| 摘要 |
A method of permanently attaching a fastening element (150), such as a nut or bolt to panels (30) having a range of panel thicknesses, such as the metal panels used by the automotive and appliance industries. The fastening element (150) includes a tubular barrel portion (154) and preferably an annular bearing face (158) surrounding the barrel portion. The method includes punching a hole (42) in the panel, then plastically deforming and drawing the panel surrounding the hole into a dome or frusto-conically shaped portion (40). The panel hole is thus enlarged to receive the fastener element barrel portion (154) from adjacent the apex of the frusto-conically shaped panel portion (40) and the bearing face (158) is then driven against the panel, deforming the panel (30) to a generally planar shape. The panel surrounding the hole is thereby driven against the tubular barrel portion (154) which, in the preferred embodiment, includes radially projecting ribs (84), forming secure anti-rotation means even in very thin panels. Finally, the free end of the barrel portion is deformed radially outwardly and preferably squeezed to form a secure interlock between the fastening element and the panel. <IMAGE> |
