DIE SET FOR SECURING A SELF-ATTACHING ELEMENT

摘要

DIE SET FOR SECURING A SELF-ATTACHING ELEMENTABSTRACT OF THE DISCLOSUREA die set for attaching a self-attaching fastener having anannular barrel portion to a panel. The die set includes a driving member and a diemember having a concave annular die cavity which is generally hemispherical incross-section and which surrounds a center die post which projects from the bottomsurface of the die cavity. The die post includes a conical side surface, adjacentthe top face, which is inclined outwardly from the axis of the post. The top faceof the die post preferably includes an annular top surface, adjacent the conicalside surface, which defines a piercing edge, and a conical top surface, adjacentthe axis of the post. The driving surface aligns the barrel portion of the self-attaching element with the center post of the die cavity and drives the free end ofthe annular barrel portion into engagement with the panel and through the openingin the panel to first engage the conical side surface of the post. The conical sidesurface accurately aligns the fastener on the post, begins outward radialdeformation of the post and prevents collapse of the barrel portion duringinstallation. The free end of the barrel portion is then received against thehemispherical bottom surface of the die cavity, deforming the free end of thebarrel portion radially outwardly in a U-shaped configuration and the panel portionadjacent the panel opening is driven into the U-shaped barrel portion, forming asecure mechanical interlock.