Abstract:
An improved end closure for food and beverage containers is provided. The end closure contains a raised bead portion for guiding and directing the opening or lifting motion of a tab portion attached to the end closure. More efficient opening features are enabled by the guided action of the tab and raised bead features.

Description:
[0001]    This U.S. Non-Provisional patent application claims the benefit of priority to U.S. Provisional Patent Application 61/792,541, filed Mar. 15, 2013, the entire disclosure of which is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to end closures for two-piece beer and beverage metal containers, having a frangible tear panel and a retained-tab secured by a rivet. More specifically, the present invention relates to improved characteristics for opening the frangible tear panel of the end. 
       BACKGROUND OF THE INVENTION 
       [0003]    Typical end closures for beer and beverage containers have an opening panel and an attached leverage tab for pushing the opening panel into the container to open the end. The container is typically a drawn and ironed metal can, usually constructed from a thin plate of aluminum. End closures for such containers are also typically constructed from a cutedge of thin plate of aluminum or steel, formed into a blank end, and manufactured into a finished end by a process often referred to as end conversion. These ends are formed in the process of first forming a cutedge of thin metal, forming a blank end from the cutedge, and converting the blank into an end closure which may be seamed onto a container. 
         [0004]    These types of container ends have been used for many years, with almost all such ends in use today being the “ecology” or “stay-on-tab” ends in which the tab remains attached to the end after the opening panel is opened. Throughout the use of such ends, manufacturers have sought to save the expense of the metal by downgauging the metal of the ends and the tabs. However, because ends are used for containers with pressurized contents, the score of the opening panel must have sufficient score residual to withstand such pressure, which in turn requires that the tab have a thickness of metal to provide strength to open the panel. Further, with the more recent popular use of large-open ends, additional problems arise with regard to openability of the ends. Because of the enlarged size of the opening panel (or tear panel), more stress is placed on the tab during opening of the tear panel, constraining efforts to further downgauge the tab. 
         [0005]    Another problem with such container ends is the restriction to the material and cost savings when seeking to make the ends from a thinner metal stock (downgauging), primarily due to the fact that the traditional geometry of such ends requires one to make the ends from a larger cutedge of metal when attempting to make the end of thinner gauge metal. 
         [0006]    As is explained in greater detail below, the present invention reduces or eliminates these problems with ecology type ends and the problems with the large-open ends. 
       SUMMARY OF THE INVENTION 
       [0007]    It is an object of the present invention to provide an end closure for a container having a central panel wall with a product side and a public side. The end has a displaceable tear panel in the central panel wall at least substantially defined by a frangible score and a non-frangible hinge segment, and a tab attached to the public side of the central panel wall by a rivet, at least a nose portion of the tab extending over a portion of the tear panel. 
         [0008]    It is further an object of the present invention to provide an end closure having a bead segment positioned under a portion of the tab nose. The bead segment has an upper surface for contact with the tab nose and is adapted to direct an opening force toward the transition zone of the score when an opening force is applied by lifting the tab from the lift end such that the nose is applied against the tear panel. 
         [0009]    It is yet another object of the present invention to provide an end closure with a severable opening, a tab for transmitting a force to the opening, and a raised bead feature for aiding in opening operations. In one embodiment, a tab rotates about a rivet such that the nose of the tab moves downward toward the tear panel or opening area. A left side of the nose of the tab contacts a raised bead feature, the raised bead feature being adjacent to a fourth segment of the score. Upon opening, the nose of the tab can no longer continue to move directly down on to the tear panel as: (1) the tab is attached to the panel wall by the rivet; and (2) the left part of the tab nose is prevented from further downward movement by the raised bead, the tab must thus tilt until the right part of the tab nose touches the tear panel adjacent to the first segment of the score, where force is now applied to continue the opening of the score. In the left part of the tab nose, on the lower surface, there is a notch which coincides with the raised bead. When the tab contacts the raised bead, the bead enters this notch which then restricts the rotation of the tab about the rivet. In this way, the force applied to the tear panel is aligned to the area adjacent to the first segment of the score. Apart from the notch portion, the nose of the tab is of uniform thickness. 
         [0010]    In one embodiment, a metallic end closure adapted for interconnection to a neck of a beverage container is provided, the end closure comprising a peripheral curl, a chuck wall extending inwardly from said peripheral curl, a countersink interconnected to a lower portion of said chuck wall, an inner panel wall interconnected to said countersink, a central panel interconnected to said inner panel wall, a lift tab having a nose end and a tail end, said lift tab operably interconnected to an upper surface of said central panel, said central panel comprising a frangible score line which defines a tear panel, said tear panel comprising a raised bead feature, and said raised bead feature provided below a portion of said nose end of said lift tab at least when the tab is provided in a first position. During an opening operation of said tear panel said tail end of said lift tab is raised and a portion of said nose end of said lift tab contacts said raised bead feature such that a contact between said nose end and said raised bead feature causes a rotation of said tab toward a lateral portion of the tear panel. 
         [0011]    Other advantages and aspects of the invention will become apparent upon making reference to the specification, claims, and drawings to follow. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosure and together with the general description of the disclosure given above and the detailed description of the drawings given below, serve to explain the principles of the disclosures. 
           [0013]    It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the disclosure or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the disclosure is not necessarily limited to the particular embodiments illustrated herein. 
           [0014]      FIG. 1  is a top plan view of features of an end closure according to one embodiment of the present invention; 
           [0015]      FIG. 2  is a side elevation view of features of an end closure according to one embodiment of the present invention; 
           [0016]      FIG. 3  is a top plan view of features of an end closure according to one embodiment of the present invention; 
           [0017]      FIG. 4  is a detailed top plan view of features of an end closure according to one embodiment of the present invention; 
           [0018]      FIG. 5A  is a cross-sectional side elevation view of one embodiment of the present invention; 
           [0019]      FIG. 5B  is a detailed view of  FIG. 5A ; 
           [0020]      FIG. 6A  is a cross-sectional side elevation view of one embodiment of the present invention along line A-A of  FIG. 8 ; 
           [0021]      FIG. 6B  is a cross-sectional side elevation view of one embodiment of the present invention along line A-A of  FIG. 8 ; 
           [0022]      FIG. 7A  is a cross-sectional side elevation view of one embodiment of the present invention along line B-B of  FIG. 8A ; 
           [0023]      FIG. 7B  is a cross-sectional side elevation view of one embodiment of the present invention along line B-B of  FIG. 8A ; 
           [0024]      FIG. 8A  is a top plan view of an end closure according to one embodiment of the present invention; 
           [0025]      FIG. 8B  is a bottom plan view of an end closure according to one embodiment of the present invention; and 
           [0026]      FIG. 9  is a perspective view of features of an end closure according to one embodiment of the present invention. 
       
    
    
       [0027]    It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the disclosure or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the disclosure is not necessarily limited to the particular embodiments illustrated herein. 
       DETAILED DESCRIPTION 
       [0028]      FIG. 1  is a top plan view of one embodiment of the present disclosure comprising a raised bead  4  for aiding in operations of a tear panel  10  of a container end closure. As shown, a tear panel  10  is provided and generally defined by a severable score line  22 . The tear panel  10  is severable about the score line  22  by a lifting action applied to a tab  6  which drives a nose portion  8  of the tab  6  downwardly into the tear panel  10 . The tab  6  is secured to the end panel via a rivet  12 . The tear panel  10  and score line  22  generally comprise first  14 , second  16 , third  17 , and fourth  18  tear segments. A first force-application area  20  is provided proximal the first segment  14 . 
         [0029]    A raised bead portion  4  is provided, the raised bead portion extending from and above a central panel of the end closure and provided beneath the tab  6 , at least when the tab  6  is in a first position. The bead portion  4  is provided to interface with an underside of the tab nose portion  8 , at least during an opening operation. Specifically, in various embodiments of the present invention, the raised bead  4  contacts a notch portion ( 26  of  FIG. 2 ) of the tab nose  8  and prevents undesired rotation of the tab  6  about the rivet  12  and directs an opening force at least partially toward the first force-application area  20 . 
         [0030]    Known devices, including that disclosed in U.S. Pat. No. 6,024,239 to Turner et al., which is hereby incorporated by reference in its entirety, fail to disclosure features of the present invention including, for example, a raised bead portion that directs force away from a transition zone and/or termination feature. Turner, for example, discloses a device that directs a force toward the transition zone and thus places increased risk of rotation and stress upon features of the end closure including, for example, the tab. 
         [0031]      FIG. 2  is a cross-sectional elevation view of an end closure according to one embodiment of the present invention. A tab  6  and raised bead portion  4  are provided on the end closure. The tab  6  comprises a contour or notch portion  26  for receiving and interacting with the raised bead  4 . The notch portion  26  and raised bead  4  comprise complementary surfaces for engaging one another and preventing rotation of the tab  6  about a substantially vertical axis extending through the rivet  12 . A peripheral edge  37  of the raised bead  4  provides a contact surface for a downwardly extending surface  39  provided on the tab  6 . Thus, a contact area  38  is provided between the raised bead  4  and the tab  6 . This contact area  38  serves to prevent undesired rotation (e.g. about a substantially vertical axis of the container) of the tab  6  during opening of the opening area. The contact area  38  further directs an opening force on the tear panel  10  toward the first segment  14 , thus directing opening force toward the preferred area of force application  20 . 
         [0032]      FIGS. 3-4  show one embodiment of a tool for forming a portion of an end closure according to one embodiment. As shown, corresponding features for the tab  60 , rivet  62 , bead  66 , and nose portion  64  are provided. Such inversed features are provided for illustration only. Preferably, and as shown and described herein, the bead  66  is formed in a central panel portion and comprises a raised feature. The tab, once formed, is positioned over the bead  66 . The tool of  FIGS. 3-4  provides for the formation and/or addition of such features. 
         [0033]      FIGS. 5A-5B  show cross-sectional elevation views of one embodiment of the present invention. An end closure  2  is provided, the end closure suitable for interconnection to a container body via peripheral cover hook portion  30 . Peripheral cover hook portion  30  is interconnected to a central panel  32  via one or more features, including but not limited to a countersink  34 , inner panel wall  35  and downwardly extending chuck wall  36 . The central panel  32  comprises a rivet  12  upon which a tab  6  is mounted. The central panel  32  further comprises a tear panel ( 10  of  FIG. 1 ) defined by a score line. Provided within the tear panel  10  is a raised bead feature  4  which extends above a remainder of the surface of the central panel  10  and opening area, the central panel  10  and opening area being provided in substantially the same plane and comprising substantially the same height. The raised bead  4  is provided beneath and in close proximity to or, in certain embodiments, in contact with the tab  6 . In certain embodiments, the tab  6  comprises a notch feature  26  within which the raised bead  4  is received. A peripheral edge  37  of the raised bead  4  provides a contact surface for a downwardly extending surface  39  of the tab  6 . Thus, a contact area  38  is provided between the raised bead  4  and the tab  6 . This contact area  38  serves to prevent undesired rotation of the tab  6  during opening of the opening area and direct an opening force on the tear panel  10  toward the first segment  14 , thus directing opening force toward the preferred area of force application  20 . 
         [0034]    As shown in  FIGS. 5A-5B , a first end  40   a  of the tab  6  is provided at a height above the central panel  32  and a second end  40   b  of the tab  6  is provided substantially flush or in contact with the central panel  32 , at least when the tab  6  is provided in a first position. As used herein, the term “first position” generally refers to a position of the tab  6  and tear panel  10  when the container is closed, such as when the container is filled, pressurized, sealed and ready for opening. The offset provided at the one side  40   a  further helps to assure that force is applied to the preferred area of the panel  10 . 
         [0035]    In various embodiments, the raised bead feature  4  comprises an upstanding feature that extends above (i.e. toward the public side) the central panel. In certain embodiments, a maximum height of the raised bead  4  extends above the central panel between approximately 0.005 inches and 0.020 inches. In preferred embodiments, a maximum height of the raised bead  4  extends above the central panel between approximately 0.010 inches and 0.015 inches. However, the present invention is not limited to raised features which extend a particular height. Indeed, various alternatives are contemplated in regards to the dimensions of the bead. 
         [0036]    In order to prevent clockwise rotation (i.e. with respect to  FIG. 1 ) of the tab  6 , the raised bead portion  4  extends radially outward beyond a lowermost portion of the tab  6  proximal the first side  40   a . The contact area  38  is provided at an opposing side of the bead, proximal the rivet  12 , such that the contact area  38  prevents such clockwise rotation. In various embodiments, counter-clockwise rotation about the rivet is enabled or not prevented. In certain embodiments, tab rotation about the rivet  6  is substantially prevented. 
         [0037]    Referring now to  FIG. 6A , one embodiment of an end closure is provided and depicted along line A-A of  FIG. 8A . As shown, a central panel  32  is provided upon which a tab  6  is secured on a rivet  12 . An upstanding bead  4  is provided, and shown as being forward of the rivet  12  in  FIG. 6A . In the depicted embodiment, the bead  4  comprises a flat-topped or plateau-shaped structure suitable for operating as shown and described herein. For reference, the score line  22  is shown, the score line  22  residing within a debossed area of the central panel  32 . The tab comprises a notch  26  or recess for interacting and/or receiving the bead  4 . The score line  22  generally defines a tear panel  10  upon which the bead  4  resides. As shown and described herein, communication between the bead  4  and the tab  6  provides for an asymmetric rotation of the tab, and applies a directed force to the tear panel  10  during opening operations. 
         [0038]    An alternative embodiment of a closure is provided in  FIG. 6B , wherein the raised bead  4  comprises a tapered or pointed feature.  FIG. 6B  provides similar structure to that of  FIG. 6A  and is taken at line A-A of  FIG. 8A .  FIG. 6B , however, provides a raised bead  4  of different cross-section, wherein the cross-section of the raised bead  4  of  FIG. 6B  is an upstanding peak rather than a plateau. It will be recognized that upstanding or raised bead  4  features of the present disclosure are not limited to any particular shape or configuration. Indeed, various shapes, sizes, and corresponding notches in the tab nose are contemplated. 
         [0039]      FIG. 7A  provides a cross-sectional view of one embodiment of the present disclosure taken along line B-B of  FIG. 8A . A nose portion  8  of the tab  6  is positioned to the left, with the user operable portion or tail of the tab  6  provided at the opposing right end. The raised bead  4  is provided beneath the nose portion  8  and comprises a flat feature, but may comprise any number of alternative arrangements as discussed. The cross-section of  FIG. 7A  is provided approximately through the center of the bead  4  and through the center of the notch  26  such that the tab  6  is being depicted as residing on top of the bead  4 . The debossed area  31  is shown as extending underneath the tab  6 .  FIG. 7B  depicts an alternative embodiment of an end closure with a raised bead  4 , also taken about line B-B of  FIG. 8A . The bead  4  of  FIG. 7B  comprises a peak or tapered feature for interaction with the tab  6 . 
         [0040]      FIGS. 8A and 8B  depict top and bottom plan views of one embodiment of the present invention, respectively. Various features as shown and described herein are provided. Although the bead portion  4  is shown in  FIG. 8A , it will be understood that the bead  4  is provided beneath at least a portion of the tab  6 . 
         [0041]      FIGS. 8A and 8B  further depict a longitudinal axis  62  of the closure and a lateral axis  64  of the closure. Although certain features of the closure (e.g. the raised bead  4 ) render the closure somewhat asymmetrical, the closure is generally divided into equally sized lateral portions on either side of the longitudinal axis as shown in plan view. The longitudinal axis  62  runs through the center of the closure, tab  6 , rivet  12  and tear panel  10 . The lateral axis  64  is provided substantially perpendicular to the longitudinal axis  62 , and similarly divides the closure into segments. 
         [0042]      FIG. 9  depicts various features of one embodiment of the present invention and illustrates an opening sequence of the same. As shown, a tab  6  is provided in a first closed position  6   a  and a second partially-raised or partially-open position  6   b . A bead  4  is shown as being visible through the nose  8  of the tab  6 . Upon raising the tab  6  to the raised position  6   b , the nose portion will apply force downwardly upon the tear panel  10 , forcing open the tear panel. In a first position  6   a  and an open position  6   b , the bead  4  prevents rotation about the rivet  12  and vertical axis extending therethrough. An additional axis of rotation  50  is depicted, about which the tab  6  is permitted to rotate, but only in one direction and toward first opening segment  14  and preferred area of force transmission  20  of the tear panel  10 . The axis  50  represents an axis extending longitudinally along a central portion of the tab  6 . The tab  6  is allowed to roll off center or pivot transversely about the axis  50 , and direct force primarily upon segment  14 , thus inducing a severing action upon a score line at an end of the score line opposing the termination feature  24 . Rotation about axis  50  is provided at least in part due to features discussed herein, namely the sizing and position of the raised bead  4 , peripheral edge  37  and interface  38 . 
         [0043]      FIG. 9  further depicts a non-frangible hinge portion  60  of the closure. The hinge portion  90  comprises an area of the tear panel  10  proximal the rivet  12  about which the tear panel  10  hinges open. Opposite rotation is substantially prevented by the extension of the bead  4  beyond the tab portion  6  on the one side. 
         [0044]    In various embodiments, it is contemplated that the tab  6  will rotate or “tilt” about axis  50  by at least approximately 10 degrees. In preferred embodiments, it is contemplated that the tab  6  rotates about axis  50  by between approximately 15 and 25 degrees during an opening operation. 
         [0045]    One of skill in the art will recognize that opening forces required to sever the tear panel  10  are reduces by focusing a pressure on or toward first opening portion  14 , as opposed to directing force from the nose of the tab  6  symmetrically about a longitudinal axis running through the center of the tab  6 . As shown in  FIG. 9 , the depicted rotation of the tab  6  about axis  50  induces the beginning of a score fracture propagation on a first side of the axis  50  (i.e. proximal first opening portion  14 ). A score fracture will then propagate clockwise (as shown in  FIG. 9 ) along the score line  22  and extend toward score termination feature  24 , which comprises an outward curvature diverting from the general path of the score line  22 . The raised bead  4  provided on the tear panel  10  and in communication with the tab during an opening operation thus biases the tab in a rotational manner as depicted and facilitates the opening process described above.