US 1888995 A
Description (Le texte OCR peut contenir des erreurs.)
Nuv. 29, 1932. A. J. MA'r'n-:R 1338995 HEADLIGHT Filed Nov. A14, 1929 Elg-l W! TNESSES: I ;WENTOE Patented Nov. 29, 1932 UNITED sTAr-Es ALBERT JOHN HATTEB', OF PARK BIDGE, ILLINOIS HEADLIGHT Application filed. November 14, 1929. Serial No. 407,075.
This invention relates to improvements in headlights for automobiles, locomotives and similar uses and has for its object to provlde means for controlling and directing practl- 5 cally all of the rays coming from a light source therein so that they form a straight beam of parallel light rays.
Another object is to jlrevent any of the rays of light emerging t erefrom, going in any direction other than parallel with the main light beam, thus eliminating glare outside of the desired limits of the main beam. i Another object is to provide means for forming the emerging light into any desired Shape of beam such as round, fan-shaped or otherwise, having a clear cut outer edge without glare-causing stray rays of light.
These objects are attained by means of the improvements illustrated in the accompanying drawing and described and claimed in the annexed specification and claims,
Referring now to the drawing, which illustrates what I consider, at the present time, to be the preferred form of the invention,
Fig. 1 is a Vertical longitudinal section through the center of a. headlight embodying` my invention.
ig. 2 is a front view, on a reduced scale, of that form of my invention shown in Fi 1. Referring now, more particularly to ig. 1, for the details of construction of that form of my invention which I now consider to be the preferred form, 1 represents a source of light which is here illustrated as anl incandescent lamp and which is positioned within and surrounded by a reflector 2. Completing the closure at the front, or forward of the source of light, is a lens 3. w
The reflector 2 is partly parabolic in form,
40 having two parts generally marked 2a and 2b, theportion 2b being` substantially concave, an the outer portion 2a being substantially parabolic. The portion 2b 1s of such shape that the light rays from the source of light are reflected from the reflector 2 through the span 'marked E, to the lens 3- so that they pass through the same in the zone B. The light rays striking the reflector 2 in the zone marked F are reflected and pass I through the lens 3'in the zone marked A;
The zone A is coincident with that part of the lens marked 3a and the zone B isl coincident with that part of the lens marked 3b. The portiona which is parabolic and the portion 2b of the reflector surface are so disposed at such angles to the source of light as to cause the angles formed by the reflected rays and the axis of the lamp to gradually decrease from the center of the reflector to its periphery as shown by the arrow lines in Fig. 1 which indicate the direction of the light rays. This concentration of light rays from the primary reflector within annular zones A and B 'permits the use of a secondary reflector as shown without interceting primary reflected rays. Thus in both re ector portions mentioned, the angle formed by a line extending radially from the source of light, to any point on said portions of the reflector and thence outwardly therefrom along the lines of reflection, increases as the distance from the source of light to the apex of said angle increases. Therefore, due to the form of the reflector and especially in the zone marked E, the light rays are reflected and enter the refractin lens 3 at various angles and as it is my obJect to project them in substantially parallel relation, I have formed the refracting lens With the outwardly curved form indicated at 3b necessary to produce this result.
The portions 30-86 of the lens operate to refract in parallel rays, the rays reflected angularly by the portions 2a-2b of the reuector 2 which is hereinafter referred to as the primary reflector.
The lens 3 is therefore provided with an annular inwardly extending concavo-convex lens portion 3a provided with a curved surface which, as here shown, serves to support a secondar -reflector 3d. This secondary reflector 3 may be a deposit formed upon the lens or it may be a sheet of metal or other` suitable material.
The lens portion 30 and the reflector 3d are so formed and positioned relative to the source of light and to the primary reflector 2, that the `rays of light which enter the lens portion 30 and are reflected by the reflector 3d are those which, if not thus intercepted,
would not strike the primary reflector. Due
secondary reflector 3d, the light raysare bent and take different. angular paths so that in order to have them emerge in parallel relation throughout the zone marked C, said portion 30 is formed with an annular concavity.-
The remaining light rays, which pass for- Wardly from the source of light, enter a concentrating refracting lens portione, which is of the necessary pronounced curvatureito insure the light rays emerging in the zone D at each side of the center l1ne in parallel relation.
lln order to perrnit of a compact relation of the parts, as well as the necesary functioning Shape, the inwardly projecting central portion of the lens is provided with a recess 3x in order to accommodate the fora ward portion of the casing or glass of the 'incandescent lamp forming the source of light 1.
From the foregoing description, it will be obvious that a most compact head lamp structure of primary reflector, secondary refiector, lens and source of light, is provided and which is of' such form, arrangement and construction that none of the light rays crosses `any other after leaving the lens. It is such divergent and uncontrolled rays which are generally responsible for the so-called headlight glare. Hence, since I have eliminated such stray rays and projected them in parallel relation, headlight glare is eliminated. At the same time, l have collected all of the rays and concentrated them so that a more eflicient utilization of the source of light is obtained;
While the primary reflector, the secondary refiector and the lens have been accurately formed, positioned and calculated to conform to the laws of reflection and refraotion to.
produce the desired result before described, it is evident that slight modifications may be made in the structure, provided the general principles, before described, are followed.
From the foregoing description, it will be evident that l have provided a construction, which, while it may be varied somewhat in Shape, forms practically all of the rays of light into a beam which 1s projected forwardly from the headlight and without cross rays.
The various advantages of my construction will now be apparent to those skilled in the art to which this appertains, without further description.
I claim as my invention:
1. A lens for a headlight oomprising a disclike body portion having an outer annular flat portion, an intermediate annular prismatic portion adj acent the flat portion, a central rearwardly projecting concaVo-convex portion having a reflecting rear surface, and
5 a plano-convex lens portion near the rear end of the concavo-convex portion and disposed concentrically thereof.
2. A light projector oomprising a 'light bulb; a refiector having its outer annular portion parabolic and its rear vertex portion concave and a lens covering the reflector, said lens comprising an outer annular flat portion positioned to receive the arallel rays projected by the parabolic re ector portion, an annular concentric prismatic portion positioned to receive the divergng rays from the concave refiector portion and refract them forwardly in aparallel beam, a central rearwardly projecting concavo-convex portion having a refiecting surface applied on the rear thereof and positioned to receive a portion of the forward direct rays from the light bulb and to refiect and refract said rays forwardly, and a plano-convex, lens portion positioned in front of the light bulb to project the divergent rays into a parallel beam, said concavo-convex portion being provided with a recess in the rear thereof to accommodate the forward portion of the light bulb.
3. A light projector oomprising a light bulb, a reflector having its outer annular portion parabolic and its rear vertex portion concave and a lens covering the reflector, said lens oomprising an outer annular flat portion positioned to receive the parallel rays projected by the parabolic reflector portion, an annular concentric prismatic portion positioned to receive the diverging rays from the concave reflector portion and refract them forwardly in a parallel beam, a central rearwardly projecting concaVo-convex portion having a reflecting surface applied on the rear thereof and positioned to receive a portion of the forward direct rays from the light bulb and to refiect and refract said rays' forwardly, there being an annular concavity in the front surface of the concavo-convex portion to project the reflecting and refracting rays in arallel, and a'plano-convex lens portion positioned in front of the light bulb to project the divergent rays into a parallel beam, said concavo-convex portion being provided with a recess in the rear thereof to ac- 1onflgmodate the forward portion of the light ul Z 4. A lens for a headlight oomprising a disc-shaped body and an annular prismatic portionprojecting from one sidethereof and a centrally disposed concave-convex portion projecting from its other side, an exterior refiecting surface on said projection, there being a central depression at the rear end of the concavo-convex portion of a sizeto accommodate the forward portion of a headlight bulb, and a concentrating lens' integral with said concavo-convex portion and intermediate the ends thereof. i
5. A light projector oomprising a reflector having an outer annular and a concave central portlon, a light source in focus with said para-bolic ortion for reflecting parallel beams with t e central portion recelvin1 rays from the light source and rojecting t em in a converging annular am, a lensiorthe projector'havin a plane annular portion op osite the para olic reflector portion to al ow parallel rays to pass therethrough, a concentric inner prismatic portion opposite to a part of the concave portion of the reflector to receive converging rays and project them into a parallel annular beam, a concavo-convex portlon opposite the central part of the concave reflector, a reflecting surface on the rear thereof to receive a portion of the direct rays and reflect`| them into a parallel beam, and a plano-convex lens portion Within the concavo-convex projection to receive the remainder of the fo'r-- Ward direct rays from the light source and 20' convert them into a parallel beam.
In test-imony whereof, I have herento set my hand, this 29th day of December, 1930;
ALBERT JolmT MATTER.