US 2330561 A
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P 1943- F. R. DIETRICH VEHICLE REAR SIGNAL Original Filed June 5, 1939 F'riedncha uqrwiewim I INVENTQR @fiSk -L i atented Sept. 28, 1943 VEHICLE REAR SIGNAL Friedrich Richard Dietrich, Munich, Germany; vested in the Alien Property Custodian Original application June 3, 1939, Serial No.
277,288. Divided and this application September 11, 1940, SerialNo.
June 20, 1938 356,273. In Germany 2 Claims. (01.177-327) This application is a division of Serial No. 277,288, filed June 3, 1939.
The invention relates to a vehicle rear signal, and its object is to enable the driver of a following car to judge his distance from the leading car.
According to the invention the rear light has at least two light sources so spaced apart that at distances beyond a certain range they are not separately distinguishable but appear as a single patch of light.
An example of the device constructed according to the invention is shown in the accompanying drawing, in which Fig. 1 shows one form of construction in perspective, and
Fig. 2- a section on the line AB through the device of Fig. 1.
In the one wall of the device I there are four windows 2, which receive their light indirectly by a common lamp. For this purpose the lamp is screened by a screen 3 from the one wall of the casing l, whereas the other wall 4 of the casing I has a plane paraboloid shape and is provided with a light dimming cover. The windows 2 emit light to the rear of the vehicle, but this light is of very moderate brightness. r
The two windows 2 on each side of the vertical centre plane of the casing l are so spaced that they are separated only by a narrow plane M, butbetween the inside windows 2 there is a much wider plane It,
With a lamp of suitable power, and a reflector of suitable brightness, the four windows are not separately distinguishable at a distance of about 100 m. At some range between this and, say, 60 m., the division due to the wide panel I4 becomes visible, and the arrangement is seen as two patches of light.
Further reduction of distance, say to 30 or 40 m., enables the four windows to be distinguished as four separate patches of light.
This is of great assistance in enabling the driver of a following car to judge his distance from the leading car.
It will be understood that the sub-division due to the outer panels l4 may be dispensed with, but in that case the equipment affords an index to only one range. Similarly it will be understood that the sub-division may be carried further, with panels of appropriate widths enabling additional stages of approach to be recognized. For obtaining windows of different degrees of luminosity transparency may be used for the windows, or provision may bemade for sliding in additional panes, or there maybe rotatable holders carrying panes which can be used alternatively, by rotating the holders. g
The reflector Ashown in the drawing is of pl aneparaboloid shape, so that it has a line focus instead of a point focus, with the lamp filament in this focus, so that the windows are uniformly illuminated. Uniformity of illumination can also be secured by diflerently coloring the parts of the reflector at difierent distances from the windows, the part at the centre being darkest.
In connection with the device! canbe provided a usual stop light 9 and a rear light 6. At the bottom of a casing 5, having the openings 6 and 9 there is an opening'with a lens l for illuminating the number pl'ate 8 by means of a lamp in the casing 5 behind'the opening 6.
Between the casings l and 5 there is'a spindle fixed to a flap Ill, which has a flange H with a colored window l2 for dimming the number plate light.
The flap I0 is so arranged on the casings I and 5 that it covers in its one position the device l and in the other position the windows t, l, 9 of tially rectangular shape, means preventing direct light from said source from falling through said windows, and a reflector disposed on the opposite side of said source, said reflector being adapted and arranged to illuminate the areas of said windows uniformly with reflected light from said source.
2. A rear light arrangement, as claimed in claim 1, in which the surfaceof said reflector is so arranged as to have better reflecting qualities at points farther removed from the light source than at points nearer the light source, thus tending to compensate for the smaller amount of light reaching the farther points and producing a substantially uniform illumination of said windows.
FRIEDRICH RICHARD DIE'I'RICH.