US Patent 8347768 Screwdriver for an inner profile screw

A screw driver for a screw having a drive socket having an axially extending shaft with a bifurcated tip, the tip having a cross-sectional profile for insertion into a cross-sectional profile of the screw socket. The shaft has a tapered section adjacent the bifurcated tip. A bushing is mounted on an outer surface of the shaft for axial movement therealong. The bushing has inwardly extending protrusions for engaging the tapered section on the shaft upon movement in the axial direction along the shaft in a direction. away from the tip. This allows the selective capture or release of the screw by the shaft tip by axial movement of the bushing away from and towards the shaft distal tip.