US Patent 8726765 Screwdriver tool with improved linear tracking

An automatic fastener driving tool, or an attachment, has an external depth of drive adjustment subassembly that is mounted external to the feed tube housing, yet has a simple adjustment that does not lose its setpoint easily. By placing the depth of drive mechanism outside of the interior areas of the feed tube, the slide body subassembly can be lengthened without increasing the overall length of the feed system. Certain surfaces of slide body subassembly exhibit a dovetail shape, which allows the slide body subassembly to be robustly mounted so that it is capable of operating with long fasteners while also having the nosepiece mounted in an extended position for use with those fasteners.