GB460463A - School orrery - Google Patents

Abstract

460,463. Orreries. HARGREAVES, J. M. Oct. 30, 1935, No. 29918. [Class 146 (ii)] A school orrery comprises movable models of the earth, moon, and sun, and the movements representing the rotation of the earth on its axis and its orbital course round the sun are automatically actuated when the whole orrery is moved to represent the motion of the solar system through space. The coloured model earth B and moon C are carried by rotatable concentric tubes, mounted on an inclinable post I on an arm D, and are driven at proportionate speeds by elastic bands Q, P and pulleys F, E respectively. The arm D and pulley F are secured to concentric tubes on a fixed post W and are respectively driven through bevel gearing H and J and chains or bands from an axle S carrying driving-wheels Y. The pulley E is fixed to the post W. The wheels Y may be driven by contact with the floor as the orrery is wheeled about, or may be raised from contact therewith by a movable leg U, on which and on castor wheels X the orrery may be supported. The orrery may then be operated by a handle O and chain or band M. An arm V, loosely attached to the arm D, is pressed against a fixed cam disc C by the bands P, Q so as to control the inclination of the post I and the orbital motion of the earth and moon. A coloured sun globe A is illuminated by an electric bulb for which batteries N are carried on platforms T. Sockets R are provided for a perambulator handle. The orrery is mounted on a pyramidal panelled casing which may be provided with an inspection door.