GB291571A - Improvements relating to motor car head lamps - Google Patents

Abstract

291,571. Workman, H. April 11, 1927. Filaments; multiplefilament lamps.-A depressed beam from vehicle headlights is obtained from a filament which lies in the transverse focal plane of the main reflector and extends upwards from the focus thereof, the filament being narrow in the part near the focus when viewed from the front. The front glass of the lamp is preferably grooved or ribbed vertically and lightly etched, to spread the light horizontally. The main light may be derived from a second filament arranged close to the focus beneath the lower end of the first filament. The first filament 17 may be straight or of V-shape, with the apex adjacent the focus, as shown in Figs. 14 and 6 respectively, or it may be of U-shape, and the second filament 20 may be of similar or different focus, arranged vertically or horizontally. The filaments may be arranged unsymmetrically with respect to the vertical, as shown in Fig. 42. Accurate adjustment of the filaments with respect to the bulb caps and the reflector may be obtained by the forms of caps and bulb-holders described in Specifications 204,464 and 204,774. The filaments may be mounted in a spherical bulb behind its centre 29, Fig. 4, so that the filament image 30 formed by the front surface of the bulb lies well away from the filaments themselves. To adjust the bulbs with respect to the horizontal, the lamp casing 86 may be mounted on pivots 72, Fig. 1, and adjusted thereon against the action of a spring 75 by means of a thumb-nut 78, or the reflector 40, Fig. 46, may be supported on two horizontally aligned springs 59 and a lower spring 66, its tilt being adjustable against the action of the spring 66 by a nut and bolt 69.