US 1670837 A
Description (OCR text may contain errors)
May 22, 1928. 1,670,837
L. BLACKMORE File d Jan. 31, 1924 2 Sheets-Sheet 1 May 22, 1928.,
L. BLACKMORE HEAD LAMP REFLECTOR Filed Jan. 31, 1924 2 Sheets-Sheet 2 Patented May 22, 1928.
' UNITED STA LLOYD BLAOKMOBE, OF HIGHLAND PARK, MICHIGAN, ASSIGNOB TO GENERAL MOTOBS CORPORATION, DETROIT, MICHIGAN, A CORPORATION OF DELAWARE.
Application filed January 31, 1924'. serial No. 889,684.
This invention relates to reflectors, and is illustrated as embodied in a reflector for the headlamp of an automobile.
An object of the invention is to provide a reflector which will be eflicient in directing the. light where it is most needed, and which is simple in form and capable of accurate manufactureon a large scale.
Having this object in view, the direction of the reflected light is accurately controlled by providing a. continuous reflecting surface which is made up of a large number of relatively small reflecting zones, preferably with plane surfaces to diffuse slightly each beam of reflected light. In the form shown in the drawings, each zone is in the form of a diamond. By suitably directing the various zones, a composite beam may be secured which is'most intense along an axis directly ahead of the car and substantially parallel to the ground, and which is diffused in each direction away from the axis, but with practically no light reflected upwardly, thus minimizing glare.
Another feature of the invention relates to obviating glare in the eyes of the driver of an approaching car, by forming the re flector so that no light is reflected to the left, while at the same time; there is adequate illumination. forwardly and oil to theright, i. e. of the ditch at the side of the road.
Other objects and features of the invention, including various desirable specific constructions, will be apparent from the following description of one illustrative embodiment shown in the accompanying drawings, in which Fig. 1 is a front elevation of a reflector embodying my invention;
Fig. 2 is a vertical section on the line 2-2 of Fig. 1; and
Fig. 3 is a horizontal section on the line 3-3 of Fig. 1.
The invention is shown in these drawings as embodied in a reflector 10 for an auto- -mobile headlamp, with a bezel 12 and an opehing 14 for an electric bulb or other source of light 16., The internal surface of the reflector is formed to provide a substantially continuous reflecting surface of general parabolic form, and which is a composite of a large number of small zones 18, each of which is shown as being of diamond shape and witha substantially plane sur- 'parallel to the ground.
face. By providing zones ofthis character,
each reflecting one small and slightly diffused beam, each zone may be considered separately, and arranged to direct its beam ararngement avoids any alternate light and dark rings in the composite beam.
As will be apparent from Fig. 2, I prefer to arrange the various zones asymmetrically with respect to a central horizontal plane, such as the plane on the line 3-3 of Fig. 1, so that while the top of the reflector will reflect the light downwardly ahead of the car, the bottom of the reflector will not waste the light by directing it upwardl but will instead direct it forwardl and su stantially his has the advantage over a truly parabolic reflector that, instead of reflecting a single intense beam of parallel rays of light, there'is a high degree of illumination along what would be the axis of such a beam, whileat the same time the light is diffused and spread out'so that its intensity decreases gradually away from such axis to give good illumination over a relatively large area. I
According to another feature of the invention, and as best shown in Fig. 3, the'zones or their equivalents are also arranged asymmetrically with respect to a central vertical plane, i. e. the plane on the line 21-2 of Fig. 1, so that while the left side of the reflector will reflect sufficient light to the. right to illuminate the ditch at the side of the road, there is practically no light reflected off to the left by the right side of the reflector, this light being re ected forwardly instead. This results in greatly minimizing glare in the eyes of the driver of an approaching car,
and on a road of any considerable width curvature above the source convex Curvature and a source of light within the reflector, said reflector having a reflecting surface which isthe composite of a series of individual substantially diamondshaped plane reflecting zones, each zone meeting the next ata distinct angle and the vertices of said diamond shaped zones lying in series of parallel horizontal and parallel vertical planes. e
2. An automobile head light comprising a concavo convex reflector composed of a plurality of individual reflecting surfaces, said surfaces being asymmetrically grouped with respect to a horizontal plane passing through the vertex of the reflector so that all of the reflected rays will fall below a substantially horizontal plane, said surfaces being asymmetrically grouped with respect to a central vertical plane passing through the vertex so as to cast a greater quantity of light at one side of said plane than the other to effect better illumination of the adjacent side of the roadway.
3. A headlight reflector having convex curvature and a source of light with in the reflector, said reflector having a curvature asymmetric with respect to a central horizontal plane, the portion of the reflector below the source-of light being formed to reflect the light rays in a generally forward direction and the portion of the reflector above the source of light being formed to reflect the rays in a generally downward and forward direction, said reflector also being asymmetrically curved with respect to a central vertical plane, the portion of the reflector on one side of the light source being formed to'reflect the rays in a generally for-