Adjustable counter-tensioning mechanism for stringed instrument tremolo device

Claim 1

An adjustable counter-tensioning mechanism for use with a stringed musical instrument having a body with a top surface, parallel strings extending over said top surface, a tremolo device having a string anchor pivotal about an axis generally perpendicular to said strings and parallel to the instrument top and also having a rear portion extending rearwardly into a recess in said instrument body, said strings being anchored to said string anchor and tending to rotate it in one direction about said tremolo axis, and at least one spring connected to said rear portion of said string anchor tending to rotate said string anchor in the opposite direction about said tremolo axis, said counter-tensioning mechanism comprising: a base adapted for fixed attachment to said body of said stringed instrument, first and second gears carried by said base for rotation relative thereto about spaced first and second parallel axes, a third gear carried by said base for rotation relative thereto about a third axis and drivingly connected with said first and second gears so that when said third gear is rotated about said third axis said first and second gears rotate in opposite directions about said first and second parallel axes, two threaded shafts each connected to a respective one of said first and second gears for rotation with said first and second gears about said parallel axes, and a spring anchor threadably received by said two threaded shafts so as to be moved in one direction or another relative to said base along said parallel axes in response to rotation of said third gear in one direction or another about said third axis, said spring anchor including means for fastening thereto one end of said at least one spring another end which is fastened to said rear portion of said string anchor.