Tamper Resistant End Closure for Containers

The present invention relates to end closures for containers and the like, and in particular to a tamper resistant end closure having a rotary top.

Various types of containers and closures have been developed for dispensing foods, condiments and similar products. One of the more popular closure designs from a convenience point of view is the rotary top closure having multiple openings, commonly used for dispensing granulated foods and flavorings.

A rotary top closure includes two major elements, a rotor and a base. The base is attached to an end of a cylindrical or rectangular container by any suitable means, such as by an adhesive or friction fit. The base comprises a web portion having one or more openings through which the contents of the container may be dispensed. Normally, to preserve freshness and provide an indication of product integrity, the dispensing openings are initially covered by a removable tab portion of the web, which can be pushed out by the consumer to open the container. The rotor also includes a web portion having one or more openings that may be aligned with the base openings when the rotor is manually rotated. The rotor may be pivotally attached to the base by a hub or stem that extends through a central opening in the base and forms a snap or friction fit between the base web and hub.

A removable base tab that has been pushed in will provide a visual indication that a container has been opened. However, with conventional containers there is often no readily perceivable indication that the base and rotor may have been pulled apart and separated. When the rotor is pulled off the base, the contents of the container may be adulterated through the central opening in the base web and the rotor reinstalled with no indication that the container was tampered with.

An object of the invention is to provide an improved rotary end closure for containers, which is both tamper resistant and convenient to use.

Another object is to provide such an end closure, that is rendered unusable in its normal operating manner when tampered with so as to contaminate the container contents.

A further object is to provide such an end closure, in which a rotor is mounted on a base in a manner to preclude removal of the rotor from the base without destruction of one or the other.

In accordance with the present invention, an improved end closure has a base and a rotor pivotally connected to the base by a hub of the rotor extending through an opening in the base. The base and rotor have webs with respective dispensing apertures therein, and a rotor dispensing aperture is alignable with a base dispensing aperture by pivotal movement of the rotor with respect to the base about the axis of the hub. The hub extends perpendicularly from the rotor web and has an axial passage therethrough and an annular flange therearound spaced from the rotor web, the annular flange has a diameter greater than that of the base opening and the hub, between the flange and rotor web, has a diameter less than that of the flange. The rotor is assembled on the base by extending the hub and its flange through the base opening, such that the hub and flange collapse radially inwardly into the hub passage as the flange is moved through the opening and then return radially outwardly as the flange moves out of the opening, whereby the flange secures the rotor to the base with the two in close, superposed relationship. The improvement is characterized by a plug extended into and substantially completely filling the hub passage of the assembled rotor and base combination, thereby to prevent radially inward collapse of the hub and flange into the hub passage upon any attempt to remove the rotor from the base. Advantageously, the rotor and plug are initially integral, such that an end of the plug is attached by a frangible web to the rotor web at an end of and in alignment with the passage through the hub. The frangible web is broken when the plug is extended into the hub passage.

The foregoing and other objects, advantages and features of the invention will become apparent upon a consideration of the following detailed description, when taken in conjunction with the accompanying drawings.

FIG. 1 is a perspective view of a container having a tamper resistant end closure according to the present invention;

FIG. 2 is a cross-sectional view of the center portion of the end closure, showing a hub of a rotor extended through a central opening of a base;

FIG. 3 is similar to FIG. 2, except that a plug is installed within a passage through the hub to prevent removal of the rotor from the base without damage to one or the other; and

FIG. 4 is similar to FIG. 2, except that the rotor and plug are initially integral and attached by a frangible web.

A container for granulated food products and condiments is shown in FIG. 1 and indicated generally at 20. The container is cylindrical in shape and has a wall portion 22, a bottom end cap 24 and a rotatable top end closure, indicated generally at 26, for dispensing the contents of the container. The closure includes a base 28 and a rotor, indicated generally at 30, pivotally attached to the base. The rotor is usually made of a plastic material, and the base of a plastic material or a light gauge deformable metal. The base has an outer annular skirt 32 that engages and is secured in a sealed manner with an upper outlet end of the container wall. The base is therefore in sealed engagement with the container to prevent leakage, spoilage or contamination of its contents.

Referring also to FIGS. 2 and 3, within the skirt 32 the base 28 includes a thin web membrane 34 extending over the upper dispensing end of the container wall 22. As is conventional, the web is provided with one or more dispensing means (not shown) through which contents of the container can be dispensed. The dispensing means comprise one or more pushout tabs (not shown), each defined by a perimeter that has a substantially reduced web thickness, so that each is easily breakable by manual force exerted thereon in a direction toward the interior of the container to establish one or more apertures in the web. The sizes and shapes of the apertures are a matter of choice, depending upon the particular dispensing arrangement required. The web also has a round opening 36 which is located centrally of the web and receives a portion of the rotor 30 for the purpose of assembling the rotor and base together, as will be described.

The rotor 30 is a disc-like member having a web portion 38 provided with one or more openings 40 that are alignable with the tabs or apertures formed in the base web 34 by pivotal movement or rotation of the rotor. The rotor is pivotally attached to and held in close, parallel, superposed relationship to the base by a circular hollow hub or stem 42, which as illustrated is coaxial with the center of the rotor. Rotation of the rotor about the longitudinal axis of the hub allows the apertures in the web of the base to either be open by alignment of the rotor openings with the base apertures, or closed by covering the base apertures with a solid portion of the rotor web, as is well known in the art.

The stem or hub 42 is integrally formed with the rotor web 38, it has a passage 44 of generally uniform diameter axially therethrough, and it extends through the opening 36 in the base web 34 with a slight radial clearance when the rotor 30 and base 28 are in assembled, superposed configuration. An annular flange 46 is formed on the free end of the stem, and provides a shoulder 48 that retainably engages the underside of the base web about the periphery of the opening. The flange defines the major diameter of the stem, and has a diameter slightly larger than that of the opening, so that upon assembly of the rotor to the base by pushing the stem through the opening, the flange and stem body collapse radially inwardly into the stem passage as the flange passes through the opening and then expand radially outwardly as the flange exits the passage to lock the stem to the base. A snap fit arrangement between the rotor and base is therefore achieved while still allowing the rotor to pivot about the axis of the stem, with the stem then retaining the rotor and base in close, superposed relationship.

To the extend described, the design of the end closure 26 is generally conventional, and while the absence of any tabs on the base web 34 having been pushed down to establish apertures provides some assurance to the end user that the contents have not been tampered with, it is nevertheless possible with the conventional design to pull the rotor 30 apart from the base 28 to gain access to the container contents through the base center opening 36. After the contents have been adulterated, the rotor could then be reinstalled onto the base and the unit would appear and operate as normal.

Accordingly, to prevent removal of the rotor 30 from the base 28 without rendering the end closure 26 nonfunctional, the invention contemplates, as seen in FIG. 3, that after the rotor stem 42 is pushed through the base opening 36 to establish a snap fit between the rotor and base, a cylindrical plug 50 be pressed into and secured within the stem passage 44. For a snug press fit, the plug advantageously has a diameter slightly greater than that of the stem passage, and may be bonded within the passage to prevent its removal. The plug completely fills the space into which the stem and flange collapsed as the flange was pressed into and through the base opening 36, without significantly expanding the stem and flange radially outwardly, and prevents any subsequent collapse of the stem and flange into the passage space if an attempt is made to pull the rotor from the base to gain access to the container contents through the base opening. Should pulling pressure increase beyond the strength of the stem and/or base material, the stem will tear off of the rotor, the base material will tear and/or the base will be deformed, rendering the end closure non-functional and providing a visual indication that the container contents may have been tampered with.

The rotor 30 and cylindrical plug 50 may initially be formed as separate parts. However, to facilitate handling of the same and insertion of the plug into the passage 44 of the rotor stem 42, the rotor and plug are advantageously initially fabricated as an integral component. To that end, and as seen in FIG. 4, in their initial integral form a lower end of the cylindrical plug 50 is attached by a frangible web 52 to the rotor web 38 around an upper end of the stem passage 44, such that the plug is coaxial and aligned with the passage. A centrally located circular recess 54 is in the lower end of the plug, and the plug has a diameter slightly greater than that of the stem passage. The frangible web holds the plug in alignment for being pressed into the stem passage after the stem is extended through the center opening 36 in the base 28. With the stem extended through the base opening and the lower part of the stem supported, sufficient pressure is applied to the top of the plug to break or fracture the frangible web and move the plug into press fit relationship in the stem passage, with the circular recess 54 providing a relieved area to facilitate initial movement of the plug into the passage. The plug then fills the passage space into which the stem and flange 46 collapsed as the same were pressed into and through the base opening, and prevents any radially inwardly movement of the stem and flange if an attempt is made to pull the rotor from the base to gain access to the container contents through the base opening.

While embodiments of the invention have been described in detail, various modifications and other embodiments thereof may be devised by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims.