Hemming method and apparatus

Abstract

A hemming apparatus for joining together an inside panel and an outside panel of a closure, such as a door. The apparatus includes inner and outer tools and sliding and scarfing dies supported on a frame at a bending station. The inner tool is moved into a position against an inner surface of an inside upstanding flange of the inside panel. The outer tool is pressed against an outer surface of an outside upstanding flange of the outside panel. The sliding die bends an upper portion of the outside upstanding flange over the inside upstanding flange. The scarfing die then folds the upper portion of the outside upstanding flange downward against the inside upstanding flange to complete the hem.

What is claimed is:  
     
         1 . A hemming apparatus for joining together an inside panel and an outside panel of a closure by hemming, the apparatus comprising: 
 an inner tool disposed at a bending station and supported and configured to move against an inner surface of an inside upstanding flange of an inside panel that is to be joined to an outside panel in a subsequent hemming operation;    an outer tool disposed at the bending station adjacent the inner tool and supported and configured to move against an outer surface of an outside upstanding flange of the outside panel;    a sliding die disposed at the bending station adjacent the inner and outer tools and movably supported and configured to bend an upper portion of the outside upstanding flange over the inside upstanding flange;    a scarfing die movably supported and configured to fold the upper portion of the outside upstanding flange downward against the inside upstanding flange to complete the hem; and    the scarfing die is supported at the bending station adjacent the sliding die in a position to complete the hem at the bending station rather than at a separate final hemming station.    
     
     
         2 . A hemming apparatus as defined in  claim 1  in which: 
 a second inner tool is disposed at the bending station and is movably supported and configured move against an inner surface of a second inside upstanding flange of an inside panel to be joined to an outside panel in a subsequent hemming operation;  
 a second outer tool is disposed at the bending station and is movably supported and configured to be pressed against an outer surface of a second outside upstanding flange of the outside panel;  
 a second sliding die is disposed at the bending station and is movably supported and configured to bend an upper portion of a second outside upstanding flange over the second inside upstanding flange; and  
 a second scarfing die is movably supported and configured to fold the upper portion of the outside upstanding flange downward against the inside upstanding flange to complete a second hem along a second edge of the panels, the second scarfing die being disposed at the bending station adjacent the second sliding die in a position to complete the second hem at the bending station rather than at a separate final hemming station.  
 
     
     
         3 . A hemming apparatus as defined in  claim 1  in which the hemming apparatus is configured to hem a plurality of upstanding flange tabs rather than a single continuous upstanding flange.  
     
     
         4 . A method of joining together an inside panel and an outside panel of a closure by hemming, the method including the steps of: 
 providing an outside panel having an upstanding flange;    providing an inside panel having an upstanding flange;    providing the inside panel on the outside panel such that the upstanding flange of the inside panel is disposed generally parallel to and adjacent the upstanding flange of the outside panel;    pre-bending an upper portion of one of the two upstanding flanges over the other upstanding flange at a bending station; and    forming a flange hem at the bending station by continuing to bend the upper portion of the pre-bent flange until it is generally parallel to and disposed flush against the other upstanding flange.    
     
     
         5 . The method of  claim 5  in which the pre-bending step includes: 
 moving an inner tool into a position against an inside surface of the inside upstanding flange;  
 moving an outer tool into a position against an outside surface of the outside upstanding flange below an upper portion of the outside upstanding flange; and  
 moving a sliding die laterally to bend the upper portion of the outer upstanding flange over the inside upstanding flange.  
 
     
     
         6 . The method of  claim 6  in which the pre-bending step includes causing the outer tool to remain in place to support the inside and outside upstanding flanges during a subsequent hemming operation.  
     
     
         7 . The method of  claim 1  in which the step of forming a flange hem includes moving a scarfing die downward to fold the upper portion of the pre-bent flange over and against the other upstanding flange.