This screwdriver was patented in 1929 by Bernhard Thal of Chesea, Massachusetts, and assigned to the Bridgeport Hardware Manufacturing Company. (Thal went on to patent a combined ashtray and cigarette snuffer: Patent 123929.)
The screwdriver was heavily advertised in 1930's Popular Mechanics magazines.
Interesting, mine has lost the ribbing on the blade that was the tool's distinctive feature. Either it was worn off with us, or some previous owner filed it off.