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Coated lift-tab for resealing pop-top containers

Coated lift-tab for resealing pop-top containers description/claims

This application claims the benefit of provisional patent application 60/952,168 filed by Hall and Taylor on Jul. 26, 2007, incorporated herein by reference.

1. Field of the Invention

The present invention relates to resealable containers, particularly re-closable seals for pop-top aluminum cans.

2. Description of the Prior Art

The term “lift-tab” is used herein to refer to that family of finger-operated lever components used to prize open an access hole in pop-top-type containers and that remain attached to the container after the container is opened. “Lift-tab” includes, by way of example, finger-tabs, pop-top tabs, pull-tabs, and the like, as are well known opening devices used for soda cans, beer cans, juice cans, and the like. Such lift-tab based pop-top cans have been a commercial success for a number of years. Their primary advantage is that they obviate the need for a separate can opener, or “church key,” in order to open a beverage can and they reduce unsightly pop-top litter because the lift-tab is permanently connected to the container.

FIG. 1 shows a typical prior art lift-tab as used in a pop-top beverage container, namely a can 101 having a generally planar top 201 that has an upper surface surrounded by and contiguous with a rim 401. An access hole, generally oval, in the top is defined by an edge. While the beverage container is closed, the access hole is occluded by a sealing plate 301 that is connected to the edge by an inscribed break-line 1001, thereby providing a frangible waterproof seal. A lift-tab 501 is connected to the top by means of a connector 901, normally a simple rivet. The lift-tab has a finger-end 701 and a swivel-end 801. Near the finger-end of the lift-tab is normally a finger aperture 601.

A ventral surface of the lift-tab is defined as the lower or bottom surface of the lift-tab when the lift-tab is pressed down against the top of the container as shown in FIG. 1. In other words, the ventral surface of the lift-tab is the surface facing the upper surface of the top of the container when the lift-tab is in the closed position prior to opening the container.

The swivel-end 801 of the lift-tab the lift-tab is rotatably connected to the top 201 by a connector 901, allowing the lift-tab to rotate 360 degrees about the rivet. In addition to a pivot point, the rivet-connection also provides a fulcrum whereby raising the finger-end 701 forces the swivel-end 801 to move downward against the sealing plate 301, prizing the sealing plate loose from the top.

But for a hinge just under the aforesaid fulcrum, the access hole is circumscribed by the inscribed break-line. Because the swivel-end 801 of the lift-tab extends beyond the fulcrum, when the finger-end 701 of the lift-tab is lifted, the swivel-end is forced downward against the sealing plate, which, in turn, is pushed downward by means of the upward finger pressure on the finger-end, augmented by the mechanical advantage gained by the fulcrum, thereby forcing break-line 1001 to shear, whereby the access hole opens as the sealing plate is pushed into the container. The lift-tab is then conveniently pressed back down flat against the top of the container, leaving the access hole open and unobstructed so that the contents of the container can be poured out or accessed either by drinking directly from the access hole or by inserting a drinking straw into the access hole.

Currently existing pop-top containers, such as described above, are not resealable. Once the sealing plate is pushed into the interior of the can the sealing plate cannot be accessed to be pulled back into it's original position. This detracts significantly from the usefulness of such cans.

U.S. Pat. No. 4,681,238 to Sanchez is an example of attempts to provide resealable pop-top devices. Sanchez provides two sealing plates, both of which are attached to the under-surface of the top, in the interior of the can. In the un-opened configuration, a first sealing plate is disposed against the access hole from underneath the top. The sealing plate has a pliable layer on its upper, or dorsal, surface that provides a watertight seal. When the can is opened, this first sealing plate is pushed downwards in the same manner described above. In order to reseal the can, the lift-tab is twisted and a second internal sealing plate is rotated into position under the access hole. This second sealing plate also has a resilient layer that seals the hole from below. This approach to providing a resealable beverage container has never attained widespread use. The device, particularly the rivet connection, is complex and difficult to produce and requires significant re-tooling by the manufacturer. Furthermore, it is difficult to position the internal second sealing plate accurately under the access hole in order to make a watertight seal.

What is needed is a resealable pop-top container that is simple and effective in its use, inexpensive to produce without the need of re-tooling or extensive design modifications of the existing art.

The invention is a resealable beverage container comprising an improved pop-top opening device of the type that is operated by pulling a lift-tab attached by one end to a fulcrum, thereby forcing a sealing plate to shear and bend downwards from the top to expose an access hole in the top of the container, the access hole being defined by an edge. The improvement comprises modifying the lift-tab by depositing or annealing a pliable pull-tab coat to at least the ventral surface of the finger-end of the lift-tab such that the coated lift-tab can be used to repeatedly to reseal the access hole Resealing the container is accomplished by rotating or swivelling the lift-tab so that the pliable pull-tab coat is adjacent the open access hole and then pressing the pull-tab down against the top of the container, wherein the pliable material on the ventral side of the pull-tab engages the edges of the opening to form a watertight seal. In order to unseal the resealed container, the coated portion of the lift-tab is lifted away from the access hole and rotated or swivelled out of the way, preferably back to its original position opposite the access hole. The preferred material of the pliable seal is medical-grade vinyl. The coated pull-tab optionally includes a straw-orifice with an orifice-closure comprising frangible break-lines that can be forced open to accommodate a drinking straw when the pull-tab is sealing the access hole.

The invention also comprises an improved lift-tab of the type used in pop-top beverage containers, the lift-tab having a finger-end, a swivel-end, and a ventral surface in which a pull-tab coat of resilient material is deposited on or annealed to the ventral surface of the finger-end.

The invention also comprises a resealable beverage container comprising: a top having an upper surface; an access hole in the top for accessing the contents of the container, the access hole defined by an edge; a rotatable swivel connector; a sealing plate connected to a substantial portion of the edge by a frangible break-line when the container is closed; and a pull-tab attached to the upper surface of the top by means of the swivel connector. The pull-tab comprises a ventral surface; a finger-end; a swivel-end opposite the finger-end, and a pull-tab coat comprising a resilient material deposited on or annealed to the ventral surface of the finger-end of the pull-tab. The rotatable connector connects the swivel-end of the pull tab to the upper surface of the top such that the pull-tab coat on the ventral surface of the finger-end of the pull-tab can be aligned over the access hole by rotating the pull-tab about the connector.

The invention also comprises a method of producing a resealable pop-top beverage container comprising the steps of depositing on or annealing a resilient pull-tab coat to the ventral surface of a pull-tab; attaching the pull-tab to the upper surface of the top by means of a rotatable connection between the pull-tab swivel-end and the top wherein the rotatable connection acts as a fulcrum whereby by raising the finger-end of the pull tab shears the connection between the sealing plate and the edge of the access hole and the sealing plate is forced into the lumen of the container, and wherein the pull-tab is rotatable about the rotation connection and configured such that the pull-tab coat on the ventral side of the pull-tab can be juxtaposed against the access hole for sealing the hole.

The method of producing the coated lift-tabs comprises the steps of treating vinyl or other material used to produce the seal with a standard aluminum to vinyl adhesive promoter, placing a lift-tab in a mold, injecting the vinyl or other material into the mold, placing the mold in an oven, baking the vinyl sufficiently long and at a sufficient temperature to cause the vinyl or other suitable material to become a resilient, solid state rubber, and removing the coated lift-tab from the mold.

• Provisional Patent
• Utility Patent

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