Patent ID: 8006578

Claim:
A converter for use in a high speed rotationally oscillating surgical burring device comprising: an output shaft; a rotationally oscillating secondary drive rotor coupled to the output shaft, the secondary drive rotor being arranged and configured with a size and mass to minimize its angular momentum; a unidirectionally rotating primary drive rotor; a linearly reciprocating transmission for converting unidirectional rotation to bidirectional rotational oscillation coupling the primary and secondary drive rotors, the transmission being arranged and configured with a size and mass to minimize its linear momentum; and an input shaft coupled to the rotating primary drive rotor to which a unidirectional rotational force is applied, wherein the secondary drive rotor has a spiral slot defined therethrough, and where the transmission comprises: a drive pin disposed through the spiral slot, so that the secondary drive rotor rotationally oscillates as the drive pin longitudinally reciprocates; a stationary guide having a linear slot defined therethrough through which the drive pin is disposed to maintain the drive pin in a fixed plane of oscillatory linear motion; and a cam follower coupled to the drive pin where the primary drive rotor has a cylindrical bore in which an elliptical groove is defined, the cam follower engaging the elliptical groove so that the drive pin is longitudinally reciprocated within the primary drive rotor as the primary drive rotor unidirectionally rotates.