Tamper-Evident Thin-Walled Container Package

1. Field of the Invention

This invention relates to a new and improved tamper-evident thin-walled container package. More particularly, the invention relates to a container and a closure for said container and the combination of the container and closure. The container is of the general type used to package dairy products such as yogurt, cottage cheese and the like.

2. Description of Related Art

Cups, tubs and other packages for dairy foods closed by lids are well known in the art. Heretofore, some of these containers have been made tamper-evident either by a thermally applied adhesive foil fitting over the lip of the container or a band of heat shrink film around the down-turned peripheral flange of the lid. These techniques are expensive, reduce packaging speeds and are not efficient. Thermally applied adhesive foils are not suitable for re-closure unless accompanied by a re-closure lid. Heat shrink films are often difficult for the consumer to remove.

Attempts have been made to supply tamper-evident features by mechanical means. However, the fact that the containers are generally of large diameter and thin-walled allows them to be easily distorted. The ease of distortion has prevented mechanical tamper-evident concepts from being effective.

Most current dairy containers are made either by thermoforming or injection molding of a suitable material such as polystyrene, polyethylene or polypropylene. The present invention provides a simple and cost effective tamper-evident package by combining a novel injection molded, thin-walled container with a complementary lid.

The container of the present invention generally has an out-turned lip projecting from the container wall. Spaced outwardly and surrounding the lip is a circular, tamper-evident band connected integrally to the container by a plurality of angularly spaced frangible bridges. The lid comprises a top disk which fits over the top of the container and preferably has a downturned outer skirt which fits between the container wall and the tamper evident band and which is formed with beads which engage below the lip of the container. The lid skirt fits between the lip and the tamper-evident band. So long as the band is intact, the lid cannot be removed because one cannot obtain access to the lid to pry it off. If an attempt is made to remove the lid without removing the band, some or all of the frangible bridges will be broken, providing evidence of tampering activity. When the band is intentionally removed after breaking the frangible bridges, the lid may be lifted off the container.

In other modifications of the invention the container is formed with an outward spaced downward extending skirt depending from the lip and the tamper evident band is connected thereto by frangible bridges. The outer skirt of the lid fits between the outer skirt of the container and the tamper evident band and engages the latter with cooperating bead means.

The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention:

FIG. 1 is a fragmentary sectional view through the upper portion of a container with the closure applied thereto as viewed approximately along the line 1--1 of FIG. 2.

FIG. 2 is a fragmentary horizontal sectional view of the container, taken substantially along line 2--2 of FIG. 1 with cap removed.

FIGS. 3 and 4 are fragmentary sectional views taken substantially along the lines 3--3 and 4--4, respectively, of FIG. 2.

FIG. 3A is a fragmentary horizontal sectional view taken substantially along line 3A--3A of FIG. 3.

FIG. 5 is a view similar to FIG. 1 with the tamper-evident band removed.

FIG. 6 is a fragmentary sectional view through the upper portion of a modified container with the closure applied thereto.

FIG. 7 is a vertical sectional view through the container of FIG. 6.

FIG. 8 is a sectional view taken substantially along the line 8--8 of FIG. 7.

FIG. 9 is an enlarged sectional view taken substantial along the line 9--9 of FIG. 8.

FIG. 10 is an enlarged sectional view through a portion of the lid of FIGS. 1 and 6.

FIG. 11 is a view similar to FIG. 2 of a modified container.

FIGS. 12 and 13 are fragmentary sectional views taken substantially along the lines 12--12 and 13--13, respectively with closure applied.

FIG. 14 is a fragmentary sectional view of a further modified lid.

FIG. 15 is a view similar to FIG. 1 of a modified container with closure applied.

Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.

Container 11 is a cup or tub used to package dairy products and the like and for other uses characterized by the fact that the walls of the container are relatively thin and are molded of a flexible plastic material such as polystyrene, polyethylene or polypropylene. The shape of the container 11 shown in FIGS. 1-5 is subject to considerable variation. As shown, container 11 has a bottom 12 and sidewalls 13 here shown as sloping outwardly-upwardly and terminating in a substantial horizontal top edge 14. A peripheral lip 16 is formed immediately below top edge 14 and said lip can be formed with serrations 17 separated by gaps 18. This geometry affords flexibility to the lip and also permits mold construction without slides. Further to this purpose, the outer surface 15 of sidewall 13 near the top is substantially vertical. Surrounding the lip 16 and spaced outwardly therefrom is a vertical tamper-evident band 21 having upper edge 22 and lower edge 23. In the embodiment of FIG. 1, the upper edge 22 is at a higher elevation than the top edge 14 and the lower edge 23 extends below the lip 16. On the inner surface of tamper-evident bands 21 at angularly-spaced intervals are pluralities of vertical internal ribs 41, here shown as two in number, which are in close proximity to the skirt 33 of lid 31 when the lid is applied to the container.

A relatively rigid, segmented, horizontal platform 43 extends outward from sidewalls 13 at a level such that its top surface is approximately at the level of the lower edge 23 of band 21. Platform 43 consists of segments 44 separated by gaps 46. As shown in FIG. 2, segments 44 are aligned with gaps 18 and gaps 46 with serrations 17. The lower ends of ribs 41 join the outer edges of platform segments 44 in bridges 24. A tear tab 26 is joined in at least one location to the lower edge of band 21. It will be understood that such tab may be joined to the upper edge of band 21. The user may grip tab 26 and pull upward, thereby sequentially breaking bridges 24 so that band 21 may be removed.

Lid 31 is the closure for container 11 and has top disk 32 which extends out beyond lip 16 and is formed with a vertical downward extending skirt 33 having its bottom edge above the bridges 24 as initially applied to the container. It will be noted that the top edge 22 of tamper-evident band 21 is about level with the upper surface of disk 32. Skirt 33 has an inward extending bead 37 at its bottom, said bead locking under serrations 17 of lip 16.

To assemble the lid 31 on the container 11, after the latter has been filled, the disk 32 is pressed downward. Bottom edge 34 fits between the band 21 and the lip 16 and downward pressure on the container causes sufficient deformation of lip 16 and skirt 33 so that the internal bead 37 slips down over lip 16 and locks thereunder, while the outside of skirt 33 is positioned in close proximity to the inside of the band 21.

As assembled, one cannot gain ready access to the lid 31 to remove it because it is closely surrounded and encased by the tamper-evident band 21. If one were to attempt to remove the lid 31 by excessive force, bridges 24 would be broken and evidence of tampering would be apparent. When it is necessary to open the container, the user pulls on the tab 26 causing the bridges 24 to break off and permitting the band 21 to be lifted away from the lid. After band 21 has been removed, the user may insert a thumb or finger in one of the gaps 46 in platform 43 and pull up on bottom edge 34 of lid 31 to remove the lid. For such purpose, gap 46 is sufficiently wide (e.g., 1/2 inch) so that a finger may be inserted.

FIGS. 6-9 illustrate a modification of the structure of FIGS. 1-5. For such purpose, the ribs 41 are eliminated and the platform 43 considerably modified. Thus, lower edge 23a of band 21a is joined to walls 13a by a plurality of angularly spaced apart, radial, frangible bridges 24a.

FIGS. 11, 12 and 13 illustrate a further modification of the structure previously described. The lid 31c shown as applied to the container in FIGS. 12 and 13 has a central depression 35 which serves two purposes. First, packages can be readily stacked by placing container bottom 12 into depression 35 of another container lid. Second, the depression forms an effective inner skirt 38 which can form a seal with the inner wall 39 of the container. The container shown in FIGS. 12 and 13 also has an inner lip 51 which promotes sealing contact with skirt 38. FIG. 14 shows a modified lid 31d having a flat top disk 32d with a depending inner skirt or plug 39 formed with a chamfer 40 on its lower edge.

Lip serration 17c is shown in FIG. 12 as being cored out, in core 50, similar to an inverted U. This structure allows the lip serration 17c to more easily flex during application of lid 31c, improves molding and saves material.

Rib 41c is attached to platform 43c through bridges 24c on the bottom side of platform 43c. With this arrangement, platform 43c need not be as pronounced. In addition, if one tries to remove the lid prior to removing the band, bridges 24c are in compression rather than tension and more effectively thwart the required upward movement. Finally, the design shown in FIG. 12 permits a snugger fit between skirt 33c and outer tamper evident band 21c.

FIG. 14 shows a modified cap 31d which may be used with container 11c. Top disk 32d has an inner skirt or plug 39 which may fit inside the inner wall 39c of container 11c shown in FIG. 13, making it unnecessary to depress central panel 31c of cap 35c shown in FIG. 13.

FIG. 15 illustrates the presently-preferred embodiment of the invention. Container 11e has side walls 13e terminating in an annular top edge 14e from which extends lip 16e. Short outer skirt 54 having terminal edge 56 depends from lip 16e. Tamper evident band 21e is spaced outward of skirt 54, the lower edge of band 21e having an inward extending shoulder 59, the inner edge of which is joined to terminal edge 56 by a plurality of radially-spaced, frangible bridges 24e which form a circumferential line of weakness to allow band 21e to be separated from container 11e on initial opening. Upward extending tear tab 26e may be gripped and pulled by the consumer to remove band 21e.

Lid 31e of FIG. 15 comprises a depressed central panel 52 having an upward extending peripheral inner skirt 53 having at its upper edge an outward extending annular ring 61 spanning top edge 14e and lip 16e and having a downward extending outer skirt 31e interposed between skirt 54 and band 21e and terminating above shoulder 59.

Inner skirt 53 has an external bead 55 which locks under bead 51e near the top of the inner wall 13e and skirt 33e has an internal bead 62 which locks under external bead 63 on skirt 54. These beads secure lid 31e to container 11e. The sloping surfaces of the beads enables the lid 31e to snap on by direct downward pressure, the members deforming sufficiently to permit capping without fracture.

Skirt 33e has an external bead 57 which locks under internal bead 58 of band 21e. So long as bridges 24e are intact, shoulder 59 prevents using the fingers to pry up the lower edge of skirt 33e and thus remove the lid 31e and, further, beads 57 and 58 also hold lid 31e from being removed. Any attempt to tamper with the contents of the container is made evident by fracture of some or all bridges 24e.

When band 21e is removed, the user may pry lid 31e off by applying the fingers to the lower edge of skirt 33e, the beads 62 and 63 and beads 51e and 55 being so shaped that such removal is facilitated. The beads interengage for reclosure when the lid 31e is re-applied by direct downward pressure.

In many respects the structures of FIGS. 6-10, 11-13, 14 and 15 resemble those of the preceding modifications and the same reference numerals followed by subscripts a, c, d and e, respectively, designate corresponding parts.

In the foregoing description and in the following claims the container and lid are described as circular, cylindrical, ring, etc. It will be understood, however, that oval, rectangular and other shapes may be used, and the terms used are to be thus interpreted.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.