Abstract:
A flanging apparatus is provided that includes a flanging tool that provides a force to an open end of a container to create an outwardly extending flange or other geometry on the open end of the container. The outwardly extending flange is adapted to receive a container end closure after the container is filled with a liquid or foodstuff. In addition, alternative embodiments of the present invention also include an air conduit for introducing pressurized air into the container to increase rigidity during the flanging operation and substantially prevent buckling of the container.

Description:
[0001]     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60\711,138, filed Aug. 24, 2005, which is incorporated by reference in its entirety herein. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to an apparatus and method for forming a neck portion of a metal container. More specifically, an apparatus and method is provided that engages an open upper edge of the metal container, thereby forming the upper edge into a flange for interconnection to a container end closure in a double seaming operation. Various embodiments of the present invention also utilize pressurized air to counteract compressive loading associated with the flanging apparatus.  
       BACKGROUND OF THE INVENTION  
       [0003]     Metal containers, such as those used for beverages, are generally comprised of a cylindrical container body interconnected to a container end closure that includes a opening device, such as a pull tab. The interconnection of the container body to the end closure is achieved by engaging an outwardly extending flange positioned adjacent to an upper edge of the container body with a lip or peripheral hook positioned around an outer edge of the container end closure. The flange and lip are then “double seamed”, a process well known in the art, to create a sealed container.  
         [0004]     Generally, flanging of the edges or “neck” that defines the open end of the container body is performed by upsetting flanging or spin flanging. Upsetting flanging utilizes at least one non-rotating flanging tool, such as a die or a stamping tool, that is pressed against the can edge to deform a portion of the container body outwardly. More specifically, upset flanging involves holding and applying pressure to round heated blanks. The neck portion is progressively formed from one end to the other, thus decreasing its length but increasing its diameter. In the case of beverage containers, a portion of the upper end is plastically deformed outwardly to form the flange. Spin flanging is generally described in U.S. Pat. No. 5,121,621 to Ihly, which is incorporated by reference in its entirety herein. Ihly discloses a receiving member secured to a rotary shaft with a plurality of rollers that are shaped for performing the flanging operation, and which is positioned against the container edge. The flanging contour is determined by the external geometry of the flanging rollers. While the upsetting flanging operation involves the disadvantage that the deforming process does not proceed uniformly under certain circumstances, the spin flanging operation has the drawback of requiring a great number of flanging rollers, which requires a complex drive assembly and increased maintenance and associated costs.  
         [0005]     There exists yet another method of flanging a container, which is very similar to upsetting flanging. More specifically, U.S. Pat. No. 5,853,275 to Lentz et al., which is incorporated by reference in its entirety herein, describes an apparatus that engages the open end of a container to permanently deform the end to form a flange. The Lentz device imparts a deforming load by periodically contacting the neck of the container body in a wobble-like fashion. This movement is advantageous due to incremental loading that results in a more uniform flange. Thus, some of the drawbacks of “upsetting” flanging devices are avoided such as exposing the container to an edge-constant load. However, damage to the neck, i.e., buckling, of the container may be realized during the operation due to the fragile nature of the thin metallic materials generally employed in container fabrication. Thus, there is a need for an apparatus or method to impart rigidity to the container during the flanging operation.  
         [0006]     Thus, there is a long felt need in the field of metal container forming and manufacturing to provide an apparatus and method of forming a flange on the open end or neck of a container body without the necessity for a complex tool that may cause damage to the container and which requires significant maintenance. The following disclosure describes an improved container end flanging apparatus that is adapted for engagement with a container body that includes an area that is adapted to form a portion of the container body and a conduit that supplies pressurized gas to the interior of the container during deformation of the open end to provide rigidity and maintain the structural integrity of the metallic container during the forming operation.  
       SUMMARY OF THE INVENTION  
       [0007]     It is one aspect of the present invention to provide an apparatus for forming a flange on a container body neck portion. More specifically, metal containers used in the canned beverage and food industries are generally sealed in a double seaming manner, wherein a flange integrated onto an open edge of the container is interconnected to a lip or peripheral end curl of a container end closure. Once the flange and the lip are engaged, a mechanism is used to plastically deform the materials such that a double seam and seal is provided. In one embodiment of the present invention, the flanging apparatus is comprised of a flanging tool that is operably interconnected to a shaft assembly. The shaft assembly includes a canted shaft that is positioned a predetermined angle from a main spindle shaft that spins at a predetermined rate. As the shaft assembly rotates, the canted shaft causes the flanging tool to wobble, wherein a periodic load is applied onto the open end of the container thereby ensuring that a flange with a generally consistent geometry is provided.  
         [0008]     Thus, it is a related aspect of the present invention to provide a dual shaft system wherein a portion thereof is canted such that spinning of the primary spindle shaft ultimately causes the flanging tool to wobble. This method is desirable because periodic loads are applied to the upper edge of the can to incrementally deflect the material of the container. More specifically, instantaneous constant loading of the container edge may lead to irregular flanges being formed or container buckling, thus making the container unusable for its intended purpose.  
         [0009]     It is still yet another aspect of the present invention to provide a conduit for supplying air or other gases to the container that provides structural support and rigidity to the container during the flanging operation. More specifically, one embodiment of the present invention includes a housing assembly with an integrated air conduit. The conduit allows for the introduction of compressed air flow into the container, thereby providing container rigidity and counteracting some of the compressive loads introduced by the flanging tool. Thus, localized and/or general buckling of the container during flanging operations is substantially prevented. Preferably, an internal pressure of between about 0 psi and 50 psi is provided to perform the task of stiffening the container, however one skilled in the art will appreciate that any suitable amount of pressurized fluid is desirable and will depend on the size and material of the container.  
         [0010]     Thus, it is one aspect of the present invention to provide a container flanging apparatus which comprises: 
        a shaft assembly comprising a first shaft interconnected to a second shaft, wherein said second shaft is positioned a predetermined angle relative to said first shaft such that rotation of said first shaft about an axis thereof will cause a free end of said second shaft to follow a generally circular path;     a ball bearing assembly comprising an inner race and an outer race that are operable engaged by a plurality of ball bearings, said inner race interconnected to said second shaft;     a flanging tool having an inner diameter that is interconnected to said outer race, said flanging tool also comprising an end with a rounded profile with a protruding outer lip that is adapted to engage the neck of the container to form a flange thereon; and     wherein rotation of said first flange forces said flanging tool to rock thereby applying deforming pressure to less than the entire perimeter of the neck of the container at one time.        
 
         [0015]     It is a further aspect of the present invention to provide a method for flanging a neck portion of a metallic container, comprising: 
        providing a metallic container comprised of a closed lower end and an open upper end, said open upper end including a neck portion;     positioning a flanging tool in operable engagement with the neck portion of the container;     injecting a predetermined volume of a gas into the metallic container, wherein the internal pressure of the container is increased; and     applying a force with said flanging tool to the neck of said container, wherein the container neck is deformed to a predetermined shape.        
 
         [0020]     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 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 Detail Description, particularly when taken together with the drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     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 these inventions.  
         [0022]      FIG. 1  is a front cross-sectional view of a flanging apparatus of one embodiment of the present invention;  
         [0023]      FIG. 2  is a front elevation view of the embodiment of  FIG. 1  shown in operable contact with a container during a flanging operation;  
         [0024]      FIG. 3  is a cross-sectional front elevation view of  FIG. 2  showing engagement with the neck of the container;  
         [0025]      FIG. 4  top plan view of a shaft assembly of the embodiment shown in  FIG. 1 ;  
         [0026]      FIG. 5  is a front cross-sectional elevation view of the shaft assembly of the embodiment shown in  FIG. 4 ;  
         [0027]      FIG. 6  is a front cross-sectional view of a flanging apparatus in another embodiment of the present invention;  
         [0028]      FIG. 7  is a front elevation view of the embodiment of  FIG. 6  shown in operable contact with a container and further depicting air flow; and  
         [0029]      FIG. 8  is a detailed cross-sectional view of  FIG. 7  showing contact with the neck of the container 
     
    
       [0030]     To assist in the understanding of the present invention the following list of components and associated numbering found in the drawings is provided herein:  
         [0031]     For clarity, the following is a list of components generally shown in the drawings:  
                                             No.   Components                                2   Flanging assembly       4   Flanging tool       6   Shaft assembly       8   Spindle shaft       10   Canted shaft       12   Central axis       16   Container       18   Open end       20   Rounded profile       22   Flange       24   Flange stop ring       25   Air flow path       26   Housing       28   Housing cap       30   Thrust washer       32   Outer lip       34   Ball bearing       36   Spacer       38   Fastener       39   Main body       40   Shaft       42   Cylindrical member                  
 
         [0032]     It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the 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  
       [0033]     Referring now to  FIGS. 1-8 , a container flanging apparatus  2  is provided that is comprised generally of a flanging tool  4  that is operably interconnected to a shaft assembly  6 . The shaft assembly  6  in one embodiment of the present invention is comprised of two members, a spindle shaft  8  and a canted shaft  10 . The spindle shaft  8  generally rotates at a predetermined velocity and is provided with a tapped hole for interconnection with the secondary shaft  10  that is canted relative to a central axis  12  of the spindle shaft  8 . The canted shaft  10  is in turn operably interconnected to the flanging tool  4 , wherein spinning of the spindle shaft  8  will cause the flanging tool to oscillate, i.e., “wobble.” 
         [0034]     In operation, a metallic container  16  such as an aluminum beverage or food container is placed proximate to the flanging tool  4 , wherein the edge of the open end  18  of the container is placed near a rounded profile  20  of the flanging tool  4 . Once the container  16  is in place, the flanging tool  4  is inserted further into the neck portion of the container  16  thus deflecting the edge generally outward to partially form a flange  22 . The spindle shaft  8  then rotates to cause a wobbling motion of the flanging tool  14 , which completes the flanging operation by creating a uniform flange  22  around the outer edge of the open container  16 .  
         [0035]     One embodiment of the present invention includes an air flow path  25  that delivers pressurized air or other gas to the container  16  during the flanging operation to help prevent buckling or other unintended deformation to the container  16  that may occur when the flanging tool  14  is pressed onto the open container  16 . That is, increased container rigidity and structural integrity may be achieved by creating an internal pressure within the container. As appreciated by one skilled in the art, the airflow path  25  may be oriented or positioned in various locations within the flanging assembly  2  to provide a sufficient volume and pressure of air or other gas.  
         [0036]     Referring now to  FIG. 1 , one embodiment of the flanging apparatus  2  is shown. More specifically, the flanging apparatus  2  generally includes a flange stop ring  24  interconnected to a housing  26 . The housing  26  also includes a housing cap  28  and associated thrust washer  30  that interacts with the shaft assembly  6 . The shaft assembly  6  includes the spindle shaft  8  interconnected to the canted shaft  10 . In operation, the spindle shaft  8  spins and is held by the housing cap  28  and a thrust washer  30  and includes an outer lip engagement with a ball bearing  34 , thus allowing free rotation thereof. The flanging tool  4  is interconnected to the canted shaft  10  in one embodiment via a plurality of ball bearings  34  and spacers  36  to allow free rotation of the canted shaft  10 . More specifically, a fastener  38  holds the flanging tool  4  to the canted shaft  10  that allows the shaft assembly  6  to freely rotate while maintaining the flanging tool  4  substantially in place. As the canted shaft  10  rotates, it interacts with the ball bearings  34  and deflects the flanging tool  4 , causing the flanging tool  4  to rock or wobble. This rocking and wobbling motion ensures that as the shaft assembly  6  rotates, the edge of the open container  16  is uniformly deformed outwardly to form the flange  22  into a predetermined shape.  
         [0037]     Referring now to  FIG. 2 , the apparatus as shown in  FIG. 1  is shown engaged to a container  16 . In operation, the container  16  is placed proximate to the flanging tool of the present invention, wherein the central axis of the flanging apparatus  12  generally coincides with the central axis of the container. In order to create the flange  22 , the container  16  is placed under the flanging tool  4  as shown and the flanging apparatus  12  is transitioned downward onto the container  16  wherein the rounded profile  20  of the flanging tool  4  initially begins to plastically deform the open end  18  of the container  16  outwardly. The flanging tool  4  also includes a curved outwardly extending lip  32  that further deflects the metal of the container  16  as pressure is applied. Further, in order to ensure that the container  16  is properly deformed by the flanging tool  4 , the flanging tool  4  wobbles to impart incremental mechanized pressure to the container edge  18  to form the outwardly extending flange  22 . Alternatively, it may be possible in other embodiments to rotate the container  16  around the flanging tool  4 .  
         [0038]     As previously discussed, in one embodiment an air source may be provided that injects compressed air into the container  16  during the flanging operation such that the force imparted by the flanging apparatus  2  does not cause substantial damage to the container  16 . More specifically, as it will be appreciated by one skilled in the art, the thin wall of the container  16  makes it susceptible to buckling, especially when an eccentric load is applied thereto. The addition of pressurized air or other fluids or gases into the container  16  during flanging operations helps prevent this buckling by stiffening the container  16  by adding axial tension onto the container  16  that counteracts the compressive load generated by the flanging apparatus  2 . Preferably at least about 1.50 psi of compressed air is provided into the container during flanging, although the pressure may vary depending on the container size, material utilized and material thickness, and as much as 100 psi may be utilized depending on the application.  
         [0039]     Referring now to  FIG. 3 , a detailed view of the flanging tool  4  illustrates how the flanging tool interacts with the neck portion of the container  16 . More specifically a flanging tool  4  is shown that depicts an outer rounded profile  20  surface that gradually decreases in diameter to provide an inclined surface that initially engages the outer edge  18  of the container  16  to begin the flanging process. The outer lip  32  associated with the flanging tool  4  is also provided with a contour that generally matches with the finished contour of the outwardly extending container flange  22 .  
         [0040]     Referring now to  FIGS. 4 and 5 , a shaft assembly  6  of one embodiment of the present invention is shown that includes the spindle shaft  8  interconnected to the canted shaft  10 . More specifically, the spindle shaft  8  is adapted to spin at a predetermined rate and is provided with a tapped hole therein. The tapped hole is adapted to receive the canted shaft  10  at a predetermined angle (θ) of between about 0 and 10 degrees. Preferably, the inner diameter of the tapped hole is slightly smaller than an outer diameter of the canted shaft  10  such that the two shafts are press fit (or interference fit) together. The canted shaft  10  also includes a tapped hole for the receipt of the fastener that interconnects the flanging tool to the shaft assembly  6 .  
         [0041]     Referring now to  FIG. 6 , another embodiment of the flanging assembly  2  is shown that is similar to that described above. More specifically, this embodiment of the flanging assembly generally includes a flanging tool  4  that interconnected at a slight angle to a cylindrical member  42 . In addition, a main body  39  with an aperture therethrough is provided that is interconnected via bearings  34  to the housing  26  of the assembly  2 . The cylindrical member  42  is interconnected to the main body  39  also via bearings  34  and is positioned at a slight angle relative to the center axis  12  of the assembly  2 . Thus, when the main body  39  rotates within the stationary housing  26 , the flanging tool  4  will oscillate.  
         [0042]     Referring now to  FIGS. 7 and 8 , the flanging assembly  2  of  FIG. 6  is shown operably engaged onto a container  16 . In addition, an air path  25  is provided directly in the shaft  40 , wherein the shaft  40  imparts rotational motion to the flanging tool and provides pressurized air to the container  16 . As shown in  FIG. 7 , the flanging tool  4  associated main body  39  is predisposed to tilt when the shaft  40  rotates, thereby causing the external lip  32  of the flanging tool  4  to wobble. More specifically, rotation of the shaft  40  will generally impart an up and down wobbling motion onto the flanging tool  4 , thereby deflecting the open end  18  of the container  16  to form the flange  22 .  
         [0043]     Referring specifically now to  FIG. 8 , a detailed cross-sectional front elevation view is provided herein, and further depicting the relationship between the container neck  16 , and the outer lip  32 , which is operably engaged to the flanging tool  4 . As appreciated by one skilled in the art, the outer lip  32  may have a variety of shapes and geometric configurations depending on the size and preferred shape of the container  16 .  
         [0044]     Referring again to  FIGS. 1-8 , the flanging apparatus  2  is generally comprised of materials commonly used in the art. However, one feature not apparent in the art is the utilization of the airflow path  24 , wherein pressurized air or fluids may be introduced to the container  16  during the flanging operation to add internal pressure and rigidity to the container  16 . One skilled in the art will appreciate that compressed air or other gases, such as inert gases may be used without departing from the scope of the invention. In addition, fluids may be used in combination or alone with air in order to substantially increase the stiffness of the container  16  during flanging operations. The ball bearings  34  generally are comprised of an outer race rotatably interconnected via a plurality of ball bearings to an inner race. The inner races are interconnected to either the spindle shaft  8  or the canted shaft  10 , thereby allowing free rotation of the shaft assembly  6 .  
         [0045]     While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the following claims.