GB407344A - Improvements in electric illuminating devices - Google Patents

Abstract

407,344. Supports for electric incandescent lamp filaments. ADAMS, M., Colony Club, 62nd Street, HOWE, R. F., 102, West 85th Street, both in New York, and NUTTING, P. G., 3216, Oliver Street, Washing- ton, both in U.S.A. July 9, 1932, No. 19477. Convention date, July 9, 1931. [Class 39 (ii).] An electric lamp comprises a heavy incandescent filament carried within an evacuated envelope entirely by rigid supporting means which are rigidly supported at one end of the lamp and are so supported at the other end as to permit free longitudinal expansion and contraction of the supporting means whilst preventing lateral movement of them. In the construction shown in Figs. 1 and 1<a> a heavy coiled filament 2 is supported by hooks 29, 35 from zirconia blocks 15, 32 which are mounted between supporting frames 9, 10 sealed into the pinch 4 of the envelope 1. The frames 9, 10 serve as lead-in wires for the filament 2. A rod 60, which is sealed into a constricted portion 61 of the envelope opposite the pinch 4 is formed with a looped end 63 which slidably engages the zirconia block 15 so as to support the filament and frame members against tilting whilst allowing for expansion and contraction of the frame members. In a modified construction the rod 60 slides in the constriction 61, or the rod may telescope, against the pressure of a spring, with a tubular member mounted in the constriction. Fig. 2b shows a rod 60 slidably supported in a constriction 61, a coiled spring 60<c> being disposed between the rod and the wall of the constriction to protect the constricted portion from the heat of the rod ; alternatively, other means, such as corrugating the rod or winding it with asbestos, may be employed to protect the constricted portion from heat. In another construction, the block 15 loosely carries a pair of rods which engage separate constrictions in the envelope whilst, as shown in Fig. 5, the envelope has a rectangular constriction 71 in which slidably fits a rectangular ring 70 carried by supports 68, 69 secured to the block 15.