GB396909A - Improvements in and relating to electric incandescent lamps - Google Patents

Abstract

396,909. Electric incandescent lamp filaments. CHAPMAN, A. E., 125, Stanley Park Road, Carshalton, Surrey. June 8, 1932, No. 16238. [Class 39 (ii).] The filament of a tubular electric lamp is supported on a longitudinal flexible member maintained in position in the lamp by wire stays bearing against the walls of the lamp, these stays and the filament supports being fused into glass beads attached to the member. Fig. 1 shows a straight tube a containing a filament b and a supporting wire c. The filament b is supported on the wire c by " pigtails " g attached to beads e, alternate pigtails are arranged on opposite sides of the filament as shown. Between the beads e are beads d carrying wire stays f bearing on the surface of the tube a. The ends of the stays f may be pointed to reduce shadows and coated with copper to avoid scratching the glass. The wire c and supports f may be of molybdenum or they may be of magnetic material and retained in place by magnets outside the tube. Springs h, i are arranged at the end of the filament b and support c. The beads d, e may be pear-shaped as shown in Fig. 5. Fig. 8 shows the stays f and pigtails g made in one piece. The support c may be insulated and serve as the return lead; the filament and support may in this case be connected to a standard cap at one end of the tube. The tube may contain several filaments mounted on separate sets of pigtails. The tube may be curved, cross-shaped &c., and the support arranged accordingly.