GB537586A - Improvements in or relating to the illumination of dials of instruments and other surfaces - Google Patents

Abstract

537,586. Light conductors. BENDIX AVIATION CORPORATION. Dec. 22, 1939. No. 32765. Convention date, Dec. 23, 1938. Addition to 482,595. [Class 75 (iv)] [Also in Group XIX] An illuminating device for instrument dials and other indicating surfaces comprising a solid rod-like elongated light conducting member along the interior of which light rays from a light source are directed longitudinally, according to the parent Specification is characterized in that the member reflects light outwardly substantially along its entire length in two directions, in one of which it illuminates a transparent or translucent dial or indicating surface. In the other direction it may illuminate a second dial or indicating surface disposed in a plane spaced from the plane of the first dial. As shown, a compass bowl 12 rotatable in a casing 10 contains a compass card 31a pivoted on the jewel bearing 26. An index 33 fixed to the base 13 of the bowl 12 co-operates with the pointer 31 on the card 31a. A translucent compass scale 37 is mounted on the bowl 12 for rotation therewith and co-operates with the fixed lubber's mark 11. Light from the lamp 42 is introduced into the end of the light-conducting ring 40, of glass, quartz, or synthetic material and is reflected downwards from the surface 40 to illuminate the card 30, the pointer 31, and the index 33, and upwards from the surface 40b to illuminate the translucent scale 37. The lightreflecting surfaces may be formed by scratching, marking, painting or silvering.