Method for blind rivet welding

Abstract

A blind rivet assembly is inserted through aligned holes provided in a top member and bottom member. The blind rivet includes a rivet head that abuts the top member and a hollow rivet shank integral with the rivet head. A mandrel includes a mandrel stem that extends thorough the hollow rivet and a mandrel head that abuts the terminal end of the rivet shank. A tool holds the rivet head in contact with the top member and forcibly withdraws the mandrel in the direction to exit the aligned holes to thereby cause the mandrel head of axially collapse and radially expand the terminal end of the rivet shank into engagement with the bottom member to thereby attach the top member and the bottom member together. Weld current is then applied to the rivet head to thereby weld the blind rivet in place.

1 . A method of blind riveting together a top member and a bottom member provided with aligned rivet holes therein, comprising the steps of: 
 inserting a blind rivet assembly through the aligned rivet holes of the top and bottom members, said blind rivet assembly including a blind rivet and a mandrel, the blind rivet having a rivet head abutting the top member and a hollow shank reaching through the aligned holes of the top and bottom members and having a terminal end, the mandrel including a stem extending through the hollow shank of the rivet and a mandrel head adjacent the terminal end of the rivet shank,    forcibly withdrawing the mandrel in the direction to exit the aligned holes to thereby cause the mandrel head to axially collapse and radially expand the hollow shank of the blind rivet into engagement with the bottom member to thereby attach the top member and the bottom member;    and applying weld current to the rivet head to weld the blind rivet in place.    
     
     
         2 . The method of  claim 1  comprising the further step of fracturing the mandrel stem from the mandrel head after the mandrel head has axially collapsed and radially expanded the hollow shank of the blind rivet  
     
     
         3 . The method of  claim 2  further comprising the step of fracturing the mandrel stem after applying the weld current.  
     
     
         4 . The method of  claim 2  further comprising the step of fracturing the mandrel stem prior to applying the weld current.  
     
     
         5 . The method of  claim 2  further comprising the step of fracturing the mandrel stem during the application of weld current.  
     
     
         6 . The method of  claim 1  in which an installation tool for installing the blind rivet assembly includes an anvil that seats on the rivet head and has a welder cable connected thereto so that the anvil functions as an electrode to apply weld current to the rivet head.  
     
     
         7 . The method of  claim 6  in which the installation tool includes an electrode that is connected to a welder cable and seats against the top member at a distance from the blind rivet so that weld current is conducted through the blind rivet and through the top member.  
     
     
         8 . A method of blind riveting together a top member and a bottom member provided with aligned rivet holes therein, comprising the steps of: 
 inserting a blind rivet assembly through the aligned rivet holes of the top and bottom members, said blind rivet assembly including a blind rivet and a mandrel, the blind rivet having a rivet head abutting the top member and a hollow shank reaching through the aligned holes of the top and bottom members and having a terminal end, the mandrel including a stem extending through the hollow shank of the rivet and a mandrel head adjacent the terminal end of the rivet shank,    applying an installation tool including an anvil seated on the rivet head and jaws for gripping and forcibly withdrawing the mandrel to thereby cause the mandrel head to axially collapse and radially expand the hollow shank of the blind rivet into engagement with the bottom member to thereby attach the top member and the bottom member;    applying an electrode to one of the top and bottom members at a distance from the blind rivet,    and conducting weld current between the anvil and electrode so that the blind rivet is melted and metallurgically bonded with at least the top member to thereby weld the blind rivet in place.    
     
     
         9 . The method of  claim 8  in which the blind rivet is welded to both the top member and the bottom member.  
     
     
         10 . The method of  claim 8  in which the mandrel is welded to the blind rivet.  
     
     
         11 . The method of  claim 8  in which the electrode is a part of the installation tool so that upon the application of the installation tool to seat the anvil upon the rivet head, the electrode is simultaneously placed against the top member.  
     
     
         12 . The method of  claim 8  in which at least a portion the mandrel stem is fractured from the mandrel head.  
     
     
         13 . A method of blind riveting together a top member and a bottom member provided with aligned rivet holes therein, comprising the steps of: 
 inserting a blind rivet assembly through the aligned rivet holes of the top and bottom members, said blind rivet assembly including a blind rivet and a mandrel, the blind rivet having a rivet head abutting the top member and a hollow shank reaching through the aligned holes of the top and bottom members and having a terminal end, the mandrel including a stem extending through the hollow shank of the rivet and a mandrel head adjacent the terminal end of the rivet shank,    applying an installation tool including an anvil seated on the rivet head and jaws for gripping and forcibly withdrawing the mandrel in the direction to exit the aligned holes to thereby cause the mandrel head to axially collapse and radially expand the hollow shank of the blind rivet into engagement with the bottom member to thereby attach the top member and the bottom member, said installation tool further including an electrode that seats against the upper member at a distance from the rivet head;    and conducting weld current between the anvil and electrode so that the blind rivet is melted and metallurgically bonded with the top member and the bottom member so that the weld assists the blind rivet in attaching the top and bottom members together.    
     
     
         14 . The method of  claim 13  in which the installation tool also causes a fracture of at least a portion of the mandrel stem from the mandrel head.  
     
     
         15 . The method  claim 14  in which the fracture of the mandrel stem occurs one of either before, during or after the application of the weld current.  
     
     
         16 . The method of  claim 13  in which the weld current causes the mandrel head to become welded to the blind rivet.  
     
     
         17 . The method of  claim 13  in which the weld current causes the rivet shank to become welded to at least one of the first member and second member.  
     
     
         18 . The method of  claim 13  in which the weld current welds the rivet shank to the first member and the second member.  
     
     
         19 . The method of  claim 13  in which the anvil of the installation tool is constructed of a copper-based alloy.