Patent Application
20090020543
The present invention generally relates to containers and container end closures, and more specifically metallic beverage container end closures adapted for interconnection to a beverage can body.
Containers and more specifically metallic beverage containers are typically manufactured by interconnecting a beverage can end closure on a beverage container body. In some applications, an end closure may be interconnected on both a top side and a bottom side of a can body. More frequently, however, a beverage can end closure is interconnected on a top end of a beverage can body which is drawn and ironed from a flat sheet of blank material such as aluminum. Due to the potentially high internal pressures generated by carbonated beverages, both the beverage can body and the beverage can end closure are typically required to sustain internal pressures exceeding 90 psi without catastrophic and permanent deformation. Further, depending on various environmental conditions such as heat, over fill, high CO2 content, and vibration, the internal pressure in a typical beverage can may at times exceed 100 psi.
Thus, beverage can bodies and end closures must be durable to withstand high internal pressures, yet manufactured with extremely thin and durable materials such as aluminum to decrease the overall cost of the manufacturing process and the weight of the finished product. Accordingly, there exists a significant need for a durable beverage container end closure which can withstand the high internal pressures created by carbonated beverages, and the external forces applied during shipping, yet which is made from durable, lightweight and extremely thin metallic materials with geometric configurations which reduce material requirements. Previous attempts have been made to provide beverage container end closures with unique geometric configurations to provide material savings and improve strength, and a commonly used 202 B-64 end closure is shown in
Other inventions known in the art have attempted to improve the strength of container end closures and save material costs by improving the geometry of the countersink region. Examples of these patents are U.S. Pat. No. 5,685,189 and U.S. Pat. No. 6,460,723 to Nguyen et al, which are incorporated herein in their entirety by reference. Another pending application which discloses other improved end closure geometry is disclosed in pending U.S. patent application Ser. No. 10/340,535, which was filed on Jan. 10, 2003 and is further incorporated herein in its entirety by reference.
The following disclosure describes an improved container end closure which is adapted for interconnection to a container body and which has an improved countersink, chuck wall geometry, and unit depth which significantly saves material costs, yet can withstand significant internal pressures.
Thus, in one aspect of the present invention, a container end closure is provided which can withstand significant internal pressures approaching 100 psi, yet saves between 3% and 10% of the material costs associated with manufacturing a typical beverage can end closure. Although the invention described herein generally applies to beverage containers and beverage end closures used to contain beer, soda and other carbonated beverages, it should be appreciated by one skilled in the art that the invention may also be used for any variety of applications which require the use of a container and interconnected container end closure. In one embodiment of the present invention, these attributes are achieved by providing a chuck wall with a substantially concave “arch”, and a predetermined “transition zone” or strengthening bead which is positioned between the arch and the countersink, and which has a prominent and defined angle and length.
In another aspect of the present invention, a container end closure is provided which is manufactured with conventional manufacturing equipment and thus generally eliminates the need for expensive new equipment required to make the beverage can container end closure. Thus, existing and well known manufacturing equipment and processes can be implemented to quickly and effectively initiate the production of an improved beverage can container end closure in an existing manufacturing facility, i.e., can plant.
It is another aspect of the present invention to provide an end closure with an arcuate, non-linear shaped chuck wall, and which may include at least two distinct radius of curvatures. In one embodiment, a portion of the lowermost chuck wall is positioned above the upper chuck wall which has a different radius of curvature. As used in the prior art, the term “chuck wall” generally refers to the portion of the end closure located between the countersink and the circular end wall (or peripheral curl or flange that forms the double seam with the can body) and which is contacted by or engaged with the chuck during seaming, as shown in FIG. 7 of the Crown '634 patent. Unlike the prior art, the seaming chuck used in seaming the end closures of the present invention does not necessarily contact or engage with the entire chuck wall during the forming operation. Rather, to avoid scuffing the end closure, a portion of the chuck wall may not be contacted by the chuck drive surface during double seaming of the end closure to the neck of the container body, but rather only a selected portion of the chuck wall is engaged with the chuck during rotation and the double seaming process.
In another aspect of the present invention, a beverage can end closure is provided with a countersink having an inner panel wall with a distinct non-linear, outwardly oriented radius of curvature of between about 0.025 inches and 0.080 inches. As referred to herein, the term “outwardly” refers to a direction oriented generally toward the container neck or sidewalls, while “inwardly” generally refers to a direction away from the container neck or sidewalls. Preferably, the curved portion of the inner panel wall is positioned just below the point of interconnection with the central panel, and has been shown to improve the strength of the end closure.
It is another aspect of the present invention to provide a beverage can end closure which saves material costs by reducing the size of the blank material and/or utilizing thinner materials which have improved aluminum alloy properties. Thus, the integrity and strength of the beverage can end closure is not compromised, while material costs are significantly reduced as a result of the blank reduction, and/or improved aluminum alloy properties provided therein.
It is a further aspect of the present invention to provide a beverage can container end closure with an upper chuck wall having a first radius of curvature “Rc1” and a lower chuck wall having a second radius of curvature “Rc2”. In another aspect of the present invention, a “transition zone” maybe positioned in either the upper chuck wall portion, the lower chuck wall portion, or substantially therebetween. The transition zone is generally a chuck wall portion with a “kink” or distinctive change in a radius of curvature over a very specified and generally very short portion of the chuck wall, and typically with a length no greater than about 0.005 to 0.010 inches, and preferably about 0.008 inches.
Alternatively, the upper and lower chuck wall maybe substantially “curvilinear,” and thus have such a moderate degree of curvature that it almost resembles a straight line, i.e., linear. Further, the unit depth between an uppermost portion of a circular end wall and a lowermost portion of the countersink has a dimension in one embodiment of between about 0.215 and 0.280 inches, and more preferably about 0.250-0.260 inches. Further, in one aspect of the present invention, the inner panel wall may additionally have a non-linear radius of curvature, which is preferably about 0.025-0.080 inches, and more preferably about 0.050 inches.
It is yet a further aspect of the present invention to reduce the distance between the inner and outer panel walls of the countersink, and to thus save material costs while additionally improving the strength of the end closure. Thus, in one embodiment of the present invention the distance between the inner and outer panel walls is between about 0.045 inches and 0.055 inches, and more preferably about 0.052 inches.
It is yet another aspect of the present invention to provide an end closure with a chuck wall with superior strength when compared to a conventional container end closure, and which can withstand significant internal pressure. Thus, in one embodiment of the present invention an end closure is provided with a chuck wall having an outwardly projecting concave arch, and which in one embodiment is positioned approximately mid-way between the countersink and the circular end wall prior to double seaming the can end to a container body. Preferably, the chuck wall arch has a radius of curvature between about 0.015 inches and 0.080, and more preferably less than about 0.040 inches, and must be preferably about 0.0180-0.025 inches. In one embodiment, the upper chuck wall and lower chuck wall may be substantially linear, or have only a gradual radius of curvature, and may include one or more transition zones positioned therebetween.
Thus, in one aspect of the present invention, a metallic container end closure adapted for interconnection to a container body is provided, and comprises:
a circular end wall adapted for interconnection to a side wall of the container body;
a chuck wall integrally interconnected to said circular end wall and extending downwardly at an angle θ as measured from a vertical plane, said chuck wall further comprising an outwardly extending arch having a radius of curvature of between about 0.015 and 0.080 inches with a center point positioned below said circular end wall;
a countersink interconnected to a lower portion of said chuck wall and having a radius of curvature of less than about 0.020 inches;
a transition zone positioned between a lower portion of said outwardly extending arch and said countersink having a length of at least about 0.0090 inches and an angle distinct from said chuck wall or said countersink.
an inner panel wall interconnected to said countersink and extending upwardly at an angle φ of between about 0 degrees and 15 degrees as measured from a substantially vertical plane; and
a central panel interconnected to an upper end of said inner panel wall and raised above a lowermost portion of said countersink.
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The end closures provided herein in the drawings are generally drawn and ironed from a substantial planar piece of metal, commonly aluminum, and formed into the distinct shapes with the geometry shown herein. As appreciated by one skilled in the art, the presses and dies used to form these end closures are commonly known in the art and generally provide support on various portions of an outer surface and inner surface of the end closure to create a preferred geometry. In some embodiments a “free forming” method of double seaming may be employed as disclosed in pending U.S. patent application Ser. No. 11/192,978, which is incorporated herein in its entirety by reference.
The geometry and performance data for each of the end closures provided in
For clarity, the following list of components and associated numbering found in the drawings are provided herein:
The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commenced here with the above teachings and the skill or knowledge of the relevant art are within the scope in the present invention. The embodiments described herein above are further extended to explain best modes known for practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments or various modifications required by the particular applications or uses of present invention. It is intended that the dependent claims be construed to include all possible embodiments to the extent permitted by the prior art.
This application is a Divisional of pending U.S. patent application Ser. No. 11/235,827, filed Sep. 26, 2005, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/613,988, filed Sep. 27, 2004, the entire disclosures of which being incorporated herein.
| Number | Date | Country | |
|---|---|---|---|
| 60613988 | Sep 2004 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11235827 | Sep 2005 | US |
| Child | 12240481 | US |
