Ratchet action. The handle and frame are a single piece, with a retaining plate on one side. The specifications describe a head with screwdriver blades on both sides or with a slot for blade inserts.
Known example appears as a ratchet wrench; a period advertisement for Strasser's Screwdriver and Wrench reprinted in Ken Cope's "American Wrench Makers 1830-1930" also shows the ratchet screw driver version.