Patent ID: 7971851

Claim:
A torque balance servo for use in conjunction with a fluidly-controlled device, the torque balance servo comprising: a pivoting table assembly, comprising: a pivoting table configured to pivot about a rotational axis and normally residing in a null position; and a roller assembly mechanically coupled to the fluidly-controlled device and contacting a surface of the pivoting table with a normal load; and an electromagnetic force bias mechanism disposed proximate the pivoting table assembly and configured to exert a variable torsional force about the rotational axis of the pivoting table to provide controlled pivoting of the pivoting table, the roller assembly readjusting its position in response to pivoting movement of the pivoting table such that the torque from the normal load applied through the roller assembly counteracts and balances torque applied to the pivoting table by the varying electromagnetic force to return the pivoting table to the null position after pivoting movement thereof.