Mechanical device for representing relative positions of Sun and planets - has rotors with reference points for Sun and planets, made with toothed edges and connected by manually rotated pinions

摘要

The device consists of a fixed reference point representing the Sun, and a series of rotors (11-17) which can turn about a common axis passing through the fixed reference point, each equipped with a reference point (11'B-17'b) representing the planets of the solar system. Each rotor has a toothed rim meshing with a pinion and the apparatus has a system for adjusting the reference point representing the planet Earth in time and a manual control for the pinions. One of the rotors (13) can be turned manually to rotate the pinions, and this rotor can be the one which carried the Earth reference point. The apparatus can also be enclosed in a housing (1) closed by a rotary transparent cover (2) which is turned to rotate the pinions and rotors and is attached, for example, to the rotor which carries the Earth reference point. In a variant of the design the rotors can turn in a space circumscribed by a crown wheel which carries representations of the main stars close to the plane of the ecliptic and graduated marks representing the days of a single orbit of the Earth round the Sun. The rotors can be made in the form of discs with turned-over edges, made of increasing diameter so that they can be stacked together. ADVANTAGE - Simple and robust design, allowing the relative positions of the Sun and planets to be set over a substantial period of time.