# US 7,608,770 B1 · Variable ratio spring return for bass drum pedal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,770 B1 - Document ID: US7608770B1 - Status: Granted - Kind: B1 - Application number: 11/511,196 - Filed: 2006-08-28 - Granted: 2009-10-27 - Earliest claimed: 2006-08-28 - Inventors: Lucas A. Jacobson - Web page: https://patentgrep.com/patent/US7608770B1 ## CPC - G10D 13/11: Pedals; Pedal mechanisms - 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 A variable ratio spring return for a bass drum pedal includes a bass drum pedal of the type having a driveshaft mounted on a frame for rotation in a positive direction from a rest position to an impact position on a longitudinal axis of the driveshaft. A spring return assembly connected between the frame and the driveshaft biases the driveshaft in a negative direction from the impact position towards the rest position. The spring return assembly includes a spring with ears at opposing ends, one ear connected to the frame and the other ear connected to a cam-shaped hub mounted on the driveshaft. The hub has a peripheral edge that varies in radius from a small radius at an upper end to a large radius at a lower end. A belt has a first end connected to the upper end of the hub and extends downwardly around a forward peripheral edge of the hub to a clip that receives the upper ear of the spring. A second end of the belt is connected to the upper end of the hub and has a second run extending downwardly therefrom along the rearward peripheral edge of the hub to the clip. A pivot arm is connected to the hub and has an outer peripheral edge that forms the lower portion of the hub forward peripheral edge. Pivoting the arm outwardly from the hub changes the radius of curvature of the lower forward peripheral edge of the hub. ## Claims ### Claim 1 A variable adjustable spring return for a bass drum pedal, the pedal of the type having a driveshaft mounted on a frame for rotation in a positive direction from a rest position to an impact position on a longitudinal axis of the driveshaft, and a spring return assembly connected between the frame and the driveshaft to bias the driveshaft in a negative direction from the impact position towards the rest position, said spring return assembly including a spring with first and second ears at opposing ends, the first ear connected to the frame and the second ear connected to the driveshaft, the spring return comprising: a cam-shaped hub mounted on said driveshaft for rotation therewith, said hub having a peripheral edge that varies in radius, an upper peripheral portion of the hub having a radius less than a lower peripheral portion of the hub; said hub peripheral edge including a forward peripheral half and a rearward peripheral half; an elongated flexible belt having a first end connected to the upper peripheral portion of the hub forward peripheral half and a first run extending downwardly therefrom along the forward peripheral half of the hub; said belt having a second end connected to the upper peripheral portion of the hub rearward peripheral half and a second run extending downwardly therefrom along the rearward peripheral half of the hub; said belt first and second runs connected together and to a spring retention clip located below the lower peripheral portion of the hub; said spring second ear connected to the clip for movement with the clip on the belt. ### Claim 2 (depends on 1) The spring return of claim 1, wherein said hub is adjustably mounted on the driveshaft, for selective adjustment about the longitudinal axis of the driveshaft. ### Claim 3 (depends on 2) The spring return of claim 2, wherein said belt second end is selectively adjustably connected to the hub, for selective lengthening and shortening of the second run of the belt. ### Claim 4 (depends on 3) The spring return of claim 3, further comprising means for selectively changing the radius of curvature of a portion of the hub forward peripheral half, to thereby selectively change the ratio of driveshaft rotation to spring tension as the driveshaft rotates between the rest position and impact position on its longitudinal axis. ### Claim 5 (depends on 4) The spring return of claim 4, wherein said means for selectively changing the radius of curvature of a portion of the hub forward peripheral half includes: a pivot arm connected at an upper end to the hub for pivotal movement on an axis parallel to the driveshaft longitudinal axis; said pivot arm including an outer peripheral edge forming a lower portion of the hub forward peripheral edge; and means connected between the arm and the hub for selectively pivoting the arm between a retracted position with the lower end of the arm proximal the hub, and an extended position with the lower end of the arm spaced from the hub. ### Claim 6 (depends on 5) The spring return of claim 5, wherein the means for selectively pivoting the arm includes: a rod pivotally connected at a first end to an inward edge of the arm; a well formed in the hub proximal and aligned with the rod; said rod extending from the first end to a second end slidably disposed within the well, and positioned to extend and retract from the well to thereby pivot the arm to the extended and retracted positions, respectively; and means for selectively retaining the second end of the rod in a selected position in the well. ### Claim 7 (depends on 1) The spring return of claim 1, wherein said belt second end is selectively adjustably connected to the hub, for selective lengthening and shortening of the second run of the belt. ### Claim 8 (depends on 1) The spring return of claim 1, further comprising means for selectively changing the radius of curvature of a portion of the hub forward peripheral half, to thereby selectively change the ratio of driveshaft rotation to spring tension as the driveshaft rotates between the rest position and impact position on its longitudinal axis. ### Claim 9 (depends on 8) The spring return of claim 8, wherein said means for selectively changing the radius of curvature of a portion of the hub forward peripheral half includes: a pivot arm connected at an upper end to the hub for pivotal movement on an axis parallel to the driveshaft longitudinal axis; said pivot arm including an outer peripheral edge forming a lower portion of the hub forward peripheral edge; and means connected between the arm and the hub for selectively pivoting the arm between a retracted position with the lower end of the arm proximal the hub, and an extended position with the lower end of the arm spaced from the hub. ### Claim 10 (depends on 9) The spring return of claim 9, wherein the means for selectively pivoting the arm includes: a rod pivotally connected at a first end to an inward edge of the arm; a well formed in the hub proximal and aligned with the rod; said rod extending from the first end to a second end slidably disposed within the well, and positioned to extend and retract from the well to thereby pivot the arm to the extended and retracted positions, respectively; and means for selectively retaining the second end of the rod in a selected position in the well. ### Claim 11 A variable ratio spring return for a bass drum pedal spring return assembly, comprising: a cam-shaped hub having means for mounting the hub to a driveshaft on a bass drum pedal, said hub having a rotational axis, said hub having a peripheral edge that varies in radius, an upper peripheral portion of the hub having a radius less than a lower peripheral portion of the hub; said hub peripheral edge including a forward peripheral half and a rearward peripheral half; an elongated flexible belt having a first end connected to the upper peripheral portion of the hub forward peripheral half and a first run extending downwardly therefrom along the forward peripheral half of the hub; said belt having a second end connected to the upper peripheral portion of the hub rearward peripheral half and a second run extending downwardly therefrom along the rearward peripheral half of the hub; said belt first and second runs connected together and to a spring retention clip located below the lower peripheral portion of the hub; said clip including means for retaining one end of a spring of the spring return assembly. ### Claim 12 (depends on 11) The spring return of claim 11, wherein said belt second end is selectively adjustably connected to the hub, for selective lengthening and shortening of the second run of the belt. ### Claim 13 (depends on 11) The spring return of claim 11, further comprising means for selectively changing the radius of curvature of a portion of the hub forward peripheral half, to thereby selectively change the ratio of driveshaft rotation to spring tension as the hub rotates on a driveshaft of a bass drum pedal. ### Claim 14 (depends on 13) The spring return of claim 13, wherein said means for selectively changing the radius of curvature of a portion of the hub forward peripheral half includes: a pivot arm connected at an upper end to the hub for pivotal movement on an axis parallel to a pivot axis of the hub; said pivot arm including an outer peripheral edge forming a lower portion of the hub forward peripheral edge; and means connected between the arm and the hub for selectively pivoting the arm between a retracted position with the lower end of the arm proximal the hub, and an extended position with the lower end of the arm spaced from the hub. ### Claim 15 (depends on 14) The spring return of claim 14, wherein the means for selectively pivoting the arm includes: a rod pivotally connected at a first end to an inward edge of the arm; a well formed in the hub proximal and aligned with the rod; said rod extending from the first end to a second end slidably disposed within the well, and positioned to extend and retract from the well to thereby pivot the arm to the extended and retracted positions, respectively; and means for selectively retaining the second end of the rod in a selected position in the well. ### Claim 16 A bass drum pedal, comprising: a frame; a footplate pivotally connected proximal a heel end to the frame; a generally horizontally disposed rotatable drive shaft supported on the frame above a forward end of the footplate; a beater, including a hammer carried at the end of a beater shaft connected to the driveshaft; a drive assembly connecting the footplate and drive shaft, for rotating the driveshaft to move the hammer in contact with a drum when the footplate is pivoted; and a spring return assembly connected between the frame and the driveshaft, for resisting rotational movement of the driveshaft, said spring return assembly including: a spring with first and second ears at opposing ends, the first ear connected to the frame and the second ear connected to the driveshaft; a cam-shaped hub mounted on said driveshaft for rotation therewith, said hub having a peripheral edge that varies in radius, an upper peripheral portion of the hub having a radius less than a lower peripheral portion of the hub; said hub peripheral edge including a forward peripheral half and a rearward peripheral half; an elongated flexible belt having a first end connected to the upper peripheral portion of the hub forward peripheral half and a first run extending downwardly therefrom along the forward peripheral half of the hub; said belt having a second end connected to the upper peripheral portion of the hub rearward peripheral half and a second run extending downwardly therefrom along the rearward peripheral half of the hub; said belt first and second runs connected together and to a spring retention clip located below the lower peripheral portion of the hub; said spring second ear connected to the clip for movement with the clip on the belt. ### Claim 17 (depends on 16) The bass drum pedal of claim 16, further comprising means for selectively changing the radius of curvature of a portion of the hub forward peripheral half to thereby selectively change the ratio of driveshaft rotation to spring tension as the driveshaft rotates between the rest position and impact position on its longitudinal axis. ### Claim 18 (depends on 17) The bass drum pedal of claim 17, wherein said means for selectively changing the radius of curvature of a portion of the hub forward peripheral half includes: a pivot arm connected at an upper end to the hub for pivotal movement on an axis parallel to the driveshaft longitudinal axis; said pivot arm including an outer peripheral edge forming a lower portion of the hub forward peripheral edge; and means connected between the arm and the hub for selectively pivoting the arm between a retracted position with the lower end of the arm proximal the hub, and an extended position with the lower end of the arm spaced from the hub. ### Claim 19 (depends on 18) The bass drum pedal of claim 18, wherein the means for selectively pivoting the arm includes: a rod pivotally connected at a first end to an inward edge of the arm; a well formed in the hub proximal and aligned with the rod; said rod extending from the first end to a second end slidably disposed within the well, and positioned to extend and retract from the well to thereby pivot the arm to the extended and retracted positions, respectively; and means for selectively retaining the second end of the rod in a selected position in the well.