Self attaching female fasteners and method of forming female fastener elements

Abstract

A method of forming a female fastener including rolling a body portion strip having a midportion and flange portions on opposed sides of the midportion, piercing spaced openings through the midportion, cutting the strip to length between the openings, cold forming a separate generally cylindrical pilot portion having a length greater than the width of the midportion and a diameter greater than the opening through the midportion, preferably including radial splines, and press fitting the pilot portion through the opening in the midportion. The self-attaching female fastener thus includes a rectangular body portion and a generally cylindrical pilot portion having an end face spaced above a plane of the midportion and may be formed of a harder metal than the body portion.

1 - 16 . (canceled)  
     
     
         17 . A self-attaching female fastener, comprising: 
 a generally rectangular body portion including flange portions on opposed sides of said body portion and a midportion between said flange portions having an opening therethrough; and    a separately formed, generally cylindrical pilot portion having an axial length greater than said midportion and a major diameter greater than said opening through said midportion of said body portion press fit through said opening having an end face spaced above a plane of said midportion.    
     
     
         18 . The self-attaching female fastener as defined in  claim 17 , wherein said pilot portion is formed of a metal harder than said body portion.  
     
     
         19 . The self-attaching female fastener as defined in  claim 17 , wherein said pilot portion includes a plurality of spaced radial splines having a major diameter greater than an internal diameter of said opening through said midportion and said midportion deformed radially inwardly between said spaced radial splines.  
     
     
         20 . The self-attaching female fastener as defined in  claim 19 , wherein said spaced radial splines include a generally cylindrical outer surface having an outer diameter greater than said internal diameter of said opening through said midportion and relatively inclined side walls.  
     
     
         21 . The self-attaching female fastener as defined in  claim 19 , wherein said spaced radial splines extend to said end face of said pilot portion.  
     
     
         22 . The self-attaching female fastener as defined in  claim 17 , wherein said opening through said midportion includes a first generally cylindrical opening through one face of said midportion adjacent said end face of said pilot portion and a second opening through an opposed face of said midportion coaxially aligned with said first opening having an internal diameter greater than said first opening, and said pilot portion having a radial flange portion adjacent one end thereof having a diameter generally equal to said diameter of said second opening received in said second opening.  
     
     
         23 . The self-attaching female fastener as defined in  claim 17 , wherein said flange portions each include an end face spaced above a plane of said midportion.  
     
     
         24 . A self-attaching nut, comprising: 
 a roll-formed rectangular body portion including a midportion having an opening therethrough and flange portions on opposed sides of said midportion extending from a plane of said midportion; and    a separately formed, generally cylindrical pilot portion including a bore through an axis of said pilot portion having an outer diameter greater than an inner diameter of said opening through said body portion press fit through said opening through said midportion of said body portion having an axial length greater than a width of said midportion of said body portion having an end portion projecting between said flange portions.    
     
     
         25 . The self-attaching nut as defined in  claim 24 , wherein said pilot portion includes a radial flange adjacent one end and said end portion of said pilot portion having a diameter less than said radial flange, and said opening through said midportion of said body portion including a first bore having an internal diameter generally equal to said outer diameter of said radial flange portion receiving said radial flange portion of said pilot portion.  
     
     
         26 . The self-attaching nut as defined in  claim 24 , wherein said pilot portion is formed of a harder metal than said body portion.  
     
     
         27 . The self-attaching nut as defined in  claim 24 , wherein said generally cylindrical pilot portion includes a plurality of spaced radial splines each having a major diameter greater than said inner diameter of said opening through said body portion and said midportion of said body portion deformed radially inwardly between said spaced radial splines.  
     
     
         28 . The self-attaching nut as defined in  claim 27 , wherein said spaced radial splines each include a generally cylindrical outer surface having an outer diameter greater than said inner diameter of said opening through said midportion of said body portion.