US Patent 7493839 Portable screw driving tool with collapsible front end

A portable hand-held screw driving tool is provided for use with collated strips of screws. The front portion of the tool is movable to a great extent, to thereby allow the tool to drive screws almost directly at the corner of two walls. A front “nose piece” is pressed against one of the walls, which causes the nose piece to move rearward “into” the remainder of the tool, in a “first stage” of movement. A screw is indexed to its drive position, and a drive bit is abutted against the screw head during this first stage. The nose piece is pressed further into the tool, which also causes a “feed tube” to move rearward “into” the remainder of the tool, in a “second stage” of movement, which rotates the screw as it is emplaced into the wall.