Self-piercing rivet

Abstract

A self-piercing rivet ( 10 ) for forming joints in stacked sheets of high or low strength, light alloy metals such as aluminium and magnesium. The rivet ( 10 ) comprises a head ( 11 ) and a substantially cylindrical shank ( 12 ) that is at least partially hollow so as to define a bore ( 13 ) that extends along at least part of its length. The outside diameter (D 1 ) of the shank ( 12 ) is at least 6 mm, the effective length of the rivet is at least 1.3 times the diameter of the shank and the bore ( 13 ) has a volume that is at least 38% of the effective solid volume of the rivet ( 10 ). The rivet geometry is such that it has enhanced column strength to withstand the high insertion forces required and a high bore volume to accommodate displaced sheet material.

1 . A self-piercing rivet comprising a head and a substantially cylindrical shank that is at least partially hollow so as to define a bore that extends along at least part of its length, wherein the outside diameter of the shank is at least 6 mm, an effective length of the rivet is at least 1.3 times the diameter of the shank and the bore has a volume that is at least 38% of an effective solid volume of the rivet. 
     
     
         2 . A self-piercing rivet according to  claim 1 , wherein the bore volume is in the range 38-50% of the effective solid volume of the rivet. 
     
     
         3 . A self-piercing rivet according to  claim 1 , wherein the bore volume is in the range 38-42% of the effective solid volume of the rivet. 
     
     
         4 . A self-piercing rivet according to  claim 1 , wherein the bore extends along the full length of the rivet. 
     
     
         5 - 14 . (canceled)