GB817326A - Improvements in or relating to incandescent electric lamps - Google Patents

Abstract

817,326. Incandescent electric lamps. PHILIPS ELECTRICAL INDUSTRIES Ltd. July 21, 1955 [July 24, 1954], No. 21149/55. Class 39(2) In an electric incandescent lamp for a motor vehicle headlight comprising a helically wound main filament 5 arranged in a plane and in the form of a curve or V- shape, with the apex of the curve or V- shape directed towards and situated nearest to a screen 6 which partly surrounds an auxiliary filament 7, the apex of the curve of V-shape of the main filament comprises a loop 14 extending out of the plane of the main filament and secured, preferably at the apex of the loop, to a support. As shown, the main filament 5, in the form of a V, is supported at its ends by a leading-in wire 2 and a longer leading-in wire 3 which supports the screen 6, and a third wire 4 sealed into the,pinch 1 is bent around the front face 8 of the screen, clear of the latter, to support the end 7b of the auxiliary filament 7. The other end 7a of the filament 7 is attached to the rear end of the screen. The apex of the V-shaped filament 5 is looped downwardly at 14 and secured by an eyelet 15 mounted on a glass bead 16 supported by a short wire 17 upstanding from the supporting wire 4. The part of the wire 4 that is bent around the top front edge of the screen 4 is connected to the latter by an insulated strut comprising two short wires 10, 11 with an intermediate glass bead 12. Fig. 2 shows a modification wherein a downwardly directed loop 34 at the apex of a horizontal V-shaped filament 33 is connected to a wire support 29 sealed within the pinch 25 of a lamp and having no connection in the lamp circuit. The screen 30 is supported by an extension of the leading-in wire 27 of the main filament 33, and one end 31a of the auxiliary filament 31 is connected to the screen 30, the other end 31b being connected to the end 28a of a leading-in wire 28 arranged to have no contact with the screen. The loop in the main filament may be produced by supporting a continuously wound length of filament on a supporting plate provided with a slot 50, Fig, 5, across which the filament is arranged transversely, and a tool 51 is pressed downwardly on the filament to carry the central portion of it into the slot. The parts of the main filament on opposite sides loop may be wound oppositely.