US1587542A - Automobile headlight - Google Patents

Description

June 8 1926.

C. A. MICHEL AUTOMOBILE HEADLIGHT Filed Feb. '7 1925 2 Sheets Sheet 1 W WMw/m mm June 8,1926. I 1,587,542

0. A. MICHEL AUTOMOBILE HEADLIGHT Filed Feb. '7, 1925 2 Sheets-$heet 2 I I a Patented June 8, 1926.

UNITED STATES CLARENCE A. MICHEL, 0F CLEVELAND, OHIO.

AUTOMOBILE HEADLIGHT.

Application filed February 7, 1925. Serial No. 7,439.

This invention relates generally to automobile headlights and more particularly to certain improvements pertaining to the lamp and reflector whereby the driving conditions are improved.

In most automobile headlights, as at present constructed, a single filament lamp is arranged centrally of the reflector, and a single filament lamp usually of less candle power than thecentral lamp is arranged near the top of the reflector. The central lamp has been used for driving, while the upper lamp has usually been employed for city driving and when passing other automobiles upon the road.

Furthermore,. in automobile headlights, as at present constructed it is common to employ a modified form of reflector or a modified form' of lens with the idea of preventing a disagreeable glare when meeting other automobiles or pedestrians. These improvements as heretofore constructed are serviceable at times, while at other times, due

either to the unevenness of the road or the up and down movement of the automobile, they are not so efiicient.

The object of my invention is to add an element of safety to the present devices by employing a double filament lamp which is centrally arranged and in combination J therewith a reflector so constructed that the top of the beam is projected forwardy within the legal limit a considerable distance in advance of the automobile for road driving, and for city driving or while passing other vehicles the top of the beam is materially deflected or drawn downwardly so as to avoid all possibility of glare.

Broadly speaking, the object of my invention is accomplished by correcting or modifying the upper part of the upper half of the reflector and the lower part of'the lower half of the reflector. More specifically stated, these corrections may be made by the modification of the true parabola; the tiltingof the reflector section downwardly; the

use of a modifying lens; or the wider sepa-\ ration of the focal points of the sectlons of the parabola,- or any combination of the specific corrections hereinbefore mentioned. Having described the broad conception of my invention, I shall now describe one form of reflector employed in comblnation with a double filament lamp and whereby the broad principle of my invention is accomplished.

wou d'be the true parabolic sections.

This specific form is shown in the accompanying drawing in which Fig. 1 is a vertical sectional view of my improved form of reflector and lamp, Fig. 2 is a face View of the same and Fig. 3 is a diagrammatic view illustrating the lines of reflection of the various rays of light.

Referring to the drawings, A indicates the incandescent lamp having two filaments B and C, the filament B being arranged slightly abovethe axis D of the reflector E and the filament C is located substantially on said axis. There are two focal points 1 and 2 indicated on the axis of the reflector and it will be understood that the filaments both upper and lower are substantially equal to or greater than the distance between the two focal points. The reflector E is a modified reflector to this extent that the lower portion of the upper half RF is described from the focal point 1, and the upper portion of the lower half RH is described from. the focal point 2 and these parabolic sections extend as far as the point F in the upper half of the reflector, and as far as the point H in the lower half of the reflector. The upper portion of the upper reflector is modified from the true parabola to the extent of brln ing the reflecting surface within what The true parabolic surface is indicated by the dotted line FG and the actual reflecting surface is indicated by the full line FG. The lower portion of the lower half of the reflector is also modified by bringing the actual reflecting surface curvature withoutthe true parabolic surface curvature. The true parabolic curvature is indicated by the dotted line HI and the actual reflectin surface is indicated by the full line H These modifications are for the purpose of controlling the beams emanating from the filaments for the purpose of preventing glare, and I willnow describe in detail the manner in which such correction is effected. Taking first a ray of light 1 (Fig. 3)

from the focal point '1 passing rearwardly to the upper parabolic section RF it would be. reflected horizontally, and a ray of light 2 emanating from the focal point 2 and striking the parabolic section RH would be reflected horizontally also. The ray of light 1 emanating from the focal point 1 and striking the lower parabolic reflecting section RH would be reflected downwardly, and

a ray of light 2 from the focal point 2 striking the upper parabolic section RF would be deflected downwardly. A ray of light 1 emanating from the focal polnt 1 and contacting with the true parabolic surthe upper filament B and between the two,

focal points 1- and 2, it is obvious that rays B in substantially the same vertical plane as the focal point 1 reaching the parabolic surface FG would be reflected above the true horizontal and a ray of light B emanating from the upper filament and substantially in vertical alignment with the focal point 2 reaching the parabolic surface F G would be reflected below the horizontal. Consequently the rays between the ends of the filament some would go above the horizontal and others below and in orderto bring all of these rays below the horizontal the actual reflecting surface FG has been brought within the true parabolic surface to such an extent that all of the rays of light reaching this portion of the reflector from the upper filament will be directed below the horizontal.

With reference to the lower portion of the reflector the same thing is true, that is to say, rays of light B emanating from the upper filament at a point in vertical alignment with the focal point 1 and striking the true parabolic surface would be deflected downwardly, but a ray of light B emanating from the u per filament in vertical ali nment with tffe focal point 2 would be de ected upwardly and in order to prevent this upward reflection the'a'ctual reflecting surface HI parabolic surface as indicated at HI, the extent of modification being that which is sufficient to cause all of the light rays of the upper filament striking the sections FG and HI to be reflected below the horizontal as indicated by the lines B and B reflected from the surface F G and the lines B and B reflected from the surface HI.

Any rays of light such as B and B from filament B striking the section RF would be deflected downwardly; and any rays of light such as B and B from filament B striking the section RH would be reflected downwardly.

Inasmuch as the lower filament C is substantially on the axis of the reflector and 5 between the focal points 1 and 2, what has been said with reference to rays emanating is brought without the true from points 1 and 2 is equally true with reference to rays emanating from the lower filament C.

In view of the foregoing the beam from the lower filament is higher than the beam from the upper filament and consequently the lower filament is used for the driving light and the upper filament for the passing or city light.

In order to facilitate the manufacture of the reflector embodying the sections RF, RH, FG, and HI without the employment of intersecting angles, I provide transition surfaces at the points where such sections intersect.

Where there are reflecting surfaces of different curvature of revolution, sharp angles are produced at their intersections and these angles not only introduce errors in the reflecting surfaces but also render the manufacture of the reflector very difficult, and to overcome these objections, I interpose tran sition surfaces L and M between the upper and lower halves of the reflector.

From the foregoing, it will be seen that when filament B is illuminated, all of the rays from sections RF and RH are reflected below the level of the rays from the filament G, and likewise, sections FG and HI have been altered or modified, to the extent that when filament B is illuminated the re s of light are reflected considerably below t e horizontal.

The lower filament C is the main or driving filament and when in use the top of the 'beam is projected forwardly a considerable distance but is kept below the horizontal so as to provide a proper legal beam of light.

When, however,'the main or driving filament is cut out and the upper filament B cut in, all of the rays of light from filament B are perceptibly deflected downwardly thereby rendering the possibility of glare substantially impossible and providing a safe beam of light for city driving or for passing other automobiles.

Although I have not shown any special construction of headlight lens arranged in front of this reflector, it is obvious that either a plain or modified lens could be employed in connection with this reflector.

It will thus be seen that I provide a very simple but highly eflicient combination of lamp and reflector for use in an automobile headlight and wherein a lamp havingtwo filaments may be employed, said filaments being brought into use preferably at separate times but capable of use in unison if necessary.

Having thus described my invention, what I claim is 1. In a light projector, the combination of a reflector and a light bulb having two independently lighted filaments, one substantially on the axis of the reflector and one memes above said axis, the focus of tho lower half of the reflector being spaced from and in front of the focus of the upper half of the reflector, the filaments being located between the focal points, the rear portion of the reflector being parabolic, the forward portions of the upper and lower halves being modified so as to reflect downwardly the rays of light from either filament.

2. In a light projector, the combination of a reflector and a light bulb having two independently lighted filaments, one in the axis of the reflector and one above said axis, the focus of the lower half of the reflector being spaced from and in front of the focus of the upper half of the reflector, said filaments being located between the vertical planes passing through the focal points, the

rear portion of the reflector being parabolic,

the upper portion of the upper half having the reflecting surface brought within the true parabolic surface and the lower portion of the lower half being brought without the true parabolic surface so as to reflect downwardly the rays of light from either filament.

3. In a light projector, the combination of a reflector and a light bulb having two independently lighted filaments, one on the axis of the reflector and one above said axis, the focus of the lower half of the reflector being spaced from and in front of the focus of the upper half of the reflector, said filaments being located between the focal points, the'rear portion of the upper half of the reflector being struck from the rear focus and the upper portion of the lower half of the reflector being described from the front focus, the forward portion of the upper half of the reflector being brought within the a true parabola and the forward portion of the lower half of the reflector being brought without the true parabola whereby the rays of light from either filament are reflected downwardly lln testimony whereof, ll hereunto afix my signature.

CLARENCE A. MIGHEL.

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