Patent GB-400680-A (GB)
Title: Improvements in and relating to vehicle head lamps, search lights and other light beam projecting lamps
IPC: B60Q1/14
Filed: 1932-05-04
Abstract: 400,680. Vehicle lamps, searchlights, &c. GUY, C. J., 38, Rockamount Road, London. May 4, 1932, Nos. 12790 and 31173. [Classes 75 (ii) and 75 (iv).] Reflectors ; adjusting reflectors from a distance ; mounting electric lamps in lanterns ; lantern screens.-In a vehicle headlamp, searchlight, or other projector lamp, a reflector for obtaining various beams of light, between those having concentrated or parallel rays and those having widely divergent rays, comprises a number of movable portions, or a spirohelically cut strip adapted to be compressed or extended, arranged so that the curvature of the reflector, which for a concentrated beam would be of substantially parabolic shape, is flattened to a saucer shape to give a diffused beam, the source of light being simultaneously movable along the axis of the reflector. In the vehicle lamp shown in Fig. 1, eight curved reflecting sector plates 4 are hinged at 5 to the fixed annular front part 6 of the reflector, and their rear edges abut against a cup part 7. The side edges of alternate plates overlap those of the plates between, and the reflecting surfaces are protected by ball-bearings or deflector plates 10. A sleeve 8 integral with the cup 7 acts as a guide for the bulb-holder 9, and is slidable in a ring 15 which is carried by arms 16 fixed to the inside of the reflector rim 18. The holder 9 is moved forward by a hinged elbow lever 12a, 12b passing through slots 13 in the holder and hinged to the rim 18 of the reflector, and operated by a bowden wire or other means. A collar 11 adjustably attached to the holder then abuts against the sleeve 8, and further movement pushes the sleeve 8 and cup 7 forward, so moving the plates 4 and flattening the reflector. The parts are returned to their normal position by the spring 20 and springs 19 at the back of some or all of the plates. The position of the lamp bulb may be initially adjusted by means of a screw 41. A metal or seini-transparent coloured screen 21 may be permanently or detachably fixed to a tongue which is hinged to, and extends through a slit in, one of the plates and which is connected by a link 23 or a small coil spring with one of the arms 16, so that, when the plate is moved forward, the screen 21 is moved into a horizontal position. Alternatively, a screening plate may be attached to the rear of the topmost sector plate, which is arranged to be pushed further forward than the others by means of a rod, adjustable in length, directly connecting it with the collar 11, so that the screening plate is brought into a horizontal position above the lamp bulb. In a third form, the topmost sector plate or plates are permanently or detachably hinged to the cup 7, and connected by an adjustable rod to the collar 11, so as to be brought into a horizontal position above the lamp bulb when the plates are moved forwardly. When the bulb is mounted at the front of the lamp, as shown in Fig. 6, the bulb holder 33 is slid in the guide tube 34 against the action of the spring 36 by means of the cable 37 sliding in the tube 38, the cable also being connected to the lever 39 operating the rearward extension 40 of the cup 7 so as to push forward the reflector segments. The lever operating the reflector in any of the forms might be a simple rocking lever pivoting at the centre. The movable reflector portions may be annular plates. The front glass may be diffusing. According to the first Provisional Specification there are two or more hinged plates which are shaped to cover parts of the usual reflecting inner wall of a vehicle lamp, and the inner ends of which may be moved forwardly together with the lamp bulb.