Method of attaching a self-attaching fastener to a panel

Abstract

The self-attaching female fastener of this invention includes a re-entrant groove having a V-shaped bottom wall including relatively inclined bottom faces of equal width having an arcuate apex centered beneath the restricted opening to the groove. A die drives a panel portion through the restricted groove opening against the bottom faces, driving the panel portion into the apex and inwardly beneath the inclined inner side wall and outwardly beneath the inclined outer side wall of the groove, resulting in a better installation and accommodating a wider range of panel thicknesses. The V-shaped bottom wall also centers and balances the rolls during the rolling process resulting in a more accurate cross-section of the fastener.

1 - 13 . (canceled)  
   
   
       14 . A method of attaching a self-attaching female fastener to a panel, said method comprising the following steps: 
 locating a panel opposite a die member, said die member including a projecting lip having an end face;    locating a self-attaching female fastener opposite said panel, said self-attaching female fastener including a central pilot portion having an end face and a bore through said end face through said pilot portion, a flange portion on at least opposed sides of said pilot portion having a generally planar panel support face, and a groove in said panel support face of said flange portion adjacent said pilot portion aligned with said projecting lip of said die member, said groove including an inclined inner side wall adjacent said pilot portion defining an outer face of said pilot portion, an inclined outer side wall and a V-shaped bottom wall, said inner side wall inclined outwardly from said bottom wall toward said outer side wall and said outer side wall inclined inwardly from said bottom wall toward said inner side wall and said V-shaped bottom wall having an apex extending away from said panel support face of said flange portion;    driving said end face of said projecting lip of said die member against said panel and substantially simultaneously driving said pilot portion of said self-attaching female fastener through an opening in said panel, said end face of said projecting lip deforming a panel portion adjacent said opening into said groove in said panel support face of said flange portion and against said bottom faces of said V-shaped bottom wall of said groove, deforming said panel portion inwardly beneath said inclined inner side wall of said groove and beneath said inclined outer side wall of said groove forming a secure mechanical interlock between said panel and said panel portion in said groove of said self-attaching female fastener.    
   
   
       15 . The method of attaching a self-attaching female fastener as defined in  claim 14 , wherein said apex of said bottom faces of said V-shaped bottom wall of said groove is substantially equally spaced between said inclined inner and outer side walls of said groove, said method including driving said panel portion into said apex and against said bottom faces of said groove, deforming said panel portion substantially equally beneath said inclined inner side wall and against said inclined outer side wall of said groove.  
   
   
       16 . The method of attaching a self-attaching female fastener as defined in  claim 14 , wherein said method includes driving said end face of said projecting lip of said die member against said panel portion, first deforming an edge of said panel portion at said opening into said groove and against said V-shaped bottom wall adjacent said apex of said bottom faces and continuing to drive said end face of said projecting lip against said panel portion, deforming said panel portion into said apex of said bottom faces and against said inclined inner and outer side walls of said groove.  
   
   
       17 . The method of attaching a self-attaching female fastener as defined in  claim 14 , wherein said end face of said projecting lip of said die member includes first and second inclined end faces having a projecting apex generally aligned with said apex of said bottom faces of said V-shaped bottom wall of said groove, said method including driving said apex of said end faces of said projecting lip against said panel portion, deforming said panel portion into said apex of said bottom faces of said V-shaped bottom wall and deforming said panel portion against said inclined inner and outer side walls of said groove.  
   
   
       18 . The method of attaching a self-attaching female fastener as defined in  claim 14 , wherein said method includes driving said end face of said pilot portion against said panel, piercing a slug from said panel, and forming said opening in said panel.  
   
   
       19 . A method of attaching a self-attaching female fastener to a panel, said method comprising the following steps: 
 locating a panel opposite a die member, said die member including generally parallel projecting clinching lips each having an end face;    locating a self-attaching female fastener opposite said panel, said self-attaching female fastener including a central pilot portion having an end face and a bore through said end face through said pilot portion, a flange portion on opposed sides of said pilot portion having panel support faces on opposed sides of said pilot portion and generally parallel grooves in said panel support faces of said flange portion adjacent said pilot portion aligned with said projecting lips of said die member, said grooves each including an inclined inner side wall defining outer faces of said pilot portion, an inclined outer side wall and a V-shaped bottom wall, said inner side wall of said grooves inclined outwardly from said bottom wall toward said outer side wall and said outer side wall inclined inwardly from said bottom wall toward said inner side wall to adjacent said panel support faces forming a restricted opening to said grooves having a width adjacent said panel support faces less than a width adjacent said V-shaped bottom wall, and said V-shaped bottom wall including relatively inclined bottom faces having an apex extending away from said panel support faces of said flange portion;    forming an opening through said panel configured to receive said pilot portion of said self-attaching female fastener;    driving said end faces of said projecting lips of said die member against panel portions of said metal panel adjacent said opening through said panel and substantially simultaneously driving said pilot portion of said self-attaching female fastener through said opening through said panel; and    continuing to drive said end faces of said projecting lips of said die member against said panel portions, deforming panel portions into said grooves and against said relatively inclined bottom faces of said V-shaped bottom wall, deforming said panel portions inwardly against and beneath said inclined inner side wall of said grooves and outwardly against and beneath said outer side wall of said grooves forming a secure mechanical interlock between said panel portions and said grooves of said self-attaching female fastener.    
   
   
       20 . The method of attaching a self-attaching female fastener as defined in  claim 19 , wherein said apex of said bottom faces of said V-shaped bottom wall of said grooves is substantially equally spaced between said inclined inner and outer side walls of said grooves, said method including driving said end faces of said projecting lips of said die member against said panel portions, driving said panel portions against said apex of said bottom faces of said V-shaped bottom wall of said grooves, deforming said panel portions inwardly beneath said inclined inner side wall and outwardly beneath said inclined outer side wall of said groove.  
   
   
       21 . The method of attaching a self-attaching female fastener as defined in  claim 19 , wherein said method includes driving said end faces of said projecting lips of said die member against said panel portions, first deforming edges of said panel portions adjacent said opening into said groove and against said V-shaped bottom wall adjacent said apex of said bottom faces and continuing to drive said end faces of said projecting lips against said panel portions, deforming said panel portions into said apex and against said inclined inner and outer side walls of said grooves.  
   
   
       22 . The method of attaching a self-attaching female fastener as defined in  claim 19 , wherein said end faces of said projecting lips of said die member each include first and second inclined end faces having a projecting apex generally aligned with said apex of said bottom faces of said V-shaped bottom wall of said grooves, said method including driving said apex of said end faces of said projecting lips of said die member against said panel portions, deforming said panel portions into said apex of said bottom faces of said V-shaped bottom wall and deforming said panel portions against said inclined bottom faces inwardly against said inner side wall and outwardly against said outer side wall of said grooves.  
   
   
       23 . The method of attaching a self-attaching female fastener as defined in  claim 22 , wherein said first end face of said projecting lips is wider than said second end face, thereby aligning said apex of said end faces with said apex of said bottom faces of said V-shaped bottom wall, said method including driving said first and second end faces of said projecting lips of said die member against said panel portions, deforming panel portions on opposed sides of said first and second inclined end faces against said V-shaped bottom wall of said groove.