US1512989A - Automobile headlight - Google Patents

Description

Dct. 28 1924. 1,512,989

J. H. LAIRD AUTOMOBILE HEADLIGHT Filed Jan. 4, 1923 Patented Oct. 28, 1924.

rraee I JOHN H. LAInn, or LOUISVILLE, KENTUCKY,

AUTOMOBILE HEADLIGHT.

'1 0 all whom it'may concern.- I

Be it known that I, JOHN H. LAIRD, a citizen of the United States, and residing at Louisville, county of Jefl'erson, and-State of Kentucky, have invented certain new and useful Improvements in Automobile Headlights, of which the following is aspecificat-ion.

My invention relates to motor vehicle lamps in which the upward rays, which would be blinding to approaching persons, are eliminated, and in addition oertain ad vantageous direction is givento certain rays to light the ground near the front and to the sides or the motor vehicle.

It is my object to provide as ii'ertect-as possible a device of the noted character and at the same time to eliminate to uw reaaa possible extent any variation over present practice in forming reflectors,installing and adjusting light 'bulbsetc.

It is more specifically myobject to provide a small piece of properly stormed reflective materiahwhich lsftO belattached at the apex of the lamp reflector, this .piece notonly interrupting rays that-tend tooliverge' upwardly from the reflector, but also reflecting said rays back to the reflector at-a proper angle, and cuttingout alltendency to'upward deflection of theserays or other rays directed backwardly.

As is well known the ordinaryparabolic reflector, with a properly located light bulb,

would throw a perfectly parallel beam of light, in a direction of theaxisoflthemeflector, if the light filament couldbe .reduced to a point. Howeven-since this isnot feasible, and since certain rays not "light emanating directly from v the lamp ware inot confined by the reflector, the presentday automobile lamps require some kind of a *special lens. in-order'to be reflective-within le al limits ofbeam direction. I

ain familiar withva'rious typeso'fspevciallyshaped reflectors to replace the normal parabolic reflectors, but these are too costly to make a good manufacturing proposition.

I am aware that others have tried to attach onto the lamp bulbs-themselves small reflective mirrors, but-the defect of doing this is that the lamps are not of uniform size, and are not spherical at the end,xand also that-such reflectors do not truly avoid the incorrect deflectio-nof rays of light.

l accomplish myv obj eot'above: set forth by pointed out and claimed;

that certain construction and arrangement of parts to be hereinafter more specifically In the drawings:

Figure l is a perspective view taken 1001a: ing into a reflector equipped with 'ilnyanovel device. I

Figure 2 is a central cross section taken vertically through a reflector, in the posi tion in whichit is to be installed in alamp.

FigureB is a top plan view ofthe attachment device.

It'will be noted that thereflector 1 is a-n ordinary parabolic reflector "of the type used in practi-callyall present day automobile lamps. i-The method cfmounting thereflector inthe lamp casing, isnot ,oi'importance to my invention and henceis :notishown or described. V k f l secure the lamp bulb 2 in the reflector in the usual manner, through a holeat the apex thereof, so that'the lampfllament lies in the axis of the reflector. I n

In addition to the reflector: myinventio-n includes special stamping or the like of metal, which is burnished, or silvered in some manner to have reflective surfaces.

This stamping has a moreor less annular strip 3, terminating at the front in a spherical shaped piece 4. This piece 4 must be far. enoughawaytrom the reflector apex to permit the lamp to be set between it and the reflector and extends from the horizontal ringportion 3 upwardlyflonly. It is also. limitedini area sothat it isless-than a quarterofa spherical surfacathe inside line :of this piece beingso .setthat it does not interrupt any rays iromthe lamp which would otherwise: strike: the reflector at some point. {It is arranged to interrupt all rays from the light bulb fllament,indicated 5v,

which would otherwise emerge from the lamprat a'slant above the horizontal, and would not strike the reflector. It does not eliminate any: rayswhich would emerge It is. also arran ed so thatthe sohericalcen I b l ter is at the centerof the filament oftho bulb when properly adjusted .in.; plac e, as shown in dotted lines in :Figure 2. i

I :At the rearfloflthering like plate another reflector 6 is formed, which is spherical or approximately so and faces forwardly of the lamp with itsreflective surface. This reflector is so arranged that the rays emanating therefrom are directed downwardly of the horizontal.

As will be noted this rear reflector is also located above the horizontal line formed by the ring shaped support, and both reflectors are integral {with the ring, and turned up and formed therefrom, as a stamping.

V The rear reflector is cut awayto clear the central hole in the back of the reflector as indicated at 7, and is formed with rivet holes'8, by means of which it is riveted to the rear of the reflector. In mounting the device the hole formed in the rear reflector is set to register with the hole in the main reflector and the said rear reflector of the insert is then riveted in place, or held in.

any other desired permanent manner.

The outer reflector l of the insert is so arranged that its focus is the same point as the focus of the parabolic reflector in which it is mounted, both of the said reflectors having a common focus at the center of the light filament.

Dotted lines have been drawn in Figure 2 to indicate the direction of light rays from the filament in my device when the light bulb is properly adjusted with its filament at the con-focal point of the main reflectorand the reflector l. 7

Light rays emanating directly are stopped by the spherical reflector t acting as an opaque body. They are then directed back through the filament to the main reflector I and thus strike it correctly to be deflected again into the truly horizontal beam from the main reflector. Such light rays as would tend to strike the main reflector fromthe filament and be deflected upwardly near the apex of the reflector, due to the fact that the filament is not a mere point of light, will be caught by the rear'reflector 6' and deflected back through the filament point, and thence downwardly out of the reflector lo the ground directly in front of the lamp.

'lhis'same deflection will take place as to rays which are incorrectly sent back by the reflector 4, due to the dimension'of the filament. The chief reason for the rear reflector 6 is to prevent the deflection which would occur if it were omitted. Rays coming in a horizontal path against the reflector -t from the main reflector would be deflected thereby to the lower half of the main reiiector and thence upwardly in the very angle that is tobe avoided. I

it will thus be noted that by my insert I take care ofthe full contingency of incorrectly escaping beams of light, and also that I do not reduce the number of beams of h light which would emerge from the lamp,

. cepting no other rays.

pensive special reflector, and I. wish to avoid any devices which form part ofthe bulbs themselves, since such devices vary with the bulbs, and cannot be truly supported in the correct con-focal position with the main reflector, since with every adjustment of the'bulbs to get them at the focal point of the parabolic reflectors, the relative positionof the attached spherical reflector elements if any, are changed with relation to the parabolic reflector. By the use of the term parabolic in the claims that follow, I desire to cover that range of reflectors which have the gene alfunctions of true parabolas, and not to be confined to true and undistorted parabolas. Thus reflectors having partially a true parabolic shape and partially distorted, or having flutings to cut out filament images, or partially on catenary curves, are generally classed by me as parabolic reflectors.

Having thus described my what I claim as new and desire to secure by Letters Patent is: c

1. in a lamp, a reflector of parabolic shape,and a device fixedly secured to the reflector so as to be located at its apex, and shaped toclear a light bulb, said device including a support anda spherical reflector having a con-focal relation with the parabolic reflector, and set in the reflector and proportioned so as to'obstruct by its opacity, direct rays of light emanating'from the bulb that'would otherwise pass out through the upper half of .the lamp, but otherwise to avoid, obstruction of light emanating from said bulb, and also including another concave reflector located to the rear of the spherical reflector entirely above the horizontal axis of the reflector and interspaced from'the spherical reflector, to prevent re-' flected rays from the parabolic reflector from striking the spherical reflector at an angle that: would ultimately result in an upward emanation from the lamp, but intere 2. An insert to be fixedly attachedto parabolic reflectors comprising a support, in the form of a hollow ring like body, a spherical reflector of less than a quarter of a sphere formed at the forward end of said support, and a concave reflector formed at the rear end of said support, said two reflectorsboth located to one side of said support, and said. support being in a single plane and all reflectors having a focus at a common. point j 3. An insert to be fixedly attached to parabolic reflectors comprising asupport, in the form of a hollow ring like body, a spherical reflectorofless than a quarter of invention,

a sphere formed at the forward end of said support, and a concave reflector formed at the rear end of said support, said two reflectors both located to one side of said support, and said support being in a single plane, the reflectors and support being formed in one piece and both reflectors having a focus at a common point.

4. In combination with a main parabolic reflector, and a light at its inner focus, a mirror element adapted to obstruct and de flect direct rays from the light that would pass out of the reflectorat an upward slant, and a separate elementadapted to shield that portion of the main reflector that would otherwise reflect rays of light to the'mirror element at such an angle as to ultimately escape from the lamp at an upward slant.

5. In combination with a main parabolic reflector, and a light at its inner focus, a mirror clement adapted to obstruct and deflect direct rays from the light that would pass out of the reflector at an upward slant, and a separate element adapted to shield that portion of the main reflector that would otherwise reflectrays of light to the mirror element at such an angle as to ultimately escape from the lamp at an upward slant, said separate element also formed as a mirror adapted to deflect rays from the light forwardly and downwardly.

6. An insert to be fixedly attached to parabolic reflectors comprising a support, in

the form of a hollow ring-like body, a shield the form of a flat ring-like body having a' portion integral therewith and turned up to form a shield covering in area around a half circle and mounted at the forward end of the ring-like body, said ring-like body adapted to clear a lamp bulb set with its filament in the plane of said ring-like body,

and the shield adapted to block only such rays as emanate from the light filament in an upward slant in a direction to escape contact with the parabolic reflector to which the insert is attached.

' JOHN H. LAIRD.

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