Patent ID: 8640321

Claim:
A method of clinching a first layer and a second layer, comprising: disposing at least a portion of a replaceable deformable insert in a clinching die cavity defined in a clinching die, the clinching die cavity having an aperture, a reaction surface opposed to a retractable punch, an annular recess adjacent to the insert, the annular recess surrounding the reaction surface and extending axially deeper into the clinching die than the reaction surface, the clinching die further including a support surface circumscribing the die cavity aperture, the support surface configured to receive the first layer overlapping the second layer; establishing the first layer on the second layer; securing the first and second layers between the punch and the clinching die using a stripper having an aperture defined therein, the stripper configured to clamp the first layer overlapping the second layer to the support surface while the punch is advanced toward the die and as the punch is retracted; pressing the punch into the first layer, thereby forming a depression in the first layer and the second layer; compressing the first layer and the second layer together between the punch and the clinching die thereby creating hydrostatic pressure in the first layer, the second layer, and the insert; and extruding a portion of the insert thereby substantially filling the annular recess with insert extrudate while simultaneously radially extruding a portion of the second layer into an annular space previously occupied by the insert and simultaneously radially extruding a portion of the first layer into an annular volume previously occupied by the second layer, thereby forming an interlocking assembly of the first layer, the second layer and the insert.