Patent ID: 7390156
Filing Date: 2008-06-24
Classification: F16B

Abstract:
1. A sheet metal fastener for securing a covering material to a lightweight insulating base material, the fastener including a head having upper and lower surfaces, at least two hollow shanks extending generally perpendicularly from the lower surface of the head and being in spaced relationship with respect to one another and from the upper surface of the head, each shank including a pair of generally u-shaped legs that are pivotally moveable relative to the lower surface of the head and wherein each leg has opposite side walls which are connected by an end wall, one of the legs being seated within the other leg with the end walls thereof being in opposing relationship to one another to thereby define a hollow space there between, each of the end walls being at least partially configured such that when the fastener is driven into an insulating base material, the opposing legs of each shank will spread apart to receive a first plug of the insulating base material there between such that separate first plugs of the insulating base material are grasped between the opposing legs of each of the at least two hollow shanks to resist fastener withdrawal from the insulating base material, and wherein the at least two hollow shanks are spaced at a predetermined distance relative to one another such that, as the fastener is driven into the base material, adjacent portions of the at least two hollow shanks expand toward one another to thereby grasp a second plug of compressed insulating base material there between when the fastener is driven into the insulating base material.