US20050252878A1

US20050252878A1 - Tamper-evident package

Info

Publication number: US20050252878A1
Application number: US10/837,766
Authority: US
Inventors: David Babcock
Original assignee: Alcoa Closure Systems International Inc
Current assignee: Closure Systems International Inc
Priority date: 2004-05-03
Filing date: 2004-05-03
Publication date: 2005-11-17

Abstract

An improved tamper-evident package includes a plastic closure having a top wall portion, a depending annular skirt portion, and a tamper band at least partially detachably connected to the skirt portion. The package includes a container having a neck portion configured for tamper-indicating cooperation with the projections on the tamper band. The container includes a plurality of circumferentially spaced ratchet-like locking teeth, each of which presents a locking surface for interfering engagement with the respective one of the projections on the closure tamper band. Notably, disposition of the flexible projections of the pilfer band in pre-determined relationship to an internal thread formation of the closure permits the flexible projections to be positioned so that each of the locking teeth on the container is engaged by a respective one of the flexible projections attendant to very little relative rotation of the closure relative to the container during removal.

Description

TECHNICAL FIELD

The present invention relates generally to tamper-evident packaging for products, and more particularly to a tamper-evident package comprising a container and cooperating closure which are configured for efficient manufacture, and which functions to provide readily visually discernable evidence of opening attendant to very limited opening movement of the closure of the package.

BACKGROUND OF THE INVENTION

Tamper-evident packaging is in very widespread use by virtue of the assurance it provides consumers that the contents of the package are fresh and unadulterated. While it is known to provide packages with tamper-evident overwraps, heat-shrinkable films, and the like, such arrangements can complicate high-speed processing, and undesirably add to the cost of packaging.
In view of this, packaging arrangements have been developed, particularly closures for containers, which include a tamper-evident feature as part of the closure structure. By way of example, U.S. Pat. No. 4,418,828, No. 4,497,765, and No. 5,205,426, all hereby incorporated by reference, illustrate tamper-evident plastic closure constructions which have met with widespread acceptance in the marketplace by virtue of their reliable function and economical manufacture.
For some packaging applications, it is desirable to provide a container closure having a so-called “multi-start” thread formation, which includes plural helical thread elements which cooperate with like elements on the container to effect closure retention and sealing. Such arrangements permit closure application and removal with relatively little rotation of the closure with respect to the associated container.
For such applications, it is necessary that any tamper-indicating arrangement function attendant to very little relative rotation of a closure with respect to the associated container, since complete closure removal is effected by little relative rotation. To this end, U.S. Pat. No. 6,557,714, hereby incorporated by reference, discloses a tamper-evident package including a container and closure having cooperating multi-start thread formations, with the tamper-evident arrangement of the package functioning to provide tamper-indication, typically attendant to no more than about 15° of rotation of the closure during removal.
In this previous construction, tamper-indication for the package is achieved by the provision of a plurality of ratchet-like locking teeth on the package container, with the associated closure including a tamper band having a plurality of flexible projections configured for cooperative engagement with the container locking teeth. In order to assure rapid tamper-indication during closure removal, the flexible projections of the closure tamper band are closely spaced together. In the event that one or more of the flexible projections is not positioned for locking engagement with a respective container locking tooth after closure application, very limited relative rotation is required during closure removal to present a successive one of the flexible projections for locking engagement with the container locking tooth.
The present invention is directed to an improved form of the tamper-evident package of the above-referenced U.S. Pat. No. 6,557,714, wherein tamper-indication is provided attendant to very little relative rotation of the package closure, preferably prior to unsealing of the container by the closure during removal.

SUMMARY OF THE INVENTION

A tamper-indicating package embodying the principles of the present invention includes a cooperating plastic closure and container, wherein the container has been particularly configured to provide tamper-indicating cooperation with the closure. The closure includes a tamper band having a plurality of circumferentially spaced, inwardly extending flexible projections which cooperate with a plurality of circumferentially spaced, ratchet-like locking teeth on the container to provide tamper-indication during opening of the package.
Notably, the flexible projections of the closure are positioned in a pre-determined relationship to the associated closure thread formation, with the flexible projections sufficiently spaced apart to permit at least one of the container locking teeth to be positioned between adjacent ones of the flexible projections when the closure is fully applied to the container. By this arrangement, preferably each one of the container locking teeth is engaged by a respective one of the flexible projections during closure removal, attendant to as little as 5° of relative rotation, or less, thereby desirably providing very rapid tamper-indication during closure removal. Such rapid tamper-indication can desirably be provided prior to unsealing of the container during closure removal, even when the package includes multi-start thread formations which permit complete closure removal with very little relative rotation.
In accordance with the illustrated embodiment, the container of the present tamper-evident package has a neck portion defining an opening, with the container having an external thread formation on the neck portion. The thread formation includes at least one helical thread element, with the presently preferred configuration comprising a plurality of thread elements, sometimes referred to as “multi-start” threads, to permit the package to be opened by very little relative rotation of the associated closure. It is within the purview of the present invention that other closure retention arrangements can be employed, such as cooperating single-thread formations, or cooperating lug-type thread elements on the container and associated closure.
In accordance with the illustrated embodiment, the container of the package includes a plurality of circumferentially spaced locking teeth positioned on the neck portion of the container beneath the thread formation. Each of the locking teeth has a generally ratchet tooth-like configuration, and includes a locking surface, and a generally outwardly tapering guide surface, opposite the locking surface, extending from the neck portion generally toward the locking surface. In the preferred embodiment, the locking surface of each locking tooth is generally radially and vertically oriented.
Notably, the locking teeth are unevenly spaced about the neck portion of the container, with the spacing corresponding to the spacing between the flexible projections on the closure pilfer band, or multiples thereof. In accordance with the illustrated embodiment, the locking teeth are provided in first and second groups positioned in diametrically opposed relationship on the neck portion of the container, with the locking teeth of each of the groups evenly circumferentially spaced apart. To facilitate locking cooperation with the flexible projections of the associated closure, the container includes an annular shoulder positioned adjacent to and above the locking teeth, and beneath the external thread formation on the container. The locking teeth are at least partially positioned beneath the annular shoulder, and preferably are positioned substantially completely beneath the annular shoulder.
The closure of the present tamper-evident package is configured for fitment to the neck portion of the container for closing the opening therein. The closure include a top wall portion, and a depending annular skirt portion having an internal thread formation for mating engagement with the external thread formation on the neck portion of the container. Again, the closure preferably includes a multi-start thread formation, including plural helical thread elements, to promote convenient and efficient application and removal of the closure.
The closure of the present package is configured for tamper-indicating cooperation with the container by the provision of a tamper band depending from and at least partially detachably connected to the skirt portion of the closure by a frangible connection. As desired, the pilfer band may be configured for complete detachment from the skirt portion of the closure, or partial detachment, whereby the tamper band remains joined to the skirt portion attendant to closure removal.
The tamper band of the closure includes an annular band portion, and a plurality of inwardly extending flexible projections, each movable about a respective hinge portion joined to the annular band portion. In the preferred form, the hinge portion of each projection is relatively thin, thus promoting high-speed application of the closure to the container with minimal resistance from the tamper band, while still permitting the flexible projections to be configured to exhibit the desired rigidity for lockingly engaging the container locking teeth, and fracturing the frangible connection between the pilfer band and the closure skirt.
At least one of the projections of the tamper band is engageable with at least one of the locking teeth on the container, during removal of the closure from the container, for fracturing the frangible connection to provide visual evidence of opening of the package. Notably, the flexible projections of the tamper band are positioned in predetermined circumferential relationship with respect to the internal thread formation of the closure. By such an arrangement, the position of the flexible projections, relative to the container locking teeth when the closure is fully applied, can be very effectively predetermined. As a consequence, the present package permits each one of the container locking teeth to be engaged by a respective one of the flexible projections during closure removal, thus permitting very rapid tamper-indication during closure removal. To effect such one-to-one locking engagement, the flexible projections are spaced apart by a distance at least as great as the circumferential dimension of each of the locking teeth, that is, the flexible projections are circumferentially spaced sufficiently so as to receive one of the container locking teeth between adjacent ones of the flexible projections when the closure is fully applied to the container.
In order to promote closely fitting relationship between the container locking teeth and the flexible projections of the closure for rapid tamper-indication during removal, the flexible projections of the closure are preferably inwardly tapering.
Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, respective view of a tamper-evident package embodying the principles of the present invention, including a cooperating plastic closure and associated container:
FIG. 2 is a cross-sectional view of the closure of the present package illustrated in FIG. 1;
FIG. 3 is a fragmentary, side elevational view of a neck portion of the container of the present package illustrated in FIG. 1;
FIG. 4 is a plan view of the interior of the closure of the present package illustrated in FIG. 1;
FIG. 5 is a cross-sectional view of the neck portion of the container of the present package, taken along lines 5-5 of FIG. 3; and
FIG. 6 is a diagrammatic view illustrating the present package, and the cooperative fitment of the closure and container of the package.

DETAILED DESCRIPTION

While the present invention is susceptible of embodiment in various forms, there is shown in the drawings, and will hereinafter be described, a presently preferred embodiment, 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 specific embodiment illustrated.
With reference to FIG. 1, therein is illustrated a tamper-evident package 10 embodying the principles of the present invention. As will be further described, package 10 includes a cooperating closure 12 and container 14 (partially illustrated in phantom line) which can be configured for economical use for beverages or like contents. It can be particularly desirable to configure the package 12 for convenient opening and removal of closure 12, with relatively little rotation of the closure relative to the container 14 when it is desired to provide a tamper-evident function prior to unsealing of the associated container. Thus, as will be further described, the tamper-evident feature of the present package is particularly configured to promote tamper-indication attendant to very little rotation of the closure relative to the container.
With particular reference to FIGS. 2 and 4, therein is illustrated closure 12 of the present tamper-evident package. Closure 12 is preferably molded from suitable polymeric material (typically polypropylene), and may be efficiently injection-molded, or compression-molded, such as in accordance with the teachings of U.S. Pat. No. 4,497,765, hereby incorporated by reference.
As illustrated, closure 12 includes a circular top wall portion 16, and a depending annular skirt portion 18. Skirt portion 18 includes an internal thread formation which, in the preferred form, comprises a plurality of generally helical thread elements 20, with the thread formation thus configured as a so-called multi-start thread. This arrangement facilitates application and removal of the closure to and from the associated container with a relatively small degree of rotation of the closure relative to the container.
To provide the desired sealing cooperation between the closure 12 and container 14, the closure includes a generally disc-shaped sealing liner 22 positioned on the inside surface of the top wall portion 16. The sealing liner 22 cooperates with the associated container 14 to form a so-called “top/inside” seal (sometimes referred to as a top/corner seal), that is, the sealing liner 22 engages the generally upwardly and inwardly facing surfaces of the finish of the container 14 (see FIG. 6). Notably, the type of sealing arrangement may be configured to have a so-called “seal length” which maintains the seal between the closure 12 and the container 14 until the tamper-evident feature of the package, as will be described below, fractures. Thus, the sealed condition of the container is maintained until and after tamper-evidence is provided, further acting to preclude undetected tampering.
In a current embodiment, sealing liner 22 has been configured to provide 0.020 inches of sealing compression, with the tamper-indicating arrangement of the present package configured to provide tamper-indication, by virtue of the corresponding thread pitch, of the multi-start thread formation, attendant to less than about 5° of relative rotation of the closure 12 and the container 14.
To provide the desired tamper-indication for the package 10, closure 12 includes a tamper band 26 at least partially detachably connected to the skirt portion 18 of the closure. The tamper band 26 includes an annular band portion 28, and a plurality of circumferentially spaced, inwardly extending tab-like flexible projections 30. Each projection 30 is joined to band portion 28 by a respective, relatively thin hinge portion (see FIG. 6) which promotes ease of application of the closure to the associated container, while still affording the desired surface-to-surface contact for locking, interfering engagement between the projections and the locking teeth (as will be described) on the container 12.
The desired detachable connection of the pilfer band 26 to the closure skirt 18 is provided by way of a frangible connection therebetween, illustrated in phantom line at 32. Frangible connection 32 can be formed during molding of the closure, or can alternatively be formed by continuous or discontinuous scoring of the closure, as is known in the art. In a current embodiment, it is contemplated that the tamper band 26 completely separate from the skirt portion 18 during closure removal, with the tamper band remaining in place on the associated container 12. However, it is within the purview of the present invention that the tamper band may be configured for partial detachment from the skirt portion 18, such as by the provision of a relatively strong connector portion between the tamper band 26 and the skirt portion 18.
With particular reference to FIGS. 3 and 5, therein is illustrated the container 14 of the present tamper-evident package. The container 14 includes a neck portion defining an opening, with the closure 12 being configured for fitment to the neck portion for closing the opening defined thereby. In order to permit rapid application and removal of the closure, the neck portion of the container 14 includes an external thread formation thereon, with the thread formation on the container configured for mating engagement with the internal thread formation of the closure 12. To this end, the thread formation of the container includes a plurality of helical thread elements 40 for respective cooperative engagement with the thread element 20 of the closure 12. In the illustrated embodiment, two of the cooperating thread elements are provided on the closure of the container. However, the present package may be configured with a single helical thread element. The present package may alternatively be provided with cooperating lug-type thread elements on the container 12 and closure 14.
In accordance with the present invention, the container 14 includes a plurality of circumferentially spaced locking teeth 42 provided on the neck portion of the container. The locking teeth 42 are configured to cooperate with the projections 30 on the closure 12 during closure removal by interferingly engaging the projections. By this cooperative engagement, the frangible connection 32 between the tamper-band 26 and the skirt portion 18 of the closure 12 is fractured, thus providing clear visual evidence that the package has been opened.
As illustrated, the neck portion of the container 14 includes an annular shoulder 44 positioned generally above the locking teeth, and below the external thread elements on the container. Locking teeth 42 are at least partially positioned beneath shoulder 44, but it is desired that the ratchet teeth 42 be of sufficient size to provide the desired locking engagement with flexible projections 30. In the illustrated embodiment, the locking teeth 42 define a circle having a diameter substantially equal to the diameter of shoulder 44, but the teeth may be enlarged to provide enhanced engagement with projections 30.
The shoulder 44 desirably acts to confine the projections 30 of the closure tamper band in a position for the desired interfering engagement with the locking teeth 42. Additionally, the outwardly tapering configuration of the upper annular shoulder 44 desirably acts to guide and upwardly flex the projections 30 during closure application. During closure application, the projections 30 are in a generally horizontal disposition, as illustrated in phantom line in FIG. 6. After closure application, the projections 30 extend generally upwardly and inwardly for engagement with the locking teeth 44, as further illustrated in FIG. 6.
Handling of the container of the preset package by automated packaging equipment is facilitated by the provision of support ring 44 positioned on the neck portion of the container generally beneath the locking teeth 42.
In accordance with the preferred form, each of the locking teeth 42 includes a generally radially and vertically oriented locking surface positioned for engagement with a respective one of the projections 30 of the closure 12. Each of the locking teeth further includes a ramp-like outwardly tapering guide surface which extends generally outwardly from the neck portion of the container, generally opposite the locking surface 48. The guide surface is oriented such that during rotational application of the closure to the container (by right-hand rotation in accordance with the illustrated embodiment), the projections 30 of the closure tamper band are guided by the guide surfaces and urged generally outwardly over the locking teeth. As each of the projections passes one or more of the locking teeth, the resilience of the projections acts to return the projections to a generally inwardly, upwardly extending orientation.
As illustrated in FIG. 5, it will be observed that the locking teeth 42 are unevenly circumferentially spaced about the neck portion of the container 14, with the spacing between the teeth corresponding to the spacing between projections 30, or multiples thereof. This assures substantially simultaneous engagement of a plurality of the projections 30 with a like plurality of the locking teeth during closure removal. FIG. 5 illustrates a mold parting line defined by the neck portion of the container 14, which corresponds to the line or plane along which the mold for the neck portion opens. As illustrated, the closure 14 includes a pair of locking teeth 42 having their respective locking surfaces aligned with the parting line.
As will be observed, the locking teeth 42 are arranged in first and second diametrically opposed groups on the neck portion of the container, with the locking teeth 42 of each group being evenly circumferentially spaced.
In a current embodiment, the locking teeth 42 of each of the first and second groups are circumferentially spaced apart at 30° intervals, as illustrated in FIG. 5.
As noted above, the tamper-evident package of the present invention has been particularly configured to promote very rapid tamper-indication attendant to removal of closure 12 from container 14. To this end, the flexible projections 30 of the pilfer band 26 of closure 12 are positioned in predetermined circumferential relationship with respect to the internal thread formation, including thread elements 20, of the closure. This is achieved during closure molding by fixing the relative position of the mold which forms the projections 30 (sometimes referred to as the tab sleeve) relative to the portion of the mold which forms the thread elements 20 (sometimes referred to as the core pin).
By virtue of this predetermined relationship, the position of the flexible projections 30 relative to locking teeth 42, after the closure is fully applied to the container, can be very precisely predetermined. In view of this, the present invention contemplates that the circumferential spacing “c” between adjacent ones of the flexible projections 30 (FIG. 4), is at least as great as the circumferential dimension of each of the locking teeth 42, that is, the spacing between adjacent ones of the flexible projections 30 is sufficiently great as to permit one of the locking teeth 42 to be received between adjacent ones of the projections 30. On balance, the spacing between the projections 30 is preferably selected to closely correspond to the spacing between the ratchet teeth 42 of each of the first and second groups of ratchet teeth to thereby position a plurality of the projections 30 for locking engagement with a respective plurality of the ratchet teeth 42 to provide a high level of resistance to relative rotation to thereby assure tamper band fracture.
By this arrangement, the flexible projections 30 and the locking teeth 42 can be fitted in very closely spaced cooperating engagement when the closure 12 is fully applied to the container 14. To further facilitate such closely spaced fitting, while still maximizing the dimension of the projections 30 for the desired degree of rigidity, each of the flexible projections 30 is preferably inwardly tapering. As shown in FIG. 4, in a current embodiment, each of the projections 30 at its relatively thin hinge portion has a dimension “b”, which is greater than a dimension “a” at an inner edge portion of each projection 30. In a current embodiment, dimension “a” is 0.180 inches, while dimension “b” is 0.200 inches.
By virtue of the closely-spaced relationship of the flexible projections 30 and locking teeth 42 after the closure is fully applied to the container, the frangible connection of the closure is broken before no more than about 5°, or less, of rotation of the closure relative to the container during removal fo the closure. By virtue of this desirably fast-acting tamper-indication function, fracture of the closure is very desirably effected prior to unsealing of the container by disengagement of sealing liner 22 from the container finish. Highly effective resistance to tampering is thus provided.
From the foregoing, it will be observed that numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiment illustrated herein is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.

Claims

1. A tamper-evident package, comprising:

a container having a neck portion defining an opening, said container having an external thread formation on said neck portion, said thread formation including at least one helical thread element,

said container further including a plurality of circumferentially spaced locking teeth positioned on said neck portion beneath said thread formation, and

a closure configured for fitment to the neck portion of said container for closing said opening, said closure including a top wall portion and a depending annular skirt portion having an internal thread formation for mating engagement with the external thread formation on said neck portion of said container,

said closure including a tamper band depending from and at least partially detachably connected to said skirt portion by a frangible connection, said tamper band including an annular band portion, and a plurality of inwardly extending flexible projections each movable about a respective horizontal hinge portion joined to said annular band portion, at least one of said projections being engageable with at least one of said locking teeth on said container during removal of said closure from said container for fracturing said frangible connection to provide visual evidence of opening of said package,

said locking teeth being unevenly circumferentially spaced about the neck portion of said container, with said flexible projections being spaced apart by a distance at least as great as the circumferential dimension of each of said locking teeth.

2. A tamper-evident package in accordance with claim 1, wherein:

said flexible projections of said tamper band are positioned in predetermined circumferential relationship with respect to said internal thread formation.

3. A tamper-evident package in accordance with claim 1, wherein:

said locking teeth include first and second groups of said locking teeth positioned in diametrically opposed relationship.

4. A tamper-evident package in accordance with claim 3, wherein:

the locking teeth of each of said first and second groups are evenly circumferentially spaced apart.

5. A tamper-evident package in accordance with claim 1, wherein:

said container includes annular shoulder positioned adjacent to and above said locking teeth and beneath said external thread formation.

6. A tamper-evident package in accordance with claim 1, wherein:

said flexible projections are inwardly tapering.

7. A tamper-evident package in accordance with claim 1, wherein:

each of said locking teeth includes a generally radially oriented locking surface for engagement by one of said projections of said closure, and a generally outwardly tapering guide surface opposite said locking surface extending from said neck portion to said locking surface.

8. A tamper-evident package in accordance with claim 1, wherein:

the spacing between said locking teeth corresponds to the spacing between said projections, or multiples thereof.

9. A tamper-evident package in accordance with claim 1, wherein:

said hinge portion of each of said projections of said closure is relatively thin.

10. A tamper-evident package in accordance with claim 1, wherein:

said external thread formation includes a plurality of helical thread elements.

11. A tamper-evident package, comprising:

said locking teeth being unevenly circumferentially spaced about the neck portion, including first and second groups of locking teeth positioned in diametrically opposed relationship, with the locking teeth of each of said first and second groups being evenly circumferentially spaced apart,

said flexible projections of said tamper band being positioned in predetermined circumferential relationship with respect to said internal thread formation, so that when said closure is applied to said container, one of said projections is positioned between each adjacent pair of said locking teeth of said first group and between each adjacent pair of said locking teeth of said second group.

12. A tamper-evident package in accordance with claim 11, wherein:

when said closure is applied to said container, each of said locking teeth is engageable by a respective one of said projections.

13. A tamper-evident package in accordance with claim 1 1, wherein:

said frangible connection of said closure is broken during removal of said closure from said container before said closure unseals said opening of said container.

14. A tamper-evident package in accordance with claim 13, wherein:

said frangible connection is broken before no more than about 5 degrees of rotation of said closure relative to said container during removal of said closure.

15. A tamper-evident package in accordance with claim 11, wherein:

said flexible projections are spaced apart by a distance at least as great as the circumferential dimension of each of said locking teeth.

16. A tamper-evident package in accordance with claim 11, wherein:

said container includes an annular shoulder positioned adjacent to and above said locking teeth and beneath said external thread formation.

17. A tamper-evident package in accordance with claim 11, wherein:

said flexible projections are inwardly tapering.