Device for damping vibrations of a movably supported unit

A passive oscillation-damper (15) is connected to the unit (10) liable to oscillate and is formed of a spring-weight system (17,16) oscillating in counter-phase with the unit. A drive mechanism (18)acts upon the weight of the oscillation damper in the oscillation direction. The oscillation amplitude of the oscillation damper increases as a result of the phase-controlled drive mechanism by an amount necessary for completely compensating for the unit's oscillation amplitude.