# US 4,397,212 A · Combination guitar vibrato and pitch control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,397,212 A - Document ID: US4397212A - Status: Granted - Kind: A - Application number: 06/340,773 - Filed: 1981-01-19 - Granted: 1983-08-09 - Earliest claimed: 1981-01-19 - Inventors: David L. Carson - Web page: https://patentgrep.com/patent/US4397212A ## CPC - G10D 3/147: Devices for altering the string tension during playing - G10D: STRINGED MUSICAL INSTRUMENTS; WIND MUSICAL INSTRUMENTS; ACCORDIONS OR CONCERTINAS; PERCUSSION MUSICAL INSTRUMENTS; AEOLIAN HARPS; SINGING-FLAME MUSICAL INSTRUMENTS; MUSICAL INSTRUMENTS NOT OTHERWISE PROVIDED FOR (organs, harmoniums or similar wind musical instruments with associated blowing apparatus G10B; pianos, harpsichords, spinets or similar stringed musical instruments with one or more keyboards G10C; automatic musical instruments G10F; electrophonic musical instruments in which tones are generated by electromechanical means G10H) ## Abstract Musician controlled relative motion between a generally standard stringed musical instrument (such as a Spanish guitar) and a false body hinged to the generally standard stringed instrument permits versatile control by the musician of the tension in one or more strings to produce both vibrato sounds and/or sustained pitch changes (both higher and lower pitches). The invention eliminates limitations of prior art which employed relative motion between neck and body of an otherwise generally standard stringed musical instrument. ## Claims ### Claim 1 In a stringed instrument having a head, a neck, a body rigidly connected to the neck on which is mounted a bridge, and a plurality of strings each connected at one end to said head and extending along said neck over said bridge, the improvement comprising: an instrument supporting, rigid frame positioned exterior of said instrument and mounted thereto by a pivot substantially perpendicular to a plane generally containing said strings, at least some selected strings being connected at their other ends to a part of the frame functioning as a lever arm, another part of the frame functioning as a torque balancing means for torques due to the movement of the instrument with respect to the frame in both directions in said plane about said pivot whereby the natural swinging movement of the instrument, by the musician during playing, about said pivot relative to the frame will vary the length, and therefore the tension on the selected strings to produce sustained pitch changes and/or desired vibrato sounds. ### Claim 2 (depends on 1) The combination of claim 1 wherein said frame has a configuration generally conforming to the body shape of a conventional stringed instrument. ### Claim 3 (depends on 2) The combination of claim 2 wherein said frame is provided with torque balancing means for the musician in both a sitting and standing position. ### Claim 4 (depends on 1) The combination of claim 1 wherein biasing means are provided between the instrument and the frame to establish a predetermined relative neutral position therebetween. ### Claim 5 (depends on 1) The combination of claim 1 wherein guide means are provided between the body and the frame to assist the pivot in maintaining the rectilinear movement therebetween in said plane. ### Claim 6 (depends on 1) The combination of claim 1 wherein said lever arm has a plurality of individual string attaching means greater in number than the number of selected strings to provide different tension adjusting positions which are adjusted to maintain a chosen relative pitch among said selected strings during a sustained pitch changes and/or vibrato actuations. ### Claim 7 (depends on 6) The combination of claim 6 wherein some of the attaching means are laterally offset from their respective strings. ### Claim 8 A supporting structure for a stringed instrument for producing a vibrato and/or sustained pitch sounds comprising: a rigid frame lying exterior of said instrument; a pivot for rotatably connecting the instrument to the frame, said pivot lying in a plane substantially perpendicular to a plane generally containing the strings of said instrument; said frame having a torque balancing means to limit the movement of the frame when the musician moves the instrument to produce the vibrato and/or sustained pitch changes; means on said frame for anchoring the ends of selected strings; whereby a relative swinging motion of the instrument by the musician with respect to the frame will change the tension on said selected strings to produce the desired sounds. ### Claim 9 (depends on 8) The supporting structure of claim 8 wherein said frame is provided with a plurality of spaced guide means for assisting the pivot in maintaining a rectilinear movement of the instrument in said plane. ### Claim 10 (depends on 8) The supporting structure of claim 8 wherein said frame has a configuration approximating the configuration of a conventional stringed instrument body. ### Claim 11 (depends on 8) The supporting structure of claim 8 on which a vertically adjustable arm is mounted for each of the selected strings connected between a bridge and the frame to maintain a chosen relative pitch among said selected strings during sustained pitch changes and/or vibrato actuations. ### Claim 12 (depends on 8) The supporting structure of claim 8 wherein biasing means are provided between the instrument and the frame to establish a predetermined relative neutral position therebetween. ### Claim 13 (depends on 8) The supporting structure of claim 8 wherein said anchoring means in said frame is a lever arm extending substantially normal to said strings, said lever arm having a plurality of individual string attaching means greater in number than the number of selected strings to provide different tension adjusting positions which are adjusted to maintain a chosen relative pitch among the selected strings during sustained pitch changes and/or vibrato sounds.