Abstract:
An end closure for food and beverage containers provides controlled opening characteristics to prevent the unintentional missiling of a tear panel. The end closure comprises a score line that defines a portion of the tear panel, and the end closure may comprise one or more anti-missile features that inhibit the propagation of a fracture down a score line, which reduces the likelihood that a tear panel will inadvertently detach from the end closure and injure the user or another.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This Non-Provisional Application is a Continuation of U.S. application Ser. No. 14/209,055 filed Mar. 13, 2014, which claims the benefit of priority from U.S. Provisional Patent Application No. 61/800,373 filed Mar. 15, 2013, the entire disclosures of which are hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     Embodiments of the present invention generally relate to containers and container end closures, specifically container end closures with controlled opening characteristics. 
     BACKGROUND OF THE INVENTION 
     Containers, and more specifically metallic beverage containers, generally have a neck on an upper portion of a container body that is adapted for interconnection to an end closure. The end closure is typically formed from a flat sheet of metallic material and generally includes a pull tab or other form of stay on tab (“SOT”). Beverage containers commonly store carbonated beverages, thus, both the container body and the end closure are required to withhold internal pressures up to 90 psi without catastrophic failure or permanent deformation. Further, the end closure must be manufactured, stacked, shipped, and sent to a filler prior to being seamed onto a container body filled with a carbonated beverage. Therefore, the container body and end closure must be designed to resist deformation and failure while utilizing thin metallic materials and allowing compact stacking during shipping and manufacturing. 
     Food and beverage containers with pull tabs or SOTs are generally known. Various SOTs and related features are disclosed, by way of example, in U.S. Pat. No. 7,926,675 to Rieck et al., the entire disclosure of which is hereby incorporated by reference in its entirety. Known devices typically contain a score and an anti-fracture score that defines a tear panel. A user may pivot the pull tab into the tear panel to dispense the contents of the container. Such an arrangement, particularly where can contents are placed under pressure, pose various complications and challenges with opening the container. Such complications include, but are not limited to, rapid score flexure or breakage, which may result in the tear panel disconnecting from the end closure and shooting outward from the end closure and thus becoming a “missile.” 
     Previous attempts have been made to manufacture end closures with controlled opening characteristics. One such feature is a check slot, which is generally a portion of the score that is cut shallower than the rest of the score, or in other words, the check slot has a larger residual of material underneath the score. A check slot is disclosed in U.S. Patent Publication No. 2011/0303672 to Fields at al., the entire disclosure of which is hereby incorporated by reference in its entirety. The additional material underneath the check slot inhibits propagation of the fracture that occurs when a user pivots a pull tab into the tear panel. However, more score residual can make the end closure difficult to open, and a score with a non-uniform depth adds complexity to the manufacturing process of the end closure, and thus expense. 
     Other attempts to provide an end closure with a tear panel that will not detach and turn into a missile include an end closure with one anti-missile feature that is an indention or depression crossing the anti-fracture score but not crossing the main score and a check slot portion of the main score. However, each of these features require different tooling and machinery, and thus, manufacturing can be expensive. 
     Due to the numerous limitations associated with the prior art described above, the following disclosure describes an improved end closure that is adapted for interconnection to a container body and that employs anti-missile features, which eliminate the missiling effect of the tear panel without increasing the difficulty of opening the container. 
     SUMMARY OF THE INVENTION 
     These and other needs are addressed by the various embodiments and configurations of the present invention. This disclosure relates to novel systems, devices, and methods for providing a food and beverage end closure with anti-missile features. The novel end closure provided herein allows the user to open the end closure without the tear panel inadvertently detaching and thus becoming a missile, which may harm the user. Note that the term “score” may be used herein interchangeably with “score line” or sometimes “main score.” Additionally, the term “anti-missile” may be used herein interchangeably with “anti-missile feature.” 
     It is one aspect of the present invention to provide an end closure that controls the release of pressure from a container when a user opens said container. After the user pivots the pull tab into the tear panel (i.e., initially flexes the score), the score begins to fracture. Initially, the start of the fracture allows the interior pressure of the container to equalize with the atmospheric pressure. In some embodiments of the present invention, a double anti-missile feature slows down the propagation of the fracture along the score to prevent the tear panel from inadvertently detaching and becoming a missile. 
     It is another aspect of the present invention to provide an end closure that reduces or eliminates the need for a check slot. Containers store different contents at different pressures. For example, soda or pop is generally stored at a higher pressure than beer. Thus, some lower pressure containers do not require a check slot to control opening characteristics of the end closure. When the check slot is reduced or eliminated, the machinery and manufacturing methods used to create score lines on end closures may be standardized across containers with varying pressures, which reduces the cost of manufacturing. 
     It is an another aspect of the present invention to provide an end closure with anti-missile features in combination with a check slot to more robustly control the opening of a tear panel. The check slot portion of a score has a larger residual of material underneath the check slot, and an anti-missile feature disposed proximate to the check slot may inhibit propagation of a fracture along the score to an even greater degree. This combination may allow the end closure and the container to store beverages or contents at even greater pressures. 
     It is another aspect of the present invention to provide different opening characteristics of an end closure. To provide these characteristics, anti-missile features may be disposed in a variety of locations, orientations, shapes, and numbers. For example, anti-missile features positioned on either side of the score at the same location on the score may provide an abrupt slowdown in the propagation of the fracture down the score. In other embodiments, anti-missile features may be adjacent on the same side of the score but spaced far apart or set off of the score by a distance, which may produce a more gradual slowdown in the propagation of the fracture down the score. Further yet, in some embodiments combinations of anti-missile features can provide a series of opening effects such as a gradual slow down in the propagation of the fracture down the score followed by an abrupt slow down. The various opening characteristics provided herein not only improve the safety of the end closure but also provide also provide the user with a comfortable opening motion that is not overly cumbersome or difficult. 
     It is yet another aspect of the present invention to provide controllable opening features for a wide range of food and beverage containers including, but not limited to, pressurized beverage containers with SOTs secured by a rivet, food containers with tear away lids, and full panel easy-open end tabs. The present invention may enjoy implementation in these containers because end closures and containers are designed to be as thin as reasonably possible to save on material costs and to improve openability of the container. In addition, although some embodiments of the present invention generally relate to end closures and containers made from metal, other embodiments of the present invention and features described herein may be implemented using plastic or any other type of material commonly used in end closures and containers. 
     It is another aspect of the present invention to provide an end closure with anti-missile features that is manufactured with conventional manufacturing equipment. In some embodiments, the anti-missile feature is formed using an insert, a knife, forms, or coins, to push the metal material toward the score. In a preferred embodiment, the anti-missile feature is formed using an insert to create an indentation in the end closure and move metal toward the main score. The insert may comprise shaped features that protrude from the insert and correspond to anti-missile features described herein. Further, devices and methods of the present disclosure contemplate forming an anti-missile feature on an end closure at various stages of manufacture. For example, an anti-missile feature may be formed on an end panel before, during, or after formation of features such as debossed features, rivets, frangible score lines defining opening areas, etc. In preferred embodiments, the anti-missile features are added after the score or scores are created on the end panel. 
     It is another aspect of the present invention to provide an end closure with anti-missile features that do not decrease tab access or increase the difficulty in opening the end closure. Embodiments of the present disclosure allow the stacking and conveying of multiple end closures during production and shipping because these embodiments do not affect the position of the tab or other features of the end closure. 
     Various embodiments of the present invention provide an end closure with anti-missile features in a variety of locations. In some embodiments, the anti-missile features are located proximate a rivet, a score loop, a content side of the end closure, a public side of the end closure, and/or over an anti-fracture score. Further, the anti-missile feature may be positioned at a number of distances from the score line. In a preferred embodiment, the anti-missile feature does not cross the main score, which reduces pop and push numbers, thereby making the end closure easier to open. Locating anti-missile features in these locations, or combination of locations, provides a variety of different opening characteristics of the end closure. 
     In a similar vein, in some embodiments of the present invention, anti-missile features are disposed in a variety of orientations. Some anti-missile features have a longitudinal axis, which may be substantially perpendicular to the main score. In other embodiments the anti-missile feature&#39;s longitudinal axis may be disposed substantially parallel to the score to provide a deformation or distortion to a greater portion of the score. In yet further embodiments the anti-missile feature is oriented an angle relative to the score, and in some embodiments a bottom surface of the anti-missile feature does not lie in a common plane with the end closure. These various orientations, and others, provide varying opening characteristics of the end closure. 
     In some embodiments of the present invention, anti-missile features have various shapes to provide different opening characteristics of the end closure. Shapes of anti-missile features when viewed from a top plan view include, but are not limited to, a rectangle, an ovoid, any polygon such as a hexagon, a trapezium, and a “U” shape. When viewed from a cross-sectional perspective, the anti-missile feature also has a variety of shapes and orientations. The bottom surface of the anti-missile feature may be flat, curved, or asymmetrical with chamfered or radiused edges. Further yet, the anti-missile feature may come in a variety of sizes as well. The physical characteristics of the anti-missile feature help determine the deformation or distortion in the material of the main score, which provides different opening characteristics of the end closure. 
     In various embodiments of the present invention, an end closure comprises a double anti-missile feature. In one embodiment, the end closure comprises two anti-missile features that are the same size and angle. These anti-missile features may be disposed proximate the rivet, proximate the main score, and over the anti-fracture score. The double anti-missile feature provides a deformation or distortion of the metal of the main score at two locations along the score and another deformation or distortion of the main score between the two anti-missile features. This double anti-missile feature slows the opening of the tear panel in this section of the main score. 
     One embodiment of the present invention is a metallic end closure with controlled opening characteristics comprising a peripheral curl which is adapted for interconnection to a neck of a container body; a central panel; a countersink positioned between the peripheral curl and the central panel; a pull tab having a nose end and a tail end, wherein the pull tab is operably interconnected to the central panel; a first score line in the central panel which defines a tear panel; and at least one anti-missile feature positioned proximate to the first score line which deforms at least a portion of the first score line to affect the rate at which the tear panel opens along the first score line when a user pivots the nose end of the pull tab into the tear panel. 
     Another embodiment of the present invention is a method of forming a metallic end closure with an anti-missile feature comprising providing a blank metallic material; forming an end closure comprising a peripheral curl, a central panel, and a countersink positioned there between; forming a first score line on the central panel, wherein the first score line substantially defines a tear panel; providing an insert tool with at least one shaped feature disposed on a distal end of the insert tool; pressing the insert tool into at least one of the central panel and the tear panel such that the at least one shaped feature contacts the at least one of the central panel and the tear panel at a location proximate the first score line, wherein the at least one shaped feature creates at least one anti-missile feature in the end closure; and interconnecting a pull tab to the central panel of the end closure, wherein a nose of the pull tab is positioned over the tear panel. 
     Yet another embodiment of the present invention is a metallic end closure with controlled opening characteristics comprising a peripheral curl which is adapted for interconnection to a neck of a container body; a central panel having a rivet disposed in a central location on a public side of the central panel; a countersink positioned between the peripheral curl and the central panel; a pull tab having a nose end and a tail end, wherein the pull tab is operably interconnected to the central panel; a first score line on the central panel defining a tear panel; a second score line on the tear panel oriented substantially parallel to the first score line, wherein the second score line is shallower than the first score line; and a first anti-missile feature and a second anti-missile feature, wherein the first and second anti-missile features are disposed over the second score line, proximate the first score line, and proximate a rivet which interconnects the pull tab to the central panel, wherein the first and second anti-missile features deform at least a portion of the first score line to inhibit propagation of a fracture along the first score line when a user engages the pull tab and forces the nose end into the tear panel. 
     The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. Moreover, references made herein to “the present invention” or aspects thereof should be understood to mean certain embodiments of the present invention and should not necessarily be construed as limiting all embodiments to a particular description. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description of the Invention and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detailed Description, particularly when taken together with the drawings. 
     These and other advantages will be apparent from the disclosure of the invention(s) contained herein. The above-described embodiments, objectives, and configurations are neither complete nor exhaustive. As will be appreciated, other embodiments of the invention are possible using, alone or in combination, one or more of the features set forth above or described in detail below. Furthermore, the Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. The present invention is set forth in various levels of detail in the Summary of the Invention, as well as in the attached drawings, the Detailed Description of the invention, and the Claims. No limitation as to the scope of the present invention is intended to either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detailed Description, particularly when taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Those of skill in the art will recognize that the following description is merely illustrative of the principles of the present invention, which may be applied in various ways to provide many different alternative embodiments. This description is made for illustrating the general principles of the teachings of this invention and is not meant to limit the inventive concepts disclosed herein. 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of the invention. 
         FIG. 1  is a top plan view of one embodiment of an end closure with anti-missile features; 
         FIG. 2  is an enlarged top plan view of the anti-missile features shown in  FIG. 1 ; 
         FIG. 3  is a top plan view of an alternative embodiment of an end closure with a dimple-shaped anti-missile feature; 
         FIG. 4  is a top plan view of an alternative embodiment of an end closure with a trapezium-shaped anti-missile feature; 
         FIG. 5  is a top plan view of an alternative embodiment of an end closure with a U-shaped anti-missile feature; 
         FIG. 6A  is a top plan view of an alternative embodiment of an end closure with a single, wide anti-missile feature; 
         FIG. 6B  is another top plan view of the embodiment shown in  FIG. 6A  where reference lines “C”, “D”, and “E” are visible; 
         FIG. 6C  is a cross-sectional elevation view of the embodiment shown in  FIG. 6B  taken at line “C-C”; 
         FIG. 6D  is a cross-sectional elevation view of the embodiment shown in  FIG. 6B  taken at line “D-D”; 
         FIG. 6E  is a cross-sectional elevation view of the embodiment shown in  FIG. 6B  taken at line “E-E”; 
         FIG. 7  is an isometric view of an embodiment of an insert tool; 
         FIG. 8  is front elevation view of the insert tool of  FIG. 7 ; 
         FIG. 9  is a side elevation view of the insert tool of  FIG. 7 ; and 
         FIG. 10  is an enlarged side elevation view showing shaped features of the insert tool of  FIG. 7 . 
     
    
    
     To assist in the understanding of the embodiments of the present invention the following list of components and associated numbering found in the drawings is provided herein: 
     
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Number 
                 Component 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 96 
                 Container Body 
               
               
                 100 
                 End Closure 
               
               
                 104 
                 Central Panel 
               
               
                 108 
                 Panel Radius 
               
               
                 112 
                 Peripheral Curl 
               
               
                 116 
                 Countersink 
               
               
                 120 
                 Rivet 
               
               
                 124 
                 Deboss Area 
               
               
                 128 
                 Main Score 
               
               
                 130 
                 Main Score Depth 
               
               
                 132 
                 Anti-Fracture Score 
               
               
                 134 
                 Anti-Fracture Score Depth 
               
               
                 136 
                 Score Loop 
               
               
                 140 
                 Pour Opening 
               
               
                 144 
                 Check Slot 
               
               
                 145 
                 First Check Slot End 
               
               
                 146 
                 Second Check Slot End 
               
               
                 148 
                 First Anti-Missile 
               
               
                 149 
                 First Anti-Missile Length 
               
               
                 150 
                 Missile-Fracture Intersection 
               
               
                 151 
                 First Anti-Missile Depth 
               
               
                 152 
                 Second Anti-Missile 
               
               
                 156 
                 Main Score Residual 
               
               
                 160 
                 Anti-Fracture Score Residual 
               
               
                 200 
                 Insert Tool 
               
               
                 204 
                 Body 
               
               
                 208 
                 First End 
               
               
                 212 
                 Second End 
               
               
                 216 
                 Flange 
               
               
                 220 
                 First Shaped Feature 
               
               
                 224 
                 Second Shaped Feature 
               
               
                 228 
                 Body Outer Diameter 
               
               
                 232 
                 Flange Outer Diameter 
               
               
                 236 
                 Flat Side Dimension 
               
               
                 238 
                 Shaped Feature Width 
               
               
                 240 
                 First Horizontal Offset 
               
               
                 244 
                 Second Horizontal Offset 
               
               
                 248 
                 Overall Length 
               
               
                 252 
                 Flange Length 
               
               
                 256 
                 Shaped Feature Length 
               
               
                 260 
                 First Body Radius 
               
               
                 264 
                 Second Body Radius 
               
               
                 268 
                 Shaped Feature Height 
               
               
                 272 
                 Angle 
               
               
                 276 
                 First Transition 
               
               
                 280 
                 Second Transition 
               
               
                 284 
                 First Centerline 
               
               
                 288 
                 Second Centerline 
               
               
                 292 
                 First Transition Distance 
               
               
                 296 
                 Second Transition Distance 
               
               
                   
               
             
          
         
       
     
     It should be understood that the drawings are not necessarily to scale, and various dimensions may be altered. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. 
     DETAILED DESCRIPTION 
     Those of skill in the art will recognize that the following description is merely illustrative of the principles of the disclosure, which may be applied in various ways to provide many different alternative embodiments. This description is made for illustrating the general principles of the teachings of this disclosure invention and is not meant to limit the inventive concepts disclosed herein. 
     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. 
     It should be understood that the drawings are not necessarily to scale, and various dimensions may be altered. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. 
       FIG. 1  shows a top plan view of the public side of an end closure  100  which is interconnected to the neck of container body  96 . The end closure  100  in this embodiment generally comprises a central panel  104  that represents the central area of the end closure  100  in  FIG. 1 . A panel radius  108  defines the outer edge of the central panel  104 . Moving outward from the panel radius  108  is a countersink  116  that leads from the central panel  104  to a chuckwall, which is interconnected to peripheral curl  112 , and the peripheral curl  112  allows for interconnection to the container body  96 . The central panel  104 , the panel radius  108 , the countersink  116 , the chuckwall, and the peripheral curl  112  are generally circular in shape as depicted in  FIG. 1 . One skilled in the art will appreciate that any one of these features may have general modifications in shape or dimensions without deviating from the scope of the invention. 
     Also shown in  FIG. 1  are two lines that pass through the center of a rivet  120 , wherein the two lines may be used to reference the location of other features disposed on the end closure  100 . One line passes vertically through the rivet  120 , and one line passes horizontally through the rivet  120 . These lines provide reference to planes that pass through the longitudinal axis of the container  96 . In this embodiment, the rivet  120  is centered on the end closure  100 , but in other embodiments, the rivet  120  may be off center and the reference lines will not necessarily partition the enclosure  100  into halves. 
     The rivet  120  provides a location for a pull tab (not shown) to be disposed. A user may engage the rear portion of the pull tab to provide a force on the nose portion to a tear panel defined by a main score  128 . As the user continues to engage and pivot the pull tab, the main score  128  fractures and the tear panel is disposed into the container  96  to define a pour opening  140 . In  FIG. 1 , the tear panel is located proximate the rivet  120  and is defined by two score lines. The outer score line is the main score  128 , and the inner score line is the anti-fracture score  132 . Typically, the anti-fracture score  132  has a shallower depth than the main score  128 . In other words, the anti-fracture score  132  has a larger score residual, or larger amount of material underneath the score, than the main score  128 . The anti-fracture score  132  is located proximate to the main score  128  to relieve stress areas around the main score  132  and prevent accidental opening of the main score  128 . 
     The two score lines  128 ,  132  may join together at a score loop  136 , which is located proximate to the rivet  120 . In the embodiment depicted in  FIG. 1 , the score loop  136  is located to the lower left of the rivet  120 , and the score loop  136  is where the end closure  100  begins to fracture as a user engages the pull tab. As the user continues to engage and pivot the pull tab, the fracture propagates down the main score  128 , defining the tear panel. As the main score  128  continues to fracture around the perimeter of the tear panel, the main score  128  may simply terminate at a location proximate to the score loop  136  such that a small portion of the end closure  100  does not fracture, and thus the tear panel that passes through the pour opening  140  remains attached to the end closure  100  via a hinge. One skilled in the art will appreciate a variety of configurations of the terminus of the main score  128  including, but not limited to, a second score loop. 
     In the embodiment shown in  FIG. 1 , the rivet  120 , the score lines  128 ,  132 , and the pour opening  140  are disposed on a deboss area  124 , which is an area of the central panel  104  that is slightly depressed or lower than the rest of the central panel  104 . The deboss area  124  aids in the prevention of interference with the pull tab during production, storage, or stacking of the containers  96 , where such interference may lead to accidental opening of the container  96 . One skilled in the art will appreciate a deboss area  124  of varying depths, sizes, shapes, and locations, or end closure which are void of a deboss area  124 . 
     As mentioned above, complications can arise during opening of the end closure  100  such as rapid fracture of the main score  128  that results in the tear panel becoming a missile or inadvertently detached. One feature that aids in mitigation of this problem is the check slot  144 . The check slot  144  in  FIG. 1  is located on the main score  128  on the opposite side of the rivet  120  from the score loop  136 . Typically, the check slot  144  is cut to a shallower depth than the main score  128 . In other words, the check slot  144  has a larger score residual. The purpose of the check slot  144  is to inhibit propagation of the fracture along the main score  128 . The fracture begins in the score loop  136 , then travels to the check slot  144  where the fracture is temporarily stopped or slowed down. This configuration allows the pressure inside the container  96  to equalize with the pressure of the atmosphere before the fracture continues to propagate past the check slot  144 . One skilled in the art will appreciate check slots  144  of varying depths, lengths, and locations that may prove advantageous. 
     Also disposed on the central panel  104  are a first anti-missile feature  148  and a second anti-missile feature  152 . The anti-missile features  148 ,  152  “push” material of the central panel towards the main score  128 , which deforms a portion of the main score  128 . In some embodiments this deformation is the pinching together of the two sides of the main score  128 . When the two sides of the main score  128  are pinched, the propagation of the fracture is inhibited, temporarily stopped, or otherwise impeded. In some embodiments, the anti-missile features  148 ,  152  allow for the reduction in size of the check slot  144 , and in some embodiments the anti-missile features  148 ,  152  allow for the complete elimination of the check slot  144 . 
       FIG. 2  depicts a top plan view of the end closure  100  shown in  FIG. 1 , and wherein the anti-missile features  148 ,  152  are enlarged for clarity. In this embodiment, the anti-missile features  148 ,  152  are both oriented at an angle of approximately 45 degrees from a horizontal plane. The second anti-missile feature  152  is offset from the first anti-missile feature  148  by approximately 0.026 inches in the horizontal direction, and approximately 0.030 inches in the vertical direction. The anti-missile features  148 ,  152  are disposed proximate the check slot  144  portion of the main score  128 . The inclusion of the second anti-missile feature  152  provides a second location of deformation or distortion of the material of the main score  128 . Further, there is deformation or distortion of the material along the main score  128  between the first anti-missile feature  148  and the second anti-missile feature  152 . 
     One skilled in the art will appreciate various angles and configurations of anti-missile features  148 ,  152  that provide various benefits. In some embodiments, anti-missile features  148 ,  152  are disposed on either side of the main score  128  at a common point on the main score  128 . If the anti-missile features  148 ,  152  are oriented substantially perpendicular to the main score  128 , then the main score  128  is deformed from both sides instead of only one side. This anti-missile configuration results in a more thorough deformation of the end closure  100  and the main score  128 . In some embodiments, the deformation is a more complete and robust deformation or distortion of the two sides of the main score  128 . Therefore, as the fracture propagates down the main score  128  the fracture will more abruptly slow down before resuming down the main score  128 . This produces a different feel for the user and a different venting response for the end closure  100 , all while reducing the risk of the tear panel turning into a missile. 
     In a further embodiment, the anti-missile features are substantially parallel to the main score  128 . This exposes a greater length of the main score  128  to the deformations in the end closure  100  produced by the anti-missile features  148 ,  152 . In this parallel orientation, anti-missile features  148 ,  152  may be disposed in series along the main score  128 . This configuration will produce a deformation that has a less pronounced effect on the main score  128  but affects a greater length of the score  128 . Therefore, this configuration will provide a smoother feel to the user as he or she opens the container and will provide a different venting response for the end closure  100 , again, all while reducing the risk of the tear panel turning into a projectile or missile. 
     In other embodiments, two anti-missile features  148 ,  152  are substantially parallel with one feature disposed on each side of the main score  128  at a common location on the main score  128 . This configuration will produce a more robust deformation of the main score  128  since the anti-missile features  148 ,  152  are disposed on either side, and the deformation is along a length of the main score  128 . As mentioned above, this provides a different feel to the user and a different venting response. 
     Further, the anti-missile features  148 ,  152  need not be disposed proximate to a common point on the main score  128 . Other embodiments of the present invention have anti-missile features  148 ,  152  that are disposed on either side of the main score  128  but at different locations along the main score  128 . Depending on the offset between the anti-missile features  148 ,  152 , the deformation of the end closure  100  and the resulting effect may be a twisting or similar distortion of the main score  128 , which provides yet another feel for the user and a difference in performance of the end closure  100 . 
     Embodiments of the present invention may comprise any number of anti-missile features. Some embodiments of the present invention utilize one anti-missile feature, while other embodiments utilize two or more anti-missile features. In the embodiment where the two anti-missile features  148 ,  152  are disposed on either side of the main score  128 , substantially perpendicular to the main score  128 , and located at a common point on the main score  128 ; a series of these pairs of anti-missile features may be disposed along the length of the main score  128  to provide a series of abrupt slow-downs in the propagation of the fracture along the main score  128 . Alternatively, some embodiments may have asymmetric combinations of anti-missile features  148 ,  152  wherein the anti-missile features  148 ,  152  are disposed on either side of the main score  128  but never at a common location on the main score  128 . This configuration of the main score  128  may provide a deformation that is a twisting or distortion of the main score  128  that produces a particular effect on the propagation of the main score  128 . 
     In some embodiments, the shape of the main score  128  drives the location, shape, orientation, and number of anti-missile features  148 ,  152 . When viewed in cross-section, the main score  128  may be shaped as a “V” or a “U”. Further, the main score  128  may have a bottom surface that is substantially perpendicular to the two side walls of the main score  128 . The main score  128  may have any number of profiles that are commonly known in the art. The profiles that have a large distance between the two sides may necessitate a more aggressive or robust anti-missile  148 ,  152  configuration. Whereas a narrow “V” with relatively close sides may require a less aggressive or robust anti-missile  148 ,  152  configuration. 
       FIGS. 3-6E  show examples of the various shapes of the anti-missile features  148 ,  152 . These are only exemplary in nature and are not meant to be limiting. The various shapes provide different deformations or distortions to the main score  128 , and thus varying opening characteristics of the end closure  100 .  FIG. 3  shows a top plan view of an end closure  100  where the first anti-missile feature  148  is circular or dimple-shaped. In this embodiment, the first anti-missile feature  148  pushes material radially from the center of the first anti-missile feature  148 . This allows for a greater length of the main score  128  to be deformed or distorted. 
       FIG. 4  shows a top plan view of an end closure  100  where the first anti-missile feature  148  is trapezium-shaped. In other words, the first anti-missile feature  148  has four sides, and no two sides are parallel. The side of the first anti-missile feature  148  proximate the main score  128  is substantially parallel to the main score  128 . This allows the first anti-missile feature  148  to deform or distort as much of the main score  128  as possible while retaining a similar angle from horizontal as the first anti-missile feature  148  depicted in  FIG. 2 . Further, the trapezium shape of the first anti-missile feature  148  allows for a greater area of the central panel  104  to be “pushed” toward the main score  128 , which provides a more through deformation or distortion of the main score  128 . 
       FIG. 5  shows a top plan view of an end closure  100  where the first anti-missile feature  148  has an arcuate shape and wherein the ends of the legs of the “U” are pointing away from the main score  128 . This orientation of the “U” allows a greater portion of the first anti-missile feature  148  to be located proximate the main score  128 . In turn, a greater portion of the main score  128  is deformed or distorted, and the propagation of the fracture during opening of the end closure  100  is slowed down or temporarily stopped. The two legs of the first anti-missile feature  148  in  FIG. 5  are not substantially parallel. Rather, the two legs are offset at an angle from a plane that traverses the anti-missile feature  148  in the longitudinal direction. One skilled in the art will appreciate other embodiments of the present invention that have an offset angle between approximately 180 degrees and approximately −15 degrees. 
       FIG. 6A  shows a top plan view of an end closure  100  that has a relatively wide first anti-missile feature  148 . In this embodiment, the width of the first anti-missile feature  148  is approximately twice the width of the first anti-missile feature  148  depicted in  FIG. 2 . The double width means there is twice as much area of the central panel  104  that is being “pushed.” This allows for a more thorough deformation or distortion of the main score  128 , which results in a slow down or temporary stop in the propagation of the fracture of the main score  128 . 
       FIG. 6B  shows an enlarged plan view of the end closure  100  of  FIG. 6A  including a first check slot end  145  that is disposed proximate the rivet  120  and a second check slot end  146  that is disposed on the end of the check slot  144  opposite the first check slot end  145 . Also shown in  FIG. 6B  is reference line “C-C”, reference line “D-D”, and reference line “E-E”. Reference line “C-C” traverses the longitudinal length of the first anti-missile feature  148  and is perpendicular to the central panel  104 . reference line “D-D” traverses the lateral dimension of the first anti-missile feature  148  at the end of the first anti-missile feature  148  that is proximate the anti-fracture score  132 . Reference line “D-D” is also oriented perpendicular to the central panel  104 . Reference line “E-E” is substantially perpendicular to the main score  128  and the anti-fracture score  132 , and the reference line “E-E” is oriented perpendicular to the central panel  104 . 
       FIG. 6C  shows a cross-sectional view of the end closure  100  at reference line “C-C”. In the background of this view is the rivet  120 . The anti-fracture score  132  intersects the first anti-missile feature  148  at the missile-fracture intersection  150 , and the anti-fracture score  132  continues to travel to the left in  FIG. 6C  as shown by a dashed line. Similarly the check slot  144  is shown on the right side of  FIG. 6C . Traveling leftward, the check slot  144  terminates at the first check slot end  145 . The main score  128  continues to travel to the left of the check slot  144  in  FIG. 6C  as shown by a dashed line. 
     Finally, the first anti-missile feature  148  is shown in  FIG. 6C , which is disposed across the anti-fracture score  132  but not the main score  128 . The first anti-missile feature  148  has a first anti-missile feature length  149 , which is 0.1 inches in this embodiment. 
       FIG. 6D  shows a cross-sectional view of the end closure  100  at reference line “D-D”. The main score  128  is disposed on the left side of  FIG. 6D , and the main score  128  has a main score depth  130 . In this embodiment, the main score depth  130  is approximately 0.0045 inches. Next,  FIG. 6D  shows a view down the longitudinal direction of the first anti-missile feature  148 . The first ant-missile feature  148  has a first anti-missile depth  151 . In preferred embodiments, the first anti-missile depth  151  is between approximately 0.0070 inches and 0.0010 inches. In more preferred embodiments, the first anti-missile depth  151  is between approximately 0.0030 inches and 0.0050 inches. In a most preferred embodiment, the first anti-missile feature depth  151  is approximately 0.0040 inches. Lastly, the anti-fracture score  132  is disposed to the right of the first anti-missile feature  148  in  FIG. 6 . The anti-fracture score  132  has an anti-fracture score depth  134 , which is approximately 0.0035 inches in this embodiment of the present invention. 
       FIG. 6E  shows a cross-sectional view of the main score  128  and the anti-fracture score  132  at reference line “E-E”. From this view, the anti-fracture score  132  is located on the left and the main score  128  is located on the right. The top side of the end closure is the public side of the container and the bottom side of the end closure is the content side of the container. An anti-fracture score residual  160  is measured from the bottom of the end closure to the bottom of the anti-fracture score  132 . Likewise, a main score residual  156  is measured from the bottom of the end closure to the bottom of the main score  128 . Thus, while the anti-fracture score  132  has a shallower depth than the main score  128 , the anti-fracture score residual  160  is larger than the main score residual  156  by approximately 0.002 inches. 
       FIG. 7  shows an isometric front perspective view of an insert tool  200  used to make an anti-missile feature. In one embodiment, the insert tool  200  has a cylinder-shaped body  204  with a first end  208  and a second end  212 . The first end  208  comprises a flange  216  such that the insert tool  200  may be secured during the manufacturing process of the anti-missile features. The flange  216  in this embodiment is shaped like a flat cylinder. The second end  212  of the insert tool  200  comprises a first shaped feature  220  and a second shaped feature  224 . The shaped features  220 ,  224  are what form the anti-missile features, and the shaped feature  220 ,  224  may be configured to generate any anti-missile features described elsewhere herein. 
       FIG. 8  shows a front elevation view of the insert tool  200  where the working end of the insert tool is visible. In this embodiment, an outer diameter  228  of the body  204  is between approximately 0.1700 and 0.1698 inches, with a position tolerance of approximately 0.0004 inches. An outer diameter  232  of the flange  216  is approximately 0.25 inches with a position tolerance of approximately 0.1 inches. Further, the outer diameter  232  of the flange  216  has a flat side. The flat side dimension  236  can be referenced from a central plane of the flange  216 . In this embodiment, the flat side dimension  236  is between approximately 0.0853 and 0.0855 inches. 
       FIG. 8  also shows the two shaped features  220 ,  224 , which are substantially the same size in this embodiment. The shaped features  220 ,  224  have a rectangular shape in  FIG. 8 , where the longer, width dimension  238  of the shaped features  220 ,  224  is between approximately 0.101 and 0.099 inches. Further, this longer dimension is substantially parallel with the flat side of the flange  216 . 
     The shaped features&#39;  220 ,  224  horizontal position, as shown in  FIG. 8 , can be expressed in terms of offset from a vertical plane through the center of the body  204 . The first horizontal offset  240  is measured from the left edge of the first shaped feature  220  to the vertical plane. In this embodiment, the first horizontal offset  240  is between approximately 0.027 and 0.025 inches. The second horizontal offset  244  is measured from the left edge of the second shaped feature  224  to the vertical plane. In this embodiment, the second horizontal offset  244  is between approximately 0.051 and 0.049 inches. 
       FIG. 9  shows a side elevation view of the insert tool  200 . The insert tool  200  has an overall length  248  measured from the top of the flange  216  down to the working edge of the shaped features  220 ,  224 . In this embodiment, the overall length  248  is approximately 0.688 inches. The flange  216  also has a length  252  in  FIG. 9 , which is between approximately 0.065 and 0.063 inches. Finally, the shaped features  220 ,  224  have a length  256  measured from the end of the tool body  204  to the tip of the shaped features  220 ,  224 . The shaped feature length  256  is between approximately 0.0095 and 0.0085 inches. 
     Also shown in  FIG. 9  are two radiuses of the body  204  of the tool insert  200 . The first radius  260  of the body  204  extends from the body  204  at the first end  208  and blends into the bottom surface of the flange  216 . The first body radius  260  in this embodiment has a radius of curvature of approximately 0.03 inches. The second radius  264  of the body  204  is a radiused edge located at the second end  212  of the body  204 . The second radius  264  in this embodiment has a radius of curvature of approximately 0.005 inches. 
     The surface of the flange  216  in this embodiment comprises a burrless etch to remove any leftover burrs from previous manufacturing. In other embodiments of the present invention, the flange  216  does not comprise a burrless etch. In further embodiments, other components of the insert tool  200  may also comprise a burrless etch. One skilled in the art will appreciate which components to apply a burrless etch to in order to enhance the performance of the present invention. 
       FIG. 10  shows an enlarged detailed view of the second end  212  of the tool insert  200 . The detailed view is at a scale of approximately 20:1.  FIG. 10  shows the size of the shaped features  220 ,  224 . As shown in  FIG. 9 , the shaped feature length  256  is between approximately 0.0095 and 0.0085 inches. The shaped features  220 ,  224  are flat at the end of the shaped feature length  256 , and this flat surface may be defined as a shaped feature height  268 . In this embodiment, the shaped feature height  268  is between approximately 0.0125 and 0.0115 inches, with a position tolerance of approximately 0.0005 inches. 
     The shaped features  220 ,  224  taper from the flat surface to the second end  212  of the body  204  at an angle  272 , which is measured between the edge that tapers from the above the shaped features  220 ,  224  and the edge that tapers from below the shaped features  220 ,  224 . The angle  272  in this embodiment is approximately 50 degrees. Further, there is a first transition  276  between the flat surface and the two edges that taper away from the flat surface. In this embodiment, the first transition  276  is a radiused edge that has a radius of curvature between approximately 0.003 and 0.001 inches. There is also a second transition  280  between the two edges that taper away from the flat surface and the second end  212  of the body  204 . In this embodiment, the second transition  280  is a radiused edge that has a radius of curvature between approximately 0.003 and 0.001 inches. 
       FIG. 10  also shows the positions of the shaped features  220 ,  224  expressed in terms of offset from a horizontal plane through the center of the body  204 . The first shaped feature  220  has a first centerline dimension  284  between the centerline of the first shaped feature  220  and the horizontal plane. In this embodiment, the first centerline dimension  284  is approximately 0.033 inches. Likewise, the second shaped feature  224  has a second centerline dimension  288  between the centerline of the second shaped feature  224  and the horizontal plane. In this embodiment, the second centerline dimension  288  is approximately 0.062 inches. 
     The positions of the shaped features  220 ,  224  may also be expressed in terms of the first transitions  276 . The distance between the uppermost first transition  276  of the first shaped feature  220  and the horizontal plane may be identified as the first transition distance  292 , which is 0.0264 inches in this embodiment. Similarly, the distance between the uppermost first transition  276  of the second shaped feature  220  and the horizontal plane may be identified as the second transition distance  296 , which is approximately 0.0554 inches in this embodiment. As mentioned above, the dimensions of the shaped features  220 ,  224 , the spatial relationship among shaped features  220 ,  224  can vary to produce any of the anti-missile features described herein. 
     The material of the insert tool  200  in this embodiment is CPM REX M4 tool steel that has been hardened and grinded. The finish of the tool insert  200  is a titanium nitride coating that is 2 microns thick, or 0.00008 inches. When coating the tool insert  200 , the temperature must not exceed 800 degrees Fahrenheit. One skilled in the art will appreciate that not all components of the insert tool  200 —or any—necessarily have to be the above tool steel or titanium nitride coating. Different combinations of materials and coatings will provide different attributes to the insert tool  200  that one skilled in the art may find advantageous. 
     The phrases “at least one”, “one or more”, and “and/or”, as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B, and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C,” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together. Further, the term “anti-missile features” as used herein may also refer to a single anti-missile feature or at least one anti-missile feature. 
     Unless otherwise indicated, all numbers expressing quantities, dimensions, conditions, and so forth used in the specification, drawings, and claims are to be understood as being modified in all instances by the term “about” or “approximately”. 
     The term “a” or “an” entity, as used herein, refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. 
     The use of “including,” “comprising,” or “having,” and variations thereof, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Accordingly, the terms “including,” “comprising,” or “having” and variations thereof can be used interchangeably herein. 
     It shall be understood that the term “means” as used herein shall be given its broadest possible interpretation in accordance with 35 U.S.C., Section 112(f). Accordingly, a claim incorporating the term “means” shall cover all structures, materials, or acts set forth herein, and all of the equivalents thereof. Further, the structures, materials, or acts, and the equivalents thereof, shall include all those described in the summary of the invention, brief description of the drawings, detailed description, abstract, and claims themselves. 
     The foregoing description of the present invention has been presented for illustration and description purposes. However, the description is not intended to limit the invention to only the forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention. 
     Consequently, variations and modifications commensurate with the above teachings and skill and knowledge of the relevant art are within the scope of the present invention. The embodiments described herein above are further intended to explain best modes of practicing the invention and to enable others skilled in the art to utilize the invention in such a manner, or include other embodiments with various modifications as required by the particular application(s) or use(s) of the present invention. Thus, it is intended that the claims be construed to include alternative embodiments to the extent permitted by the prior art.