CONTAINER HAVING ENHANCED WALL INTEGRITY AND ALIGNMENT ELEMENT

Abstract

A container having enhanced wall integrity is provided that includes a sidewall comprising at least one alignment structure formed therein or as a part thereof. The alignment structure is adapted for orienting the container with respect to a second container such that the containers become aligned or indexed such that they may be fully nested one within the other. The alignment structures can each include a protrusion that extends radially outwardly relative from the sidewall to form peaks along an external surface of the container and valleys along an inner surface of the container. Each alignment structure may further include an alignment ridge protruding from the peak of the alignment structure. Such alignment ridges may project outwardly from a remainder of the peak of the alignment structure at an angle, radius, or curvature that is different than that of the remainder of the peak.

Claims

1. A container comprising: an upwardly-extending generally frustoconical sidewall, the sidewall including a plurality of alignment structures circumferentially spaced around the sidewall and extending at least a portion of a height of the sidewall; an exterior surface of the sidewall, the exterior surface having a peak and a valley; and an interior surface of the sidewall, the interior surface radially and axially conforming to the exterior surface of the sidewall; wherein each alignment structure further includes an alignment ridge protruding from a peak of the alignment structure; wherein the container is capable of being fully nested within a second identical container; wherein the plurality of alignment structures form a plurality of intermittent valleys in the interior surface of the sidewall corresponding to a plurality of intermittent peaks on the exterior surface of the sidewall.

2. The container of claim 1, wherein each alignment ridge projects outwardly from a peak of the respective alignment structure and has a radius that is different from a radius of the remainder of the peak.

3. The container of claim 1, wherein each alignment ridge projects outwardly from a peak of the respective alignment structure at an angle that is different from an angle of the remainder of the peak.

4. The container of claim 3, wherein the generally parabolic lower end is configured to reduce the likelihood of binding as the container is nested within a second identical container.

5. The container of claim 1, wherein the intermittent valleys in the interior surface of the sidewall of the container are configured for receiving the intermittent peaks on the exterior surface of the sidewall of the second identical container when the container is nested within the second identical container.

6. The container of claim 1, wherein bottom ends of the alignment structures of the container rests on the stacking shoulder of the second identical container when the container is nested within the second identical container.

7. The container of claim 1, wherein the plurality of alignment structures are located below and are spaced apart from a lip of the container.

8. The container of claim 1, wherein a top end of each alignment structure is vertically aligned with a bottom end of such alignment structure.

9. The container of claim 1, wherein a top end of each alignment structure is circumferentially offset relative to a bottom end of such alignment structure.

10. A container comprising: a plurality of alignment structures, the plurality of alignment structures forming a generally frustoconical sidewall having an interior surface that conforms to an exterior surface; wherein each of the alignment structures extend radially outward relative to the sidewall in the direction of a longitudinal apex forming valleys along the longitudinal apex on the interior surface of the sidewall and peaks along the longitudinal apex on the exterior surface of the sidewall; wherein each alignment structure is circumferentially curved; and wherein the container is capable of being fully nested within a second identical container.

11. The container of claim 10, wherein the plurality of alignment structures are connected together forming valleys on the exterior surface of the sidewall at intersections adjacent the alignment structures.

12. The container of claim 10, wherein the alignment structures are located below and are spaced apart from a lip of the container.

13. The container of claim 10, wherein each peak has an alignment ridge.

14. The container of claim 10, wherein each alignment structure has a spiral orientation.

15. The container of claim 10, wherein a bottom end of each alignment structure has a curved shape.

16. A container comprising: an upwardly-extending frustoconical sidewall comprising a plurality of alignment structures oriented relative to one another, the sidewall having an exterior surface and an interior surface that radially and axially conforms to the exterior surface; wherein the alignment structure includes a protrusion extending radially outward, forming a valley on the interior surface of the sidewall and a peak on the exterior surface of the sidewall; wherein each alignment structure includes an alignment ridge extending from the peak on the exterior surface of the sidewall; and wherein the substantially rigid container is capable of being fully nested within a second identical container.

17. The container of claim 16, wherein the plurality of alignment structures are arranged circumferentially around the container and adjacent alignment structures intersect one another to fully enclose the sidewall.

18. The container of claim 16, wherein the alignment ridges have a parabolic shape extending radially outward from the alignment structure.

19. The container of claim 16, wherein each alignment ridge is configured to reduce the likelihood of the substantially rigid container binding on the second identical container during nesting.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0011] In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith in which like reference numerals are used to indicate like or similar parts in the various views:

[0012] FIG. 1 is a side perspective view of a container in accordance with a preferred embodiment of the present invention;

[0013] FIG. 2A is a side perspective view of two partially nested containers having their respective panel sections angularly offset from one another in accordance with a preferred embodiment of the present invention;

[0014] FIG. 2B is a sectional view of the containers of FIG. 2A taken generally along line 2B-2B in the direction of the arrows in accordance with a preferred embodiment of the present invention;

[0015] FIG. 3A is a side perspective view of two partially nested containers having their respective panel sections parallel with one another in accordance with a preferred embodiment of the present invention;

[0016] FIG. 3B is a sectional view of the containers of FIG. 3A taken generally along line 3B-3B in the direction of the arrows in accordance with a preferred embodiment of the present invention;

[0017] FIG. 4 is a side perspective view of a container having identical finger structures in accordance with a preferred embodiment of the present invention;

[0018] FIG. 5 is a side perspective view of a container having indentions in accordance with a preferred embodiment of the present invention;

[0019] FIG. 5A is a sectional view of the container of FIG. 5 taken generally along line 5A-5A in the direction of the arrows in accordance with a preferred embodiment of the present invention;

[0020] FIG. 6 is a side perspective view of a container having protrusions in accordance with a preferred embodiment of the present invention;

[0021] FIG. 7 is a side perspective view of a container in accordance with a preferred embodiment of the present invention;

[0022] FIG. 8A is a side view of the container of FIG. 7 in accordance with a preferred embodiment of the present invention;

[0023] FIG. 8B is a side sectional view of the container of FIG. 7 taken generally along line 8B-8B in the direction of the arrows shown in accordance with a preferred embodiment of the present invention;

[0024] FIG. 8C is a sectional view of the container of FIG. 7 taken generally along line 8C-8C in the direction of the arrows shown in accordance with a preferred embodiment of the present invention;

[0025] FIG. 8D is an enlarged view of the container of FIG. 7 of the section designated in FIG. 8C in accordance with a preferred embodiment of the present invention;

[0026] FIG. 9 is a side perspective view of a container in accordance with a preferred embodiment of the present invention;

[0027] FIG. 10A is a side view of the container of FIG. 9 in accordance with a preferred embodiment of the present invention;

[0028] FIG. 10B is a sectional view of the container of FIG. 9 taken generally along line 10B-10B in the direction of the arrows shown in accordance with a preferred embodiment of the present invention;

[0029] FIG. 10C is a sectional view of the container of FIG. 9 taken generally along line 10C-10C in the direction of the arrows shown in accordance with a preferred embodiment of the present invention; and

[0030] FIG. 10D is an enlarged view of the container of FIG. 9 of the section designated in FIG. 10C in accordance with a preferred embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0031] The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures.

[0032] A storage container 10 embodying various features of the present invention is shown in the figures. The container 10 may be suitable for holding food and beverage products or any other goods or products that would typically be held within a container. In a first embodiment, as shown generally in FIGS. 1-3B, the container 10 includes a circumferential sidewall 12 extending upwardly from a bottom wall 14. The sidewall has interior and exterior surfaces 22 and 26. An annular rolled rim or lip 18 may be provided at the top end of the sidewall 12 to form a comfortable drinking surface for the mouth of a user, may provide rigidity to the top of the container 10 and, optionally, for attaching a lid (not shown) to the container 10.

[0033] The container 10 preferably is an open-ended container of any suitable size, shape and configuration. In one embodiment, the container 10 has a frustoconical shape; that is, the container 10 has a generally circular cross-section decreasing in diameter as the sidewall 12 tapers from top to bottom such that the top open mouth 16 is generally larger than the bottom wall 14. The upwardly and outwardly taper of the container 10 provides a means for stacking a plurality of containers 10, as illustrated in FIGS. 2A-3B. It will be appreciated, however, by those skilled in the art that different shapes may serve equally as well and may be required by a desired application. The container 10 may be manufactured of a thin polymeric, non-polymeric or plastic material and in manner utilizing a thermoforming process as is typically known in the art. As such, the container 10 can be made of materials such as polyethylene, polypropylene, polyester, polystyrene or another suitable material now known or hereafter developed.

[0034] In order to increase the structural rigidity and integrity of the sidewall 12, as compared to commonly-known round containers, the sidewall 12 may have a generally symmetrical polygonal cross-sectional shape. This sidewall 12 structure increases the strength and rigidity of the sidewall 12, allowing the sidewall 12 to be made thinner, thereby potentially reducing the container's 10 weight and cost. The sidewall's 12 cross-sectional shape may take a variety of shapes, including but not limited to, octagonal, nonagonal, decagonal, hendecagonal, dodecagonal or any other suitable polygonal shape.

[0035] The sidewall 12 may be formed of a plurality of generally rectangular-shaped panel sections 20 extending upwardly from the container's bottom wall 14. As set forth above and shown in the figures, the sidewall 12 has an upwardly and outwardly taper allowing a plurality of containers 10 to be stacked or nested together during shipping and storage. The sidewall 12 may be of any suitable size, shape and configuration. As such, in one embodiment, each sidewall panel section 20 is in the shape of an isosceles trapezoid in order for the container 10 to have a generally frustoconical shape. Similar to the sidewall 12, panel sections 20 are each tapered such that they are wider at their top ends and narrower at their lower ends.

[0036] When a plurality of containers 10 having polygonal sidewalls 12 are stacked one on top of the other, it is generally preferred that the respective sidewall panel sections 20 of the containers 10, particularly those of two adjacently-stacked containers 10, are aligned parallel with one another so that the containers 10 become fully nested one within the other. However, when such containers 10 are stacked, it is common that the two adjacently-stacked containers 10 will be oriented in a manner such that their respective sidewall panel sections 20 are not aligned parallel to each other. In such a case, the containers 10 cannot become fully nested. When this happens, the stack of containers 10 may be more susceptible to tipping and will take up more space than if all of the containers 10 were fully nested. Additionally, it can result in multiple containers sticking together during the manufacturing process or when a user intends to grab only one container from the stack. Thus, it is desirable for the respective panel sections 20 of adjacently-stacked containers 10 to be aligned.

[0037] As illustrated in FIG. 1, the container 10 includes at least one generally axially-extending rotational element or alignment structure 30 associated with one or more of the sidewall panel sections 20 for urging misaligned containers 10 to become aligned. In doing so, the alignment structure 30 is adapted to cause one container 10 to rotate and orient itself with respect to a second container 10 about a longitudinal axis A-A as the two containers 10 are being stacked.

[0038] As shown in FIGS. 2A and 2B, when one container 10a is partially inserted within another generally identical container 10b during the stacking process, the two containers 10a and 10b may not be aligned with one another as described above. In FIG. 2B, one of the panel sections 20 of one container 10a lies in plane A while the respective panel section of the other container 10b lies in plane B. As demonstrated, the two containers 10a and 10b are axially misaligned from one another by an angle ?. Absent the alignment structure 30, the two containers 10a and 10b would not rotate axially with respect to one another and therefore would never become fully nested.

[0039] As shown in FIGS. 1-3B, the container 10 may include ribs 28 protruding outwardly from the corners formed at the intersections of adjacent sidewall panel sections 20. In another embodiment, the container does not include such ribs 28 protruding from its corners.

[0040] In the embodiment illustrated in FIGS. 1-3B, the alignment structures 30 of container 10 are at least partially recessed within the sidewall 12. In other words, the alignment structures 30 are indented into the exterior surface 26 of the sidewall 12 and, thus, correspondingly protrude inwardly from the interior surface 22 of the sidewall 12 into the interior of the container 10. The alignment structures 30 can each be shaped to include a boundary edge 34, which may protrude outwardly from the exterior surface 26 of the sidewall 12 and form a v-shaped lower edge 36. As shown in FIGS. 2B and 3B, because the alignment structure 30 is recessed into the sidewall 12, a resulting alternating series of generally radially intermittent, circumferentially-spaced peaks 38 and valleys 40 are formed into the interior surface 22 of the sidewall 12. Each interior peak 38 is divided to include first and second faces 42 and 44 sloping in opposite directions. Due to its formation into the sidewall 12, the alignment structure 30 also results in an alternating series of generally circumferentially-spaced peaks 46 and valleys 48 formed into the exterior surface 26 of the sidewall 12.

[0041] The alignment structure 30 urges one container 10a (or container 10b, as the case may be) to rotate with respect to an adjacently stacked container 10b (or container 10a, as the case may be). It should be understood that the containers 10 may be stacked in an upright orientation, such that one container 10b is placed within another container 10a, or stacked in an upside-down orientation, such that one container 10a is placed over another container 10b. The alignment structures 30 are designed to cause rotational movement of one container 10 with respect to another container 10 until and to the point where the respective sidewall panel sections 20 of the containers 10 are generally aligned parallel with one another as shown in FIGS. 3A and 3B. As one container 10b is inserted into another container 10a, the corners (or the ribs 28 protruding therefrom) of the first container 10b engage the interior peaks 38 of the second container 10a. As described above, the peaks 38 each have first and second faces 42 and 44 meeting at an apex and sloping away from one another. The apex of each peak 38 splits the peak 38 and causes the corner (or protruding rib 28) of the other container to engage either the first face 42 or second face 44 of the peak 38.

[0042] FIGS. 2A and 2B illustrates one container 10a partially inserted within another container 10b during the stacking process, wherein the two containers 10a and 10b are not be aligned with one another. The ribs 28 of container 10b contact the interior peaks 38 of container 10a as the two containers 10a and 10b are stacked. The ribs 28 are directed to either the first faces 42 or second faces 44 of the peaks 38. If the ribs 28 engage the first faces 42, then container 10b will rotate clockwise (as shown from this angle) with respect to container 10b as the two containers 10a and 10b become stacked. If the ribs 28 engage the second faces 44, then container 10b will rotate counter-clockwise (as shown from this angle) with respect to container 10b as the two containers 10a and 10b become stacked. Such rotation will continue to the point where the respective sidewall panel sections 20 of the containers 10a and 10b are substantially aligned parallel with one another, as shown in FIGS. 3A and 3B. In this sense, the containers 10 are adapted to be generally self-aligning. Consequently, little or no manipulation may be required for the containers 10 to properly nest.

[0043] As demonstrated in FIG. 3B, when the respective sidewall panel sections 20 of the containers 10a and 10b are aligned parallel with one another, the corners or ribs 28 of container 10b are generally received within the valleys 40 of container 10a. Once the containers 10a and 10b are aligned with one another, as shown in FIGS. 3A and 3B, the containers 10a and 10b may become fully nested. The containers 10a and 10b are considered fully nested when the bottom of one container 10b comes into contact with the one or more stacking shoulders 24 indented into the other container 10a.

[0044] The alignment structure 30 may have a parabolic-like shape, as shown in FIG. 1, a curvilinear shape or any other shape suitable for achieving the alignment outcome described herein. The alignment structure 30 may be either recessed into the sidewall 12, protruding outwardly from the sidewall 12 or both recessed into and protruding outwardly from the sidewall 12. In one embodiment, the container 10 includes some alignment structures 30 which are recessed into the sidewall 12 and some alignment structures 30 that are protruding therefrom. The alignment structure 30 can increase the structural rigidity and integrity of the sidewall 12 and can provide the sidewall 12 with contoured edges which aid a user in gripping the container 10.

[0045] Turning now to another embodiment, FIG. 4 shows a container 10.1 having an alignment structure 50 that comprises a plurality of circumferentially-spaced fingers 52 that may be recessed into or protruding from the container's sidewall 12. In the illustrated embodiment, the fingers 52 are indented into the sidewall 12 and extend inwardly into an interior of the container 10.1. The indented fingers 52 form radially intermittent peaks 58 and valleys 60 along the interior surface 22 of the sidewall 12. They also form corresponding peaks 62 and valleys 64 along the exterior surface 26 of the sidewall 12. The fingers 52 have first and second ends 54 and 56. In FIG. 4, the fingers 52, which form the peaks 58 along the interior surface 22 of the sidewall 12, are tapered and decrease in width from a wider first (lower) end 54 to a narrower distal second (upper) end 56. Correspondingly, the valleys 60 along the interior surface 22 of the sidewall 12 are tapered and increase in width from a narrower lower (not shown) end to a wider upper end 61.

[0046] The valleys 60 formed into the interior surface 22 of the sidewall 12 of one container are adapted for receiving the peaks 62 protruding from the exterior surface 26 of a second generally identical container (not shown) when the second container is placed within the container 10.1. Likewise, the valleys 64 formed into the exterior surface 26 of the sidewall 12 of one container are adapted for receiving the peaks 58 formed into the interior surface 22 of a second generally identical container (not shown) when the second container is placed within the container 10.1. As the containers 10.1 are stacked together, the narrow ends of the peaks 58 and 62 engage the wide ends of the valleys 64 and 60, respectively. This engagement of the tapered peaks 58 and 62 and tapered valleys 64 and 60 aligns the two containers as they move closer together during the stacking process such that the sidewall panel sections 20 of the containers are aligned substantially parallel to one another. Like alignment structures 30, alignment structures 50 can increase the structural rigidity and integrity of the sidewall 12 and can provide the sidewall 12 with contoured edges which aid a user in gripping the container 10.1.

[0047] FIGS. 5 and 5A show yet another embodiment of a container 10.2 including an alignment structure 66 comprising a plurality of circumferentially-spaced indentions 68. The indentions 68 form a parabolic-like shape and have a v-shaped lower edge 70. Because the alignment structure 66 is recessed into the sidewall 12, a resulting alternating series of generally radially intermittent, circumferentially-spaced peaks 72 and valleys 74 are formed into the interior surface 22 of the sidewall 12. Due to its formation into the sidewall 12, the alignment structure 66 also results in an alternating series of generally circumferentially-spaced peaks 76 and valleys 78 formed into the exterior surface 26 of the sidewall 12. Such a design allows for more stacking alignment opportunities as the container 10.2 may include more peaks 72 and 76 and valleys 74 and 78 than compared with other containers. For example, in one embodiment, the container 10.2 includes approximately 20 or more peaks 72 and 76 and the same number of corresponding valleys 74 and 78. Such an embodiment generally requires the container 10.2 to undergo less rotation in order to become aligned with an adjacent container 10.2 than embodiments having fewer alignment structures that are spaced radially further apart from one another. In principle, the alignment structure 66 of this embodiment operates in a manner similar to the alignment structure 30 of the first embodiment described above in order to align the containers together as they are stacked. Like the other embodiments described above, the alignment structure 66 can increase the structural rigidity and integrity of the sidewall 12 and can provide the sidewall 12 with contoured edges which aid a user in gripping the container 10.2.

[0048] FIG. 6 illustrates a further embodiment of a container 10.3 having an alignment structure 80 comprising a generally parabolic-shape protrusion 82 extending from each sidewall panel section 20. The protrusions 82 include an exterior surface 84 extending or bulging from the exterior surface 26 of the panel sections 20 and a corresponding interior surface 86 recessed into the interior surface 22 of the panel sections 20 that forms a valley 88. The protrusion 82 may form a v-shaped lower edge 90. In principle, the alignment structure 80 of this embodiment operates in a manner similar to the alignment structures of the other embodiments described above. As one container 10.3 is being stacked with a second generally identical container (not shown), the protrusion 82 of the inner container engages the valley 88 of the outer container. As the two containers move closer together during the stacking process, the containers become aligned such that the sidewall panel sections 20 of the containers are aligned substantially parallel to one another. Like all the other embodiments described herein, the alignment structure 80 can also increase the structural rigidity and integrity of the sidewall 12 and can provide the sidewall 12 with contoured edges which aid a user in gripping the container 10.3.

[0049] FIGS. 7-8D illustrate an embodiment of a container 100 having an exterior surface 156 and an interior surface 136. The container 100 has a sidewall 104 that includes a series of connected or adjacent alignment structures 108 that may extend fully or partially between a lower shoulder 112 and an upper shoulder 116. In one embodiment, the series of alignment structures 108 creates a sidewall 104 that does not include any separate panel sections and, in another embodiment, each alignment structure 108 may form a separate panel section.

[0050] The upper shoulder 116 extends radially outwardly relative to the sidewall 104. The upper shoulder 116 may be part of, or independent from, a lowermost portion of a rim 120. The rim 120 may include an uppermost lip 124 located above the upper shoulder 116. As shown, the lip 124 may extend radially outwardly as is generally known in the art.

[0051] The lower shoulder 112 may be part of, or independent from, the bottom end 164 of the alignment structures 108. One of ordinary skill in the art will appreciate that the lower shoulder 112 may be located, for example, either above or below the bottom end 164 of the alignment structures 108. As shown, the lower shoulder 112 is located above the uppermost part of an end cap 128 of the container 100. In some embodiments, the lower shoulder 112 may extend inward to form a stacking shoulder on the interior surface 136 of the container 100. The end cap 128 may optionally include an indentation 140 that extends upwardly into a bottom portion of the container 100.

[0052] As illustrated, the sidewall 104 of the container 100 may be comprised of a series of connected or adjacent alignment structures 108. As demonstrated, in one embodiment, each alignment structure 108 is oriented generally vertically on the sidewall 104 and has a peak 148 with two valleys 152 formed on either side of it on the exterior surface 156 of the container 100. The valleys 152 are shared or otherwise located between two alignment structures 108. The top end 160 and/or bottom end 164 of each alignment structure 108 may optionally have a curved, parabolic, or v shape. The shape of the bottom end 164 of the alignment structure 108 can help the container 100 rotate when nesting with an identical container 100 so the alignment structures 108 in each container 100 are aligned. Additionally, these shapes reduce the potential of binding or snagging during nesting resulting from the exterior surface 156 of the bottom end 164 contacting the interior surface 136 of the alignment structures 108 of a second identical container 100.

[0053] Each alignment structure 108 may have an alignment ridge 168 located at the radially distal or outermost portion of the peak 148. The peak 148 is generally located between two walls 172 that each extend from a corresponding valley 152. Each alignment ridge 168 may project outwardly from a remainder of the peak 148 of the alignment structure 108 and at a different angle, radius, or degree relative to the remainder of the peak 148. As shown in this embodiment, each wall 172 has a corner 176 with a radius on the interior surface 136 of the container 100. The alignment ridge has a ridge corner 180 on the interior side with a radius that may be different than the radius of the corners 176. While the depicted embodiment features walls with tight radius that can be classified as a corner, in other embodiments the walls 172 may be radiused along their length, and the alignment ridge 168 may also be evenly radius along its length. The alignment ridge 168 assists in aligning and/or indexing the corresponding alignment structures 108 of multiple containers 100 when the containers 100 are being nested.

[0054] FIGS. 9-10D illustrate a container 200 according to another embodiment. The container 200 has a sidewall 204 that includes a series of connected or adjacent circumferentially curved, twisted, or spirally oriented alignment structures 208. The upper shoulder 216 extends radially outwardly relative to the sidewall 204. The upper shoulder 216 may be part of, or independent from, a lowermost portion of a rim 220. The rim 220 may include an uppermost lip 224 located above the upper shoulder 216. As shown, the lip 224 may extend radially outwardly as is generally known in the art.

[0055] The lower should 212 may be a part of, or independent from, the bottom end 264 of the alignment structures 208. One of ordinary skill in the art will appreciate that the lower shoulder 212 may be located, for example, either above or below the bottom end 264 of the alignment structures 208. As shown, the lower shoulder 212 is located above the uppermost part of an end cap 228 of the container 200. In some embodiments, the lower shoulder 212 may extend inward to form a stacking shoulder on the interior surface of the container 200. The end cap 228 may optionally include an indentation 240 that extends upwardly into a bottom portion of the container 200.

[0056] As is illustrated, a top end 260 of each alignment structure 208 is circumferentially offset from a bottom end 264 of the alignment structure 208. As a container 200 is nested within a second identical container, the circumferential curve will cause one or both of the containers 200 to rotate. Each alignment structure 208 contains a peak 248 and two valleys 252 shared with the adjacent alignment structures 208.

[0057] The bottom end 264 of the alignment structures 208 may be curved, parabolic, or v-shaped. The bottom end 264 may alternatively have a tilted J-shape, as illustrated. The v-shape or parabolic shape reduces the potential of binding or snagging as the container 200 is inserted into a second identical container.

[0058] Each alignment structure 208 may consist of an alignment ridge 268 and two walls 272. Each wall 272 may have a different curvature, or lack of curvature to contribute to circumferentially curved shape of the alignment structure 208. This may result in the illustrated embodiment where one wall 272 has a corner 280, and one wall 272 does not. The alignment ridges 268 may also have a non-uniform curvature or a corner 280 and may protrude outwardly more from one wall compared to a second wall as a result of different wall 272 shapes.

[0059] From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure.

[0060] It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

[0061] Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.