Patent ID: 6125524
Filing Date: 2000-10-03
Classification: B23P,F16B,Y10T

Abstract:
A method of attaching a fastening element to a plastically deformable metal panel, said method comprising the steps of:providing a fastening element including a head portion and a generally cylindrical fastener portion integrally joined to the head portion and extending axially from a bottom surface thereof to terminate at a free end, wherein the bottom surface of the head portion is defined by an outer perimeter, an inner perimeter, a planar bearing surface, and a plurality of pockets, wherein the pockets are recessed from the bearing surface into the head portion and extend generally radially along the head portion toward the outer perimeter of the head portion, wherein the pockets do not fully extend to the outer perimeter and are surrounded by the bearing surface, wherein each pocket includes a bottom wall and two side walls, and wherein the fastener portion has a groove spaced between the free end and the bearing surface of the head portion;providing a plastically deformable metal panel;forming a generally cylindrical hole through the panel, the hole having a diameter greater than a diameter of the fastener portion;providing a die assembly including a die member having an upper planar surface defining an opening having a diameter greater than that of the hole, and an annular lip surrounding the opening and extending upwardly from the upper planar surface;supporting the panel on the die assembly such that the hole is coaxially aligned with the opening and the panel rests on the annular lip;inserting the fastener portion through the hole and into the opening such that the bearing surface rests against the panel with the annular lip in axial alignment with the pockets; and thendriving the bearing surface against the panel, thereby causing the annular lip to deform a portion of the panel into the pockets and into the groove while the bearing surface bears against the panel, such that a secure mechanical interlock is formed between the fastening element and the panel.