Rotating Hand Tool - Valve Grinder?

by Tom Weems
(Euless TX)

This tool resembles a drill but the interchangable "bit" is flat and rather thin. The tool has a wooden knob on top and a hand crank on the side. When the crank is turned the "bit" turns approximately 250 degrees in one direction then reverses direction for approximately 110 degrees resulting in a progression in one direction. The "bit" is too thin to be a boring tool. I do not know its function.