CROSS REFERENCES TO RELATED APPLICATIONS
- STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
- BACKGROUND OF THE INVENTION
The present invention relates to reclosable containers in general, and more particularly to containers having elements which indicate that the container has been opened after its original closure.
There are a number of consumer products, such as bakery or deli foods, which are placed in containers which are closed and put on display for consumer selection. This type of merchandizing can reduce retailer labor, and allows consumers to select the products they desire at their own pace. However, particularly with consumable foodstuffs, customers may seek some assurance that the products they are purchasing have not been tampered with or been pilfered by others. This can be done by applying a shrink-wrapped plastic band to the sealed container, although this requires special equipment and can unduly add cost.
Containers are also known which employ press-fit connectors on the container base and lid which engage with one another when the container is closed to retain the container in a closed configuration. Weakened regions of material such as perforations are disposed such that the force necessary to open the lid causes portions of the container to be severed, either to be separated from the container or to be retained on an opposed container part. Such arrangements provide evidence of tampering either due to the absence of some package part, or due to the open condition of the container. Yet for the untrained observer, the absence of a container part may not immediately indicate tampering, and, although an open container is readily understood, customers may wish to have containers that are reclosable for retention of partial quantities of product.
- SUMMARY OF THE INVENTION
What is needed is an economical container that effectively presents consumer merchandise, is reclosable, and which clearly indicates that it has been opened after its initial closure.
The container of the present invention is preferably formed of thermoformed thermoplastic material, and has a lid which closes on a base in a retention fit. A signal tab is hinged to the base and has a tubular projection which folds over the lid and is received in a friction fit with a downwardly extending lid projection. After the container is filled with product, the signal tab is pressed into place on the lid and lies flat. In order to open the lid the signal tab is pulled up, thereby severing a perforated line extending around the lid projection, and separating the lid projection from the lid which prevents the signal tab from again engaging with the lid, thereby serving as an indicator to a customer that the package has been opened. The lid may be hinged to the base, or the lid may be entirely separable from the base and multiple signal tabs may be provided on multiple sides of the container to engage with multiple lid projections. Because the signal tab plays no part in retaining the lid in its closed condition, the package may always be reclosed.
It is an object of the present invention to provide a reclosable container which provides an indication of access to its interior after its original closure.
It is a further object of the present invention to provide a tamper evident mechanism suitable for a wide variety of reclosable containers.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.
FIG. 1 is an isometric view of the container of this invention in an open configuration.
FIG. 2 is a fragmentary isometric view of the container of FIG. 1 with the lid closed on the base, prior to engagement of a signal tab.
FIG. 3 is a fragmentary isometric view of the container of FIG. 2 with the signal tab closed on the lid.
FIG. 4 is a fragmentary isometric view of the container of FIG. 3 with the signal tab opened and indicating that the container's closure has been disturbed.
FIG. 5 is a cross-sectional view of the container of FIG. 1 in the process of being closed.
FIG. 6 is a cross-sectional view of the container of FIG. 3 taken along section line 6-6.
FIG. 7 is a cross-sectional view of the container of FIG. 4 taken along section line 7-7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 8 is an exploded isometric view of an alternative embodiment container of this invention having a lid which is fully separable from the base.
Referring more particularly to FIGS. 1-8, wherein like numbers refer to similar parts, a reclosable container 20 is shown in FIGS. 1-7. As shown in FIG. 1, the container 20 is preferably thermoformed from a sheet of thermoplastic material, for example transparent polyethylene terephthalate (PET). The container has a base 22 with a bottom wall 24 and an upwardly extending side wall 26 which define a container interior 28 which will receive contents such as food products. The side wall 26 extends to an upper lip 30 which has a surrounding peripheral skirt 32 which terminates in an outwardly extending terminal flange 34.
An integral hinge 36 extends from the terminal flange 34, and a lid 38 is connected by the hinge so it may be pivoted into a closed position on the base 22. The lid 38 has an outwardly extending flange 40 which is connected to the hinge 36, and a peripheral skirt 42 which extends upwardly from the flange. A top wall 44 extends from the skirt 42, such that when the lid 38 is closed on the base 22 the container interior 28 is sealed. The top wall 44 is preferably formed with an interior skirt 46 which is configured such that the peripheral skirt 42 and the interior skirt snap into engagement with the base peripheral skirt 32 and portions of the base side wall to retain the lid in a closed configuration on the base. The container 20 may thus be loaded with product and then placed on display in a retail establishment for consumer self-service. However, because the lid may be repeatedly opened and resealed on the base, a consumer will desire to know that the contents of the container have not been tampered with after the initial loading with product by the retailer. The consumer is provided with this information by a tamper-evident mechanism 48 which is integrally formed with the container 20.
The tamper-evident mechanism 48 has a signal tab 50 which is connected by an integrally formed hinge 52 to the base terminal flange 34. The signal tab 50 has a narrow rectangular spacer element 54 which is joined by an intermediate integrally formed hinge 56 to a main element 58. The main element 58 is formed with a tubular projection 60 which may be generally cylindrical or tapered like the frustum of a cone.
The tamper-evident mechanism 48 further has a cooperating structure formed on the lid 38 of the container 20. As shown in FIG. 5, the lid 38 has an upper wall 62 which extends inwardly from the peripheral skirt 42. A lid projection 64 extends downwardly from the lid upper wall 62 and is of a size and shape to engage with the signal tab projection 60 in an interference or friction fit. For example, the lid projection 64 may be generally square in section, to engage with the frustoconical signal tab projection.
The base 22 has an upper wall 66 which extends inwardly from the base peripheral skirt 32 and is positioned to directly underlie the lid upper wall 62 when the lid 38 is closed on the base. The base upper wall 66 and the lid upper wall are thus substantially parallel and in close proximity to one another when the lid is closed on the base. A relief 68 is formed in the base upper wall 66 to allow the lid projection to pass through without obstruction. The relief 68 may be a die-cut opening, but for ease of manufacturing it is formed as a downwardly extending closed projection. The relief 68 is larger than the lid projection and does not engage it. Hence when the lid 38 is closed on the base 22, the lid projection does not hamper the snap fit seal between the lid and the base.
As shown in FIG. 2, a region of weakened material 70 is formed in the lid upper wall 62 around the lid projection 64. The region of weakened material 70 may be formed, for example, by a die-cut with notched segments or perforations, or by a thinning of the plastic or by other means. As shown in FIG. 6, the region of weakened material 70 may define, for example, a circle, which is greater in diameter than the size of the base upper wall relief 68, such that the region of weakened material is supported on the base upper wall 66 and separation of the lid projection 64 at the region of weakened material is prevented when the lid projection 64 is pressed downwardly. It will be noted that the closed cavity of the base relief 68 serves to protect the downwardly extending lid projection from inadvertent engagement by a customer which might tend to push the projection 64 upwardly and disturb the region of weakened material 70.
Two detents 72 are formed, one on either side of the signal tab projection 60. These detents prevent the main element 58 of the signal tab 50 from approaching so close to the base upper wall 66 so as to prevent a user from engaging the main element 58 and pulling it upwardly. The height of the detents 72 serves to maintain a narrow gap between the base upper wall 66 and the signal tab main element, so an edge of the main element can be readily engaged and manipulated.
The container 20 is loaded with product while the lid 38 is opened, as shown in FIG. 1. The lid 38 is then closed on the base 22 as shown in FIGS. 2 and 5. The lid 38 has molded structure which engages the base 22 and secures the lid in a closed configuration on the base. For example, the lid outer peripheral skirt 42 and interior skirt 46 engage the base peripheral skirt 32 and side wall 26 respectively. Once closed on the base, the lid 38 may be opened and closed repeatedly. To provide a customer an indication of whether the container has been opened after its initial loading, the signal tab 50 is pivoted on the hinges 52, 56, to bring the signal tab projection 60 into engagement with the lid projection 64, as shown in FIGS. 3 and 6. The signal tab spacer element 54 is at least as wide as the distance the base upper wall 66 is spaced above the base terminal flange 34. The signal tab projection 60 is dimensioned so that when it is pressed into engagement with the lid projection 64 the parts are deformed to retain the two in engagement with one another. As shown in FIG. 3, the lid upper wall 62 is preferably slightly relieved below the level of the surround lid top wall 44, such that the engaged signal tab 50 does not project substantially above the top wall and provide an obstruction which might be readily engaged when handling loaded containers, for example while stacking them one on another.
Once the signal tab projection 60 is secured to the lid projection 64, the lid 38 may not be opened without first getting the signal tab 50 out of the way. However, the dimensions of the parts are such that the force required to separate the signal tab projection 60 from the lid projection 64 is greater than the force required to sever the line of weakened material 70 and separate the lid projection 64 and its surrounding portion of the lid upper wall 62 from the lid. Thus, as shown in FIGS. 4 and 7, when the signal tab 50 is engaged by a user and pivoted away from the lid, the discrete element 73 containing the lid projection 64 remains affixed to the signal tab, leaving a perforated opening 75 in the lid above the base relief 68. The signal tab 50, no longer connected to the lid, then extends away from the base 22 providing a clear signal that the container has been tampered with after its initial closure. The hinge 52 may undergo plastic deformation when the signal tab is folded into engagement with the lid, with the result that the signal tab extends vertically when released from the lid, as shown in FIG. 7. Although the container 20 may still be closed, the signal tab 50 can not be restored to its engagement with the lid 38. It should be noted that the perforated opening 75 does not communicate with the container interior 28, and hence does not compromise the seal of the container.
It should be noted that although the projection on the signal tab has been illustrated as extending from the signal tab towards the lid to engage with a downwardly extending projection on the lid, it and the lid projection could also be projecting upwardly.
It should be noted that, although in the FIGS. 1-7, the container is shown having a clamshell construction with a lid which is attached by an integral hinge to the base, the container may have an unhinged lid. An alternative embodiment container 74, shown in FIG. 8, employs a lid 76 which is not hinged to the container base 78 but is entirely separable from the base. In such a configuration, the container 74 has multiple tamper-evident mechanisms 48, at least one on multiple sides of the container, for example on two opposite sides of the lid, whereby at least one of the tamper-evident mechanisms must be disturbed to gain access to the container interior. The mechanisms 48 may be similar to the ones discussed above.
It should be noted that the container lid may have a perforation along the hinge or parallel to the hinge to permit it to be separated from the base by the consumer.
It should be noted that although a particular friction fit arrangement is disclosed between the signal tab projection and the lid projection, other structures which allow the engagement between the two parts may be employed, so long as the arrangement is such that the force required to separate the two parts is greater than the force required to sever the region of weakened material.
It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims.