# US 9,520,110 B1 · String vibration frequency altering shape > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,110 B1 - Document ID: US9520110B1 - Status: Granted - Kind: B1 - Application number: 14/753,621 - Filed: 2015-06-29 - Granted: 2016-12-13 - Earliest claimed: 2014-07-23 - Assignees: University of South Florida - Applicants: Ismet Handzic; Kyle B. Reed - Inventors: Ismet Handzic; Kyle B. Reed - Web page: https://patentgrep.com/patent/US9520110B1 ## CPC - G10F 1/20: to be plucked - G10F: AUTOMATIC MUSICAL INSTRUMENTS (non-musical aspects of toy instruments A63H5/00; sound recording or reproducing G11B; working in association with recording or reproducing apparatus G11B31/02) ## Abstract The present invention is a novel variable tension string instrument that relies on a kinetic shape to actively alter the tension of a fixed length taut string. A mathematical model was derived that relates the two-dimensional kinetic shape equation to the string's physical and dynamic parameters. With this model, an automated instrument was designed and constructed to play frequencies within predicted and recognizable frequencies along with programmed melodies. ## Claims ### Claim 1 A variable tension instrument comprising: a kinetic shape object, wherein the kinetic shape object further includes: two lateral sides creating a width and a contacting perimeter; an aperture through the two lateral surfaces at a predetermined location on the kinetic shape object and in an orthogonal orientation with respect to the contacting perimeter of the kinetic shape object, wherein the aperture is adapted to receive an axle; a string having a first end and a second end, wherein the first end is secured at a stationary point and the second end is secured to the axle thereby creating a tension in the string; a predetermined vertical force imposed on the axle; a platform on which the contacting perimeter of the kinetic shape object is disposed; and the kinetic shape object rotatable about the axle, thereby altering the tension in the string as the kinetic shape object rotates. ### Claim 2 (depends on 1) The variable tension string instrument of claim 1, wherein the kinetic shape object further includes frequency-identifying indicators around the perimeter. ### Claim 3 (depends on 1) The variable tension string instrument of claim 1, further comprising a second kinetic shape object receiving the axle such that the two kinetic shape objects are parallel to each other. ### Claim 4 (depends on 1) The variable tension string instrument of claim 1, wherein the contacting perimeter has a nautilus-like shape with respect to an axial viewpoint. ### Claim 5 (depends on 1) The variable tension string instrument of claim 1, further comprising: a second kinetic shape object, wherein the second kinetic shape object further includes: two lateral sides creating a width and a contacting perimeter; an aperture through the two lateral surfaces at a predetermined location on the second kinetic shape object and in an orthogonal orientation with respect to the contacting perimeter of the second kinetic shape object, wherein the aperture is adapted to receive a second axle; a second string having a first end and a second end, wherein the first end is secured at a stationary point and the second end is secured to the second axle thereby creating a tension in the second string; a predetermined vertical force imposed on the second axle; a platform on which the contacting perimeter of the second kinetic shape object is disposed; and the second kinetic shape object rotatable about the second axle, thereby altering the tension in the second string as the second kinetic shape object rotates. ### Claim 6 A method of using the variable tension kinetic shape string instrument comprising: securing a first end of a fixed length string at a stationary point; securing a second end of the string to an axle passing through a kinetic shape object, the kinetic shape object further including: two lateral sides creating a width and a contacting perimeter; and an aperture through the two lateral sides at a predetermined location on the kinetic shape object and in an orthogonal orientation with respect to the contacting perimeter of the kinetic shape object, wherein the aperture is adapted to receive an axle; applying a vertical force on the axle; orienting the kinetic shape object, such that a tension force in the string and the vertical force on the axle allow the kinetic shape object to rest in a static equilibrium; rotating the kinetic shape object, such that the tension force in the string changes; and producing a vibration in the string creating varying frequencies based on the tension in the string. ### Claim 7 (depends on 6) The method of claim 6, wherein the contacting perimeter has a nautilus-like shape with respect to an axial viewpoint. ### Claim 8 (depends on 6) The method of claim 6, wherein the step of rotating the kinetic shape object further includes a moveable platform on which the contacting perimeter of the kinetic shape object is disposed, such that movement of the platform rotates the kinetic shape object. ### Claim 9 (depends on 6) The method of claim 6, wherein the steps of rotating the kinetic shape object and contacting the string further include using an automated machine to rotate the kinetic shape object and to contact the string. ### Claim 10 (depends on 6) The method of claim 6, further comprising: securing a first end of a second fixed length string at a stationary point; securing a second end of the second string to a second axle passing through a second kinetic shape object, the second kinetic shape object further including: two lateral sides creating a width and a contacting perimeter; and an aperture through the two lateral sides at a predetermined location on the second kinetic shape object and in an orthogonal orientation with respect to the contacting perimeter of the second kinetic shape object, wherein the aperture is adapted to receive a second axle; applying a vertical force on the second axle; orienting the second kinetic shape object, such that a tension force in the second string and the vertical force on the second axle allow the second kinetic shape object to rest in a static equilibrium; rotating the second kinetic shape object, such that the tension force in the second string changes; and producing a vibration in the second string creating varying frequencies based on the tension in the second string. ### Claim 11 (depends on 6) The method of claim 6, further comprising measuring force or stress in the string by relating string frequency to the vertical force. ### Claim 12 A kinetic shape instrument, comprising: two lateral sides creating a width and a contacting perimeter, wherein the contacting perimeter has a nautilus-like shape; and an aperture through the two lateral surfaces at a predetermined location on the kinetic shape instrument and in an orthogonal orientation with respect to the contacting perimeter of the kinetic shape instrument, wherein the aperture is adapted to receive an axle. ### Claim 13 (depends on 12) The kinetic shape instrument of claim 12, further including being rotatable about the axle. ### Claim 14 (depends on 12) The kinetic shape instrument of claim 12, further including a predetermined vertical force imposed on the axle. ### Claim 15 (depends on 12) The kinetic shape instrument of claim 12, further including a string having a first end and a second end, wherein the first end is secured at a stationary point and the second end is secured to the axle thereby creating a tension in the string. ### Claim 16 (depends on 12) The kinetic shape instrument of claim 12, further including frequency-identifying indicators around the contacting perimeter.