ELECTRIC FILAMENT LAMP Russian patent published in 1997 - IPC

FIELD: electrical engineering. SUBSTANCE: electric lamp has base, transparent bulb, holder, and spiral filament body made as frame. Filament body is divided into sections by insulators and is mounted in holder for movement and alternate energizing of every section. Ends of holder metal part have flat contact surfaces for interaction with moving frame. The latter is hinged to glass part of holder. Contact surfaces of frame are positioned over circle arc. EFFECT: more efficient light source. 3 dwg