Three ball rotating pendulum display for clock - has fixed pin acting as stop for projection on pendulum to prevent excess rotation of latter

摘要

The rotary pendulum (1) is suspended by a torson wire or tape (11) from a mounting (14, 15, 17) including a spring permitting natural adjustment in the vertical direction. The pendulum is prevented from excess swing by a projection attached to the pendulum which can strike a stop (8b). The pendulum has a fixed natural frequency of about eleven seconds but is forced to oscillate with a frequency of ten seconds by means of an intermittent force applied by six spokes (25a) of a wheel (25) driven by the second shaft (27) of the clock. This wheel is driven via a spring (30) which ensures a smooth application of force just sufficient to turn the pendulum at this frequency.