Damped torsional rod oscillator

Claim 1

A torsional oscillator adapted to be driven by a periodic signal derived from an external generator, said oscillator comprising: A. an erect torsion rod anchored at its base, said rod having a natural resonance frequency Subject to change, B. a load element mounted on the free end of the rod and swinging therewith, and C. a motor driving said rod to sustain it in oscillation, said motor including an armature secured to the rod at a point adjacent said base and an electromagnet associated with said armature to produce in response to said periodic drive signal a torque to excite said rod into oscillations at the natural resonance frequency thereof, the section of said rod below said point having a spring constant which closely approaches the spring constant of the section above said point to produce a coupling between said sections acting to dampen said oscillator and to broaden its mechanical bandwidth, whereby the oscillator continues to function efficiently should the periodicity of the signal deviate from the natural frequency of the rod or the natural frequency of the rod deviate from the frequency of the drive signal.