The use of torsion suspensions in vibration- and shockproof instruments

Abstract

1. A shockproof and vibrationproof circular-dial rack-mounted instrument with torsion suspensions can be designed for a sufficiently wide frequency range. 2. In producing such an instrument it is necessary to aim at a minimum weight for the moving part and maximum tensioning of the suspensions. Moreover, the natural frequencies of the instrument's components and units should be, as far as possible, outside the range of the vibration frequencies which may be encountered in the instrument's application. 3. The displacement of the instrument's moving part must be limited, and the limiter gaps should be made smaller than the effective gaps between any other components of the instrument and its moving parts under vibration conditions, taking into consideration the contraction of gaps under vibrations and the possibly accompanying resonance effects. 4. It is recommended that the limiter gaps be filled with polysiloxen liquid of medium viscosity, and all the surfaces limiting the spreading of polysiloxen should be carefully treated with a substance which prevents the wetting of the surface by the liquid. 5. The displacement of the damping springs in the direction away from the moving system should also be limited. Moreover, the gaps in these limiters should be smaller than the corresponding gaps in the limiters of the moving system's displacement in the same direction. 6. All these provisions are additional to and do not replace the measures normally taken in designing shockproof instruments for the purpose of damping the whole instrument or its measuring mechanism.