GB261020A - Improvements in and relating to multiple filament electric lamps - Google Patents

Abstract

261,020. British Thomson-Houston Co., Ltd., (Assignees of Falge, R. N.). Nov. 5, 1925, [Convention date]. Multiple - filament lamps; bulbs. -In lamp bulbs intended for use in headlights &c., three filaments are concentrated near the focus of the associated reflector. one being of comparatively low power for parking purposes, and the others of high power, the main filaments being of bent form and all the filaments being connected at one end to separate positive leads and at the other end to a common negative lead connected to the metal base of the cap, as described in Specification 193,325. An external switch enables all the filaments to be lighted separately, or the two high-power filaments together. One of the high-power filaments 12 may be located at the focus, as shown in Fig. 2, and the other similar filament 13 closely above or beneath it, and the parking filament 14 above them, or the filaments 12, 13 may be arranged one on each side of the focus, as shown in Fig. 3. The bulb may be corrugated at 11, as described in Specification 205,747, to prevent the formation of images of the filament.