Rear-access trussed neck construction for stringed musical instruments

Abstract

In an improved trussed neck construction for stringed musical instruments such as guitars, a straight truss rod is disposed in a uniform groove along the rear side of the neck, exposing a surface of the truss along its full length, substantially flush with the rear neck surface. At one end, the truss rod is anchored to the neck, while at the other end it is anchored adjustably to enable correction of unwanted fingerboard curvature, typically concave curvature due to string-tension-induced neck strain. Additional capability is provided to reverse the compensation should this be required, for example to counteract convex fretboard curvature due to neck warpage. The adjustment system, implemented by a machine nut which is adjusted using a wrench, is more rugged than the usual screwdriver system. Adjustment access from the rear of the neck is more convenient than conventional front access. Easy removal of the truss enables field service or replacement without any other disassembly, whereas such removal is difficult or impossible in conventional enclosed truss configurations. The one piece neck configuration and easy assembly of the truss into the neck facilitate original manufacture and provide cost savings. The rear-access trussed neck construction of this invention is applicable to a variety of guitars and other stringed instruments; it has been commercially introduced in a modified version of The Chapman Stick (Registered Trademark, U.S. Pat. Nos. 3,833,751, 3,868,880 and 4,633,754) ten-stringed fingerboard musical instrument, which is related to the guitar family but is played by tapping rather than plucking the strings.