Fastener and panel assembly

Abstract

An installation apparatus and method of attaching a female element, such as a nut, to a panel, wherein the panel is pierced and the female element is permanently installed in the pierced panel opening in a continuous operation. The female element includes a body portion and an annular barrel portion. In one of the methods disclosed, the panel is pierced by the free end of the barrel portion and the panel slug is disposed in the barrel portion as the nut is installed in the panel. In the presently preferred method, the panel is pierced by a punch received through the body and barrel portions, prior to driving the female element into a mechanical interlock with the panel. In the preferred installation, the free end of the barrel portion is deformed into a hook-shaped end portion, opening toward the body portion, and the panel is simultaneously driven into the hook-shaped barrel end portion, forming a very secure mechanical interlock. The preferred installation apparatus includes an annular plunger which drives the female element into the panel and which is reciprocally supported in a chamber in a base member attached to one die member of a press. A punch is located within the annular plunger which pierces the panel prior to driving the female element into the panel, as described.