210b and 215a/215b. Bottom flaps 220, 230 are hinged to the side panels 210, 215 at fold lines 217 and 212, respectively. In this blank 200, flanges 213, 218, 231a, 231b are provided to facilitate closure of the lid 240.

[0060] Unlike the blank 100 shown in FIG 1, the bottom flaps 220, 230 of the blank 200 in FIGS 4A-4D are of essentially equal size. As such, there is no preferred ordering or sequence for layering the respective flaps 220 and 230 during assembly of the container, as neither flap is capable of providing a continuous interior surface.

[0061] A further feature shown in the blank 200 of FIGS 4A-4D is that flaps 220 and 230 are each provided with a flange 231b and 231a respectively extending laterally therefrom, so as to permit a continuous flange structure to be formed when the container is assembled. In the blank 200 in FIGS 4A-4D, flanges 231a and 231b do not fully extend across the full length of the side edge of their respective flap 220, 230. As a result, the outer corners of flaps 220 and 230 have a notch 233. When the container is assembled, notches 233 are aligned and overlie each other to allow the 231a/231b to abut one another when the bottom flaps 220, 230 are secured, so as to form an essentially continuous shelf-like flange extending along the bottom panel of the container assembled from the blank 200.

[0062] Figures 5A through 5D show further embodiments wherein the width of the container is narrower than the preceding embodiments. Again, similar reference numerals in the '300' series are used to denote analogous features.

[0063] Briefly, each blank 300 comprises an end panel 305 hinged to side panels 310, 315 at fold lines 306 and 307. A lid 340 and central flap 325 are also hinged to the end panel 305 at fold lines 308 and 309. The lid 340 may include a window 350. Apical fold lines 311, 316 which begin at an apex 321 and end at a hypotenuse 329 divide the side panels 310, 315 into subpanels 310a/310b and 315a/315b. Bottom flaps 320, 330 are hinged to the side panels 310, 315 at fold lines 317 and 312, respectively. In this blank 300, flanges 313, 318, 331a, 331b are provided to facilitate closure of the lid 340.
Notches 333 are provided at the outer corners of the bottom flaps 320, 330, which can be aligned to provide a continuous shelf like flange extending along the bottom panel of the container assembled from the blank 300.

[0064] The container formed from a blank 100, 200, 300 according to the present invention can have various dimensions. For example, the blanks 100 and 200 shown in FIGS 1-4D are designed to provide a container suitable for two triangular halves of a sandwich, whereas the blanks 300 of FIGS 5A-5D are designed to hold a smaller article, such as one half of a sandwich. In blank 300, this is accomplished by reducing the width of the end panel 305, lid 340, window 350, central flap 325, and bottom flaps 320,330. The blanks 300 in FIGS 5A-5D also include windows 350 having a variety of configurations similar to those of Figures 4A through 4D.

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[0065] It will be understood that in the blank 300 shown in FIGS 5A-5D
may be too narrow to permit the second flat configuration shown in FIG 2B, since there may be insufficient room to fold the side panels 310 and 315 inwards. This occurs where the area of subpanel 315a or 310a cannot be circumscribed within the area of end panel 305 when the blank 300 is folded along fold lines 306 and 307. In such situations, the first flat configuration shown in FIG 2A would be used.

[0066] The embodiments of the present application described above are intended to be examples only. Those of skill in the art may effect alterations, modifications and variations to the particular embodiments without departing from the intended scope of the present application. In particular, features from one or more of the above-described embodiments may be selected to create alternate embodiments comprised of a subcombination of features which may not be explicitly described above. In addition, features from one or more of the above-described embodiments may be selected and combined to create alternate embodiments comprised of a combination of features which may not be explicitly described above. Features suitable for such combinations and subcombinations would be readily apparent to persons skilled in the art upon review of the present application as a whole. The subject matter described herein and in the recited claims intends to cover and embrace all suitable changes in technology.

Claims (35)

CLAIMS:

1. A blank for forming a container having a generally triangular prism shape and an opening for receiving an article, comprising:
a quadrilateral end panel having first and second opposing sides, third and fourth opposing sides, and a longitudinal axis extending from the third side to the fourth side;
a generally triangular first side panel having first, second and third sides, said first and third sides meeting at an apex, said first side panel joined by a hinge along its first side to the first side of the end panel and comprising a central fold extending from the apex to an intermediate point on the second side of the first side panel which substantially bisects said second side whereby said first side panel is subdivided into two essentially equal triangular portions that can be folded inwardly or outwardly;
a second side panel comprising a mirror image of the first side panel about the longitudinal axis, the second side panel joined by a hinge to the second side of the end panel;
first and second flaps joined by a hinge to the third side of the first and second side panels, respectively, said flaps being aligned whereby when said side panels are inwardly folded along their respective hinges to be parallel to each other, said flaps overlie each other to form an end wall which opposes the quadrilateral end panel when the blank is formed into the container; and a lid connected by a hinge to the third side of the quadrilateral end panel for closing the opening when the blank is formed into the container;
wherein the end panel and lid are aligned along the longitudinal axis and the first and second side panels extend laterally outwardly from said axis; and whereby an assembled, flattened container is formed by fastening said flaps together in overlying relationship and folding the triangular portions of said side panels together in overlying relationship by folding said first and second side panels inwardly or outwardly along the central fold lines thereof.

2. A blank for forming a container having a generally triangular prism shape and an opening for receiving an article, the blank comprising:
a quadrilateral end panel, the quadrilateral end panel having first and second opposing sides and third and fourth opposing sides;
a generally triangular first side panel having first, second, and third sides, the first side panel hinged along its first side to the first side of the quadrilateral end panel and comprising a first central fold line extending from a vertex of the first and fourth sides of the quadrilateral end panel to an intermediate point on the second side of the first side panel;
a generally triangular second side panel having first, second, and third sides, the second side panel hinged at the first side of the second side panel to the second side of the quadrilateral end panel and comprising a second central fold line extending from a vertex of the second and fourth sides of the quadrilateral end panel to an intermediate point on the second side of the second side panel;
a first flap hinged to the third side of the first side panel and a second flap hinged to the third side of the second side panel, wherein the first and second flaps form a panel that opposes the quadrilateral end panel when the blank is formed into the container; and a lid hinged to the third side of the quadrilateral end panel for closing the opening when the blank is formed into the container.

3. The blank of claim 1 or claim 2, further comprising a third flap hinged to the fourth side of the quadrilateral end panel for covering the apex of the quadrilateral end panel and the opposing panel formed by the first and second flaps when the blank is formed into the container.

4. The blank of any one of claims 1 to 3, wherein the intermediate point on the second side of the first or second side panels is a midpoint.

5. The blank of any one of claims 1 to 4, wherein upon assembly of the container from the blank, all attachment points necessary to secure the container are presented on a single face of the container.

6. The blank of any one of claims 1 to 5, wherein the first and second flaps can be secured to one another at a single point of attachment.

7. The blank of any one of claims 3 to 6, wherein the first and second flaps and the third flap can be secured to one another at a single point of attachment.

8. The blank of any one of claims 1 to 7, wherein the first and second flaps are of substantially the same size.

9. The blank of any one of claims 1 to 8, wherein the first or second flap is substantially congruent with the quadrilateral end panel.

10. The blank of any one of claims 1 to 9, further comprising flanges positioned on the second side of the first and second end panels and at least one of the first or second flaps, the flanges disposed along at least three sides of the opening when the container is assembled from the blank.

11. The blank of claim 10, wherein the flanges and the lid comprise a heat sealable material.

12. The blank of any one of claims 1 to 11, wherein manufacture of the blank requires no cuts within the periphery of the blank, other than to form a window in the lid.

13. The blank of any one of claims 2 to 12, wherein the area between the first central fold line, the second side of the first side panel, and the third side of the first side panel can be circumscribed by the quadrilateral end panel.

14. The blank of any one of claims 1 to 13, wherein when the blank is assembled into the container, the container can be unfolded along the central folds of the first and second side panels to transition the container from a first substantially flat configuration to a second substantially erect position for receiving the article.

15. A container having a generally triangular prism shape and an opening for receiving an article, the container comprising:
a quadrilateral end panel having first and second opposing sides, third and fourth opposing sides, and a longitudinal plane substantially normal to the quadrilateral end panel;
a generally triangular first side panel having first, second and third sides, said first and third sides meeting at an apex, said first side panel joined by a hinge along its first side to the first side of the end panel and comprising a central fold extending from the apex to an intermediate point on the second side of the first side panel which substantially bisects said second side whereby said first side panel is subdivided into two essentially equal triangular portions that can be folded inwardly or outwardly;
a second side panel comprising a mirror image of the first side panel about the longitudinal plane, the second side panel joined by a hinge to the second side of the end panel;

first and second flaps joined by a hinge to the third side of the first and second side panels, respectively, said flaps being aligned whereby when said side panels are inwardly folded along their respective hinges to be parallel to each other, said flaps overlie each other to form an end wall which opposes the quadrilateral end panel; and a lid connected by a hinge to the third side of the quadrilateral end panel for closing the opening of the container;
wherein the container is formed by fastening said flaps together in overlying relationship and folding the triangular portions of said side panels together in overlying relationship by folding said first and second side panels inwardly or outwardly along the central fold lines thereof.

16. A container having a generally triangular prism shape and an opening for receiving an article, the container comprising:
a quadrilateral end panel, the quadrilateral end panel having first and second opposing sides and third and fourth opposing sides;
a generally triangular first side panel having first, second, and third sides, the first side panel hinged along its first side to the first side of the quadrilateral end panel and comprising an first central fold line extending from a vertex of the first and fourth sides of the quadrilateral end panel to an intermediate point on the second side of the first side panel;
a generally triangular second side panel having first, second, and third sides, the second side panel hinged at the first side of the second side panel to the second side of the quadrilateral end panel and comprising a second central fold line extending from a vertex of the second and fourth sides of the quadrilateral end panel to an intermediate point on the second side of the second side panel;

a first flap hinged to the third side of the first side panel and a second flap hinged to the third side of the second side panel, wherein the first and second flaps form a panel that opposes the quadrilateral end panel; and a lid hinged to the third side of the quadrilateral end panel for closing the opening of the container.

17. The container of claim 15 or claim 16, further comprising a third flap hinged to the fourth side of the quadrilateral end panel for covering the apex of the quadrilateral end panel and the opposing panel formed by the first and second flaps.

18. The container of any one of claims 15 to 17, wherein the intermediate point on the second side of the first or second side panels is a midpoint.

19. The container of any one of claims 15 to 18, wherein all attachment points necessary to secure the container in its assembled form are presented on a single face of the container.

20. The container of any one of claims 15 to 19, wherein the first and second flaps can be secured to one another at a single point of attachment.

21. The container of any one of claims 17 to 20, wherein the first and second flaps and the third flap can be secured to one another at a single point of attachment.

22. The container of any one of claims 15 to 21, wherein the first and second flaps are of substantially the same size.

23. The container of any one of claims 15 to 22, wherein the first or second flap is substantially congruent with the quadrilateral end panel.

24. The container of any one of claims 15 to 23, further comprising flanges positioned on the second side of the first and second end panels and at least one of the first or second flaps, the flanges disposed along at least three sides of the opening of the container.

25. The container of claim 24, wherein the flanges and the lid comprise a heat sealable material.

26. The container of any one of claims 15 to 25, wherein manufacture of the blank requires no cuts within the periphery of the blank, other than to form a window in the lid.

27. The container of any one of claims 16 to 26, wherein the area between the first central fold line, the second side of the first side panel, and the third side of the first side panel can be circumscribed by the quadrilateral end panel.

28. The container of claim 17 to 27, wherein the first and second flaps sandwich the third flap.

29. The container of any one of claims 15 to 28, wherein the container can be unfolded along the central folds of the first and second side panels to transition the container from a first substantially flat configuration to a second substantially erect position for receiving the article.

30. A method of forming a generally triangular prism-shaped container having an opening for receiving an article, the method comprising:
providing a blank according to any one of claims 1 to 13;
folding said first and second side panels inwardly or outwardly along the central fold thereof; and securing the first and second flaps to one another in overlying relationship.

31. The method according to claim 30, wherein the first and second flaps are secured to one another at a single point of attachment.

32. The method according to claim 30, wherein the blank is according to any one of claims 3 to 13, the first and second flaps sandwich the third flap, and the first, second, and third flaps are secured to one another at a single point of attachment.

33. The method of any one of claims 30 to 32, wherein the first and second flaps are secured by the application of heat to a heat sealable material.

34. The method of any one of claims 30 to 32, wherein the first and second flaps are secured using glue.

35. The method of any one of claims 30 to 34, further comprising the step of unfolding the blank along the central folds of the first and second side panels to transition the container from a first substantially flat configuration to a second substantially erect position for receiving the article.