Abstract: A damper containing magneto-rheological (“MR”) fluid and a plunger lies between and is mechanically coupled both to a fixture and a vibration source. The plunger has a head immersed in the MR fluid. Annular magnets circumscribe the damper and produce a magnetic field surrounding the damper. A tubular shielding sleeve composed of magnetically impermeable material surrounds a portion of the damper. The sleeve is mechanically coupled both to the fixture and the vibration source by springs, and can translate relative to the damper to affect the strength of the magnetic field acting on the MR fluid surrounding the plunger head. The sleeve oscillates responsive to vibration of the vibration source and controls the viscosity of the MR fluid surrounding the plunger head in proportion to the amplitude of the sleeve's oscillation. The resonant frequency of the sleeve is adjusted to approximate the fundamental resonance of the fixture.

Abstract: A fixture is isolated from the transmission of vibration emanating from a vibration source by a damper containing magneto-rheological (“MR”) fluid and a plunger mechanically coupling the damper and the fixture. The isolation apparatus is mechanically coupled to the vibration source. The viscosity of the MR fluid contained in the damper is controlled by a magnetic field produced by the vibration of an isolation system responsive to the vibration of the vibration source. The resonant frequency of the isolation system is adjusted to approximate that of the fixture.