GB228366A - Improvements relating to head lamps for vehicles - Google Patents

Abstract

228,366. Lilienfeld, J. E. Feb. 28, 1924. Bulbs; reflectors and screens within bulbs; filaments; multiple-filament lamps; holders. - A vehicle head-lamp is constituted by a lens-shaped incandescent lamp bulb 3, Fig. 1, having an internally-silvered parabolic back portion 1, with or without a protective covering 2, a filament 5 partly behind and mostly in front of the focus F and a conical internal reflector 4 which is supported by one of the leading-in wires and directs light on to the main reflector 1. The filament 5 may be conical, as shown in Fig. 5, or cylindrical, and for town driving a second filament 6 may be mounted above the reflector, as shown in Fig. 8, substantially horizontal in a plane normal to the axis of the parabolic reflector. The reflector 4 cuts off some rays of the filament 6 from the lower part of the reflector 1 in order to reduce dazzle, and this action may be assisted by a screen or rim 7 on the reflector. Direct emergence of rays from the filament may be prevented by means of metal blades on the screen 7, by a pane of frosted silica or glass, or by frosting or silvering a circular area A-B on the front of the bulb, in which case the front of the bulb is preferably made concave, as shown in dotted lines. The two filaments 5, 6 may be illuminated separately or in series or'parallel. The covering 2 may be of a plastic rubber compound or of plaster or the like covered with sprayed aluminium or other metal, or, alternatively, it may be replaced by an all-metal hood. The lamp is secured to the holder 13 of the vehicle by a clamp 12 which serves also to prevent the bayonet joint from working loose.