Patent attributes
A locking screw assembly is provided which allows installation into a plate-like member using relatively little force, but which requires relatively great force for removal. The fastener has an annular locking ring provided within a groove in the head of the screw to allow the screw to sit within or flush with the anterior surface of the plate. The through-hole in the plate which receives the locking screw comprises an entrance, a collar section, an undercut, and an exit. The locking ring resides within the undercut. The locking ring has a leading surface that is chamfered or radiused and a trailing surface that is flat. The chamfer allows the locking ring to easily be inserted into the through-hole by interacting with a lead chamfer in the entrance. After installation, the flat trailing surface abuts a lip adjoining the collar section and the undercut and prevents the screw from being easily removed from the through-hole.
