GB1580571A

GB1580571A - Container with sealed tamper indicating pull tabs

Info

Publication number: GB1580571A
Application number: GB1709077A
Authority: GB
Original assignee: Owens Illinois Inc
Current assignee: OI Glass Inc
Priority date: 1976-04-26
Filing date: 1977-04-25
Publication date: 1980-12-03
Also published as: JPS52130773A; CA1105883A; NZ183760A; AU515438B2; JPS5723630B2; AU2444477A

Description

(54) CONTAINER WITH SEALED TAMPER-INDICATING PULL TABS (71) We, OWENS-ILLINolS INC., a Corporation organised under the laws of the State of Ohio, of Toledo, Ohio, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a container having an opening, or mouth, covered with a flexible sheet of material, and an outer closure lid disposed above the flexible sheet.

Such containers are generally used in the food packaging industry and embody various sizes, shapes and forms for packaging various food products, particularly of the flowable type.

Cottage cheese, butter, yogurt and similar food-stuffs are commonly packaged and marketed in a container that is generally wax-coated or wax-impregnated paper or plastic. The container has a receptacle portion, consisting of a base and upwardly extending sidewall, an outer closure lid which is pressed onto the sidewall top peripheral opening, or mouth, as snugly as possible so as to minimize the entry of air or the escape of food-stuff from the closed container, and an underlying flexible sheet closure.Outer closure lids for such containers are either the plain disc-like lids which engage a peripherally extending head located below the mouth rim on the container on the interior surface of the sidewalls, or so-called flush-type lids which fit across the opening of the container and have a depending skirt for snap-on engagement with an exterior portion of a beaded rim of the container, or socalled plug-type lids which project into the interior of the container adjacent the inner surface of the upwardly extending sidewall and engage the sidewall opening in snap-on relation.

Conventionally, with containers of this type, it is relatively easy for the consumer, or other person, to remove the outer lid as well as the underlying flexible sheet closure. Because of the relative ease with which the flexible sheet closure and the outer closure lid may be removed from the top of the container, innocent, or wilful and malicious tampering with the container's internal contents is possible. After removing the outer lid closure, a potential consumer may lift up a portion of the flexible sheet closure from engagement with the top of the container. With such containers, it is possible to determine if the flexible sheet closure has been loosened from the top of the container, but only by lifting the outer closure lid from the container and performing a close inspection.

In known containers which include a flexible sheet inner closure underneath the lid, such as those disclosed in U.S. Patent Nos. 3,301,464; 3,338,027 and 3,471,992, a thin film or sheet of flexible material is disposed across the opening of the top of the container and is in contact with, and supported by, the top peripheral surfaces of the rim of the container. With those containers employing plug-type lids, the plugtype lid presents a substantially vertical and peripherally-extending wall area, which will lie adjacent to the interior surface of the container sidewall immediately below the top edge of the rim of the container when the lid is placed thereon. This verticallv disposed peripheral wall area of the plug-type lid will engage a portion of the flexible sheet film and press it against the interior surface of the sidewall of the container.In some conventional containers, the flexible sheet closure is heat-sealed to the portion of the container sidewall adjacent the vertical and peripherally-extending wall area of the plug-type lid. In other containers, the flexible sheet closure material may be heat-sealed across the upper surface of the rim of the container. Further, instead of heat-sealing, adhesive means can be employed.

While such double-seal containers have functioned generally satisfactorily, several problems have been encountered, both in manufacture and in ultimate use. With respect to manufacturing, in accordance with known techniques, it is necessary to cut the sheet closure to a relatively precise size and shape corresponding to the size and shape of the container lid and the mouth of the container. And, it is necessary to maintain the sheet in relatively precise registry with the lid and to secure the sheet to the lid prior to insertion of the lid into the mouth of the container. The strength of the attachment between the lid and sheet must be accurately controlled to prevent the lid from tearing the sheet when the lid is removed, as for example, to check the tamper-proof integrity of the container.And since the sheet does conform in size and shape to the lid and mouth of the container, there are no readily graspable tabs to facilitate removal of the sheet when it is desired to get access to the contents of the container.

Owing to the possibility and ease of opening of the flexible sheet closure, as a result of inadvertent shipping and handling activities or as a result of innocent potential consumer curiosity or malicious tampering, it is desirable to be able to determine more easily if the flexible sheet closure has been opened. Further, it is desirable that a tamper-indicating construction be employed with such flexible sheet closures that will allow the closure to be used with many types of lids and containers now in use. Advantageously, such a tamper-indicating construction of a flexible sheet closure should be effective regardless of the manner of engagement of the closure with the upper rim of the container.That is, the tamperindicating flexible sheet closure construction should be effective regardless of whether or not the flexible sheet closure is heatsealed or adhesively secured to the top rim of the container or just non-sealingly supported thereon. Further, it is desirable that the tamper-indicating construction of the flexible sheet closure not require visual inspection through complicated, relatively more expensive, transparent windows in the outer closure lid -when such outer closure lid is used. The tamper-indicating flexible sheet closure construction should also work with -a large variety of different types of flexible sheet materials that may be used.

According to the present invention there is provided a - container, tamper-indicating closure - sheet and lid combination,- comprising a container having a base; a sidewall extending upwardly from the periphery of said base and defining a circular open top; a quadrilateral sheet of flexible material disposed across the said open top and supported by the top edge of said sidewall, the length of each side of said sheet being equal to or greater than the diameter of the rim about the open top of said container, the said sheet having a portion of each corner projecting downward along said sidewall, each said portion being releasably secured to the external surface of said sidewall; and a disc-shaped lid removably disposed over the said sheet, but not attached to said sheet, the said portion of the sheet extending below the lid.

The container comprises a base with a sidewall extending upwardly from the periphery of the base and defining a substantially circular open top, or mouth. In the preferred embodiment, the base and mouth of the container are circular and the sidewall is frusto-conical. The mouth is preferably defined by an outwardly rolled beaded rim. Disposed across the rim is a quadrilateral, suitably square-shaped, sheet of flexible, film-like material wherein the length of each side of the sheet is at least equal to the outer diameter of the container rim. With some types of closures, such as the plug-type, the length of each side of the sheet closure material must be somewhat greater than the outer diameter of the container rim as will be explained hereinafter.The tamper-indicating closure sheet is placed across the container rim so that it covers all points on the container rim and so that the corners of the sheet project beyond the outer periphery of the rim.

In the preferred embodiment, the tamperindicating closure sheet is a thick plastics film which is waxcoated on at least one surface. The wax-coating is heat-sensitive and adapted for being heat-sealed to the side exterior surface of the sidewall of the container. In the preferred embodiment, an outer closure lid of the plug-type is engaged with the rim and upper portion of the container sidewall. The closure sheet is pressed between, and engaged by, the container rim on one surface of the sheet and by the outer closure lid on the other surface of the sheet. The corners of the closure sheet project outwardly and downwardly from the periphery of the outer closure lid and extend alongside the exterior surface of the sidewall of the container where they are preferably secured by heat-seal affixation.

In the container of the present invention, the outer closure lid is not secured to the tamper-indicating closure sheet.

The method and apparatus for associating the closure sheet with the lid, and for assembling the associated closure sheet and lid onto a filled receptacle is disclosed in detail in our copending application Serial No. 17091/77 (1 580 572) entitled "Method and Apparatus for Applying a Lid and Tamper-Indicating Sheet to a Container", and one embodiment of the method and apparatus for sealing the tabs to the container sidewall is disclosed in detail in our copending application Serial No.

17092/77 (1 580 573) entitled "Method and Apparatus for Sealing Tamper-Indicating Tabs to a Container Sidewall", the disclosures of both of said applications being incorporated herein in their entirety by this reference. Thus, the outer closure lid can be relatively easily removed without tearing or pulling away the flexible closure sheet.

If the outer closure is removed wholly or partially from the container, the container contents are still protected by the tamperindicating closure sheet disposed across the container opening beneath the outer closure lid.

To gain access to the interior content of the container, it is required to remove, at least partially, the tamper-indicating closure sheet. The common method of removing the tamper-indicating closure sheet would be to grasp one of the corners that is sealed to the exterior surface of the container sidewall and to pry it away, or pull it away, from the sidewall by breaking the seal and then lifting up the closure sheet by pulling the corner further upwards above the top of the container. After this has been done, and the tamper-indicating closure sheet is subsequently lowered onto the rim of the container and the outer closure lid is subsequently engaged about the rim of the container over the closure sheet, then the loosened corner of the tamper-indicating closure sheet will not be sealed to the exterior wall of the container.This provides visual indication that the container has been opened. Note that the visual indication of tampering is thus determinable without removing the outer closure lid and without requiring the use of transparent window, or such device, in the outer closure lid.

In the preferred embodiment of the invention, the container sidewall is circular in cross-section and larger in diameter at the upper end than at the lower end. Most preferably, the container is frusto-conically shaped. And, in such preferred embodiments, it is desired that the lids be of the plugtype described above, so that the dished, or recessed, central portion of the lid will serve to seat and retain the lower portion of a container stacked thereon for display in a retail establishment, such as a supermarket.

Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and of one embodiment thereof, from the claims, and from the accompanying drawings in which each and every detail is fully and completely disclosed as part of the specification.

In the accompanying drawings forming part of the specification, and in which like numerals are used to designate like parts throughout the same, FIG. 1 is a perspective view of a filled and sealed container of this invention; FIG. 2 is an exploded perspective view of the container of FIG. 1; FIG. 3 is an enlarged cross-section view of the container taken along plane 3-3 of FJG. 1; and FIG. 4 is an enlarged fragmentary sectional view taken along plane 44 of FIG. 1.

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings, and will herein be described in detail, a preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention is defined by the appended claims.

Referring first to FIG. 1 of the drawings, the container in accordance with the invention is generally indicated by reference numeral 20. As shown in FIG. 2, the container is comprised of three major elements: a lower receptacle portion 22, a flexible quadrilaterally-shaped closure sheet 24 disposed across a mouth of the container receptacle portion 22, and an outer closure means in the form of lid 26. The container of the present invention is similar to the containers described and claimed in the above-mentioned U.S. Patent to Amberg et al., No. 3,301,464, which is assigned to the assignee of the present invention, and reference may be made to that patent for background information relating to containers of the so-called "double-seal" type.

In the container of the present invention, the receptacle portion 22 is preferably made of wax-coated paper, although it will be understood that the receptacle portion might also be made of other materials. As illustrated in FIG. 3 of the drawings, the receptacle portion 22 is basically frustoconically shaped and includes a circular base 24 depending downwardly from, and supporting, bottom portion 26. Sidewall 28 extends upwardly from the base 24 and defines an open top or mouth. The receptacle portion 22 is shown in FIG. 3 as containing a food-stuff such as a flowable liquid, generally indicated by reference numeral 29.

In the upper portion of sidewall 28 near the top edge of the sidewall 28 is a peripherally extending and outwardly projecting bead 30. Since bead 30 has a cross section that is curved with respect to the straight cross section of sidewall 28, more sidewall material is present per unit height of the sidewall in a shape that gives that portion of the sidewall a greater section modulus thereby strengthening the sidewall against buckling and/or bending. Bead 30 may also function to receive a projecting, mating, lid-locking bead from a plug-type lid (not shown) that could be used in place of the preferred lid 26 illustrated and described herein. Depending on the type of lid used and depending upon the thickness of sidewall 28 and upon the height of the container 20, bead 30 may be omitted.

Extending upwardly and outwardly flared, or conically tapered, from bead 30 is wall 32 which serves to guide and seat lid 26 in place on the container 20. The mouth of the receptacle portion 22 is defined by a conventional outwardly rolled beaded rim 34. Rim 34 provides additional rigidity and strengthens the sidewall 28 against buckling and bending. Rim 34 also serves as a support for flexible closure sheet 24 and lid 26.

In the preferred embodiment, lid 26 is of the plug-type and is of one-piece construction. Lid 26 is generally disc-shaped and has an annular channel which opens downwardly about the periphery of the lid for receiving the rim 34 of the container 20.

The annular channel is designated generally by reference numeral 36 in FIG. 4. The annular channel 36 has three walls: an outer depending peripheral skirt 38, a flat top wall 40, and a slanting inner wall 42.

Extending from and below slanting inner wall 42 in a substantially vertical orientation is vertical wall 44. Inner wall 42 is outwardly flared or conically tapered to join top wall 40 with vertical inner wall 44.

A flexible closure sheet 24 is disposed across the mouth of receptacle portion 22 and contacts beaded rim 34 at all points on the periphery of the rim 34. Closure sheet 24 is generally centered over the mouth of the container and preferably has a square shape with the length of the sides of the square being slightly greater than the outer diameter of the rim. With the opening of the container completely covered by closure sheet 24, the lid 26, when in place on the container, engages the sheet 24 against the beaded rim 34 along the entire periphery of the mouth of the container. To this end, the inner mating surfaces of the walls 38, 40 and 42 of the annular channel 34 press against the upper surface of flexible closure sheet 24 and urge the sheet 24 into conformable contact engagement with container rim 34 and container wall 32.

As illustrated in FIG. 1, corners 50 of closure sheet 24 project from below lid 26 and extend downwardly adjacent sidewall 28. Each of the four corners thus forms a tamper-indicating pull tab, which may be conveniently manually grasped and pulled when it is desired to remove sheet 24 and obtain access to the contents of the container. The corners, or tabs 50, are secured to the sidewall 28 by any attachment means that permits the tabs to be peeled away from sidewall 28 and not become reattached. In the preferred embodiment, the corners or tabs 50 of the flexible sheet 24 are heat-securable, as by a heat-sealable wax coating, to the sidewall 28. In any case, the tabs 50 are each secured to the sidewall by suitable means, another possibility being to coat them with a pressure-sensitive adhesive. To open the container 20, it is necessary to first remove lid 26.Following removal of lid 26, one or more of the four tabs 50 must be removed from the secured engagement with the sidewall 28. Generally, this would be accomplished by a person putting the edge of a fingernail along the edge of a tab and prying the tab away from secured engagement with the sidewall 28. When enough of the tab 50 has been pried away, the pried away portion can be grasped between the thumb and index finger and pulled away from the sidewall 28 in an upward direction to pull the remaining portion of the tab 50 completely away from sidewall 28. By continued pulling on one of the tabs 50, the entire flexible closure sheet 24 can be lifted off of the container.

Should one of the tabs 50 tear while it is being pulled, three other tabs are available for pulling.

In accordance with one significant feature of this invention, flexible closure sheet 24 is completely unattached or unsecured to lid 26. That is, in contrast to standard "double-seal" type containers, there is no adhesive or heat-sealable bond between the under surface of lid 26 and flexible closure sheet 24. Preferably, closure sheet 24 ins coated on the one side facing away from the lid 26 with heat-securable coating. The heat-securable coating serves two purposes: (1) closure sheet 24 can be heat-secured to the wall 32 of the inner surface of sidewall 28 and (2) the corners or tabs 50 can be heat-secured to the exterior surface of sidewall 28. Depending on the materials used in the construction of the sidewall and/or upon the coating thereon, and the type of heat-securable coating on the flexible closure sheet 24, the heat-secured attachment of the closure sheet 24 to the container may or may not be gas-tight or liquid-tight. The flexible closure sheet 24 need not be sealed at all to the wall 32 of the upper portion of the container sidewall 28. However, the corners or tabs 50 must be secured to the exterior surface of the sidewall 28 to function as tamper-indicating tabs as contemplated in this invention.

The flexible closure sheet can be made of a variety of materials, such as Cellophane (trade mark), plastics film, foil, or paper. The sheet can be transparent, translucent, or opaque, and can be adapted for receiving printed matter. Further, the flexible sheet 24 may be comprised of two or more laminated layers of different materials. While a wide variety of materials are contemplated for the closure sheet and container (as well as coatings thereon) it is important that the combination of materials and/or coatings have one characteristic, i.e., the ability to be secured to one another only once, and not resealable, so that once a tab has been lifted it cannot thereafter be reattached to the container sidewall.The flexible closure sheet 24 of this invention is qualrilateral, preferably square, for ease of fabrication from rolls of sheet material whereby a quadrilateral or square sheet can be formed by simply making parallel cuts in the length of sheet material as it is pulled from a bulk roll.

Th container with a tamper-indicating closure sheet of this invention thus provides a novel but simple means for determining if the container has been opened.

it has been shown that it is very easy to determine if a container has been opened by merely observing the state of highly visible flexible sheet corners or tabs. The outer closure lid need not be removed from the container. Further, no complex and relatively expensive, window-type lid need be provided.

The container of the present invention may be formed by apparatus of the type disclosed in the above-mentioned applications. While it is contemplated that any apparatus for applying heat and/or pressure (depending on the nature of the material) to the tabs may be satisfactory to secure them to the container sidewall, the apparatus described in our above-mentioned application No. 17092/77 (Serial No. 1580573) has functioned well and is briefly summarized herebelow. The container is received at the first station with the corners or tabs of the flexible sheet unsecured to the sidewall of the container.

At this first station, the projecting corners or tabs of the flexible sheet are pushed downward adjacent the sidewall of the container. In addition, the flexible sheet is heat-sealed to the inner periphery of the top of the container by a known closure sealing procedure. By appropriate conveyor means, the containers are then moved to a second and last station wherein the tabs are heated and then pressed against the container sidewall between a heated rail and a rotating belt which serves to cool the tabs to form a heat-sealed attachment.

WHAT WE CLAIM IS: - 1. A container, tamper-indicating closure sheet and lid combination, comprising a container having a base; a sidewall extending upwardly from the periphery of said base and defining a circular open top; a quadrilateral sheet of flexible material disposed across the said open top and supported by the top edge of said sidewall, the length of each side of said sheet being equal to or greater than the diameter of the rim about the open top of said container, the said sheet having a portion of each corner projecting downwards along said sidewall, each said portion being releasably secured to the external surface of said sidewall; and a disc-shaped lid removably disposed over the said sheet, but not attached to said sheet, the said portions of the sheet extending below the lid.

2. A container, tamper-indicating closure sheet and lid combination as set forth in claim 1 wherein the said sidewall has a frusto-conical shape.

3. A container, tamper-indicating closure sheet and lid combination as set forth in claim 1 or 2 wherein the top edge of said sidewall is rolled over upon itself to form an outwardly rolled, beaded rim.

4. A container, tamper-indicated closure sheet and lid combination as set forth in claim 1 wherein said lid is of the plug type engaging a portion of said sheet against the interior surface of said sidewall, and having a recessed central portion suitable for seating a similar container therein.

5. A container, tamper-indicating closure sheet and lid combination as set forth in claim 4 wherein said lid has an annular channel opening downwardly about the periphery of said lid for receiving said sheet and the top edge of said sidewall.

6. A container, tamper-indicating closure sheet and lid combination as set forth in claim 1 wherein said lid has a downwardly extending skirt embracing the upper end of said sidewall, the said portions of the corners of said sheet extending below the lower edge of said skirt.

7. A container, tamper-indicating closure sheet and lid combination as set forth in any of claims 1 to 6 wherein said sheet has on the side thereof facing the container sidewall a heat sealable substance compatible with the container material.

8. A container, tamper-indicating closure sheet and lid combination as set forth in any of claims 1 to 7 wherein said sheet

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. to the wall 32 of the upper portion of the container sidewall 28. However, the corners or tabs 50 must be secured to the exterior surface of the sidewall 28 to function as tamper-indicating tabs as contemplated in this invention. The flexible closure sheet can be made of a variety of materials, such as Cellophane (trade mark), plastics film, foil, or paper. The sheet can be transparent, translucent, or opaque, and can be adapted for receiving printed matter. Further, the flexible sheet 24 may be comprised of two or more laminated layers of different materials. While a wide variety of materials are contemplated for the closure sheet and container (as well as coatings thereon) it is important that the combination of materials and/or coatings have one characteristic, i.e., the ability to be secured to one another only once, and not resealable, so that once a tab has been lifted it cannot thereafter be reattached to the container sidewall.The flexible closure sheet 24 of this invention is qualrilateral, preferably square, for ease of fabrication from rolls of sheet material whereby a quadrilateral or square sheet can be formed by simply making parallel cuts in the length of sheet material as it is pulled from a bulk roll. Th container with a tamper-indicating closure sheet of this invention thus provides a novel but simple means for determining if the container has been opened. it has been shown that it is very easy to determine if a container has been opened by merely observing the state of highly visible flexible sheet corners or tabs. The outer closure lid need not be removed from the container. Further, no complex and relatively expensive, window-type lid need be provided. The container of the present invention may be formed by apparatus of the type disclosed in the above-mentioned applications. While it is contemplated that any apparatus for applying heat and/or pressure (depending on the nature of the material) to the tabs may be satisfactory to secure them to the container sidewall, the apparatus described in our above-mentioned application No. 17092/77 (Serial No. 1580573) has functioned well and is briefly summarized herebelow. The container is received at the first station with the corners or tabs of the flexible sheet unsecured to the sidewall of the container. At this first station, the projecting corners or tabs of the flexible sheet are pushed downward adjacent the sidewall of the container. In addition, the flexible sheet is heat-sealed to the inner periphery of the top of the container by a known closure sealing procedure. By appropriate conveyor means, the containers are then moved to a second and last station wherein the tabs are heated and then pressed against the container sidewall between a heated rail and a rotating belt which serves to cool the tabs to form a heat-sealed attachment. WHAT WE CLAIM IS: -

1. A container, tamper-indicating closure sheet and lid combination, comprising a container having a base; a sidewall extending upwardly from the periphery of said base and defining a circular open top; a quadrilateral sheet of flexible material disposed across the said open top and supported by the top edge of said sidewall, the length of each side of said sheet being equal to or greater than the diameter of the rim about the open top of said container, the said sheet having a portion of each corner projecting downwards along said sidewall, each said portion being releasably secured to the external surface of said sidewall; and a disc-shaped lid removably disposed over the said sheet, but not attached to said sheet, the said portions of the sheet extending below the lid.

comprises a laminate of two or more different materials.

9. A container, tamper-indicating clossure sheet and lid combination as set forth in any of claims 1 to 8 wherein said sheet is a plastic film.

10. A container, tamper-indicating closure sheet and lid combination as set forth in claim 7, wherein said sidewall and side of said sheet facing said sidewall are waxcoated.

11. A container, tamper-indicating closure sheet and lid combination as set forth in any of claims 1 to 10 wherein the said portions of the corners of said sheet on the side facing the external surface of said sidewall have thereupon a pressure sensitive adhesive which adheres to said sidewall.

12. A container tamper-indicating closure sheet and lid combination as claimed in claim 1, substantially as hereinbefore described with reference to the drawings.