Drive apparatus for independently changing the phase of the moon for planetarium

摘要

Apparatus comprising a moon projector including an element for changing the phase of the moon, a gear system for transmitting a drive force to the moon phase changing element, a drive system for annual motion, a drive system for independently changing the phase of the moon provided independently of the annual motion drive system, differential gear means for selectively transmitting the operation of the annual motion drive system or of the drive system for independently changing the moon phase to the drive force transmitting gear system, and switching means for selectively operating the annual motion drive system or the drive system for independently changing the moon phase, whereby changes in the lunar phase as related to annual motion or changes in the lunar phase independent thereof can be selectively projected without impairing the continuous changing mode of the lunar phase.