Patent ID: 6311557
Filing Date: 2001-11-06
Classification: B06B,G01H

Abstract:
A magnetically-tunable beam for detecting a particular frequency of vibration comprising:a beam element having an end and a surface, and being fixedly disposed on the end;a stress-sensitive means for controlling stiffness of the beam selected from the group consisting of a stress sensitive coating having a stiffness that varies with the stress therein affixed on the surface of the beam element and the beam element material having a stiffness that varies with the stress therein;a first ferromagnetic means for exhibiting magnetic polarity from the group consisting of: a ferromagnetic coating disposed on a surface of the beam element and a ferromagnetic property of the beam element material;a second ferromagnetic means for exhibiting magnetic polarity fixedly disposed generally parallel to the first ferromagnetic means and separated from the first ferromagnetic means by a gap formed therebetween; anda magnetic field means suitably disposed and connected for providing magnetic polarity upon the first ferromagnetic means and the second ferromagnetic means to cause magnetic force between the first ferromagnetic means and the second ferromagnetic means so that magnetic force therebetween causes the beam element to bend, and thus produces a change in stress in the stress-sensitive means and a change in the resonance frequency of the magnetically-tunable beam.