Flush-driven self-piercing and clinching nut and method of securing to a member

Claim 1

A SELF-PIERCING AND CLINCHING NUT ADAPTED TO BE DRIVEN THROUGH A SHEET MEMBER TO PROVIDE FLUSH MOUNTING OF THE UPPER PORTION THEREOF, COMPRISING, A NUT BLANK HAVING AN UPPER FACE AND A CENTRAL AXIAL BORE, AN ENLARGED UPPER PORTION PROVIDED WITH A PERIPHERAL WALL EXTENDING AXIALLY FROM SAID UPPER FACE AND INCLUDING A PLURALITY OF INTERSECTING PLANAR SURFACES PROVIDING INWARDLY DIRECTED RADIAL NOTCHES, A CIRCULAR CLINCHING RECESS IN THE MEDIAL PORTION OF SAID BLANK, A CONICAL SURFACE INCLINED UPWARDLY AND DOWNWARDLY FROM THE TOP OF SAID RECESS TO THE BOTTOM OF SAID PERIPHERAL WALL NOTCHES, SAID BLANK INCLUDING A LOWER PORTION OF REDUCED DIAMETER PROVIDED WITH A CIRCULAR DOWNWARDLY DIRECTED PIERCING EDGE ON THE OUTER PERIPHERY THEREOF OF A DIAMETER GREATER THAN SAID RECESS BUT LESS THAN SAID PERIPHERAL WALL, A SHOULDER ADJACENT AND IMMEDIATELY BELOW SAID RECESS DISPOSED WITH ITS SURFACE PROJECTING DOWNWARDLY AND OUTWARDLY, SAID LOWER PORTION HAVING AN AXIALLY PROJECTING PERIPHERY EXTENDING FROM SAID PIERCING EDGE TO SAID SHOULDER, AND A SHOULDERED EXTENSION AXIALLY PROJECTING DOWNWARDLY FROM THE BOTTOM OF SAID BLANK LOWER PORTION AND CONCENTRICALLY DISPOSED IN TERMEDIATE SAID BORE AND SAID PIERCING EDGE.