Rotating ball pendulum for four-hundred-day clock - with rigid pendulum rod and concentric return spring

摘要

The decorative rotating ball pendulum is used for a four-hundred-day clock, with a balance mechanism or quartz-oscillator circuit for operating the time display. The rigid pendulum rod is acted on by a concentric return spring, which has a diameter only slightly greater than that of the pendulum rod. The bottom end of the spiral return spring is fixed to the pendulum rod while its upper end is fixed to the radial bearing for the pendulum rod. The length of the spring is such that an axial force supporting the weight of the pendulum is exerted on the pendulum rod. A transmission element acted on by the clock mechanism transmits a torsion moment to the spring for rotating the pendulum.