Patent Document ID: 20060260828
Application ID: 11461744
Patent Flag: 0

Claim One:
1. An apparatus for moving correcting masses to dynamically balance a rotating shaft having an axis, the apparatus comprising: a housing, substantially symmetric along each of a first plane perpendicular to the axis, a second plane containing the axis an perpendicular to the first plane; a first stepper motor attached to the housing; a second stepper motor attached to the housing in opposed relationship to the first stepper motor within the first plane and symmetric to and offset from the second plane such that the mass of the first stepper motor will counterbalance the mass of the second stepper motor upon rotation of the shaft; a first correcting mass assembly attached to the housing, the first correcting mass assembly configured to engage the first stepper motor such that rotation of the first stepper motor will move a first center of gravity along a first line extending radially from the axis and perpendicular to the second plane; and a second correcting mass assembly attached to the housing, the second correcting mass assembly configured to engage the second stepper motor such that the rotation of the second stepper motor will move a second center of gravity of the along a second line extending radially from the axis, perpendicular to the second plane and symmetrically offset from the first plane.