Ventable container assembly

A ventable container comprising a container bottom having an inner cavity, the container bottom further having a side wall that terminates in a container rim; and a selectively detachable lid, the lid including a central panel and peripheral sealing lip that surrounds the panel, the peripheral sealing lip having a generally inverted U-shaped cross-section that defines a lid channel, the lid channel being adapted to receive the container rim, the lid channel being further adapted to position the lid at a first position wherein sealed engagement of the container is effectuated and at a first position relative to the container rim wherein an air passage from the inner cavity to the container surroundings is provided.

FIELD OF THE PRESENT INVENTION

The present invention relates generally to reclosable containers. More particularly, the invention relates to a detachable container lid that selectively provides venting for a container when attached thereto.

BACKGROUND OF THE INVENTION

Thermoplastic containers are well known in the art. The noted containers generally include a lid that is selectively detachable from a bowl (or container bottom) and are commonly designed to provide a variety of features, including being reusable, disposable, microwavable, and the like.

Numerous types of container assemblies and means for effecting sealable engagement of a lid on a bowl have been devised. Illustrative are the containers and engagement means disclosed in U.S. Pat. No. 6,170,696.

One problem that is associated with a conventional, microwavable container stems from the rapid temperature changes that it must endure. The container must be permitted to vent during microwaving due to the high pressures that arise as moisture in the container contents vaporizes and gas temperatures increase. Thus, the container must be left open to some degree during microwaving. However, it is also desirable to keep the bowl covered as much as possible to prevent the contents from splattering the inside of the microwave.

A further problem that is often encountered with thermoformed containers is the ability to accommodate produce respiration while maintaining the sealed integrity of the container. As is well known in the art, providing adequate venting (or breathing rate(s)) to accommodate produce respiration can, and in most instances will, enhance produce freshness.

Various methods and container designs have been employed to provide adequate venting of a container during and after microwaving, and to accommodate produce respiration. One common practice is to remove the lid and place it loosely over the container bowl to accommodate produce respiration and, during microwaving, to allow air and steam to escape. Another common practice is to only partially remove the lid (i.e., “crack open” the lid) by disengaging only part of the lid from the bowl.

Both of the noted practices generally accommodate produce respiration. However, in both instances, the container is subject to leaking, i.e., no longer leak-proof.

The noted practices also permit sufficient air and steam to vent during microwaving because the increased pressure within the container will tend to force the container open, increasing any space between the lid and the bowl. However, once microwaving is complete, the steam will cool and the pressure in the container will drop significantly. Because the pressure differential no longer tends to open the container, the above-noted venting practices often do not permit sufficient air to vent back into the container to compensate for the pressure drop. This problem can be aggravated by the accumulation of steam or vapor, which can form a vapor seal between the lid and bowl. A vacuum can result, which can permanently damage the container.

Various container designs have been employed to provide venting. For example, in U.S. Pat. No. 3,362,565 a lid is disclosed that includes a sidewall, which has a sealing bead near the base and a shoulder near the top. The sealing bead seals against an internal shoulder provided in a container. Notches are intermittently disposed about an outer periphery of the sealing bead. These notches provide a venting passageway through which gases generated in a sealed container can escape when the gas or vapor pressure is sufficient to flex the lid upward at its center, causing a fulcruming action.

In U.S. Pat. No. 5,147,059 a lid is disclosed having a series of vent-defining protuberances on the inner surface of a vertical, outer sealing portion of a lid. The protuberances engage a container rim to permit venting when the lid is loosely placed on the container. The venting prevents internal/external pressure differentials that might resist the proper seating and removal of the lid.

One commercial product, i.e., Tupperware® Fridgesmart™ container, includes two (2) push button vents in the bowl that are adapted to accommodate produce respiration.

There are several drawbacks and disadvantages associated with prior art container venting means. A major drawback is that the prior art venting means typically include complex design features that are difficult to manufacture. Lids employing the complex design features are thus quite costly.

It would thus be advantageous to provide a ventable container lid having effective, easy to use venting means (i) that is adapted to effectuate sealable engagement of the lid and a container bottom in a first position and provide an effective air passage when the venting means is in a second position and (ii) can be readily manufactured via a conventional thermoforming process.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the invention, disclosed herein is a ventable container having a lid and a bottom, the bottom including an inner cavity and a side wall that terminates in a rim, the lid including a central panel and a peripheral sealing lip that surrounds the panel, the peripheral sealing lip having a generally inverted U-shaped cross section that defines a lid channel, the lid channel being adapted to receive the container rim, the lid channel including a transition region adapted to position the lid at a first position relative to the container rim wherein the lid and bottom are tightly occluded to prevent liquid leakage and a second position relative to the container rim wherein an air passage is provided, the lid channel further including a positioning region adapted to position the lid in the second position.

In a preferred embodiment of the invention, the lid positioning region is further adapted to releasably secure the lid in the second position.

Preferably, the lid transition region is in communication with the lid positioning region.

Preferably, the lid positioning region extends around the lid sealing lip.

In one embodiment of the invention, the lid positioning region is substantially continuous.

In another embodiment of the invention, the lid positioning region is discontinuous.

In accordance with a further embodiment of the invention, disclosed herein is a ventable container having a lid and a bottom, the bottom including an inner cavity and a side wall that terminates in a rim, the lid including a central panel and a peripheral sealing lip that surrounds the panel, the peripheral sealing lip having a generally inverted U-shaped cross section that defines a lid channel, the sealing lip including a lid stop, the lid channel being adapted to receive the container rim, the lid channel being further adapted to position the lid at a first position relative to the container rim wherein the lid and bottom are tightly occluded to prevent liquid leakage and a second position relative to the container rim wherein an air passage is provided, the lid stop being adapted to communicate with the container rim when the lid is in the second position, whereby the lid is releasably secured in the second position.

DETAILED DESCRIPTION OF THE INVENTION

Before describing the present invention in detail, it is to be understood that this invention is not limited to particularly exemplified container lid designs, configurations or sizes, materials and methods as such may, of course, vary. Thus, although a number of container lid designs and configurations similar or equivalent to those described herein can be used in the practice of the present invention, the preferred container lid designs and configurations are described herein.

It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only and is not intended to be limiting.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one having ordinary skill in the art to which the invention pertains.

Further, all publications, patent and patent applications cited herein, whether supra or infra, are hereby incorporated by reference in their entirety.

Finally, as used in this specification and the appended claims, the singular forms “a “an” and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to “an air flow path” includes two or more such paths.

The present invention substantially reduces or eliminates the disadvantages and drawbacks associated with prior art container bowl and lid assemblies. As discussed in detail herein, the container lid of the invention includes highly effective, simple to operate venting means. According to the invention, during microwaving, the venting means permits air and steam to vent from the inner volume of the container and also permits sufficient air to vent back into the container lid after microwaving (i.e., cooling) to compensate for the pressure drop. The venting means also accommodates produce respiration.

Referring first toFIG. 1, there is shown a conventional container bottom12, which is sealably closed by a flexible container lid40(seeFIGS. 3 and 4). As illustrated inFIG. 1, the container bottom12, has a bottom surface14, four sidewalls15,16,17,18, a denesting shoulder22, and a closure device (or rim)24. The bottom surface14provides a stacking recess (not shown) extending upwardly to a substantially horizontal central panel surface (also not shown).

The sidewalls15,16,17,18extend upwardly and slightly outwardly from the periphery of the bottom surface14. At the termination of the sidewalls15,16,17,18an outwardly and substantially horizontally extending denesting shoulder22is provided, which merges into the base of the closure device24. The terms “inwardly” and “outwardly” are used herein with respect to the reference line100and moving in a clockwise direction101, as shown inFIGS. 5 and 6.

Referring toFIG. 5, the closure device24includes an inner sealing wall26, a retention bead24a, an outer wall30and a skirt32. The sealing wall26preferably extends from the denesting shoulder22and merges into the retention bead24a.

The retention bead24acan include at least one upwardly and outwardly extending undercut or cut-back portion23, an inner vertical portion25, an upwardly and inwardly extending lead-in portion27, a horizontal rim surface28, a downwardly and outwardly extending lead-in portion29, an outer vertical portion31, and a downwardly and inwardly extending undercut or cut-back portion33.

Referring now toFIG. 2, there is shown a container lid40that is adapted to sealingly engage the container bottom12, as discussed above. As illustrated inFIG. 2, the container lid40generally includes a central panel42, a gripping tab43and a peripheral sealing lip or closure device44that is adapted to sealingly engage the closure device24of the container bottom12.

Referring now toFIG. 6, the closure device44extends from the central panel42and has a generally inverted U-shaped cross section. As illustrated inFIG. 6, the closure device44includes an inner wall46that extends upwardly and inwardly from the panel42, an upwardly and outwardly extending inner nesting portion48, a horizontal rim surface50, a downwardly and outwardly extending outer nesting portion52, a downwardly and inwardly extending undercut or cut-back portion53, a outer vertical portion54a downwardly and outwardly extending lead-in portion55, and a substantially horizontal lip56.

When the lid40is secured to the container bottom12, undercut23engages undercut46to provide a first inside peripheral seal and undercut30engages undercut53to provide a second outer peripheral seal. Hence, the closure device of sealing lip44of the lid40acts as a sealing channel to receive the closure device (or rim)24of the container bottom12.

Further details of the container lid40and bottom12are set forth in U.S. Pat. No. 6,170,696 B1, which is incorporated herein in its entirety.

Referring now toFIGS. 7,8A and8B, there is shown one embodiment of the ventable container lid and bottom of the invention. Although the invention is described with respect to a substantially square lid and container assembly (i.e., where the closure portions are generally square in top profile view), it is to be understood that the venting means of the invention can be employed on virtually any size and shape lid and container assemblies, including but not limited to lid and container assemblies having round, rectangular and/or complex curve profile configurations.

As will further be appreciated by one having ordinary skill in the art, numerous suitable materials may be chosen to fabricate the ventable container lid of the invention. Preferably, the container lid and container bottom are made from a resilient polymeric material suitable for both freezing and microwave reheating.

Referring now toFIG. 7, there is shown a perspective view of one embodiment of a ventable container lid60of the invention positioned on (or engaged to) a conventional container bottom12. For purposes of clarity, all reference numerals used to describe the various elements of the conventional container bottom12depicted inFIGS. 1-6are carried over in the description of the embodiments of the present invention shown and described inFIGS. 7 to 10Binfra. As illustrated inFIG. 7, the lid60similarly includes a central panel42and a peripheral sealing lip or closure device62. The closure device62further includes a downwardly extended skirt78and a gripping tab63.

Referring now toFIG. 8A, the lid closure device62has a generally inverted U-shaped cross section and includes an upwardly and outwardly extending transition or lead-in portion65, an inner wall or undercut64that extends inwardly and upwardly from the lead-in portion65and an upwardly extending inner nesting portion66. The closure device62further includes a horizontal rim section68, a downwardly and outwardly extending outer nesting portion70, a downwardly and inwardly extending cut-back portion or undercut72and a downwardly and outwardly extending lead-in portion74.

The outermost wall portion of the lid closure device62(generally designated by reference numeral69) further includes a downwardly extending lid transition region76, an outwardly extending skirt78and an undercut region77disposed therebetween. As discussed in detail below, the undercut region77functions as a container lid locking device to hold the lid60′ in place when moved in a second position relative to the container bottom12(i.e., venting position), as shown inFIG. 8B.

As illustrated inFIGS. 8A and 8B, the lid closure device62of the present invention is similarly adapted to receive and sealingly engaged the closure device24of the container bottom12. Referring now toFIG. 8A, there is shown a first position of the lid60relative to the container bottom12, which is achieved by exerting a closure force on the lid60in the direction denoted by Arrow S. According to the invention, when the lid60is in the noted first position, sealed engagement of the container lid60to the container bottom12is effectuated. In this embodiment, a first inner seal is formed by the engagement between inside undercut23of the container bottom closure device24and inside undercut64of the lid closure device62and a second outer seal is formed by the engagement between outside undercut30of the container bottom closure device24and outside undercut72of the lid closure device62.

Referring now toFIG. 8B, there is shown a second position of the lid60relative to the container bottom12, which is achieved by raising the lid60in the direction denoted by Arrow V. According to the invention, when the lid60is in the noted second position, an air passage through the closure region (designated by Arrows A, A′) is provided.

As stated, when the lid60is raised in the direction denoted by Arrow V, the lid stop or undercut region77of the sealing lip62contacts the skirt32of the container bottom closure24to position and retain the lid60in the noted second position. The lid transition region76of outer wall69is of sufficient length to permit lead-in portions65and74to rest loosely on top of respective lead-in portions27and27of the container bottom closure device24and to permit venting through the closure region in the second venting position. To fully remove the lid60, the user simply applies additional lifting force to the lid pull tab (not shown) in order to move the lid stop or undercut77out of locking engagement with the container bottom closure device24. Alternately, the user may “pop” the lid off by placing a finger or thumb under the skirt78to outwardly flexing the skirt78and release the undercut77from locking engagement with the skirt32of the container bottom closure device24. It is understood that thermoformed containers can be formed to provide a desired amount of flexibility and elastic memory to permit repeated flexures to fully open the container lid from the container bottom and still retain desired seal integrity when the lid is moved back into the first sealed engagement position.

The lid60is loosely positioned on the container bottom12when in the noted second, venting position. To fully remove the lid60from the container bottom12the user simply continues raising the lid in the direction of Arrow V to move the undercut region77beyond its engagement with the skirt32. Depending on the dimensions selected for the length of the lid transition region76and inward relief of undercut region77, one or more regions of air tight contact can be realized. Such contact seal regions may be useful in certain applications such as microwave cooking wherein controlled steam venting is desirable. As internal steam pressure builds within the confined space of the container, the contact seal regions, being relatively weak, allow for controlled release of pressurized steam through the closure. The controlled release of steam substantially eliminates the high pressure conditions that cause the lid to blow off and the cooked food to splatter from the confined space of the container to the inside walls of the microwave oven.

Referring now toFIG. 9, there is shown a perspective view of another embodiment of a ventable container lid90of the invention positioned on a conventional container bottom12. As illustrated inFIG. 9, the lid90similarly includes a central panel42, a peripheral sealing lip or closure device92, a downwardly extended skirt78and a gripping tab63.

Referring now toFIG. 10A, the closure device92of lid90is substantially similar to the closure device62of lid60, discussed above. However, as illustrated inFIG. 10B, in this embodiment, the undercut region77of the lid90is discontinuous to enhance the air flow into and out of the container cavity. The enhance airflow afforded by this embodiment is suitable for refrigerated storage of high respiring produce.

According to the invention, the discontinuity can comprise one or more opens79in the undercut region77, which can have various sizes and spacing to achieve the desired air flow.

As will be appreciated by one having ordinary skill in the art, the ventable container lids of the invention and, hence, container assemblies employing same readily accommodate produce respiration when the produce is disposed therein. The container assemblies also provide an effective air passage during and after microwaving to accommodate pressure differentials between the container cavity and the container surroundings.

Without departing from the spirit and scope of this invention, one of ordinary skill can make various changes and modifications to the invention to adapt it to various usages and conditions. For example, while the present invention has been illustrated in the context of a particular type of sealing container having both inside and outside sealing regions that are formed by the engagement of mating inside and outside undercuts between the lid and container bottom closures, it is understood that other closure configurations for the lid and container bottom are possible such as a container bottom closure with only one under cut as disclosed in U.S. Pat. No. 6,032,827. As such, these changes and modifications are properly, equitably, and intended to be, within the full range of equivalence of the following claims.