US Patent 7464454 Method for setting self-tapping rivets

A rivet setting device for setting a self-tapping rivet in a work piece includes a rotatable head for rotating a self-tapping rivet to form a hole in the work piece and a shank retracting assembly for compressing and spreading the hollow body of the self-tapping rivet, allowing the head of the self-tapping rivet to detach from the shank upon application of a predetermined tensile force. The rotatable head comprises a clutch having a body enclosing a plurality of bearings circumferentially located around the shank, for gripping the shank. The clutch is formed with a plurality of tapered channels for urging the bearings into engagement with the shank upon rotation of the clutch.