Fastening bolt assembly with anti-rotation device and providing both axial and radial holding forces

摘要

A tubular and preferably elastomeric radial holding and centering expandable bushing having a bore sized to pass a threaded shank of a fastening bolt and having a radially enlarged flanged one end thereof. The bore tapering outwardly toward the periphery to create a conical cavity between the bushing body from the flange rearwardly. The cavity receives a tubular expansion insert having a tapered periphery and internal bore slightly larger than the diameter of the threaded shank of the fastening bolt which insert is positioned to the side of the tubular bushing remote from the head of said fastening bolt. A folding wing nut structure includes a trunion nut having a tapped bore threaded on said shank of the bolt, axially outwardly of the tubular expansion insert to the side opposite to the tubular bushing. The structure includes a pair of foldable wings. A longitudinal slot within the body of the tubular bushing receives a mating rib which extends radially outwardly of the periphery of the tubular expansion insert. A pyramidal cross-section axial projection on the end of the tubular expansion insert facing the foldable wings is sized to project internally between laterally opposed side walls of one or both of the wings to prevent rotation of the folding wing nut structure during a tightening down of the folding wing nut structure as the wings are drawn into contact with the rear surface of the vertical wall via the trunion nut.