Patent Publication Number: US-2015069062-A1

Title: Can end and method of making same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of application Ser. No. 13/347,262, filed Jan. 10, 2012, and entitled “CAN END AND METHOD OF MAKING SAME”; which is a divisional of application Ser. No. 12/137,958, filed Jun. 12, 2008, now U.S. Pat. No. 8,109,405. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates generally to containers and, more particularly, to cans ends. The invention also relates to methods of making can ends. 
     2. Background Information 
     Many metallic containers for holding products (e.g., without limitation, food; beverages) are sometimes provided with an easy open end, wherein a pull tab is attached to a tear strip or panel that is defined by a scoreline. The pull tab may be lifted and then pulled to provide an opening for dispensing the contents of the container. 
       FIGS. 1 and 2  illustrate a conventional can end  1  as disclosed, for example, in U.S. Pat. No. 5,038,956. The can end  1  includes a recessed panel  3  defined by a generally vertical chuckwall  5 , which surrounds the periphery of the panel  3 .  FIG. 1  shows the exterior (i.e., public) side  7  of the can end  1 , whereas  FIG. 2  shows the interior (i.e., product) side  9 . A peripheral scoreline  11  ( FIG. 1 ), which is disposed at or about the base of the chuckwall  5 , defines an opening section  13  that is intended to be drawn away or removed from the can end  1  to provide access to the contents of the container (e.g., can) (not shown) to which it is attached. To facilitate rupture of the peripheral scoreline  11 , an opening mechanism such as, for example, the pull tab  15  shown in  FIG. 1 , is coupled to the panel  3 . More specifically, the pull tab  15  is typically riveted to the opening section  13  of the panel  3  by a rivet  17 . A finger well  19  is sometimes included to enable the end user to reach beneath the pull tab  15  to initiate rotation thereof. 
     As shown in  FIG. 2 , in an effort to enhance the openability of the can end  1 , some can ends  1  include a back scoreline  21  disposed inboard (i.e., toward the center of the can end  1 ) of the rivet  17  on the product side  9  of the can end  1 . The back scoreline  21  is structured to facilitate initial rupture of the peripheral scoreline  11  ( FIG. 1 ) that defines the opening section  13 , and to avoid the pull tab  15  ( FIG. 1 ) being accidentally torn off of the panel  3  during the can opening process. The back scoreline  21  of  FIG. 2  is arch-shaped and includes an arcuate portion  23  and two substantially straight legs  25 , 27  extending outwardly away from the arcuate portion  23  toward a safety fold  29  that is contiguous with the base of the chuckwall  5 . Thus, it will be appreciated that the can end  1  is a “panel safe” can end  1 , meaning that the peripheral safety fold  29  remains with the panel  3 , and is structured to shield any raw-edge residual metal remaining with the panel  3  when it is removed from the can end  1 . 
     Scorelines, such as the arch-shaped back scoreline  21  of  FIG. 2 , suffer from a number of disadvantages. Among them is the fact that the arcuate portion  23  of the back scoreline  21  is disposed inboard of the rivet  17  a relatively significant distance  31  (e.g., at least about 0.03 inches). The position and geometry of the scoreline (e.g.,  21 ) directly affect the opening mechanics of the can end  1 . Additionally, as shown in  FIG. 2 , the example back scoreline  21  is disposed on the product side  9  of the panel  3 . This increases the possibility of contamination of the product, for example, due to corrosion or oxidation of the scoreline  21 . At a minimum, when using a relatively rigid container material (e.g., without limitation, steel) that oxidizes, the product side back scoreline  21  mandates a post score coating protection operation to coat the product side  9  of the panel  3  and, in particular, the back scoreline  21  thereof, in order to resist oxidation. 
     There is, therefore, room for improvement in can ends, and in methods of making can ends. 
     SUMMARY OF THE INVENTION 
     These needs and others are met by embodiments of the invention, which are directed to a can end (e.g., easy open can end) having a rivet base scoreline structured to improve the opening mechanics (e.g., without limitation, reduce pop and pull forces) of the can end, in order to provide the end user with increased opening convenience, without sacrificing the ability of the can end to withstand scoreline abuse commonly experience, for example, from shipping, corrosion or any other forces common to easy open can ends. 
     As one aspect of the invention, a can end is provided, which is structured to be affixed to a can body. The can end comprises: a severable panel having a product side structured to face toward the can body when the can end is affixed to the can body, and a public side structured to face away from the can body when the can end is affixed to the can body; a peripheral scoreline defining the periphery of the severable panel; an opening mechanism coupled to the severable panel, the opening mechanism being actuatable to sever the peripheral scoreline; a rivet coupling the opening mechanism to the severable panel, the rivet having a base disposed at the severable panel and a stem extending outwardly from the severable panel; and a rivet base scoreline in the public side of the severable panel. The rivet base scoreline is disposed about 0.025 inch or less from the stem of the rivet. 
     The severable panel may have an interior, and the rivet base scoreline may include an arcuate head portion, first and second arm portions extending from the arcuate head portion and first and second ends. The rivet may have an inboard side facing the interior of the severable panel, and an outboard side facing the periphery of the severable panel. The arcuate head portion of rivet base scoreline may be disposed on the inboard side of the rivet. The first and second arm portions of the rivet base scoreline may generally extend toward the outboard side of the rivet. The base of the rivet may have a radius of curvature, wherein the radius of curvature forms an intersection between the stem of the rivet and the public side of the severable panel. The arcuate head portion of the rivet base scoreline may be contiguous with the radius of curvature of the base of the rivet. 
     The opening mechanism may be a pull tab including a nose and a lift portion disposed opposite and distal from the nose. The rivet may have a diameter and a centerline. The pull tab may have a dimension, X, measured by the distance between the nose of the pull tab and the centerline of the rivet, and a dimension, Y, measured by the total length of the pull tab between the nose of the pull tab and the lift portion of the pull tab. In one non-limiting embodiment, the ratio X/Y may be about 0.20 or less, and the diameter of the stem of the rivet may be about 0.1875 inch or less. 
     The arcuate head portion of the rivet base scoreline may have a first radius of curvature, and the first and second arm portions of the rivet base scoreline may have a second radius of curvature. The first radius of curvature of the arcuate head portion may be the same as the second radius of curvature of the arm portions. The first and second arm portions of the rivet base scoreline may extend beyond the outboard side of the rivet toward the periphery of the severable panel, and the first and second ends of the rivet base scoreline may curve back away from the periphery of the severable panel, 
     The opening mechanism may have a longitudinal axis. Upon actuation of the opening mechanism, the rivet base scoreline is structured to propagate toward the peripheral scoreline of the can end, thereby defining a bend axis. The bend axis may extend generally perpendicularly with respect to the longitudinal axis of the opening mechanism, and may be disposed between the outboard side of the rivet and the peripheral scoreline proximate to the peripheral scoreline. The opening mechanism may be structured to be lifted, pivoted to a substantially inverted position and pulled, in order to remove the severable panel. Responsive to being lifted, the opening mechanism may be structured to initially sever the peripheral scoreline and, responsive to being pivoted to the substantially inverted position, the opening mechanism may be structured to sever at least 40 percent of the peripheral scoreline. 
     The opening mechanism may be a pull tab. The pull tab may include a nose portion and a lift portion disposed opposite the nose portion. The nose portion of the pull tab may overlay at least a portion of the rivet base scoreline, and may include a number of apertures structured to be aligned with corresponding portions of the rivet base scoreline thereunder. 
     As another aspect of the invention, a method of making a can end is provided. The method comprises: forming a rivet on a panel portion of the can end, the panel portion having a public side and a product side, the rivet including a base disposed on the public side of the panel portion and a stem extending outwardly from the public side of the panel portion; and scoring the public side of the panel portion to form a rivet base scoreline, the rivet base scoreline being disposed about 0.025 inch or less from the stem of the rivet. 
     The method may further comprise: forming a pull tab including a nose portion and a lift portion disposed opposite the nose portion, the nose portion including a rivet hole and a number of apertures disposed proximate to the rivet hole, sliding the nose portion of the pull tab over the stem of the rivet in order that the stem of the rivet is disposed in the rivet hole of the nose portion, and aligning the number of apertures of the nose portion of the pull tab with corresponding portions of the rivet base scoreline thereunder. The method may further comprise applying a post score repair agent to the can end, the repair agent being received through the number of apertures of the nose portion of the pull tab, in order to coat the rivet base scoreline. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: 
         FIG. 1  is a top plan view of the public side of a can end; 
         FIG. 2  is a bottom plan view of the product side of the can end of  FIG. 1 , showing a product side back scoreline therefor; 
         FIG. 3A  is a top plan view of the public side of a can end and rivet base scoreline therefor, in accordance with an embodiment of the invention; 
         FIG. 3B  is a top plan view of the public side of the can end of  FIG. 3A , with the pull tab removed to show underlying features; 
         FIG. 3C  is a sectional view taken along line  3 C- 3 C of  FIG. 3A ; 
         FIG. 3D  is an enlarged view of a portion of the can end and rivet base scoreline therefor of  FIG. 3C ; 
         FIGS. 4-6  are simplified top plan views of rivet and rivet base scoreline configurations, in accordance with embodiments of the invention; 
         FIG. 7  is an isometric view of a pull tab, in accordance with an embodiment of the invention; 
         FIG. 8  is a top plan view of the pull tab of  FIG. 7 ; 
         FIGS. 9A-9C  are side elevation views showing a can end opening sequence in accordance with an embodiment of the invention; 
         FIG. 10  is a graph comparing the improved opening forces of the can end of the invention to the opening forces of a conventional can end; and 
         FIGS. 11A-11F  are top plan views showing the sequential steps for a method of making a can end, in accordance with an embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For purposes of illustration, embodiments of the invention will be shown and described as applied to a circular can end having a safety fold, although it will become apparent that they could also be applied to enhance the opening mechanics of any known or suitable type of container end (e.g., without limitation, circular can ends with an alternative number and/or configuration of safety folds; standard can ends without a safety fold; non-circular can ends with or without a safety fold) made from any suitable material (e.g., without limitation, a suitable metallic material such as aluminum or steel). 
     Directional phrases used herein such as, for example, clockwise, counterclockwise, up, down, top, bottom and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein. 
     As employed herein, the statement that two or more parts are “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts. 
     As employed herein, the term “can” refers to any known or suitable container, which is structured to contain a substance (e.g., without limitation, liquid; food; any other suitable substance), and expressly includes, but is not limited to, beverage cans, such as beer and soda cans, as well as food cans. 
     As employed herein, the term “can end” refers to the closure that is structured to be coupled to the can, in order to seal the can. 
     As employed herein, the term “can end shell” is used substantially interchangeably with the term “can end.” The “can end shell” or simply the “shell” is the member that is acted upon and is converted by a suitable tooling assembly within a conversion press in order to provide the desired can end. 
     As employed herein, the term “repair agent” refers to a liquid, lacquer or other suitable coating (e.g., without limitation, sealant), which is applied to the can end after it has been scored, in order to cover and protect (e.g., seal) the scoreline(s) of the can end. 
     As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality). 
       FIG. 3A  shows a can end  101 , which is structured to be affixed to a can body  102  (partially shown in  FIGS. 9A-9C ). The can end  101  includes a severable panel  103  having a public side  107  and a product side  109  ( FIGS. 3C ,  3 D and  9 A- 9 C). The product side  109  is structured to face toward the can body  102  when the can end  101  is affixed to the can body  102 , and the public side  107  is structured to face away from the can body  102  when the can end  101  is affixed to the can body  102 , as shown in  FIGS. 9A-9C . 
     A peripheral scoreline  111  on the public side  107  of the can end  101  defines the periphery  113  of the severable panel  103 . An opening mechanism, such as the pull tab  115  which is shown, is coupled to the severable panel  103 , and is actuatable to sever the peripheral scoreline  111 , as will be described hereinbelow. A rivet  117  couples the pull tab  115  to the severable panel  103 . The rivet  117  includes a base  119  disposed at the severable panel  103 , and a stem  120  extending outwardly from the severable panel  103 , as shown in  FIGS. 3C and 3D . 
     Continuing to refer to  FIG. 3A , and also to  FIGS. 3B-3D , the can end  101  further includes a rivet base scoreline  121  on the public side  107  of the severable panel  103 . As best shown in the enlarged view of  FIG. 3D , the rivet base scoreline  121  is disposed about 0.025 inch or less from the stem  120  of the rivet  117 , and preferably is contiguous with the base  119  of the rivet  117 . That it is, the rivet base scoreline  121  is preferably immediately adjacent to, or in an abutting or overlapping relationship with a portion (e.g., without limitation, radius of curvature  137 , discussed hereinbelow) of the rivet  117 , as opposed to being spaced apart from the rivet a relatively substantial distance (see, for example, the product side back scoreline  21  of  FIG. 2 , which is spaced relatively substantial distance  31  (e.g., without limitation, at least 0.03 inch) from rivet  17 ). More specifically, as best shown in  FIG. 3D , the base  119  of the example rivet  117  has radius of curvature  137 , which forms the intersection between the stem  120  of the rivet  117 , and the public side  107  of the can end severable panel  103 . An arcuate head portion  123  of the rivet base scoreline  127  is contiguous with such radius of curvature  137 . 
     Among other benefits, by being contiguous with the base  119  of the rivet  117 , the rivet base scoreline  121  substantially improves the opening mechanics of the can end  101 . Specifically, as will be described in greater detail hereinbelow, it results in decreased opening forces being required to be exerted by the end user, while maintaining a predetermined requisite scoreline residual (e.g., without limitation, about 0.002 inches to about 0.003 inches) so that the can end  101  and, in particular, the scorelines (e.g., without limitation, peripheral scoreline  111 ; rivet base scoreline  121 ) are capable of withstanding abuse caused, for example, from shipping, corrosion and other forces to which easy open can ends are commonly exposed. 
     As shown in  FIG. 3B , in which the pull tab  115  ( FIG. 3A ) has been removed to show the rivet base scoreline  121  in greater detail, in addition to the aforementioned arcuate head portion  123 , the rivet base scoreline  121  includes first and second arm portions  125 , 127  extending from the arcuate head portion  123 , and first and second ends  129 , 131 . The arcuate head portion  123  is disposed on an inboard side  133  of the rivet  117 , which faces the interior  104  of the severable panel  103 . The first and second arm portions  125 , 127  of the rivet base scoreline  111  generally extend toward an outboard side  135  of the rivet  117 , which faces the periphery  113  of the severable panel  103 . The arcuate head portion  123  of the rivet base scoreline  121  has a first radius of curvature  139 , and the first and second arm portions  125 , 127  of the rivet base scoreline  121  have a second radius of curvature  141 . In the example of  FIGS. 3A and 3B  (see also rivet base scoreline  121  of  FIG. 5 , and rivet base scorelines  521  and  621  of  FIG. 6 ), the first radius of curvature  139  of the arcuate head portion  123  is substantially the same as the second radius of curvature  141  of the first and second arm portions  125 , 127 . It will, however, be appreciated that the various portions (e.g., without limitation, arcuate head portion  123 ; first and second arm portions  125 , 127 ; first and second ends  129 , 131 ) of the rivet base scoreline  121  may have any known or suitable shape and/or configuration, without departing from the scope of the invention. Specifically, referring to  FIGS. 4-6 , several EXAMPLES of rivet and rivet base scoreline configurations are shown, and will now be described. It will be appreciated that the following EXAMPLES are provided for illustrative purposes only and are not limiting upon the scope of the invention. 
     EXAMPLE 1  
     As shown in  FIG. 4 , the rivet  217  preferably has a diameter  243 , which is smaller than the rivet of a conventional end (see, for example, rivet  17  of can end  1  of  FIG. 1 ). In one non-limiting embodiment, the rivet diameter  243  is about 0.1875 inch or less. It will, however, be appreciated that the rivet may have any known or suitable diameter. For example and without limitation, rivet  317 , which is also shown in  FIG. 4 , has a diameter  343  of about 0.250 inches. 
     Continuing to refer to  FIG. 4 , it will be appreciated that the smaller diameter  243  (e.g., without limitation, about 0.1875 inch or less) of the exemplary rivet  217  advantageously reduces the opening force required to initially sever the rivet base scoreline  221 . Specifically, by reducing the rivet diameter  243 , the amount of the arcuate head portion  223  of the scoreline  221  that must be severed upon initial actuation of the pull tab  115  to vent the can end  101  ( FIG. 3C ) is reduced. This segment of the rivet base scoreline  221 , which is disposed at the inboard side  233  of the rivet  217 , is shown in exaggerated form and is identified by reference number  245  in  FIG. 4 . By way of comparison, the corresponding segment  345  of the arcuate head portion  323  of rivet base scoreline  321  at the inboard side  333  of the larger (e.g., without limitation, about 0.250 inch) rivet  317  is significantly larger. Thus, the smaller rivet diameter  243  equates to a smaller segment  245  that must be initially severed during opening of the can end  101  ( FIG. 3C ), as compared to the relatively larger segment  345  associated with the larger diameter rivet  317 . Less opening force is required to open the smaller segment  245 . 
     Yet another benefit afforded by the reduced diameter  243  ( FIG. 4 ) of the preferred rivet  217  ( FIG. 4 ; see also rivet  117  of  FIG. 3C ) will be appreciated with reference to  FIG. 3C . Specifically, the rivet  117  has a centerline  118 . Dimension, Y (see also  FIG. 8 ), is the overall length of the pull tab  115  measured by the distance between the nose  151  of the pull tab  115  and the opposing end  153  (e.g., lift portion) of the pull tab  115 . Dimension, X (see also  FIG. 8 ), is the distance between the rivet centerline  118  and the nose  151  of the pull tab. Reducing the rivet diameter  243  ( FIG. 4 ) correspondingly reduces the dimension, X. As a result, the ratio X/Y is also reduced, thereby improving the opening mechanics of the can end  101 . The dimension, X, is preferably about 0.30 inch or less, and the ratio X/Y is preferably about 0.20 or less. 
     Stated another way, the mechanical levering capabilities of the pull tab  115  are dictated, in large part, by the distance  152  between the rivet centerline  118  and the end  153  (e.g., lift portion) of the pull tab  115 , as well as the distance  154  between the end  153  (e.g., lift portion) of the pull tab  115  and the edge (e.g., stem  120 ) of the rivet  117 . Reducing the size (e.g., diameter) of the rivet  117  increases the distance  154  relative to distance  152 , thereby adding length to the lever arm of the pull tab  115  and improving its opening mechanics (e.g., decreasing the force required to be exerted on the pull tab  115  to open the can end  101 ). 
     EXAMPLE 2  
     The first and second ends  229 , 231  of the rivet base scoreline  221  may curve back, away from the periphery  213  (partially shown in  FIG. 5 ) of the severable panel  203 , (partially shown in  FIG. 5 ) as shown in  FIGS. 4 and 5 . See also first and second ends  329 , 331  of rivet base scoreline  321  of  FIG. 4 . 
     EXAMPLE 3  
     The first and second arm portions  125 , 127  and/or first and second ends  129 , 131 , respectively, thereof may extend beyond a tangential axis  238 , which extends laterally outwardly from, and tangential to, the outboard side  235  of the rivet  217 , as shown in  FIG. 5 . See also the first and second arm portions  425 , 427  of rivet base scoreline  421 . 
     EXAMPLE 4 
     The first and second arm portions (e.g.,  425 , 427 ) of the rivet base scoreline (e.g.,  421 ) can have any known or suitable radius of curvature. For example and without limitation, unlike the first and second arm portions  125 , 127  of rivet base scoreline  121 , previously discussed with respect to  FIGS. 3B and 5 , the first and second arm portions  425 , 427  of rivet base scoreline  421  of  FIG. 5  are substantially straight. 
     EXAMPLE 5  
     The rivet base scoreline (e.g.,  521 , 621 , 721 ) may have any known or suitable length. For example, scorelines  521 , 621 , and  721 , shown in  FIG. 6 , extend from the inboard side  233 ′ of rivet  217 ′ toward the outboard side  235 ′ of the rivet  217 ′, but stop short of the tangential axis  238 ′, which extends laterally outwardly from the outboard side  235 ′ of the rivet  217 ′. 
     In view of the foregoing EXAMPLES, it will be appreciated that the size and/or configuration of the rivet  117  ( FIGS. 3A-3D ),  217  ( FIGS. 4 and 5 ),  217 ′ ( FIG. 6 ) and the shape, size and/or configuration of the rivet base scoreline  121  ( FIGS. 3A-3D  and  5 ),  221  ( FIGS. 4 and 5 ),  321  ( FIG. 4 ),  421  ( FIG. 5 ),  521  ( FIG. 6 ),  621  ( FIG. 6 ),  721  ( FIG. 6 ) can be arranged to dictate the opening mechanics of the can end  101 . For instance, referring again to  FIG. 3A , it will be appreciated that, upon actuation of the pull tab  115 , the disclosed rivet base scoreline  121  is structured to propagate towards the periphery  113  of the severable panel  103  and, in particular, towards the peripheral scoreline  111  thereof. Specifically, upon actuation (e.g., without limitation, lifting, pivoting and/or pulling (as shown, for example, in  FIGS. 9A-9C  discussed hereinbelow) of the pull tab  115 , the rivet base scoreline  121  severs and propagates toward the peripheral scoreline  111  of the can end  101 , thereby defining a bend axis  147 . The bend axis  147  extends generally perpendicularly with respect to the longitudinal axis  145  of the pull tab  115 , and is disposed between the outboard side  135  of the rivet  117  and the peripheral scoreline  111 , proximate to the peripheral scoreline  111 , as shown. 
     As shown in  FIGS. 7 and 8 , the example pull tab  115  includes a nose portion  151  and a lift portion  153  disposed opposite nose portion  151 , and being adapted to be lifted by an end user to initiate severing and/or removable of the severable panel  103 , as shown in  FIG. 9A . The nose portion  151  includes a number of apertures  155 , 156  and a rivet hole  157 . When the pull tab  115  is coupled to the can end  101 , the apertures  155 , 156  overlay at least a portion of the rivet base scoreline  121 , which is disposed beneath the pull tab  115 , as shown in  FIGS. 3A and 11F . In this manner, the apertures  155 , 156  of the pull tab  115  provide a mechanism (e.g., passageway) for receiving a suitable repair agent (not shown), as defined herein, in order that the repair agent is delivered to and sufficiently covers (e.g., coats; seals) the rivet base scoreline  121  disposed on the public side  107  of the can end severable panel  103  beneath the pull tab  115 . It will be appreciated that the pull tab  115  may have any suitable alternative number and/or configuration of apertures (not shown) other than the pair of apertures  155 , 156 , shown and described herein. The rivet hole  157  of the pull tab  115  receives the stem  120  of the rivet  117 , as best shown in  FIG. 3D . After the pull tab  115  is disposed on the stem  120  of the rivet  117 , the rivet  117  can be suitably staked in a generally well known manner to provide the finished rivet  117 , shown in  FIGS. 3C and 3D , thereby fastening the pull tab  115  to the severable panel  103 . 
     A method of opening the can end  101  is depicted sequentially in  FIGS. 9A ,  9 B, and  9 C. Specifically, the pull tab  115  is structured to be lifted ( FIG. 9A ), pivoted to a substantially inverted position ( FIG. 9B ), and pulled ( FIG. 9C ), in order to remove the severable panel  103  from the can  102 . The first step of lifting the pull tab  115 , shown in  FIG. 9A , is commonly referred to as the “pop” stage of the can opening process. The pop stage of opening the exemplary can end  101  begins with a venting operation wherein the pull tab  115  is lifted from the initial substantially horizontal position (see, for example,  FIG. 3C ) to sever the aforementioned segment  245  ( FIG. 4 ) of the rivet base scoreline (see, for example, rivet base scoreline  221  of  FIG. 4 ; see also rivet base scoreline  121  of  FIGS. 9A-9C ), thereby venting the can  102 . Continuing to lift the pull tab  115  causes the rivet base scoreline  121  to propagate toward the peripheral scoreline  111 . Then, the nose portion  151  of the pull tab  115  initially severs the peripheral scoreline  111 . The aforementioned bend axis  147  ( FIG. 3A ) is also formed at this stage. It will be appreciated that the pull tab  115  in accordance with the invention does not require any unique feature (e.g., without limitation, a tongue; a suitable protuberance) extending outwardly from the nose portion  151  thereof, in order to suitably sever the peripheral scoreline  111 , although such features could be optionally employed without departing from the scope of the invention. 
     The second opening stage, shown in  FIG. 9B , is commonly referred to as the “flip” stage of opening. The flip stage involves pivoting (e.g., rotating) the pull tab  115  to a substantially inverted position (e.g., without limitation,) about 200 degrees from the original substantially horizontal position), and engaging the rim of the can end  101 , as shown. The pull tab  115  can then be further rotated, using the rim of the can end  101  as a fulcrum, in order that the nose portion  151  of the pull tab  115  forces the severable panel  103  away from the can body  102 . The severable panel  103  reacts by shearing a substantial portion of the peripheral scoreline  111 . For example, in one non-liming embodiment of the invention, at least 40 percent of the peripheral scoreline  111  is severed during the second, or flip, stage of the can end opening process. As shown in Table 1 hereinbelow, this represents about 20 percent greater panel severance (e.g., tear) as compared to a conventional easy open can end (see, for example, can end  1  of  FIGS. 1 and 2 ). 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 INITIAL PANEL SHEAR 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Can 
                 Standard 
                 Standard 
                 Standard 
               
               
                   
                 End 
                 Aluminum Tab/ 
                 Aluminum Tab/ 
                 Steel Tab/ 
               
               
                   
                 101 
                 Aluminum End 
                 Steel End 
                 Steel End 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                 Initial Disc 
                 42.3 
                 21.8 
                 19.8 
                 18.4 
               
               
                 Tear (%) 
               
            
           
           
               
               
               
            
               
                 Average 
                 42.3 
                 20.0 
               
               
                 Tear (%) 
               
               
                   
               
            
           
         
       
     
     The third and final opening stage, which is shown in  FIG. 9C , is the pull and/or panel removal stage. Specifically, during this opening stage, the pull tab  115  is pulled away from the can body  102  in the direction of the arrow shown in  FIG. 9C . In response, the remaining portion of the peripheral scoreline  111  severs and the severable panel  103  follows the pull tab  115  until it is removed from the can end  101 . It will be appreciated that, because of the substantial portion (e.g., without limitation, at least about 40 percent) of the peripheral scoreline  111  that was previously severed during the previous flip stage ( FIG. 9B ) of the can end opening process, that less force is required to complete removal of the severable panel  103  than would otherwise be required. The improved opening mechanics of the exemplary can end  101  will be further appreciated with reference to Table 2 hereinbelow. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 OPENING FORCES 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Can 
                 Standard 
                 Standard 
                 Standard 
               
               
                   
                 End 
                 Aluminum Tab/ 
                 Aluminum Tab/ 
                 Steel Tab/ 
               
               
                   
                 101 
                 Aluminum End 
                 Steel End 
                 Steel End 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                 Score Pop 
                 3.15 
                 2.80 
                 4.75 
                  4.55 
               
               
                 Force 
               
               
                 Tab Flip 
                 6.55 
                 — 
                 — 
                 — 
               
               
                 Force 
               
               
                 Panel Pull 
                 5.25 
                 8.35 
                 8.80 
                 12.65 
               
               
                 Force 
               
               
                   
               
            
           
         
       
     
     As shown in Table 2, the opening mechanics associated with the exemplary can end  101  are substantially improved as compared to conventional can ends (see, for example, can end  1  of  FIGS. 1 and 2 ). For example, the pop force has been reduced by about one pound, from a standard average force of four pounds to approximately three pounds. The pull force (associated with the final pull stage of opening, shown in  FIG. 9C ) has been reduced by about 50 percent, from a standard average of ten pounds, to about five pounds. The can end opening stage that requires the greatest force is the flip stage ( FIG. 9B ), discussed hereinabove. Nonetheless, the force associated with the flip stage for opening can end  101  is about 6.5 pounds, which is still less than the highest force associated with a standard easy open can end. Additionally, the position of the pull tab  115  and the direction of the applied force during the flip stage ( FIG. 9B ) provides an advantageous mechanical advantage over the opening forces and opening mechanics associated with conventional easy open can ends (see, for example,  FIG. 10 , discussed hereinbelow). 
     The improved opening mechanics of the exemplary can end  101  as compared to a conventional easy open can end (see, for example, can end  1  of  FIGS. 1 and 2 ), will be further appreciated with reference to the comparative graph of  FIG. 10 . As shown in  FIG. 10 , the steps for opening the standard can end  1  are sequentially identified by reference numbers  50 ,  60  and  70 . Specifically, reference number  50  identifies the pop stage of opening a standard can end  1 , by lifting the pull tab  15 . Reference number  60  shows the standard can end  1 , fully popped and being flipped, and reference number  70  shows the pull stage of opening the standard can end  1 . The forces associated with these opening stages  50 , 60 , 70  are identified as specific locations on the solid plot line of  FIG. 10 . Specifically, the solid plot line depicts the forces applied to the pull tab  15  throughout the entire opening process of the standard can end  1 . By way of comparison, the dashed plot line of  FIG. 10  illustrates the forces applied to the pull tab  115  of the exemplary can end  101  throughout the entire opening process of the improved can end  101 . In particular, reference number  150  refers to the initial vent and pop stage, wherein the pull tab  115  is lifted to sever and propagate the rivet base scoreline  121  to define the bend axis  147  ( FIG. 3A ), as previously discussed. Reference number  160  correlates to a similar to that depicted by reference number  60  with respect to the standard can end  1 . Reference number  170  depicts the flip stage of opening the improved can end  101 , and reference number  180  shows the pull stage. By way of one non-limiting example, the pull stage  180  of the exemplary can end  101  involves applying about 5.25 pounds of force to the pull tab  115 . Accordingly, it will be appreciated that the forces identified in the graph of  FIG. 10  generally correlate with those which are set forth in Table 2 hereinabove. 
       FIGS. 11A-11F  show the general steps associated with a method of making a can end  101  in accordance with one non-limiting embodiment of the invention. For example, the can end  101  (e.g., can end shell) may be initially folded in a first step, shown in  FIG. 11A . In a subsequent step, depicted in  FIG. 11B , the rivet may be initiated as a bubble  117 ′.  FIG. 11C , shows a further rivet forming step in which the peripheral scoreline  111  may also be made. The rivet  117  may be finally formed and the can end  101  (e.g., can end shell) may be further folded in the step depicted in  FIG. 11D . Additional features such as, for example and without limitation, a suitable number and configuration of projections  161 , 163 , and beads  165 , 167 , 169  may be added to the severable panel  103  in a subsequent step, shown in  FIG. 11E . The rivet base scoreline  121  in accordance with the invention, may also be formed at this step. Finally, the pull tab  115  can be attached to the rivet  117 , and the rivet  117  can be staked, as shown in  FIG. 11F . 
     It will be appreciated that the method depicted in  FIGS. 11A-11F  generally involves the conversion of a can end shell into the desired can end  101  end product. It will also be appreciated that the method may include additional and/or different steps, and that such steps can be performed in a different sequence than that which is illustrated, all without departing from the scope of the invention. Additionally, as previously discussed, the can end  101  may undergo additional processing. For example and without limitation, the aforementioned repair agent (not shown) may be applied to the can end  101  to suitably seal the rivet base scoreline  121 . In this regard, the exemplary pull tab  115  and, in particular, the apertures  155 , 156  in the nose portion  151  thereof, facilitate delivery of the repair agent to the rivet base scoreline  121  to ensure that the rivet base scoreline  121  is effectively coated (e.g., sealed). 
     Accordingly, the disclosed can end  101  and associated method of making the same, provide a unique rivet base scoreline  121  that substantially improves the opening mechanics of the can end  101 . Additionally, the unique pull tab  115  of the can end  101  enables the rivet base scoreline  121  to be efficiently and effectively coated, as necessary, despite the fact that it is disposed on the public side  107  of the can end severable panel  103 , at least partially beneath the pull tab  115 . 
     While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.