Fretted/fretless stringed musical instrument

摘要

A stringed instrument intended to be alternately played in a fretted mode or an unfretted mode by raising a separate fingerboard to the tops of the frets for the unfretted mode and lowering it for the fretted mode. A pair of meshed rack-and-pinion assemblies are driven back and forth by a lever the motion of which racks are translated to rails that cam the separate fingerboard up and down through pins protruding inwardly from the rails into slide slots in flanges of the fingerboard.