CLOSURE VENT FOR TAMPER EVIDENT CONTAINER

Abstract

A plastic container includes a lid adapted for leak-proof sealing state with a base. Mating surfaces of the lid and base rims form one or more proximal seal zones when the lid rim and base rim are in an initially sealed state. Hinge-forming structure extends from a first hinge-joining section of the lid rim to a second hinge-joining section on the base rim. In the initially sealed state the first hinge-joining section superposes over all or part of the second hinge-joining section, the area at which the first hinge-joining-section superposes the second hinge-joining section defines an overlapping portion of the first and second hinge-joining sections. One or more vent channels are formed in either of the lid rim or base rim and located within the radially overlapping portion. The one or more channels form a complete discontinuity in the one or more proximal seal zones. Because the channels are within the overlapping portion, they are protected from tampering access.

Claims

1. A plastic food container capable of assuming a loading state and an initially sealed state in which the container rims are engaged, the container comprising: a base and a lid; the base having a base rim peripherally encompassing the base and the lid having a lid rim peripherally encompassing the lid; hinge-forming structure extending from a first hinge-joining section of the lid rim to a second hinge-joining section on the base rim; in the initially sealed state the first hinge-joining section superposing over all or part of the second hinge-joining section, the area at which the first hinge-joining-section superposes the second hinge-joining section defining an overlapping portion of the first and second hinge-joining sections on the engaged rims; in the initially sealed state the base rim and lid rim frictionally engage each other such that they form one or more proximal seal zones; one or more vent channels formed in either of the lid rim or base rim and located within the overlapping portion; and when the container is in the sealed state, the one or more channels form a complete discontinuity in the one or more proximal seal zones.

2. The plastic food container of claim 1 wherein the container does not have any vents outside of the overlapping area.

3. The plastic food container of claim 1 wherein when the container is in the initially sealed state, the base rim and lid rim frictionally engage each other such that they form a first distal seal zone and the one or more channels each form a partial discontinuity in the first distal seal zone.

4. The plastic food container of claim 3 wherein when the container is in the initially sealed state, the base rim and lid rim frictionally engage each other such that they form a second distal seal zone distal to the first seal zone.

5. The container of claim 1 wherein the lid of the container is adapted to remain engaged to the base, but allow the egress of gases and vapors inside the initially sealed container through the one or more vent channels upon the pressure in the sealed container reaching a certain level without manually repositioning of the lid on the base.

6. A plastic food container capable of assuming a loading state and an initially sealed state in which the container rims are engaged, the container comprising: a base and a lid; the base having a base rim peripherally encompassing the base and the lid having a lid rim peripherally encompassing the lid; hinge-forming structure extending from a first hinge-joining section of the lid rim to a second hinge-joining section on the base rim; in the initially sealed state the first hinge-joining section superposing over all or part of the second hinge-joining section, the area at which the first hinge-joining-section superposes the second hinge-joining section defining an overlapping portion of the first and second hinge-joining sections on the engaged rims; the lid rim having a lid retaining bead, the lid retaining bead having a peripherally projecting bottom segment, a peripherally projecting lid rim flange and an outer vertically oriented segment disposed between the peripherally projecting horizontal segment and the peripherally projecting lid rim flange; the base rim having a base retaining bead, the base retaining bead having a peripherally projecting platform segment, a peripherally projecting top segment and an inner vertical wall disposed between the peripherally projecting platform segment and the peripherally projecting top segment; in the initially sealed state the base rim and lid rim frictionally engage each other such that: the peripherally projecting bottom segment of the lid rim and peripherally projecting platform segment of the base rim contact each other and form a first proximal seal zone; and the outer vertically oriented segment of the lid rim and the inner vertical wall of the base rim contact each other and form a second proximal seal zone; one or more vent channels formed in either of the lid rim or base rim and located within the overlapping portion; and when the container is in the sealed state, the one or more channels form a complete discontinuity in the first proximal seal zone and in the second proximal seal zone.

7. The plastic food container of claim 6 wherein the container does not have any vents outside of the overlapping area.

8. The plastic food container of claim 6 wherein in the initially sealed state the base rim and lid rim frictionally engage each other such that the peripherally projecting lid rim flange of the lid rim and the peripherally projecting top segment of the base rim contact each other and form a first distal seal zone and the one or more channels each form a partial discontinuity in the first distal seal zone.

9. The plastic food container of claim 8 wherein when the container is in the initially sealed state, the base rim and lid rim frictionally engage each other such that they form a second distal seal zone distal to the first seal zone.

10. The container of claim 6 wherein the lid of the container is adapted to remain engaged to the base, but allow the egress of gases and vapors inside the initially sealed container through the one or more vent channels upon the pressure in the sealed container reaching a certain level without manually repositioning of the lid on the base.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a perspective view of a preferred embodiment of the present invention container in the sealed state.

[0016] FIG. 2 is a perspective view of a preferred embodiment of the present invention container in the loading state.

[0017] FIG. 3 is a detailed perspective view of the base rim with a vent channel formed therein of a preferred embodiment container of the present invention.

[0018] FIG. 4 is a detailed cross section view of the engaged rim structure outside of the area where hinge-forming structure connects to the container for a preferred embodiment container in the sealed state.

[0019] FIG. 5 is an identical image of the structure shown in FIG. 4 with the seal zones indicated instead.

[0020] FIG. 6 is a detailed cross section view of the engaged rim structure proximate the hinge-forming structure of a preferred embodiment container in the sealed state.

[0021] FIG. 7 is an identical image of the structure shown in FIG. 6 with the seal zones indicated.

DETAILED DESCRIPTION

[0022] A preferred embodiment container 1 of the present invention in the initially sealed state and loading state is shown in FIGS. 1 and 2. As seen in the figures, the inventive plastic food container is capable of assuming an initially sealed state and a loading state. In practical use, the outer surface of floor 26 of base 3 will normally rest upon a surface (such as a table top) considered horizontal in reference to the user. Thus, the directional terms vertical and horizontal and the like are used to describe the container 1 and its components with respect to the orientation illustrated in FIGS. 1-7 and are employed merely for the purposes of clarity and illustration. For example, FIG. 1 and FIGS. 6-7 show the container and the hinge area of container 1 when container 1 is in an initially sealed state. In the orientation shown in FIG. 6, lid flange 9 is vertically higher than base flange 10. The directional terms inner and inwardly and the like are used herein with respect to the described container to refer to directions along the directional component toward the geometric center of the container when lid 2 of container 1 is sealed or closed upon the base 3. Similarly, the directional terms radially, outer, peripherally and the like are used herein with respect to the described container to refer to directions along the directional component away from the geometric center of the container when lid 2 of container 1 is sealed or closed upon the base 3. Additionally, the terms upward, downward and the like are used to describe spatial relationships among structure when lid 2 of container 1 is sealed or closed upon the base 3.

[0023] The container includes hinge-forming structure 40 that includes an opening mechanism 45 which an end user will use to open the container from the initially sealed state. In the case of the shown preferred embodiment container, the opening mechanism 45 is representatively shown to be that as depicted in U.S. Pat. No. 9,580,219 (Cimmerer, et al). This is merely exemplary as the invention described herein will work with containers using other opening mechanisms that are located in hinge-forming structure. When the opening mechanism 45 for the initially sealed container has been utilized, the container is then in a ready-to-open state. When the lid is separated from the base from this ready-to-open state, the container is in an opened state.

[0024] As shown by these figures, container 1 includes lid 2 and base 3. Lid 2 includes cover portion 33, which extends outwardly to form inner wall 18 of preferred embodiment multi-segment rim 4. Rim 4 preferably includes a bead formed from inner vertical wall 18, outer vertical wall 19 and peripherally projecting bottom segment 20 disposed in between inner wall 18 and outer wall 19. Lid 2 and base 3 are manufactured from a conventional plastic material. Lid 2 is preferably clear. Cover portion 33 may be flat or domed and may include cover bead 34 in accordance with the prior art to enhance such factors as restricting access to lid rim flange 9 and stacking of sealed containers. Base 3 has a base rim 5 that peripherally encompasses base 3 so as to form container cavity 7. Lid 2 has a lid rim 4 that peripherally encompasses lid 2.

[0025] The structure of preferred embodiment lid rim 4 will now be discussed in further detail. As best shown in FIGS. 4 and 5, lid rim 4 includes peripherally projecting bottom segment 20, which extends between inner wall 18 and outer wall 19, creating lid rim channel 23. The cross-section profile of segment 20 is generally horizontal. The profile, however, can be shaped to include structure such as ribbing, curves or bends to modulate rim strength, rigidity or flexibility so as to enhance the closing, sealing and opening functions of the rim as needed. The drawings depict a preferred embodiment cross-section profile of this peripherally projecting segment. As viewed in FIGS. 4 and 5 outer wall 19 extends upwardly between peripherally projecting segment 20 and peripherally placed and projecting flange 9. Outer wall 19 may be canted to better frictionally engage inner wall 12 of base rim 5 further described below.

[0026] Base 3 includes a bottom-most level or floor 26 adjoined to sidewall 27. Sidewall 27 extends between base floor 26 and preferred embodiment, multi-segment rim 5. Sidewall 27 preferably includes beveled corners 30 for strength. Rim 5 includes ascending inner wall 12. The structure of preferred embodiment base 3 and its rim structure 5 are best shown in FIGS. 4 and 5. Base rim 5 includes peripherally projecting platform segment 6. Platform segment 6 curves upwardly to form inner wall 12. Inner wall 12 extends upwardly from peripherally projecting platform segment 6 to form peripherally projecting top segment 14. Inner wall 12 is preferably inwardly canted to provide maximum frictional engagement against outer wall 19. As viewed in FIG. 4, in the preferred embodiment peripherally projecting top segment 14 is horizontal and spans between inner wall 12 and outer wall 13. Rim 5 preferably includes peripheral flange 10, extending outwardly from base 3 from the bottom of outer wall 13.

[0027] As shown in the figures, in the preferred embodiment wall 12 comprises three sections: upper section 12a; middle section 12b; and lower section 12c. Upper section 12a is preferably formed as a chamfer between top segment 14 and middle wall section 12b. Lower section 12c curves or chamfers upward from platform 6 to middle section 12b. Middle section 12b is disposed between upper section 12a and lower section 12c. As seen in the figures and described below, the engagement of rims 4, 5 creates one or more proximal seal zones and one or more distal seal zones.

[0028] By virtue of the canting of inner wall 12 of rim 5 and outer wall 19 of rim 4, when container 1 is in the sealed state peripherally projecting segment 20 of lid rim 4 is pressed down upon and firmly contacts platform segment 6 of lid rim 5 to form a first proximal seal zone A. In the preferred embodiment, this first proximal seal zone A is horizontally oriented. Also, when container 1 is in the sealed state, wall 12 (preferably at section 12b) of base rim 5 firmly contacts wall 19 of lid rim 4 to form a second proximal seal zone B. In the preferred embodiment, this second seal zone B is vertically oriented. By virtue of the shape and structure of the components of rims 4, 5, when lid 2 is sealed upon base 3, rims 4, 5 tightly engage. Thus, in the normally sealed state, the mating rim surfaces provide a leakproof seal. Additionally, when container 1 is in the sealed state, lid rim flange (an outer peripherally projecting segment) 9 contacts outer peripherally projecting top segment 14 of base rim 5 to form a first distal seal zone C. In the preferred embodiment, this first distal seal zone C is horizontally oriented. Flange 9 is accessible by those handling container 1, but its short length and the tight tolerances of the structures of rims 4, 5 make it very difficult to grasp.

[0029] As shown in the FIGS. 6 and 7, container 1 also includes hinge-forming structure 40. Hinge-forming structure 40 extends from base rim 5 to distal point 49 and then returns to lid rim 4 and defines a contained hinge space 46. Hinge-forming structure 40 connects to lid rim flange 9 via transition section 41. Hinge-forming structure 40 connects to base rim flange 10 via transition section 42. Along its connection with lid rim 4, hinge-forming structure 40 defines a first hinge-joining section 43 on lid rim 4. This is best shown in FIGS. 1 and 2. Similarly, along its connection with base rim 5, hinge-forming structure 40 similarly defines a second hinge-joining section 44 on base rim 5. This can be best seen in FIGS. 2 and 3. As is shown in FIG. 1, first hinge-joining section 43 has a length L.sub.1 along lid rim 4 that extends between end points 47a and 47b. Second hinge-joining section 44 has a length L.sub.2 that extends between end points 48a and 48b and is best seen in FIG. 3. In most containers, first hinge-joining section 43 will have the same length as that of hinge-joining section 44. In other words, L.sub.1 will equal L.sub.2 and end points 47a and 48a will be vertically aligned, as will be end points 47b and 48b. In such case, first hinge-joining section 43 and second hinge joining section 44 will also be completely vertically aligned and will fully overlap vertically. However, hinge forming structure 40 could be manufactured such that first hinge-joining section 43 and section hinge-joining section are offset, of different lengths or both in which case first hinge-joining section and section hinge-joining section will only partially vertically overlap. In either case, in the initially sealed state the first hinge-joining-section 43 on lid rim 4 and second hinge-joining section 44 on lid rim 5 will have a superposed position with respect to each other such that they define a vertically overlapping portion of the first and second hinge-joining sections. In the depicted preferred embodiment, because L.sub.1 and L.sub.2 have identical endpoints, overlapping portion on engaged container rims 4, 5 would be within the area demarcated by endpoints 47a and 47b and by endpoints 48a and 48b. Thus, in FIG. 3, the overlapping portion corresponds to the distance L.sub.2 and in FIG. 1 where the container is shown in the initially sealed state, the overlapping portion corresponds to the distance L.sub.1.

[0030] As seen in FIGS. 2 and 3, one or more vent channels 50 are formed in base rim 5 within second hinge-joining section 44. This is merely a representative the one or more vent channels 50 could be formed in the lid rim 4 within the first hinge-joining section 43. In the depicted preferred embodiment, a vent channel 50 is a groove disposed transversely in base rim 5. The one or more vent channels 50 are located on either or both of rims 4 or 5 such that they are within the confines (endpoints) of both hinge-joining sections 43 and 44 and such that they are within the vertically overlapping portion (L.sub.1 in FIG. 1). Thus, when the container is in the sealed state, hinge-forming structure 40 is positioned adjacent to, but outwardly from one or more vent channels 50. More preferably, one or more vent channels will be located in the overlapping portion (coinciding with L.sub.1 of FIG. 1) of rims 4, 5 sufficiently inboard from end points 47a, 47b, 48a and 48b to be out of reach of a handler's finger or any practically available tampering implement. This is best seen in FIG. 3. By being so located, the one or more vent channels 50 are not directly accessible to tampering because hinge-forming structure 40 would block the approach of any such finger or tool to the one or more vent channels 50. To reduce the chance of tampering, rims 4, 5 of preferred embodiment container 1 should not include a vent channel outside of the area defined as the vertically overlapping portion on engaged rims 4 and 5.

[0031] As seen in FIGS. 3 and 5, when the container is in the sealed state, the one or more channels form a complete discontinuity in the horizontal first proximal seal zone A and a complete discontinuity in the vertical second proximal seal zone B. In the preferred embodiment, the vent channel forms a partial discontinuity in the first distal seal zone C. The complete discontinuity in one or more proximal seal zones A and B creates a pathway from the interior of the container to one or more distal seal zones, first distal seal zone C through which pressurized vapors may flow. The pressure behind those vapors is sufficient to lift flange 9 off of top segment 14 of base rim 5. Once flange 9 lifts from top segment 14, the container vapors may exit container 1 and exhaust into hinge space 46. As seen in FIGS. 6 and 7, vent channel 50 modifies the shape of segment 14 so as to create a partial discontinuity 51 of seal zone C at the location of vent 50.

[0032] As shown in FIGS. 6 and 7, the container can be made with a second distal seal zone D preferably formed between transition segment 41 of hinge-forming structure 40 and outer wall 13 leading to flange 10. As in the case of first distal seal zone C, the pressure behind container vapors that is sufficient to separate transition section 41 off of top segment 14 of base rim 5 also separates segment 41 from its contact with wall 13. Once segment 41 separates from wall 13, the container vapors may exit container 1 and exhaust into hinge space 46. Thus, with the present invention container, the lid of the container is adapted to remain engaged to the base, but allow the egress of vapors inside the sealed container through the one or more vent channels 50 upon the pressure in the sealed container reaching a certain level without having to manipulate the lid on the base. The inclusion of one or more vent channel 50 in the overlapping portion of the container at the hinge joining area of the rims means that the proximal surfaces of rims 4, 5 can engage tightly around the periphery of the container to seal the container and make it tamper proof. There is thus no secondary venting movement of the engaged rims at those proximal surfaces. Instead, the only secondary venting movement occurs at the distal areas of the engaged rims, past the position of a vent channel and only in the overlapping portion of the engage rims. Thus, this secondary movement is minimal compared to that of the prior art container. Once pressurized vapors have been purged, flange 9 and segment 41 assume their original sealed and leakproof state without manual intervention.

[0033] The vent feature described above means that a true tamper evident container can be provided with a venting mechanism that does not compromise the tamper evident quality of the container. The inventive container thus eliminates the need for a typical lid vent hole, which reduces the probability of tampering with the package contents after lidding. Additionally, the vent feature utilizes a seal area, between the vent groove and atmosphere, allowing the package to remain leak resistant while the contents are not under pressure. When the package contents create pressure, as in the case of cut fruit, the pressure is relieved as it forces open the seal area between the vent groove and the atmosphere. Additionally, if a consumer squeezes the sides of the package with too great a force, the vent feature allows pressure release before the lid might otherwise pop off the base. Placement of the vent feature, beneath the hinge, reduces visibility and detection of the feature. In carrying out the invention it is not important which rim, lid or base, is provided with the one or more venting channels 50. Accordingly, in another embodiment, outer wall 19 and segment 20 of lid rim 4 could be provided with venting channel 50.

[0034] A container constructed in accordance with the present invention can be manufactured in a variety of shapes and sizes, and is preferably formed of resins or plastic materials including, but not limited to, polyethylene, polypropylene, polyvinyl chloride or polyethylene terephthalate (PET). The container may be thermoformed, blow-molded or injection molded. The container lid and base can be transparent or translucent, and may be colored in either instance. Further, the container can be of any shape, including round or polygonal.

[0035] Having described the invention in detail, those skilled in the art will appreciate that modifications may be made of the invention without departing from its spirit. Therefore, it is not intended that the scope of the invention be limited to the specific embodiment illustrated and described.