Captive screw for electronic devices, has screw captivated on ferrule and collar that does not permit movement of inner annular ring past collar but permits ring passing through of threads of screw through collar

摘要

The screw has a ferrule (20) containing an inner annular ring on an interior surface of the ferrule. A screw (40) has a head and a shank to pass through the ferrule and a spring (50) extends on the shank. The screw is captivated on the ferrule between the head and the collar (48). The collar does not permit movement of the ring past the collar but permits the passing of threads of the screw through the collar.