Patent Application
20130220964
This disclosure relates to metal beverage containers, and more particularly, but not by way of limitation, to finish portions of metal beverage containers.
A bottle shaped metal beverage container may include an opening at one end sealed by a closure element, such as a cap. A bottle cap is typically installed by machinery and, in certain examples, twisted or pressed onto the beverage container. This twisting or pressing operation generally causes a certain amount of force for the cap to be properly seated. This force may result in axial loading of the beverage container and damage to the beverage container. To reduce material and transportation costs, beverage containers having configurations that reduce material consumption and weight while retaining the ability to withstand applied loads are desirable.
To minimize or prevent damaging a beverage container due to axial forces, compressive forces, and other forces being applied during a capping process, for example, the following disclosure provides for incorporating an arc structure that is outwardly convex below a lip area of the beverage container. The arc may be shaped based on a wall thickness of the beverage container, material of the beverage container, amount of force or load to be applied, and possibly other factors. The shape of the arc may vary in radius, the radius setting an angle at a transition section below the lip at the top of the beverage container, if shaped as a bottle.
More particularly, a finish portion of a metal beverage container includes a lip portion and a threaded portion. The finish portion also includes a transition section. The transition section may include an outwardly convex portion connecting the lip and threaded portions. The lip portion may define a sealing surface that seals against a closure element. The threaded portion may engage threads of the closure element. The outwardly convex portion may have a thickness between approximately 0.125 millimeters and approximately 0.75 millimeters. The outwardly convex portion may have a radius of curvature between approximately 1.0 millimeter and approximately 6.0 millimeters. The outwardly convex portion may have an arc length between approximately 1.0 millimeter and approximately 5.0 millimeters. The transition section may comprise aluminum, steel, or alloys thereof. The outwardly convex portion may be shaped such that the transition section can bear an axial load between approximately 100 Newtons and approximately 3000 Newtons, depending on the style and configuration of beverage container and manufacturing process, without plastically deforming. Other dimensions of the thickness, radius of curvature, and arc length are also contemplated and may vary depending on the materials, manufacturing process, or otherwise.
A metal beverage container includes a body portion, a neck portion connected with the body portion, and a finish portion connected with the neck portion. The finish portion includes a lip portion defining a sealing surface that seals against a closure element (e.g., cap), a transition section, and a threaded portion that engages threads of the closure element. The transition section may include an outwardly convex portion connecting the lip and threaded portions. The finish portion may comprise aluminum, steel, or alloys thereof. The finish portion may have a maximum diameter between 20 millimeters and 42 millimeters. The outwardly convex portion may be shaped such that the transition section can bear, for example, an axial compressive load between approximately 800 Newtons and approximately 1000 Newtons without plastically deforming. Higher loads are also possible since container top load specifications of beverage containers may be 350 lbs or approximately 1560 Newtons or higher. The shape of the outwardly convex portion may also provide a certain compliance or elastic deformation to absorb a certain level of axial forces and other forces. In this manner, the convex portion may resist permanent plastic deformation and yielding, and may allow for wider manufacturing tolerances. Other axial loads that are higher or lower are also contemplated.
One embodiment of a metal beverage container may include a body portion, a neck portion connected with said body portion, and a finish portion. The finish portion may include a threaded portion, a lip portion, and a transition portion coupled between the threaded portion and the lip portion. The transition portion may include an outwardly convex shape.
One method of manufacturing a metal beverage container may include forming a body portion, forming a neck portion connected with the body portion, and forming a finish portion connected with the neck portion. The finish portion may be formed by forming a threaded portion, forming a lip portion, and forming a transition portion coupled between the threaded portion and the lip portion. The transition portion may include an outwardly convex shape.
Axial loading of a bottle shaped metal beverage container may cause the beverage container to deform. Certain deformations (e.g., plastic or permanent deformations) may be undesirable. A metal beverage container, however, may be designed to withstand certain amounts of axial loading. For example, a thickness of the metal used to form the beverage container may affect the container's ability to bear axial load (e.g., the thicker the metal for a given container design, the greater the ability of the container to withstand axial loads, generally speaking).
Metal is often purchased by weight. A thicker beverage container may be associated with increased material and transportation costs. Hence, relatively thin (and/or light weight) metal beverage containers capable of withstanding axial loads sufficient to properly seat a closure element (e.g., bottle cap, either twist or pop-off) may be desirable.
Referring to
By way of example, but not by limitation, the overall height of the beverage container 100 may be approximately 185 millimeters, the overall height of the finish portion 106 may be approximately 20 millimeters, the outside diameter of the beverage container 100 at its widest may be approximately 53 millimeters, and the outside diameter of the finish portion 106 at its widest may be in the range of 20 to 42 millimeters. Of course, other dimensions and/or shapes are also contemplated.
The metal from which the beverage container 100 is formed, in the example of
Referring to
A line 216 is shown passing through the transition section 206 connecting the lip portion 202 and threaded portion 204. As apparent from the figure, the transition section 206 is aligned with the line 216. Put another way, the transition section 206 is straight.
It has been discovered that axial loads applied during capping operations may cause deformation of the finish portion 106. For example, a hinge point 218 may form at the interface between the transition section 206 and the threaded portion 204. The transition section 206 is shown to be at an angle θ from horizontal. A length SL between the hinge point 218 and centerline 220 of the sealing surface 212 (curl) may range from approximately 3.3 mm and 6.1 mm. The higher the length SL, the axially stronger the transition section 206 as a result of being more vertical. Stresses associated with axial loads may concentrate at this hinge point 218, thereby causing deformation in the vicinity of the hinge point 218 as well the threads 214. This deformation may result in (i) an improper seal between the finish portion 106 and the cap and/or (ii) increased opening torque. In addition, inclusion of an arc in the transition section 206 helps to account and adjust for variations in manufacturing of the lip portion 202 as variations (e.g., non-uniformity) in height and/or shape of the lip portion 202 may cause different axial compressive forces to be applied to different portions of the lip portion 202 and, consequently, the transition section 206. The finish portion 106 and the hinge point 218, or transition sections, as explained above, may be thickened to reduce the tendency to deform under axial loads. Thickening these transition sections, however, may result in heavier and, thus, more costly beverage containers.
It has also been discovered that modifying the geometry of transition sections such that they have a convex shape or radially outward profile (see
Simulation has revealed that, for a given metal thickness, a convexly shaped transition section may result in improved resistance to permanent deformation relative to a straight or concavely shaped transition section. One reason for such an improvement is that the substantial linearity of a straight transition section provides for a linear spring response, whereas the convexly shaped (
Convexly shaped transition sections may be particularly suitable for finish portions having diameters in the range of 26 millimeters to 40 millimeters, for example. Such convex shapes, however, may be used with finish portions of any suitable diameter.
Referring to
A straight line 316 is shown relative to the transition section 306 connecting the lip portion 302 and the threaded portion 304. As apparent from
Referring to
A straight line 414 is shown relative to the transition section 406 and connects the lip portion 402 and threaded portion 404. As shown, the transition section 406 has a convex shape or radially outward profile. In the example of
Referring to
A straight line 512 is shown relative to the transition section 506 connecting the lip portion 502 and threaded portion 504. As shown, the transition section 506 has a convex shape or radially outward profile. Furthermore, the compound transition section may have a portion that extends away from and toward the interior of the beverage container.
As can be seen between each of
As an example of optimizing the finish portion, a number of design options are presented below in TABLE I, which varies arc radius of the transition section and finish thickness.
As shown in these results, the larger the radius of the arc of the transition section 306, the higher the peak force and displacement. This is, in part, as a result of the transition section 306 being more vertical. Similarly, the thicker the finish thickness, the higher the peak force capabilities, where the peak force and displacement indicates a force and displacement at which the transition section 306 fails or permanently deforms. While a finite element analysis shows that a transition that is straight has a peak force and displacement that is higher than a transition section with an arc configured with a radius, use of a straight transition portion may make the transition portion susceptible to plastic deformation given that stresses are concentrated at a hinge point, as described in
With regard to
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to: cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.
Furthermore, the figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the principles of the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, may be desired for particular applications or implementations.
The previous detailed description is of a small number of embodiments for implementing the invention, and is not intended to be limiting in scope. One of skill in the art may envisage methods and variations used to implement the principles of the invention in other areas than those described in detail herein.
This application claims priority to co-pending U.S. Provisional Application Ser. No. 61/600,074 filed Feb. 17, 2012, the contents of which are hereby incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61600074 | Feb 2012 | US |
