US20040069842A1

US20040069842A1 - Container with locking flanges

Info

Publication number: US20040069842A1
Application number: US10/270,446
Authority: US
Inventors: John Boutin
Original assignee: Georgia Pacific LLC
Current assignee: Georgia Pacific LLC
Priority date: 2002-10-15
Filing date: 2002-10-15
Publication date: 2004-04-15
Also published as: CA2409796A1

Abstract

A carton, and a blank for forming the carton, are provided having interlocking flanges that may be folded down into a locked configuration in a variety of sequences and that may retain the locked configuration when folds are misaligned. The carton includes a plurality of walls having locking flanges foldably attached thereto. Each one of the locking flanges is adapted to engage adjacent locking flanges in a folded configuration. Each one of the locking flanges includes a first side portion and an opposing second side portion. Each of the side portions includes a first tab, a second tab spaced apart from the first tab, and an engagement edge disposed between the first tab and the second tab. In a folded configuration, each one of the tabs and the engagement edge of a side portion engages corresponding tabs and the engagement edge of an adjacent flange side portion.

Description

FIELD OF THE INVENTION

This invention relates generally to containers having locking flanges. More particularly, the present invention relates to containers made from folded sheet material having locking flanges that may be folded in various configurations and sequences.

BACKGROUND OF THE INVENTION

Containers having foldable flanges, such as fiberboard cartons, are known and come in a variety of shapes and sizes. Many of these cartons include interlocking flanges on a top and/or a bottom end of the carton that fold over to cover an opening to the carton. For example, U.S. Pat. No. 6,293,460 discloses a carton that includes flange-locking mechanisms. Conventional flange-locking mechanisms typically require the flanges to be folded over in a particular sequence and often require additional locking steps, such as placing tabs into slots. These folding sequences and complex locking mechanisms may be inefficient and time-consuming in a production environment.

Fiberboard cartons are generally formed from blanks, which are normally easy to ship and store. When needed, these blanks can be assembled into a carton for storing a commodity or other item, such as fruits and vegetables. They are assembled by folding the blank along fold lines that divide the blank into carton walls and flanges. Because the blanks are often assembled as needed in a commercial environment, it is preferable that they are easy to quickly assemble.

Variability in the location of pre-determined fold lines on a carton blank or the fold lines in an assembled carton, can affect the final carton configuration. Further, such variability may cause flange-locking features to function improperly. Tight manufacturing tolerances may be used to reduce variability; however, maintaining such tolerances may be expensive. As such, many conventional cartons may have ineffective flange locks due to manufacturing or assembly variability.

SUMMARY OF THE INVENTION

The present invention provides a carton, and a carton blank for making the carton, having interlocking flanges that may be folded into a locked configuration by a variety of fold sequences. Further, according to one embodiment, flanges may be locked and maintained in a locked configuration when folds or fold lines between walls are misaligned.

According to one embodiment of the invention, a carton having locking flanges adapted for folding in various sequences includes a plurality of walls having locking flanges foldably attached thereto. Each one of the locking flanges is adapted to engage adjacent locking flanges in a folded configuration. Each one of the locking flanges includes a first side portion and an opposing second side portion. Each of the side portions includes a first tab, a second tab spaced apart from the first tab, and an engagement edge disposed between the first tab and the second tab. In a folded configuration, each one of the tabs and the engagement edge of a side portion engages corresponding tabs and the engagement edge of an adjacent flange side portion.

In a carton blank embodiment of the invention, adjacent locking flanges are spaced apart forming a slot therebetween, and pre-determined fold lines are formed between adjacent walls. Each one of the fold lines is substantially centered with one of the slots. Each slot is preferably wider than the corresponding fold line, which allows the assembled carton to adapt to fold variability as well as to stresses that may be encountered by the carton while in the locked configuration. Whether the fold lines are centered or slightly offset from the corresponding slot, the flanges of the assembled carton are adapted to be retained in a locked configuration.

In one aspect of the invention, the first tab of each side portion extends further from the engagement edge than the second tab, which may encourage the second tab to bend past a corresponding second tab from another flange. In another aspect, the first tab is rounded to reduce potential tearing. In a further aspect, the second tab is rounded, which may also reduce potential tearing. Additional aspects of the invention include methods for folding a blank into a carton and locking the locking flanges in various sequences.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in detail in the following description of preferred embodiments with reference to the following figures wherein: [0009]
FIG. 1 is a perspective view of a carton according to the present invention in an assembled condition, showing locking flanges in a locked configuration; [0010]
FIGS. 2A and 2B are enlarged perspective views of one of the corners of the carton of FIG. 1, showing steps in a method of interlocking the locking flanges of the assembled carton according to an embodiment of the invention; [0011]
FIG. 3 is a plan view of the assembled carton of FIG. 1; [0012]
FIG. 4 is a plan view of one of the corners of the assembled carton of FIG. 1, showing the locking flanges in a locked configuration; [0013]
FIG. 5 is a plan view of a carton blank for forming the carton of FIG. 1; [0014]
FIG. 6 is an enlarged view of the [0015] Area 6 designated in FIG. 5;
FIGS. 7A and 7B are enlarged perspective views of one of the corners of the carton of FIG. 1, showing steps in an alternative method of interlocking the locking flanges of the assembled carton according to an embodiment of the invention; [0016]
FIG. 7C is an enlarged perspective view of one of the corners of the assembled carton of FIG. 1, showing another alternative method of interlocking the locking flanges of the assembled carton according to an embodiment of the invention; [0017]
FIG. 8 is a plan view of a carton blank having pre-determined fold lines offset from their corresponding slot according to an embodiment of the invention; [0018]
FIG. 9 is a plan view of a carton assembled from the carton blank of FIG. 8; and [0019]
FIG. 10 is a plan view of the carton of FIG. 1 showing locking flanges interlocked in an alternative configuration from FIG. 3. [0020]

DETAILED DESCRIPTION OF THE INVENTION

The invention may be embodied in various forms. As shown in FIGS. [0021] 1-6, one embodiment according to the present invention includes a carton 10 that generally includes a first pair of opposing walls 12, 14, a second pair of opposing walls 16, 18, and a bottom 21 that together define an interior volume 20. A corresponding locking flange 22, 24, 26, 28 is foldably attached to each wall 12, 14, 16, 18 respectively on a top end thereof. The locking flanges 22, 24, 26, 28 may be folded and interconnected in a locked configuration to cover at least a portion of an opening 30 formed at an end of the carton. The locking flanges 22, 24, 26, 28 may extend to completely cover opening 30 or, as shown in FIG. 1, may simply cover a portion of opening 30.
Each [0022] locking flange 22, 24, 26, 28 has a locking feature 32 formed at the periphery or side portions 34 (e.g. corner region) of each flange. The locking feature 32 provides several advantages such as permitting a person to interlock the flanges of the carton 10 in various sequences. In one embodiment, each locking feature 32 generally includes an inboard tab 36 spaced apart from an outboard tab 40 with an engagement edge 38 disposed in between the tabs. In a locked configuration, adjacent locking features 32 from adjacent flanges 22, 24, 26, 28 are alt-superimposed. As used herein, the term “alt-superimposed” means that at least a first tab of a first locking feature is at least partially superimposed above a first tab of a second locking feature and a second tab of the second locking feature is at least partially superimposed above a second tab of the first locking feature. For example, FIG. 4 shows adjacent flanges 22 and 26 in an alt-superimposed locked configuration. As shown, outboard tab 36 for flange 22 is superimposed above flange 26 and inboard tab 40 for flange 22 extends under flange 26.
FIG. 5 shows a blank [0023] 46 for forming carton 10. The blank 46 may be formed from various materials, such as fiberboard or plastic sheets that can be cut and folded, as is known in the relevant art. The blank 46 may be formed via a die cut operation, a laser-cutting operation, or other known methods for configuring carton blanks. Each blank 46 may include pre-determined fold lines 48, 62, 66 and 68 such as scores cut into the blank or creases formed in the blank. The pre-determined fold lines 48, 62, 66 and 68 serve to further define portions of the blank. For example, fold lines 62 divide portions that form walls 12, 14, 16, 18, and fold lines 68 divide flanges 22, 24, 26, 28 from their respective wall. The blank 46 may also include portions for forming bottom flanges 50, which are divided from their respective wall by fold line 48, and an assembly flange 52 for retaining the carton 10 in an assembled form. As discussed later, fold line 66 is an alternate fold line to allow fold flexibility.
Referring now to FIG. 6, an enlarged view of the [0024] side portions 34 of adjacent flanges 22 and 26 are shown. The side portions discussed along with FIG. 6 serve as examples for any of the side portions of flanges 22, 24, 26, and 28. In general, the side portions 34 of each flange 22, 24, 26 and 28 include an outboard tab 36 separated from an inboard tab 40 by an engagement edge 38. Further, adjacent side portions of adjacent flanges are substantially mirror images of each other separated by a slot 42.
Each [0025] outboard tab 36 of the side portions 34 is a convex protrusion that may be partially formed from an edge 44 of the corresponding flange 22, 24, 26, 28, which also forms a border of slot 42. The inboard portion of outboard tab 36 may be formed by a rounded edge 54 that extends from the top of slot 42 at the upper flange corner and slopes away from the corner to a termination point 56.
The [0026] engagement edge 38 extends from the termination point 56 at the outboard tab 36 to a second termination point 58 at the inboard tab 40. In a rectangular carton embodiment, the edge 38 preferably has an angle a of about 45 degrees from a line parallel with flange fold line 68. As shown in FIG. 4, the angle a corresponds with a geometrically complementary angle β formed with flange fold line 68 for flange 26. As also shown in FIG. 4, engagements edges 38 of adjacent flanges 22 and 26 mate along imaginary line 39, which preferably bisects the corner formed between walls 12 and 16 of assembled carton 10.
In other embodiments, angle β may be larger than complementary angle α, and angle α may be correspondingly smaller. For example, in a rectangular carton scenario, angle β′ (not shown) could be 30 degrees and angle α′ could be 60 degrees. As such, engagement edges [0027] 38 would not mate along a bisector of the corner, but at a line (not shown) along the termination sides of angles α′ and β′.
Further embodiments may include cartons with more or less than four sides having corner angles greater or less than ninety degrees. Preferably, angles α and β in such alternative embodiments would be substantially equal so that corresponding engagement edges may mate along their respective corner bisector line (not shown). As an example, in a hexagonal carton scenario (e.g. carton having a bottom, six walls, and six interlocking flanges) (not shown), each corner (not shown) would be approximately 120 degrees. In such a scenario, mating engagement edges (not shown) would preferably mate along a bisector line (not shown) and have angles α″ and β″ of about 60 degrees each. [0028]
The design of engagement edges [0029] 36 of locking feature 32 allow the carton 10 to adjust for variability from the folding operation as well as for adjusting to stresses encountered by the carton 10 in an interlocked state. For example, if carton 10 becomes skewed such that a top view of carton 10 resembles a trapezoid, interlocked flanges 22, 24, 26 and 28 may simply translate along their respective mating engagement edges 38 to retain their locked configuration. It may be easier for engagement edges 38 to translate against each other when they mate along a bisector of the corresponding corner, because the bisector equally divides the corner and does not favor a particular flange.
The [0030] inboard tab 40 may be formed by a rounded edge 60 extending away from the second termination point 58 and blending into the top surface 61 of flange 22, 24, 26 and 28. The rounded edge 60 reduces potential tearing in the locking area. Further, as discussed later with relation to methods for interlocking the locking flanges, rounded edge 60 permits adjacent flanges to be easily interlocked and separated by encouraging inboard tab 40 to bend past a corresponding inboard tab 40.
In one embodiment of the invention, a [0031] distal point 63 of outboard flange 36 shown in FIG. 6 is aligned with top flange edge 61. As such, inboard flange 40, engagement surface 38 and outboard flange 36 define a notch 65. When flanges of an assembled carton are interlocked, notch 65 of one flange, such as flange 22, receives side portion 34 of an adjacent flange, such as flange 26, and vice versa.
As shown in FIG. 6, [0032] slot 42 is formed between the outboard tabs 36 of adjacent flanges, such as flanges 22, 26. In one embodiment, slot 42 is generally U-shaped, which reduces potential tearing at the corners when assembled as a carton. As such, the bottom portion of the slot includes a curved portion 43. The slot 42 is preferably oversized in comparison to the corresponding pre-determined fold line 62 between wall sections (e.g. sections 12 and 16). For example, suppose the width of fold line 62 is ⅜ inch ±{fraction (1/16)} inch and the location tolerance for the fold line is ±⅛ inch. As such, the width of slot 42 is preferably ¾ inch or more to allow for expected variability. In general, slot 42 is large enough such that fold line 62 is aligned with slot 42, which means slot 42 may have a width that is twice or more as large as the fold line.
[0033] Slot 42 is preferably centered in alignment with fold line indicator 62. The designs of oversized slot 42 and locking features 32 permit retention of the locked configuration in the event fold line 62 is slightly offset from the corresponding slot 42. In such a situation, which is discussed further with regard to FIGS. 8 and 9, corresponding locking features 32 of the assembled carton 10 may simply translate along mating engagement edges 38 while retaining the locked configuration. The slot 42 together with the design of locking feature 32 allows the carton 10 to adjust for variability from the folding operation as well as for adjusting to stresses encountered by the carton 10 in an interlocked state.
The design of locking [0034] feature 32 provides other advantages. For instance, the curvature of outboard tab 36 and inboard tab 40 minimize tearing in the locking area. Additionally, as discussed later with relation to methods for interlocking the locking flanges, rounded edge 60 permits adjacent flanges to be easily interlocked and unlocked. Also, as discussed further with regard to FIG. 10, the flanges 22, 24, 26, 28 according to the present invention may be folded and interlocked in a variety of sequences and configurations.
Adjacent locking features [0035] 32 from adjacent flanges 22, 24, 26, 28 may be alt-superimposed in an interlocked configuration, as shown in FIG. 4. In such a configuration, corresponding engagement edges 38 mate against each other, and tabs 36, 40 on each side of the corresponding engagement edges 38 are alt-superimposed to retain the locked configuration. As such, locking features 32 may translate relative to each other along engagement edges 38 in a locked configuration to allow for folding and manufacturing variability, as well as to provide flexibility for adjusting to stresses encountered by carton 10.
The [0036] flanges 22, 24, 26, 28 are locked together by folding them inward toward the volume 30 of carton 10 into a position substantially perpendicular to their respective walls; however, the flanges may be folded and interlocked in a variety of sequences. As shown in FIGS. 2A and 2B, according to one embodiment of the invention, the flanges may be interlocked by folding adjacent side portions 34 at substantially the same time while alt-superimposing tabs 36, 40 such that one of tabs 36 and 40 of the same side portion 34 are superimposed opposite to the other tab. For example, a person may fold side portions 34 of flanges 22 and 26 inward at substantially the same time. While folding flanges 22, 26, the person ensures that outboard tab 36 of one flange (e.g. flange 26) is folded inward of outboard tab 36 of the other flange (e.g. flange 22). Additionally, as the folding process continues, the person ensures that inboard tabs 40 are superimposed with each other in a configuration opposite to the outboard tabs 36 (e.g. outboard tab 40 of flange 22 is inward of outboard tab 40 of flange 26).
Referring now to FIGS. 7A, 7B and [0037] 7C, different interlock folding methods are shown. According to these folding method embodiments, a first flange such as flange 22 is folded into an engagement position perpendicular to the walls, and a second flange such as flange 26 is subsequently folded into the engagement position. As shown in FIG. 7B, the second flange 26 may be flexed to permit the sliding of inboard tab 40 of flange 26 inward of inboard tab 40 of flange 22 in an alt-superimposed configuration. A pair of scores 66 and 68 may be formed along the base of the flanges to facilitate necessary flexing, as well as to provide additional flexibility in accommodating misaligned folds as discussed below along with FIGS. 8 and 9.
As shown in FIG. 7C, the [0038] second flange 26 may folded into flange 22 until inboard tabs 40 of flanges 22, 26 bend past one other. At this point, the adjacent flanges 22, 26 are interlocked with their respective engagement edges 38 making contact with each other. Because outboard tabs 36 extend further from their respective interface edge 38 than inboard tabs 40, inboard tabs 40 have a smaller bending moment than outboard tabs 36. As such, inboard tabs 40 are encouraged to bend past each other according to such a method rather than outboard tabs 36. The round edge 54 of each inboard tab 40 further encourages them to bend past each other.
These features permit the interlocked flanges to be unlocked with similar reverse methods, as needed, to open [0039] flanges 22, 24, 26, 28 for disassembly or to provide additional access to objects stored within carton 10. For example, the round cut 54 of inboard tabs 40 permits adjacent flanges to be unlocked (not shown) without tearing flanges in the locking area. A first flange may be unlocked by keeping an adjacent flange perpendicular to the walls and moving the first flange into a position parallel to its corresponding wall. Initially, in a locked state, the first flange inboard tab 40 may be located inside of the second flange and the second flange inboard tab 40 may be located outside of the first flange. As the first flange is moved from the interlocked position, the inboard tabs 40 of each flange interfere with the adjacent flange. The radius cut 54 of the inboard tabs 40 encourage them to bend past each other rather than to tear at the second termination point 58 or at another location in the locking area.
Referring now to FIGS. 8 and 9, a blank [0040] 146 and carton 110 formed from blank 146 are shown. Aspects and features of carton 110 and blank 146 are the same as carton 10 and blank 46, except for aspects and features related to the location of pre-determined fold lines 162 and 163. The locking features of the present invention allow for manufacturing variability in the location of the pre-determined fold lines. As such, fold lines such as 162 and 163 may be slightly misaligned without degradation of the ability to interlock the top flanges or without degradation of the ability to retain the interlocked position.
As shown in FIGS. 8 and 9, the [0041] fold line 162 between wall sections 112, 116 corresponding to first flange 122 and second flange 126 is misaligned such that a larger portion of the U-shaped slot is disposed along wall 112 than wall 116. In the misaligned condition, the locking features are displaced relative to each other along engagement edge 138. Inboard tab 140 and outboard tab 136 of each adjacent flange 122, 126 (and 126, 124), however, are still able to interact with the corresponding adjacent flange and to retain the locked position. In an optional embodiment, multiple scores 66 and 68 for folding flanges 122, 124, 126, 128 may be provided to allow flange length to be adjusted as needed for misaligned folds between walls (e.g. 162 and 163).
Referring now to FIG. 10, a top view of [0042] carton 10 is shown having an interlocked configuration different from FIG. 1. FIG. 3 shows the locking features 32 of flanges 22 and 28 alt-superimposed in the same manner to FIG. 10. As such, outboard tab 36 of flange 28 is inward of outboard tab 36 of flange 22, which indicates that tab 28 may have been folded inward prior to flange 22. In contrast, locking features 32 between flanges 22 and 26 in FIG. 10 are shown alt-superimposed in a configuration opposite to FIG. 3.
FIG. 3 suggests that [0043] flanges 26 and 28 were folded inward prior to flange 22. FIG. 10, on the other hand, suggests that locking feature 32 of flange 28 adjacent to flange 22 was folded inward prior to flange 22, and that locking feature 32 of flange 22 adjacent to flange 26 (opposite side of flange 22) was folded inward prior to the corresponding locking feature 32 of flange 26. Accordingly, FIGS. 3 and 10 demonstrate that the flanges may be folded and interlocked in various configurations, and that even opposing sides of the same flange may be interlocked in different configurations, in accordance with the locking features 32 of the present invention.
While the present invention has been described in connection with the illustrated embodiments, it will be appreciated and understood that modifications may be made without departing from the true spirit and scope of the invention. In particular, various shapes, sizes, and orientations of flanges, tabs and interface edges may be formed. Additionally, the invention is applicable to a variety of container shapes, sizes and types, including containers having more or less than four walls. For example, a three-sided triangular container may make use of the present invention using locking features that form different angles with the walls than the present embodiments. [0044]

Claims

I claim:

1. A carton having locking flanges, the carton comprising:

a first wall, and first flange pivotally attached thereto, the first flange having a first side portion including:

a first tab;

a second tab spaced apart from the first tab; and

a first engagement edge disposed between the first tab and the second tab; and

a second wall, pivotally coupled to the first wall, and a second flange pivotally attached to the second wall, the second flange having a first side portion proximate to the first flange first side portion; the second flange first side portion including:

a third tab;

a fourth tab spaced apart from the third tab; and

a second engagement edge disposed between the third tab and the fourth tab;

wherein the first side portions of the first and second flange are adapted to mate in a locked configuration.

2. The carton of claim 1, wherein the carton is made from folded fiberboard.

3. The carton of claim 1, wherein the first flange and the second flange each have a second side portion opposing the respective first side portion, each of the second side portions including:

a fifth tab;

a sixth tab spaced apart from the fifth tab; and

a third engagement edge disposed between the fifth tab and the sixth tab.

4. The carton of claim 3, further comprising:

a third wall opposing the first wall and pivotally coupled to the second wall, and a third flange pivotally attached to the third wall, the third flange having opposing side portions, one of the third flange side portions adapted to mate with the second flange second side portion in a locked configuration; and

a fourth wall opposing the second wall and pivotally coupled to the first wall and the third wall, and a fourth flange pivotally attached to the fourth wall, the fourth flange having opposing side portions, one of the fourth flange side portions adapted to mate with one of the third flange side portions in a locked configuration, and another one of the fourth flange side portions adapted to mate with the first flange second side portion in a locked configuration;

wherein each of the third wall and fourth wall side portions includes:

a seventh tab;

a eighth tab spaced apart from the seventh tab; and

a fourth engagement edge disposed between the seventh tab and the eighth tab.

5. The carton of claim 4, further comprising a bottom attached to each one of the walls.

6. The carton of claim 1, wherein the first tab and the third tab extend further from their respective engagement edge than the corresponding one of the second tab and the fourth tab.

7. The carton of claim 6, wherein the first tab and the third tab are each closer to the slot than the corresponding one of the second and the fourth tab.

8. The carton of claim 1, wherein each of the tabs are substantially convex.

9. The carton of claim 1, wherein the first tab and the third tab each include a rounded edge disposed proximate to their corresponding engagement surface.

10. The carton of claim 1, wherein the second tab and the fourth tab are substantially rounded.

11. A blank for forming a carton in a folded condition, the blank comprising:

a carton body having adjacent first and second sections for forming walls in a folded condition;

a first flange pivotally attached to the first section and having a first side portion including:

a first tab;

a second tab spaced apart from the first tab; and

a first engagement edge disposed between the first tab and the second tab; and

a second flange pivotally attached to the second section and having a second side portion, the second flange disposed adjacent to the first flange and the second side portion disposed adjacent to the first side portion of the first flange, the second side portion comprising:

a third tab;

a fourth tab spaced apart from the third tab; and

a second engagement edge disposed between the third tab and the fourth tab; and

a slot formed between the first flange and the second flange.

12. The blank of claim 11, further comprising a pre-determined fold line formed on the carton body between the first and second section, the fold line being substantially aligned with a center of the slot.

13. The blank of claim 12, wherein the slot is substantially wider than the fold line.

14. The blank of claim 11, wherein the slot comprises a U-shaped slot.

15. The blank of claim 11, wherein the first tab and the third tab extend substantially further from their respective engagement edge than the corresponding one of the second tab and the fourth tab.

16. The blank of claim 15, wherein the first tab and the third tab are each closer to the slot than the corresponding one of the second and the fourth tab.

17. The blank of claim 11, wherein each of the tabs are substantially convex.

18. The blank of claim 11, wherein the first tab and the third tab each include a rounded edge disposed proximate to the corresponding engagement surface.

19. The blank of claim 11, wherein the second tab and the fourth tab are substantially rounded.

20. The blank of claim 11, wherein the blank is made from a fiberboard sheet.

21. A carton formed from a blank, the blank including a carton body having a plurality of sections for forming walls in a folded condition and a plurality of flanges, each flange pivotally attached to a corresponding one of the sections, each flange substantially being a mirror image of an adjacent flange, each flange having a pair of opposing side portions, each side portion having a notch formed therein, each notch having an engagement edge, each side portion defining a border of a slot formed between adjacent ones of the side portions, a first projection being formed on each side portion between the corresponding slot border and the respective notch, a second projection being formed on each side portion between the respective notch and the opposing side portion of the same flange, the carton comprising:

a plurality of walls formed from corresponding sections of the blank;

a bottom attached to the walls;

a plurality of flanges formed from corresponding flanges of the blank, each flange pivotally attached to a corresponding one of the walls, each flange alt-superimposed with adjacent ones of the flanges in a locked configuration wherein, the notches of each flange receive one of the engagement edges of the corresponding adjacent flange, the first projections of each flange superimpose the corresponding first projections of the corresponding adjacent flanges, and the second projections of each flange superimpose corresponding second projections of an adjacent one of the flanges in an alt-superimposed configuration with their respective first projection.

22. The carton of claim 21, wherein the slot is substantially U-shaped.

23. The carton of claim 21, wherein the each one of the projections is rounded.

24. The carton of claim 21, wherein the blank is made from a fiberboard sheet.

25. A method of locking end flanges of a carton, the carton comprising a plurality of walls forming an inner space and having corresponding locking flanges foldably attached thereto, each one of the locking flanges having opposing side portions, each one of the side portions comprising a first tab, a second tab spaced apart from the first tab, and an engagement edge disposed between the first tab and the second tab, the method comprising:

selecting any one of the locking flanges as a first locking flange;

folding the first locking flange inward toward the inner space from a first position into an engagement position;

folding a second locking flange adjacent to the first locking flange inward toward the inner space from a first position into an engagement position; and

superimposing a first one of the first tab and the second tab of the second locking flange with the corresponding one of the first tab and second tab of the first locking flange; and

alt-superimposing a second one of the first tab and the second tab of the second locking flange under the corresponding second one of the first tab and second tab of the second locking flange

wherein the first tab, engagement edge, and second tab of the first locking flange engage the corresponding first tab, engagement edge, and second tab of the second locking flange in an alt-superimposed locked configuration.

26. The method of claim 25, further comprising the step of forming the carton from a blank, the step of forming comprising the step of folding the blank along a fold line formed between the wall attached to the first locking flange and the wall attached to the second locking flange, the fold line being translated off-center from a fold line indicator, wherein the first flange and the second flange are adapted to translate along corresponding engagement surfaces in accordance with the translated fold line in the locked configuration.

27. The method of claim 25, wherein the steps of folding the first locking flange, folding the second locking flange, superimposing, and alt-superimposing occur at substantially the same time.

28. The method of claim 25, wherein the step of folding the first locking flange occurs first, and the steps of folding the second locking flange, superimposing, and alt-superimposing occurs at substantially the same time.

29. The method of claim 25, wherein the step of folding the first locking flange occurs first, the step of folding the second locking flange occurs second, the step of superimposing occurs third, and the step of alt-superimposing occurs in response to the second locking flange being folded into the first locking flange.