GB636391A - Improvements in or relating to apparatus applicable more particularly for publicity purposes in places untouched by sunlight - Google Patents

Abstract

636,391. Signs. JOURNEL, J. Sept. 18, 1946, No. 28069. [A Specification was laid open to inspection under Sect. 91 of the Acts, Sept. 18, 1946.] [Classes 3(i) and 3(ii)] [Also in Groups XX and XXXVII] A display apparatus under heliostatic control for illuminating a transparency or screen by sunlight comprises a frame ABC, one face AC of which forms an angle with the horizontal plane equal to that of the latitude at the display point and carries, in a gimbal frame a-h, a mirror constantly rotating about an axis x-y; the outer part of the gimbal frame a-d is arranged to rotate about an axis o-o<SP>1</SP> once in 24 hours and so keeps the axis x-y at right angles to the sun's rays which are thus reflected by the rotating mirror and an adjustable mirror L to direct an intermittent beam towards the transparency or screen. The rotating mirror is double-sided and is driven by an electric motor P, the circuit of which is completed through a thermal switch (see Group XXXVII) which breaks the circuit when the sun is obscured. The outer gimbal frame is driven by clockwork M. The mirror L may be convex, may be replaced by a prism, or both a mirror and a prism may be provided. The Specification as open to inspection under Sect. 91 describes a series of mirrors arranged in pyramid-fashion on a rotatable vertical shaft to illuminate a ring of transparencies. This subject-matter does not appear in the Specification as accepted.