Receptacles – Closures – Superposed closures for common opening
Reexamination Certificate
2000-05-15
2001-03-27
Newhouse, Nathan J. (Department: 3727)
Receptacles
Closures
Superposed closures for common opening
C220S278000, C220S906000, C222S541800, C222S083500, C413S015000, C413S022000, C413S023000
Reexamination Certificate
active
06206222
ABSTRACT:
TECHNICAL FIELD
This invention pertains to the field of easy-open devices for beverage cans. These devices, when actuated by the consumer, provide an opening through the can end or lid for pouring and drinking.
BACKGROUND ART
Approximately 100 billion thin-walled metal beverage cans are sold annually in the United States alone. Nearly all of these beverage cans have a stay-on-tab type closure according to my U.S. Pat. Nos. 3,967,752 and 3,967,753, which issued on Jul. 6, 1976. These closures are part of a can end or lid which is double seamed to the can body in a conventional manner with conventional equipment in a beverage filling line.
The stay-on-tab end has a number of attributes which have enabled it to remain the industry standard for over 20 years. These attributes include (a) the ability to be manufactured by commercially available machines; (b) low material and manufacturing costs; (c) low rates of defective ends produced by the end manufacturing lines; (d) nestability for ease and economy in handling the shells (blanks) and ends in the manufacturing lines, shipping them, and handling them in the beverage filling lines; (e) ease and speed of filling the can with the beverage and then seaming the end onto the can, again at low cost; (f) reliable containment and protection of the beverage during shipping, distribution, display, and handling and use by the consumer, with respect to carbonated as well as non-carbonated contents; (g) ease of opening by consumers of widely varying finger sizes, strengths, and dexterity; (h) consumer safety; (i) reliability of opening by consumers; (j) pourability; (k) drinkability; and (l) recyclability, in terms of both the value of its constituent material and the cost of recovering it.
The attribute most lacking in stay-on-tab ends is resealability.
Numerous attempts have been made to provide resealable threaded closures for beverage cans. Some of these merely sought to replicate, in the metal can and end, the structure of the neck and closure of a bottle neck and cap. Others employed more ingenious, and sometimes complex, solutions. Examples of such solutions and concepts used for other containers may be found in Henderson U.S. Pat. No. 2,771,218, Meissner U.S. Pat. No. 3,339,812, Salamone U.S. Pat. No. 3,401,819, Dubreul U.S. Pat. No. 5,292,025, and French patent 1,048,219.
Such solutions, including the simple as well as the complex, have not been commercially successful for at least two reasons. First, they have failed to match one or more of the attributes of the stay-on-tab closures listed above. Low cost is probably the criterion which is most frequently not satisfied. It is safe to say that if cost were no object, all of the remaining criteria could be satisfied. Second, these solutions have failed to equal or surpass conventional PET bottles and caps, which, though not possessing all the attributes of a can with a stay-on-tab closure, possess many of them and nevertheless have resulted in an excellent package for beverages.
DISCLOSURE OF THE INVENTION
The object of the present invention is to provide an easy-open closure for thin-walled metal beverage cans which has the attribute of resealability, as well as attributes of stay-on-tab ends to a degree which is consistent with the commercial needs of the beverage industry.
The present invention provides an assembly for closing and sealing a thin-walled metal can containing a beverage. The assembly may be quickly and easily opened by the consumer, provides a spout for pouring and drinking the beverage, and is conveniently resealable by the consumer. The assembly consists of three parts—a metal end and two threaded closure elements.
The end, which has been cut and formed from sheet metal, has a weakened line, for example a score line. The weakened line defines a hinge and a tear panel which can be pivoted downward about the hinge.
One threaded element is a stationary spout element which is attached to the end so as to surround the tear panel. The other threaded element is a rotatable cap element which has a bottom bearing surface immediately above and aligned with the periphery of the tear panel. Sealing surfaces on the respective closure elements face each other and are designed to engage each other for resealing, but are spaced apart initially.
When the consumer rotates the cap element clockwise, it is driven downward by the threads so that its bottom bearing surface ruptures the weakened line at a location distant from the hinge. Continued rotation causes the rupture to propagate along and around the weakened line in two directions toward the hinge. As this is occurring the cap element's bottom bearing surface is also forcing the tear panel to pivot downward about the hinge, until eventually the tear panel has been swung down and out of the way of the opening it has left.
The consumer rotates the cap element in the counter-clockwise direction to remove it from the spout element in the usual manner, and pours or drinks the beverage through the opening in the end and the spout. The consumer may reseal the closure by replacing it on the spout element and rotating it clockwise in the usual manner, past the position which pivoted the tear panel down, until the reseal surfaces engage and form a pressure seal.
Preferably the spout element has internal threads, the cap element has external threads, and the cap element has a skirt which surrounds the spout. The skirt may have knurled gripping surfaces and a tamper-evidencing feature. The spout element and the cap element may be molded from thermoplastic materials of different hardnesses.
To provide for an easy and reliable initial rupture, the tear panel may have configured into it a reinforcing structure to increase its rigidity at the place where the initial rupture is to occur and to concentrate the rupturing forces there. To provide for gradual, controlled, and reliable propagations of the rupture, the initial distance between the bottom bearing surface of the cap element and the surface of the periphery of the tear panel directly below it should vary inversely as a function of distance from the hinge.
The stationary and rotatable closure elements may be attached to the end either before or after the end is seamed onto the can in a beverage filling line. Attaching them in a separate operation after seaming permits the use of conventional equipment in the filling line, as well as in the end manufacturing plant.
REFERENCES:
patent: 3339812 (1967-09-01), Meissner
patent: 4911323 (1990-03-01), Arfert et al.
patent: 5292025 (1994-03-01), Dubreul
patent: 5348182 (1994-09-01), Luch et al.
patent: 1442319 (1966-09-01), None
patent: 531817 (1955-08-01), None
Ball Corporation
Newhouse Nathan J.
Sheridan & Ross P.C.
LandOfFree
Resealable closure on seamed can end does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Resealable closure on seamed can end, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Resealable closure on seamed can end will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2465823