US 5,251,370 A · Method of attaching a fastening element to a panel

Abstract

A method of permanently attaching a fastening element, such as a nut or bolt to panels having a range of panel thicknesses, such as the metal panels used by the automotive and appliance industries. The fastening element includes a tubular barrel portion and preferably an annular bearing face surrounding the barrel portion. The method includes punching a hole in the panel, then plasticly deforming and drawing the panel surrounding the hole into a dome or frusto-conically shaped portion. The panel hole is thus enlarged to receive the fastener element barrel portion from adjacent the apex of the frusto-conically shaped panel portion and the bearing face is then driven against the panel, deforming the panel to a generally planar shape. The panel surrounding the hole is thereby driven against the tubular barrel portion which, in the preferred embodiment, includes radially projecting ribs, forming a secure anti-rotation assembly 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.

Claims12

Dependent claims

A method of attaching a fastening element to a plastically deformable metal panel, said fastening element including a body portion and a tubular barrel portion extending from said body portion and said body portion having an annular bearing surface surrounding said tubular barrel portion, said method comprising the steps of:

(a) forming a hole through said panel;
(b) forcing a plastic member against said panel adjacent said hole thereby drawing and plasticly deforming said panel into a generally frusto-conical portion surrounding said hole with said hole at a smaller diameter of said frusto-conical portion;
(c) inserting said tubular barrel portion through said hole from adjacent the apex of said generally frusto-conical portion and said bearing surface of said body portion engaging a panel portion surrounding said panel hole;
and
(d) driving said body portion annular bearing surface of said fastening element against said panel portion surrounding said hole plasticly deforming said panel frusto-conical portion to a generally planar shape, thereby reducing the internal diameter of said hole into engagement with said tubular barrel portion and substantially simultaneously plasticly deforming a projecting free end of said tubular barrel portion radially outwardly entrapping said panel portion between said annular bearing surface and said radially deformed free barrel portion end.

2 more elements

A method of attaching a fastening element to plasticly deformable metal panels having a range of panel thicknesses, said fastening element having a body portion and a tubular barrel portion extending from said body portion and said body portion having a bearing face on at least opposed sides of said barrel portion, said method comprising the steps of:

(a) forcing a plastic member against said panel thereby drawing and deforming a portion of said panel into a generally conical shape while substantially simultaneously punching a hole in said panel adjacent an apex of said conical portion, said hole having an inside diameter greater than an outside diameter of said barrel portion to loosely receive said barrel portion;
(b) inserting a free end of said barrel portion through said panel hole and driving said fastening element body portion bearing face aganist a panel portion adjacent said hole, deforming said conical panel portion to a substantially planar shape, said hole reducing in size as said panel is deformed and driving said panel portion against said tubular barrel portion;
and
(c) plasticly deforming said barrel portion free end radially outwardly forming a mechanical interlock between said panel and said fastening element.

1 more element

Dependencies are inferred from the claim text.

Method of attaching a fastening element to a panel

Life of this patent

Method of attaching a fastening element to a panel

Life of this patent

Abstract

Claims12