CONTAINERS WITH INTERLOCKING COVERS
A container 100 includes a cover 102 and a base 104. The cover 102 of the container 100 includes a first closure portion 310, an engagement portion 308, and an alignment portion. The base 104 includes a second closure portion 212. The first closure portion 310 of the cover 102 is sealingly engageable with the second closure portion 212 of the base 104 to define a sealed storage area. Multiple covers 102 stack together in two different ways. First, the covers 102 may be stacked into an “aligned” stack. Second, the covers 102 may be stacked into a locked stack. The alignment portion of the cover 102 is engageable with the alignment portion of a second cover to form an aligned cover stack. The engagement portion 310 of the cover 102 is receivingly engageable by the engagement portion 308 of a second cover 602 to form a locked cover stack 728.
The present invention relates generally to containers, and, more particularly, to containers whose covers align together when stacked in a first position and which may be locked together in a second position.
BACKGROUND OF THE INVENTIONRigid, thermoplastic food containers are generally known. Users often accumulate a large number of these containers in different sizes and shapes. When not in use, the containers are often stored haphazardly into drawers. In this case, the unused containers take up a great deal of room, and finding a matching base and cover, which make up a container, in a disarranged drawer may be difficult. To avoid this, some users stack the containers in cabinets. While the bases of the containers usually nest and therefore take up less room than in a disorganized drawer, it may still be difficult to match a base with a cover. In addition, the covers may not stack and the covers may tend to topple down. When the containers are in use to store food, the containers are often stacked one on top of another in cabinets or in a refrigerator. These stacks may be precarious, and their fall may cause food to spill from the containers. Many users would find it desirable if the containers, whether empty or in use, could be stored in a manner space efficient, less precarious, and more structurally rigid.
During large-scale manufacturing, the covers may be transported in bulk before being separated out for individual packaging. During bulk handling, manufacturers would find it desirable if the covers would form a stack stable enough to resist the vertical and lateral movements caused by forces typically encountered during manufacturing operations.
The present invention has as a general aim to provide containers that satisfy both users and manufacturers.
SUMMARY OF THE INVENTIONEmbodiments according to the principles of the present invention provide containers whose covers may be stacked together in two different ways. First, the covers may be nested and stacked and configured into an “aligned” stack. The aligned stack provides enough structural rigidity for bulk handling during manufacturing. Second, the covers may be stacked, interlocked one to another, and configured into a “locked” stack. The locked stack provides even more structural rigidity than does the aligned stack and is useful when storing unused covers. Finally, once the stack of covers is locked, the top cover of the stack may be easily released from the locked stack and removed.
In some embodiments, the cover includes a first closure portion, an engagement portion, and an alignment portion. The base of the container includes a second closure portion that is sealingly engageable with the first closure portion of the cover to define a substantially sealed, leak-proof, and re-sealable storage area for items such as food. It is well known to those of ordinary skill in the art, that the cover may be sealingly engaged with its base.
The alignment portion of the cover is engageable with the alignment portion of a second cover to form an aligned cover stack. The engagement portion of the cover is engageable with a second cover to form a system of covers in a locked cover stack.
In one embodiment, once engaged to form a locked stack of covers, the engagement portion of the top cover of the locked stack is disengageable from the cover immediately below the top cover in the cover stack. The top cover is removable from the locked stack by a simple lifting action supplied by the thumb or forefinger of a user on a gripping tab coupled to the cover.
In one embodiment, the engagement portion of the cover is positioned on a gripping tab of the cover. The engagement portion is configured as a downwardly directed protrusion on the top of the cover of the container. A male cap component of the engagement portion, cooperates with a female well component of the engagement portion of a second cover aligned immediately below the cover to lock the two covers together in a stack. The male cap component may be nearly vertical and fits with minimal clearance inside the female well component so that cover stacking is provided when the cover stack is not kept in a vertical orientation. In one embodiment, the male cap component of a cover physically contacts the female well component of a second cover and provides a friction fit that locks the covers stacked together. The male cap component may have a shape similar to an opened topped hollow tub having a wedge-shaped outer surface wall. The male cap component may further include at least one undercut and at least one lead-in. The lead-in of the cover cooperates with the undercut of a second cover to provide a “snap” fit, well known to those of ordinary skill in the art, to lock the cover with the second cover. Thus, The covers may either nest by sitting on top of each other in a stack that may be shear de-nested, or the male cap component may abuttingly engage into the female well component to lock the covers into one unit for convenient storage.
In another embodiment, the cover includes a first closure portion at the outer peripheral edge of the bottom of the cover. The first closure portion of the cover cooperates with a second closure portion on the top perimeter rim edge of the base of the container to form a seal. The container uses a rim or perimeter design that includes both inside and outside seals. Containers may be embodied with a variety of closure portion designs including outer closures and/or inner closures. The engagement portion is in a position spanning between an inner sealing wall and an outer sealing wall at the top of the first closure portion. The engagement portion of the cover is configured as a locking lug integral with the first closure portion.
The covers and bases of container may be economically constructed from relatively thin-gauge plastic so that the user may either wash them after use or dispose of them with the view that their purchase price allows them to be used as a consumable good. The container may be readily manufactured, for example, with conventional thermoforming equipment or thin-walled injection molding. The cover may be made from a semi-transparent material to ensure satisfactory visibility of the container's contents. The container may be suitable for refrigerator, freezer, microwave, and machine dishwasher use.
The features of the present invention will become apparent to one of ordinary skill in the art upon reading the detailed description, in conjunction with the accompanying drawings, provided herein.
Reference will now be made to the drawings wherein like numerals refer to like parts throughout, and wherein:
An embodiment according to the principles of the present invention is illustrated in
As seen in
The cover 102 further includes a first closure portion 310 at the outer peripheral edge of the bottom of cover 102. In
The first 310 and second 212 closure portions may be configured to be slightly different in size to form an interference fit therebetween. The interference between the closure portions may provide the sealing engagement between the closure portions. As a result, when the two pieces are engaged, a positive seal may be formed between sealing surfaces around the perimeters of the base 104 and of the cover 102. The engagement of the first 310 and second 212 closure portions may be accompanied by an audible “snap” indicating that the container 100 is securely closed.
As described and illustrated above with reference to
As shown in
In other embodiments, more than one engagement portion 308 may be located on the top surface of the cover 102 to accommodate locking engagement of multiple container covers at more than one position on the top surface of the cover 102. In some embodiments, a standard shape and configuration of the engagement portion 308 is used with covers 102 of various shapes and sizes. This enhances storage flexibility by allowing different types of covers 102 to be stored together in a locked stack. A standard shaped and configured engagement portion 308 may be used with, for example, circular, square, rectangular, and elliptical shaped covers or with similarly shaped covers but differently sized covers.
The engagement portion 308 may also be chosen to have a shape or otherwise include alignment portion elements that provide rotational alignment of a stack of covers 102. Rotation is defined about an axis normal to the plane formed by orthogonal midlines, i.e., first midline 318 and second midline 320, of the cover 102 (
Referring again to
The female well component 516 of the engagement portion 308 of the cover 102 includes a lead-in 526. Lead-in 526 is configured as a groove or indentation along at least a portion of the top edge of the female well component 516. In this embodiment, lead-in 526 is indented around the entire inner surface wall of the engagement portion 308 making up the female well component 516.
Referring to
The engagement portion 608 of a second cover 602 is configured as described above for the cover 102. More particularly, the engagement portion 608 of the second cover 602 includes a male cap component 614. The male cap component 614 of the second cover 602 includes an undercut 624 configured as a lengthwise bead along the entire bottom edge of the male cap component 614 of the second cover 602. Further, in this embodiment, the engagement portion 608 of the second cover 602 includes a female well component 616 defined by the inner surface wall of the engagement portion 608. The female well component 616 of the engagement portion 608 of the second cover 602 includes a lead-in 626. Lead-in 626 of the second cover 602 is configured as a groove or indentation along at least a portion of the top edge of the female well component 616 of the engagement portion 626 of the second cover 602. In this embodiment, lead-in 626 is indented around the entire inner surface wall of the engagement portion 608 making up the female well component 616 of the second cover 602.
As best seen in
In locking the second cover 602 with the cover 102, engagement portion 308 of the cover 102 is rotationally aligned above the engagement portion 608 of the second cover 602 (
Referring to
A stack of locked covers, each with at least one undercut on the male cap component of its engagement portion and at least one cooperating lead-in on the female well component, may be unlocked by pulling upwardly on the tab of the top cover while holding the stack of locked covers below the top cover and so on until the entire stack of covers is unlocked. The unlock covers may nest on top of each other in a stack that may be shear de-nested as is well know to those of ordinary skill in the art. Advantageously, in this embodiment, the engagement portions may be nearly vertical and accordingly the male cap components of the engagement portions fit with minimal clearance inside the cooperating female well components. Cover locking is provided without excessively increasing the height of a stack of locked covers over the height of a stack of unlocked covers that have no engagement portions.
As with the shape of the container 100 itself, the engagement portions of the covers may assume a variety of shapes, locations, and matingly engageable surface configurations. Another embodiment in accordance with he principles of the present, for example, is described and illustrated more fully below with reference to
In
Referring to
As described and illustrated more fully below with reference to
The second closure portion 912 of the base 804 is a raised ring that extends from an upper edge of the sidewall 911 of the base 804 (See also
The first closure portion 1010 and the second closure portion 912 may be configured to be slightly different in size to form an interference fit therebetween. The interference fit between the first closure portions 1010 and the second closure portion 912 may provide a sealing engagement between the closure portions. More particularly, the first sealing surface of the inner sealing wall 1130 of the first closure portion 1010 abuttingly contacts the third sealing surface of the inner sealing wall 1138 of the second closure portion 912 to provide an inner sealing engagement; and the second sealing surface of the outer sealing wall 1132 of the first closure portion 1010 abuttingly contacts the fourth sealing surface of the outer sealing wall 1140 of the second closure portion 912 to provide an outer sealing engagement.
The second inner lead-in 1134A of the first closure portion 1010 cooperates with the inner lead-in 1142A of the second closure portion 912 to enhance and maintain the inner sealing engagement between the cover 802 and the base 804. In a similar manner, the second outer lead-in 1134B of the first closure portion 1010 cooperates with the outer lead-in 1142B of the second closure portion 912 to enhance and maintain the outer sealing engagement between the cover 802 and the base 804. As a result, when the cover 102 and the base 104 are abuttingly engaged, a compound positive seal is formed between the sealing surfaces around the perimeters of the cover 802 and the base 804.
The abutting engagement of the first closure portion 1010 and second closure portion 912 may be accompanied by an audible “snap” indicating that the container is securely closed and sealed. To facilitate sealing engagement of the cover 802 with its base 804, a user applies a downward force on the cover 802, or, more conveniently, only to the top of the engagement portion 1008 of the cover 802, while the first closure portion 1010 of the cover 802 is aligned with the second closure portion 912 of the base 804.
The engagement portion 1208 of the second cover 1202 includes an inner undercut portion 1244A above and integral with an inner lead-in 1234A of the engagement portion 1208 of the second cover 1202. Likewise, the engagement portion 1208 of the second cover 1202 includes an outer undercut portion 1244B above and integral with an outer lead-in 1234B at the engagement portion 1208 of the second cover 1202. A retention bead 1241 of the engagement portion 1208 of the second cover 1204 is integral with and spans between the inner lead-in 1234A and the outer lead-in 1234B of the engagement portion 1208 of the second cover 1204.
The engagement portion 1208 of the second cover 1202 is adapted to cooperate with the first closure portion 1010 of the cover 802 to lockingly engage the second cover 1202 with the cover 802. Thus, the configuration of the engagement portion 1208 of the second cover 1202 mimics a part of the second closure portion 912 of the base 804 (
To lockingly engage the second cover 1202 with the cover 802, the first sealing portion 1010 of the cover 802 is aligned above the engagement portion 1208 of the second cover 1202 as shown in
In a similar manner, a third cover may be locked to the second cover 1202, a fourth cover may be locked to the third cover and so on to form a stack of locked covers. In this embodiment, the stack of locked covers, each with a first closure portion and a cooperating engagement portion as described above, may be unlocked by pulling upwardly on the tab of the top cover while holding the stack of locked covers below the top cover and so on until the entire stack of covers is unlocked. The unlock covers may nest on top of each other in a stack that may be shear de-nested as described in related U.S. Provisional Patent Application No. 60/655,830.
In the embodiment shown in
The covers described above may be constructed with a wall thickness thinner than that of its base. The covers may be made from any suitable plastic and may be integrally made by any suitable technique, such as thermoforming. In one embodiment, the covers may be formed from polypropylene. Due to the thermoforming process, the wall thickness of the covers may vary. Thinner covers reduce material costs and increase flexibility to more easily accommodate their removal from, and engagement with, their bases. The covers may maintain adequate flexibility for proper sealing even during typical freezer temperatures.
The covers may be sufficiently flexible to allow a user to create a vacuum in containers upon sealing. In order to create a vacuum, the user could for example depress a cover during the closing of the container. A return force imparted upon the cover by the resiliency of the material of the cover will urge the cover to return to its normal position, thereby creating a vacuum.
The base may be integrally made from any suitable plastic with sufficient thickness to withstand without deforming the heat of microwave cooking and of top-shelf dishwashing. It should also remain sturdy during lifting while laden with hot food. The base may be made from any suitable plastic and may be made by any suitable technique, such as co-extrusion, lamination, injection molding, thermoforming, or overmolding. As is well known in the art, the same forming process is typically used to form both the base and the cover of the container. In one embodiment, the base is formed from polypropylene. The wall thickness of the base may vary due to the manufacturing process.
Other embodiments of the engagement portion may include one or more of the following features to enable locking engagement: convex portions or ribs, concave portions or ribs, linear or curvilinear undercuts, discrete snap elements or buttons, interference fits, textured surfaces, or elements that modify surface friction or tackiness at or around the points of engagement.
In some embodiments, the force required to connect the covers may differ substantially from the force required to disengage the covers. For instance, it may be beneficial during manufacturing that the force needed to connect the covers is less than the force required to separate the covers. As a result, the covers are relatively easy to connect during manufacturing, yet they will lock securely and not undesirably separate during the manufacturing process. To accomplish this, the protrusions on the engagement portion may be designed where, for a given protrusion, the upper protrusion edge comprises a gradual taper whereas the lower protrusion edge comprises a more abrupt shape. For example, in one embodiment, the shape of the protrusion may be similar to a barbed hook with gradual taper on the upper edge of the barb that would impart little resistance during engagement and with an abrupt shape on the lower edge of the barb that would impart relatively high resistance during disengagement. Conversely, it may be beneficial to design the engagement portion so that the force that needs to be applied to connect the covers is more than the force required to separate the covers, since the user may perceive that a high connecting force equates to satisfactory locking integrity, whereas a weak connecting force may lead the user to perceive that the cover stack lacks the integrity required to insure the expected organizational benefit. Thus, the high connecting force provides the perceived benefit, yet a lower disengagement force does not require that the user untowardly struggle during separation of covers. To accomplish this, the protrusions on the engagement portion may be designed where, for a given protrusion, the upper protrusion edge comprises an abrupt shape whereas the lower protrusion edge comprises a more gradual taper. For example, in one embodiment, the shape of the protrusion may be a reversed barb with an abrupt shape on the upper edge of the barb that would impart relatively high resistance during engagement and with a gradual taper on the lower edge of the barb that would impart little resistance during disengagement. Furthermore, during the process where the user applies force to aligned covers in a direction normal to the general cover plane so as to lock the covers together, the engagement portion may provide tactile or audible feedback upon locking. In this way, the user would sense that the covers are connected and that no further force need be applied.
In accordance with embodiments of the present invention, the container may be reusable, but it may also be constructed cheaply enough that consumers see it as a disposable item, with replacement covers and bases available separately for retail sale. The base and the cover may be fabricated by thermoforming a plastic such as clarified polypropylene homopolymer material. In another embodiment, the container may be fabricated by thermoforming a clarified random copolymer polypropylene material. Other plastic materials that would be suitable for fabricating the container by thermoforming include opposing PS (polystyrene), CPET (crystalline polyethylene terephthalate), APET (amorphous polyethylene terephthalate), HDPE (high density polyethylene), PVC (polyvinyl chloride), PC (polycarbonate), and foamed polypropylene. The material used may be generally transparent to allow a user to view the contents of the container.
The container may include a visual indication of closure between the cover and the base. The visual indication may be a color change in the area where the cover engages the base. In one embodiment, the first closure portion on the cover may be a first color and the second closure portion on the base may be a second color. When the closure portions are sealingly engaged, the first and second colors produce a third color which is visible to the user to indicate that the container is sealed.
The container may include a rough exterior surface to reduce slipping and to improve grasping by the user, especially if the user's hands are wet or greasy. In addition, the pinching bar may all have a rough exterior to aid in application of the pinching force supplied by a user to disengage locked covers.
The container may include a self-venting feature. The pressure in the sealed container may increase when the sealed container and contents are heated in a microwave oven. Thus, the cover may include a self-venting mechanism that opens when the pressure in the container exceeds a predetermined value.
The container may be divided to separate foods in the container. A divider may be integral with the container or may be a separate component. Either the base only may include a divider or both the base and the cover may each include a divider. The divider located in the cover may only partially engage the divider in the base so as to provide splash protection, or it may fully engage the divider in the base to provide varying degrees of inter-compartmental leak resistance.
The container may include a strip indicating the temperature of the container and its contents.
The gripping tab may include a relieved portion that provides less interference contact with the base during the removal or engagement of the cover while still providing an adequate first closure portion to maintain proper sealing of the container. The relieved portions of the gripping tab permit venting by allowing a portion of the cover to be unsealed from the base while still maintaining a seal around the remaining perimeter of the container. This feature is useful in microwave cooking where the cover prevents food from splattering onto the inside surface of the microwave while still allowing the container to vent. By using the gripping tab, less force is required to remove the cover from the base. This lower opening force also reduces the possibility of container failure from stress and fatigue. The lower opening force may improve the ability of the user to maintain control over the container components while removing the cover from the base and thus to reduce the possibility of spilling the contents stored in the container.
The use of the terms “a,” “an,” “the,” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise indicated.
While the invention is described herein in connection with certain preferred embodiments, there is no intent to limit the present invention to those embodiments. On the contrary, it is recognized that various changes and modifications to the described embodiments will be apparent to those skilled in the art upon reading the foregoing description, and that such changes and modifications may be made without departing from the spirit and scope of the present invention. Skilled artisans may employ such variations as appropriate, and the invention may be practiced otherwise than as specifically described herein. Accordingly, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of the invention. Moreover, any combination of the above described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
Claims
1. A plastic container comprising:
- a cover including a first closure portion at the outer peripheral edge of the cover and an engagement portion;
- a base including a second closure portion;
- wherein said first closure portion of said cover is sealingly engageable with said second closure portion of said base so that when said first closure portion and said second closure portion are sealingly engaged with each other, said cover and said base define a substantially sealed storage area, and;
- wherein said engagement portion of said cover is lockingly engageable with a second cover.
2. The plastic container of claim 1 wherein said cover defines a gripping tab.
3. The plastic container of claim 2 wherein said gripping tab of said cover defines said engagement portion of said cover.
4. The plastic container of claim 1 wherein said engagement portion of said cover is a projection downwardly directed from the top of said cover, and;
- wherein said projection is in the form of a hollow cup-like structure.
5. The plastic container of claim 4 wherein said projection comprises:
- a male cap component, and;
- a female well component.
6. The plastic container of claim 5 wherein said male cap component includes at least one undercut configured as a lengthwise bead along at least a part of the bottom edge of said male cap component.
7. The plastic container of claim 5 wherein said female well component includes at least one lead-in configured as an indentation along at least a portion of the top edge of said female well component.
8. The plastic container of claim 1 wherein said plastic container comprises at least one additional engagement portion.
9. The plastic container of claim 1 wherein said plastic container comprises thermoformed plastic material.
10. The plastic container of claim 9 wherein said plastic material is selected from the group consisting of PS (polystyrene), CPET (crystalline polyethylene terephthalate), APET (amorphous polyethylene terephthalate), HDPE (high density polyethylene), PVC (polyvinyl chloride), PC (polycarbonate), polypropylene, and foamed polypropylene.
11. The plastic container of claim 1 wherein said engagement portion of said cover is integral with said first closure portion of said cover.
12. The plastic container of claim 11 wherein said engagement portion of said cover is configured as a locking lug.
13. The plastic container of claim 11 wherein said engagement portion is formed around the entire perimeter edge of the cover.
14. The plastic container of claim 11 wherein said engagement portion is formed in discrete segments around the perimeter edge of the cover.
15. A cover for a plastic container comprising:
- a first closure portion at the outer peripheral edge of said cover, wherein said first closure portion of said cover is sealingly engageable with a second closure portion of a base so that when said first closure portion and said second closure portion are sealingly engaged with each other, said cover and said base define a substantially sealed storage area, and
- an engagement portion wherein said engagement portion of said cover is lockingly engageable with a second cover.
16. The cover of claim 15 wherein said cover defines a gripping tab.
17. The cover of claim 16 wherein said gripping tab of said cover defines said engagement portion of said cover.
18. The cover of claim 15 wherein said engagement portion of said cover is a projection downwardly directed from the top of said cover, and;
- wherein said projection is in the form of a hollow cup-like structure.
19. The cover of claim 15 wherein said engagement portion of said cover is integral with said first closure portion of said cover.
20. The cover of claim 15 comprising thermoformed plastic material selected from the group consisting of PS (polystyrene), CPET (crystalline polyethylene terephthalate), APET (amorphous polyethylene terephthalate), HDPE (high density polyethylene), PVC (polyvinyl chloride), PC (polycarbonate), polypropylene, and foamed polypropylene.
Type: Application
Filed: Jan 16, 2007
Publication Date: Apr 2, 2009
Inventors: Ryan J. Coonce (Palatine, IL), Jason R. Maxwell (Elgin, IL)
Application Number: 12/160,298
International Classification: B65D 21/036 (20060101); B65D 43/03 (20060101);