GB329173A - An improved dimming device for automobile head-lamps and other search-lights - Google Patents

Abstract

329,173. Giese, P. May 22, 1929. Mounting electric lamps in lanterns.-In a vehicle lamp or other searchlight, both the source of light and a dimming device are mounted inside the reflector on a carrier attached to a sleeve through which pass the electrical conductors and the means for controlling the dimming device. Two or more lamps may be attached to a rotary axle so that any lamp may be brought to the focus of the reflector by an electromagnetically operable, switching device. In the form shown, the sleeve 4 carries two tubular arms 6, 7. These support the spindle 8 bearing three electric lamps which emit different kinds of rays, and a turning device. Two discs 13 and 17, the former fixed to the axle and the latter freely rotatable, have three ratchet teeth each on adjacent faces, and are pressed together by a helical spring 18, which also tends to rotate the disc 17 in a counterclockwise direction, a pin 21 limiting this motion. When a current is passed through the electromagnetic device 28, the cord 20 is pulled and rotates the disc 17 in a clockwise direction. When the lost motion x has been traversed, the pin 16 is disengaged from the bore in the disc 13 by the projection 22 pressing on the projection 23, and the disc 13 is rotated until the next lamp is brought into focus. It is then engaged by the pin 16, now released. On releasing the cord, the spring 18 brings the disc 17 back to its original position, the disc rising on the teeth of the lower disc and being held up by the nose 22 passing over the projection 23 while the lost motion is being established. The lamp brought into focus at the same time enters the electric lighting circuit.