US1559212A

US1559212A - Reflector for headlights

Info

Publication number: US1559212A
Application number: US378481A
Authority: US
Inventors: Winston Overton
Original assignee: Individual
Current assignee: Individual
Priority date: 1920-05-03
Filing date: 1920-05-03
Publication date: 1925-10-27
Anticipated expiration: 1942-10-27

Description

Oct. 27, 1,559,212

0. WINSTON ammscwon FOR xwwmears Originai Filed May 5, 1920 4 Sheets-Sheet 1 ZZZZMWWM 0. WINSTON REFLECTOR FOR nswmeafs Original Filed May 5, J 920 4 Sheets-Sheet 2 0 WINSTON REFLECTOR FOR HEADLIGHTS Original Filed Maya, 1920 4 Sheets-Sheet 5 Oct. 27 1925 O. WINSTON asrwc'ron FOR HEADLIGHTS Original Filed May 5, 1920 4.Shects-Sheet 4 Patented Oct. 27, 1925.

UNITED ATE-Si ea orries ovsmou wmsrou, or mmumrousgmmussoma I anrrnc'ronron HnAnme'HTsb Application -filedMayi 3,1920, Serial No. 378,481. Renewed. May 18, 1923.-

T 5 all whom 62 maytco'nccrn:

Beit known that I, OVERTON \VVINS'FON, a citizen ofthe United States, residing at Minneapolis, in thecounty of 'Hennepin and State of Minnesota; have invented certain new and useful Improvements in Reflectors for- Headlights; and' I do herebyv declare the following-to be a fulli clear; and exact description of-the inventionysuch as will' enable others skilled inthe art to which it appertains to make and usethe same.

My present invent-ion relates to head lights,

acters indicate like" p'ai-*ts-throughout theseveral views:

' Referring to the drawings:

Fig; l is a diagrammatic front elevation of-the reflector;

F ig, 2 is a diagraimnatic vertical section takenonthe line 2 2 of 1 Fig; 3 isa diagrammatic obl que section taken-oneitherof the lines 3'8 or 8"3 of Fig. 1;

Fig; 4 is a diagrammatic-horizontal sectiontaken on the line l4 of Fig. 1;

Fig. 5 is a diagrammatic View of the reflector in oblique projection;

Fig; 6 is 'a side elevation of an assumed cone on which one of the directing curves is shown;

Fig.7 directing curve shown in-=Fig.- 6;

F ig. 8 is a development of-thensurface of the'cone shown in Figs. 6 and 7f The form of mypresent'improved reflector may be made clear by assuming a reflector with a lightsource therein and by stat ing that the surface of saidreflector may be regarded being. generated by a conic'revolved downwardly, in opposite directions,

on the approximately horizontal axis of "the come, while continuously increas1ng, at the same time both its rad al distance from with said axis.

is an'end elevati-on of the cone and said-axis and the distance from said light source of its vertex or. "point of intersection This produces a reflector, the reflecting surface of which will be without offsets or 'brokensurfaces,'butin which the upper portion of the reflector willbemuch closer to said lightsource than will the lower portion of said reflector. In a horizontal section, the reflector is preferably bisymrnetrical, as shown in Fig.- 4.

Referring-now to 5, it should be noted that the Vertical axial section of the reflec tor consists'oftwo conics 202 and 00 42.

The said conic 2:c isthe assumed initialposition of the generating conic, and the conic m.2-i stheassumed terminal position; of-the said generatinggconic; and here it should be'noted, that during.- the semi-revolts tion from topito bottoimthe vertex or point of intersection of the generating; conic with its axis 1 1 continuously. moves rearward from the-most forward point x to the 'most rearward point 00 The. conic at the horizontal axial section of the reflector is represented bythecurved line4 m 4; and hereit willbe noted that the vertex orpoint of intersection ofsaid conic with axis y y at 00 is between the above,-noted pointson and 00 v The generating-conic at the oblique axial section -ofthe;reflector, on theline 3-3; is representedby the curved lines 3-x land 90 3,

Hereit may, be further stated that the conics 2 m and af2 are the conics illustratedin- FigJQ; that theconic 4 m 4 is the conic represented in Fig.4; and that the;-

conics-3r and 00 -6 aretheconics representedin-Fig: The conics 3'w and ar -3 are conics' -that correspond; respectively, totheconics 30p and m -8 of Fig. 5, taken on the opposite oblique axial section from section 3-3;- V

Fig. 5 also clearly, illustrates the already. stated fact that the generating-conic, in revolvingfrom itsassumed initial or upper most-position-2w to-its terminal or lowermost position 2x continuouslyincreases,

at the same time, both-its radial distance from its axis and-the distance fromsaid light 1 source of its =vertex or-po1ntofinter section with said axis, and successively passes throughthe' upper oblique, horizontal, and lower oblique positions, diagrammatically shown-in-Fig 5 and this statement is true; regardless of, in which direction the; said generating conic is downwardly revolved on said axis.

It follows from statements already made, and from the illustrations in Fig. 5, and also in Figs. 2, 3 and 4, that the axis y-y of the reflector is the common axis of all of the conics center a whose connnon focal center a is also clearly illustrated in Figs. 2, 3, at and 5.

From the foregoing description, it will be seen that, in the reflector illustrated, two progressions or variations are involved in the generation of the surface, to wit: one varying the distance between the focus and the vertex, and the other increasing the radial distance from the axis of revolution as the generating conic revolves from its uppermost to its lowermost position. In the illustrated form of the reflector, the first named progression is secured by moving the vertex rearward as the generating conic revolves downward, which is by far the best way of securing this variation, because it enables the light to be kept on the focus. The progression of the vertex of the generating conic, along the line of the axis: of revolution, of itself, produces a. radial progression, inasmuch as the cross sections of the generated surface, thereby produced, will not, generally speaking, be curves which are symmetrical, in respect to both the horizontal and vertical planes through the axis of revolution, due to the fact that the distance from the focus to the vertex is changed by said progression of the vertex.

The peculiar contour of the above described reflector will necessarily distribute the reflected light in a manner radically dif ferent from the distribution secured from an ordinary reflector, wherein the surface is 'simply one of revolution, regardless of which one of the three conics, ellipse, parabola, or hyperbola, may be used. In all of such ordinary reflectors, as is well known, the surface normals are in radial planes and intersect the axis of revolution, and, consequently, the incident ray, the surface normal and the reflected ray are in one and the same radial plane; and the general result is that there will be an equal amount of light reflected both above and below the horizontal plane of the axis of the reflector, when the light is located at the focus.

In practice, the reflector will usually have an axial hole to accommodate a light bulb socket, which hole is not shown in the diagrammatic drawings.

The peculiar contour of my reflectors (whether of the form described in said prior application, or in the further improved form hereinafter more fully described) will have an entirely different effect in the distribution of the reflected light, from that of a symmetrical reflector, for the controlling reason that any surface normal is necessarily outof and under the radial plane pass ing through the point of intersection of said normal and surface of the reflector, and hence, it necessarily follows that all of the incident rays, which strike any portion of the reflector above the horizontal plane of its axis, will be reflected out of and under their respective radial planes. The same principles, in respect to the surface normals and in respect to the reflected rays, of course, apply to that portion of the reflector below the horizontal plane of its axis, and hence, the light source can be so adjusted that all reflected rays from that portion of the reflector below the horizontal plane of its axis are deflected downwardly to a greater degree and strike the road nearer the reflector than rays reflected from the lower portion of the ordinary symmetrical reflector. In other words, in my improved and peculiar reflectors, all of the reflected light from the lower portion (to wit: that portion below the horizontal plane of the axis of the reflector) and a large part of the light from the upper portion (to wit: that portion above the said horizontal axial plane) becomes available for illumination of the road.

Nevertheless, notwithstanding the truth of the foregoing statements, some of the incident rays, which strike the portion of the reflector above its horizontal axial plane, will not be reflected downwardly to such a degree as to pass below the horizontal plane of the axis of the reflector, and will co-operate with the unreflected rays from the light source, to afford all of the light needed above the horizontal plane of the axis of the reflector.

The following are features which distinguish the present invention from my prior invention, to wit:

The generating conic, while being re.- volved in a downward direction, as described, is guided by two predetermined di recting curves.

In a commercial reflector, there is no way of the manufacturer guaranteeing that a certain predetermined designed filament is to be used in the light bulb and that the COIL sumer is going to always have the hot spot of his filament at any one predetermined point, with the result that it will be impossible for the manufacturer to design a reflector and be assured that the reflector will be used as designed. As is well known, if the light bulb is placed too far forward of the focus, then the bottom portion of the reflector will illuminate objects above the surface of the road, while the upper portion of the reflector will illuminate the roadway;

while if the light source is plac d way back toward the vertex, then the tendency will be for the upper portion of the reflector to illuminate objects above the road and for the lower portion of the reflector to illuminate Cal or w.

the-surface of the: road These variations of positions of'th'e light source beinggduern tl-lely tO the consumer s'inattention to the;

laws-of the-science of il l umination, it is" easily seen th at iffthemanufacturer designs a reflector in which the upper portion of the" reflector is to illuminate objects above the road and 'the lo-Wer portion of the reflector is to 'illiiniinate' the' surface of: the road, which willneci'ssitate'the light source being at one predetermined position, ifthe consumer" places his light 1 source far "ahead of the predetermined position, then, instead of the upper portion ofthereflector illum i nating objects above the road; it will illuminate-the surfaceoftheroad with the resultthat the 'reflector 'will be used-in away in which 'it was not intended that it should b used.

It is nowwreadilyseen that a commercial 'refiector should =be non-blinding; regardless ofw-hethei" the light source 1s-way back toward theyerteX OIVWELY forward near the rim, consequently the "geometrical "characteristics of the lower half of the reflector must be the same as the geometrical characteristics of the'upper half of the reflector, so that {substantially the same illuminating result is produced, regardless of whether the surface of th'e roadyor an object' abo've the road 'is illuminated by reflected'light from either the'upper or lower portion of the re- Hector.

A refl ctor as shown in-the drawings of the present application: has a directing curve-in-a plane perpendicularto the axis y-y ='oftl 1ereflector, with -suc h geometrical characterist-icsthat i the normals to the surface of the reflector; at points on the lower -h'alf of thedirectingcurve; are de-' tl'c'ct'ed reversely to -th'e- 1nanner in which are deflected, thz normals to the surface of the reflector at points onthe upper half *of the-directing curve- T re second directing CLUE-V which is one cone, the-axis of which' is coincidentuitlrthe axis y-y of the -reflee-tor and whose 'VQTtGX'iS- in the plane which contains'the firstdirecting curve,- also has such geometrical characteristics that thenormals ,tothe surfac": ofthe' reflector; at

obtained suclr characteristics in: the reflector that ':'-thezre sult' is' the: same kind of iilunnna tron and fith'e same character-'of lrghting er-r source isv in the rear-or :the forward @part of the reflector: The best result is-believed to be obtained by passing through these-two directingcurves; conics. with a 'fixed focalpoint and a: corninonraxis, and such design-is;- shown :in :thedrawings; There'wiil 'be condi'tions which make it'desirable', or in: fact 119,65 ssary; to use conics of 'varyingeccem tricities with :fixed 3 or varying foci, either independently ortogether," onea' With theother. Those conditions-which will-impose: such variations will hereinafter bedis cussedm 7 It will, of course, be seen in my preferred form, that ione'directing curve is in a vertical plane passing through the focus of, the reflectOr,-while the other directingicurveis on the surface of a cone, yet'the same result may be substantially. orr nearly. obtained when both directing curvesaare predetermined on the surfaces of 'cones orswhen'b'oth directing curves are predetermined in' Vertical planes.

The reliectingsurfa'ce illustratedv diagram-- niaticall'y' invFigs. lto 8; inclusive, is, as follows:

The reflecting surface generated and now to be considered has two directing: curves, to wit: 0116ShOWIljlDJFlgi' 1, indicated by c and the-second-curvc shown 'in:Fig;1 ins dicated by 0 Gurve c isstaken Ell'li'flflplal'le through the focus.perpendicular to the axis, and the curve '0 is takenron a rcone of 60 degree vertex' angle, .t-l1e vertex-of thescone being at the-focus Iir the description ofthe two directing:

curves'c and cflzth e: fact-unust be reinembelied" that the axisofthe con'e upon whichone ofthe directing-curves is designed, and the axis -y g of the reflector,=' and the axis of the gencrating: conic are all one and the same-"and that the generating coniczhas fixed focal center whi'ch is at thepro-deter mined point a on the axis syz of the reflector. The axis g g of the reflectoinalso con-: tains the -pcenter of the directing-1 curve 0, on which center the radius of the directing curve-r rotates.

The curve c is taken in aplane perpendicular to the axis g -3 of'the reflector; saidplane passingthrough thefixed focus of the generating :conic. The curve '0 is a compound spiral curvevso *designed that the angle, hetween the radius of, and the normal: tothe-curve, increases .in. arithmetical progression -per angle of rotation "of :the radius of the directing. curve c as 'saidradius rotates in either direction downwardly,

'frorn -its uppermost vertical position to the horizontal :1 plane of the: axis; g 3 The said (angle, between the"iradiusmof, and the &

normal to the curve decreases in the reverse order of said arithmetical progression, per angle of rotation of the radius of the directing curve 0 as the said radius rotates in either direction downwardly from the horizontal plane of the axis g,/-3 to its lowermost vertical position; or stated in another way, the said angle, between the radius of, and the normal to the curve 0 increases arithmetically, per angle of rotation. as the axial radial plane of the reflector revolves in either direction downwardly from its uppermost position to the horizon tal plane of the axis g -y, and also, said angle, between the radius of, and the normal to the curve 0 increases in the same arith metical progression, per angle of rotation, as the axial radial plane or the reflector revolves in either direction upwardly from its lowermost vertical position to the horizontal plane of the axis 7 g The curve 0 is continuous and unbroken and is symmetrical in respect to the vertical axial plane of the reflector. 4

From statements already made it is seen that any radial plane of the reflector contains a radius of the directing curve 0 a radius of the directing curve and the axis g of the reflector, said axis being the axis of revolution of the radial planes of the reflector.

The curve 0, Fig. 1, is so designed that the angle between the radius of, and the normal to the curve, is one-fifth of the angle of rotation of the radial plane of the re flector, in revolving from its uppermost position, downwardly .to the horizontal plane of the axis y- 1/, and, reversely, the angle between the radius of, and the normal to the curve. is one-fitth of the angle of rotation f the radial plane of the reflector, in revolving upwardly from its lower vertical position to said horizontal plane. To illustrate: after rotating downwardly the radius of the curve 0 degrees from zero or its upper vertical. position, the angle between the radius of, and the normal to the curve 0, is 6 degrees; after degrees similar rotation of: the radius of the curve 0, the angle between th radius of, and normal to the curve 0 is 12 degrees; and after 90 degrees, similar rotation of the radius of the curve 0, the angle between the radius of, and the normal to the curve 0 is 18 degrees; and, reversely, after rotating upwardly the radius of the curve 0 30 degrees from its lower vertical position, the angle between the radius of, and the normal to the curve 0 is 6 degrees; after 60 degrees similar rotation upwardly oi the radius of the curve 0 the angle between the radius of, and the normal to the curve 0 is 12 degrees; and after 90 degrees similar rotation upwardly of the radius of the curve 0 to wit: at the horizontal plane of the axis y-w,

the angle between the radius of, and the normal to the curve 0 is 18 degrees. In Fig. 1, the normals to the curve 0 are indicated by fine unbroken lines marked a, the radii being shown by broken lines I), which lines 6 also represent the radii of the reflector.

The statement above made is a specific illustration of what is meant by the statement that there are reverse progressions in the change of the angle between the normal to, and the radius of the directing curve, in the top and bottom, or in the upper and lower parts, of the reflector.

Thevalues of the angles for the rotation of the axial radial plane of the reflector, are shown outside of the curve 0 in Fig. 1; and the values of the angles between the radii of, and the normals to the curve 0 are shown within the curve 0 in Fig. 1. It will be noted that, throughout the rotation of the 'adius of the curve 0 from top to bottom, the said normals are on the undersides of the respective radii, or stated in another way, when a normal to the curve 0 and a radius of the curve 0 intersect at a point of the curve 0 then the said normal is under the said radius and makes an angle with the said radius. The above sentence explains what is meant by an angle between a normal to, and a radius of a curve; in other words, an angle between a radius and its normal to a curve, or an angle between a radius of, and a normal to a curve.

In Fig. 1, the angles between the normals to, and the radii of the curve 0 are marked on one side only of the vertical plane through the axis, but it will be understood that in a iii-symmetrical reflector, such as illustrated in the drawings, the angles will be the same for corresponding positions on both sides.

The second directing curve 0 is a space curve on the surface of a cone whose axis is coincident with the axis g of the reflector and the vertex of said cone is on the axis of the reflector at the point a, where the axis pierces the plane of the curve 0 said point a, being the fixed focus of the generating conic. The angle between the axis of the said cone and the elements thereof is 30 degrees in the drawings. The said curve 0 being a space curve, is shown in end elevation in Figs. 1 and 7. The radial distances of the points of the curve 0 as they appear in Fig. 7, are equal to the true perpendicular distances of the respective points of the space curve 0' from the axis y-@ In Fig. 6, the space curve 0 is shown in side elevation. In Fig. 6, the length on the element of the cone, from the vertex a to that point of the curve 0 which is in the upper vertical axial plane of the reflector, is taken an assumed definite length, from a to 1, and the lengths of all of the other elements "of the cone from the I vertex a to the ourrrexc are determined sueli manner tha t the angle between the normal to,wa-ndi'the radiusof the curve'c "in' Figz'-7, avlii'chiis anv end elevation -'ot thespace curve 0 inoreases the axial radial :plane ofthe reflector as said axial radialplanerevolves in either dire'ction upwardly from its lowermost vertical position to the horizontal planeofi theaxis The curve '0 ,-F'ig; 7, is s'o-designed that the anglezbetweenthe radius of, and the normal to the curve 0 Fig. 7, is one-fifth oftheangle of rotation-of'the axial radial plane of the reflector, in revolving froin'its L upper Vertical: position downwardly to the horizontal plane of'the axis y-z ,fand, re-

versely', the angle between the radius of, and

the normal to'the curvevc Fig. 7, is onefifth-of theangle of rotation of the axial radial: plane of the reflector, in revolving:

upwardly from its lower vertical positio'nto saidlhorizontalplaneof the-axis y-y. To illustrate: after rota-ting" downwardly the radius "ofthe curve 0",, Fig; 7 thirty degrees .iilQOlll-gZGTO for its uppervertical position, theangle between the radius of, and the normal to the curve 0 Fig." 7, is fixdegrees; after 60 degrees, rotation downwardly- ,ofthe radius of the curve 0- Fig. 7 theangle between the-radius of, and the normal-to the curve 0 Fig 7-, is- 12 degrees; and after 90 degrees rotation downward-1y: of the radius of the ourveo .Eig. 7 ,theangle between the radius of, and the normal to-thez'eurvecfl,

Fig; 7, is- 18 1 degrees; and, .reversely, after rotating upwardly tlIj,1tdluS of the curve 0 Fig. 7, 30 degreesirom' itslower verticalposition, the angle-between the radius of, and the normal to the curve 0 Fig, '7, is 6 degrees after 60; degrees rotation upward- 1y of the radius-of the curve 0 Fig: 7,,the angle between the radius of, and -'the'normal to the curveo Fig, 7, is 12-degirees;,and: after 90 degrees rotation upwardly of the radius of the curves Fi e; 7- to witza t' the horizontal plane of the axis-'y-fl/pthe angle: between the radius of, and the norm-altothe.

curve 0- Fig. 7, is-18 degrees In Fig.- 7,

vthe normals to the curve 0 are indicated by the fine unbroken lines marked N, the radii= of the curve 0 being shown by; broken lines 5, I

The Values of, the, angles for therotation' of the axial radial plane of the reflector; in

Fig. 7, are shown inside of thedotted base of'the cone, and the Values ot the an'g'Llesi b'etween the i'adii 'of-,-and the normals to=the curve-0 Fig-7 are sho'wnjust outside of the-vie of curve 6 a. U

It will be further noted th BEt tlHOHgliOUt' 7 said rotationfi'om top to bottom, the -nor-j male ZUIG-OIII the undersides: of the radii, or 'stated in anotlier'way-,' when a normal to the cu-ra e 0 Fig: 7 and a radius ot the curve 7 05 Fig; intersect at point'o-f the 3CU1VG'I02', Fig, .7,ithen the saidn'orm'al is'under the said radius:

In Fig: 7-,ithe angles between themor'inals'; to,nand the radii of the curve "0 aremar ke'di on one? side only ofthe vertical plane through the axis, hut it willj'beunderstood that: in ea bi-symmetrical reflector, such as illiistreted in the drawings-the angles: will be the same for corre'sp'ondingpositioirs on both: sides of the vertical I plane through the axis: of the reflector. The: curve-0321's shoWnrin Fig. 7, isoontinuousand iinbiokenz The true lengthsOH the'L'elements or the cone from thevertex to thecurve 0 Fig. '6, are'sshown in'Fig. 8.,C Fig: Sisia developmtant ofthe difeoting'curye c shown irr'sideele, vation in Fig. 6. The end ele-"vaition o f the;

points ;on the curvesto the axis of the refleoy tor, and if the generating conic has a fixed axis and a fixed fo'ous, and lf'ihains'of the;-

co'n'e is coincident with the fixe'd axisjof the 1 generating. conic, and itthe vertex;- of the cone is at the fixed-focus of the generating conic, then the generating conic will have a J constant eccentricity}; Thetwo directing, curves-c?- ando illustrated in Figs: 1, tend 7, have the characteristics just stated.-

Imthe reflector as described above, :the re;- fleoting:surfaoe -may be obtained by drawing througl revelfy two Corresponding points onthe two directingcurves, 0 and c ,'(the two said points :bQ-iiiglsituatd} in oneand the samea-xial radial plane of the reflector) a conic Whos'e focusris at-ai andwhose aX-isis' coincident with the axisy-y of the reflector;

The ourve--c' -,-,Fig. 1, -is an end elevation of the intersection of the- -1'efieetingi' surface generated, with a ;degree cone, or 'aoone whose elements are 60 degrees to the axis, of'the-r'efleotor, the taX-is-ofsa-id coneis coin-" cident vWith the axis of the reflector,- thevertex of said cone is at a, the fixed focus of the generating conic. Elements of this cone are also shown in Figs. 2, 3 and l. The reflecting surface obtained from the two directing curves 0 a plane curve, and 0 a space curve, may be obtained from two directing space curves, that is, one on a cone of a given angle and another on a second cone of a different angle, but having the same vertex and the same axis as the first cone, the method employed in determining the direct curves on the cones being analogous to that described for the determination of the curve 0 the axes of the cones being coincident with the fixed axis of the generating conic, to wit: the axis of the reflector.

The curve 0 at the rim of the reflector is determined by the mode of generation of the reflecting surface and the angle and the place at which the plane of the rim intersects the axis y-y of the generated reflecting surface. In Figs. 1 to 5,'inclusive, the rim of the reflector is shown as in a plane that intersects the axis 1 at a right angle.

As above stated, the characteristics of the two directing curves may, or will, determine the eccentricity of the generating conic in each axial radial plane of the reflector.

The directing curves are in all cases, continuous, that is, unbroken curves which are symmetrical in respect to the vertical plane through the axis of the reflector. The radii of said curves are in all cases understood to mean the perpendicular distances of the points of the curve from the axis of the reflector.

The ratio of the angle between the radius of, and the normal to the directing curve (contained in the plane perpendicular to the axis), in respect to the angle of rotation of the axial radial plane of the reflector, may be taken any desired value, and the said ratio may be greater than, equal to, or less than the ratio of the angle between the radius of, and the normal to the curve (which is a projection of the directing curve on the cone, onto a plane perpendicular to its axis), in respect to the angle of rotation of the axial radial plane of the reflector.

The reflecting surface may be obtained by drawing conics through every two corresponding points of two directing curves selected from the various types of directing curves previously mentioned, the said two corresponding points being situated in one and the same axial radial plane of the reflector. All of the conics passing through the said two corresponding points of the directing curves, have a common axis which is coincident with the axis of the cone and the axis of the reflector.

If all of the conics have a common focus which was predetermined at a fixed point on the said common axis of the conics, then the two above described directing curves will determine 'the eccentricity. of the conics. However, if all of the conics have a constant eccentricity, then the two above described directing curves will determine the position, along the common axis of the conics, of the foci of the respective conics. Said axis is also the axis of the cone and the axis of the reflector, in all reflectors designed in accordance with the above described mode of generation.

It is a well known fact that automobiles make about ninety per cent of their mileage in the immediate vicinity of the home of the owner of the car, and that almost all cars delivered by manufacturers to a local agent will be sold to the consumers who live in that vicinity. It follows that cars sold by the. particular local agent will be used almost exclusively in that territory.

The manufacturer knowing these facts will, in many instances, slightly modify the the design of the reflector to meet the conditions under which the car to which the reflectors are to be applied, is to be generally used. For instance, head lights to be used on cars in Arizona, where roads are sandy and light in color, should be of somewhat different design from. headlights to be used on cars that are tobe run chiefly in large cities where dark oiled roads are encountered.

It is well known that in symmetrical reflectors as at present used, all of the reflected light from one half thereof is projected above the road surface, while all reflectedlight from the other half of the reflector reaches the surface of the road, with a resuit that per unit of area, there will .be less light on the surface of the road than there will be on a vertical object above the road. One of the objects of the present invention is to throw as much light, per unit of area, upon'the road as is thrown upon a vertical object above the road.

Other conditions which make it necessary or desirable to modify the design of the reflector may be stated as follows:

The power of the light source or bulb, which may vary greatly but will probably be about 40 C. P. for average purposes.

The weight of the car; it being understood that light cars, such as Fords, will when overloaded sag at the rear more than heavy cars.

The color of the road, that is, dark roads such as oiled roads and light roads such as sandy roads.

Local atmospheric conditions, such as generally prevailing, clear or cloudy atmosphere.

Shifting of the light source caused by warping of the filament of the liglrt bulb or the moving of the carbon electrode of an arc lamp.

Design of the filament, to wit, vertically mesa-212i extended filament, horizontally extended filament, obliquely extended filament, conical. filament, cylindrical filament and circular filament; v

Nature of the roads, to witywhether the majority of the roads of a particular district are level or undulating, quite straight or circuitous.

Desired distribution of light beam; for narrow roads or wide roads,-forv short beam projectionor for long beam projection.

What I claim is:' V I 1; A lieadlightset for approximately horizontal projectionand comprising a reflector and a' light source therein, said reflector having asurface substantially corresponding'to volved in a downward direction onthe approximately horizontal axis of the conic while increasing-at the sametime, both its radial-distance from said axis and the distaiicefroin said light source of its Vertex or point of intersection with said axis, the majorportion'of the upper part of sai'dsue face being the reverse of the corresponding major portion of the lower part of said surface. r p

2. A- headlight set for approximately horizontal projection and comprising a reflctor-and a light source therein, a material portion of the reflector having a surface substantially corresponding-to asurface generat-ed by aconic revol'i' ed in a downward direction on the approximately horizontal axisof the conic while increasing the dis tancefroin'said light source of its vertex or point'of intersection with said axis, and the verticesor points of intersection with said axis of the curves of the lower portion of;

the reflector being at greater distances from saidlight source than the'vertices or points of intersection with said axis of the curves of the upper portion of the reflector, the lower part of'sai'd surface being the reverse of-the upper part of saidfsurface."

3. Are'fiector having-areflecting surface substantially corresponding; to a surface generated by'a conic revolved downwardly on the approximately horizontal axis of-said conic, said-conic being'guided' lllltS revolu-z tionby a directing" line so'designed that when saiddirecting lineiisprojected on to a" 'plane which is substantially perpendicular to said approximately horizontal axis, the resulting projection isa plane figure, the lower portion of which is a constant percentage of its upper portion;

4. A headlight'set for approximately horizontal projection and comprising a'reflector' and a light source therein, said reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing the di'stancefrom said light a surface generated by a conic re source of its vertex-tor point ofi intersection with said axis, said conic being guided in its'revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane whichissubstantially perpendicular to said approximately horizontalaxis, by means of lines parallel to-said approximately horizontal axis, the resulting projection is a plane figure which has upper segments and lower segments whose radii pass throughand rotate on the point of" intersection of said approximatelyhorizontal axis with said plane, andfor and throughout successive fractional parts of the totalangle of the downward rotation of the radius of an upper segment there are accompanying increases of the angle between the radius and its'normal tosaid upper segment, which increases of saidlatter angie are substantially constant percentages" respectively of the increases of'the angle between the radius and its normal to a lower segment, which latter-increasesoccur for vandthroughout like and corresponding fractional parts of the total angle ofthe upward rotation of "the radius of said lower se'g ment.

5. A headlight set-for approximately hor,-- izontal projection andcomprising a reflector and a-light source therein, said' refictor axis,- the resulting projection is a-planefig-* ure which has upper segments and lower segments'whose rad i pass through and rotate on the point of intersection of said'approximately horizontal axis withsaid plane,"

andfor and throughout successive fractional parts of the total angle o-fthe downward rotation of the radius of an upper segment there are accompanying increases of the angle between the radius and its normal'to s'aidupper segment, which increases of-said latter angle are substantially constant percentages respectively of'the increases of the anglebetween the radius and its: normal tov a lower segment, which latter increases occurifor and througl'iout like and corresponding fractional partsof the total angle of'the upwardrotation of the radius of said lower segment. i

6. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, a material portion of the reflector having a surface substantially corresponding to a surface generated by a conic, revolved in a downward direction on the approximately horizontal axis of the conic while increasing the distance from said light source of its vertex or point of intersection with said axis, and the vertices or points of intersection with said axis of the curves of the lower portion of the reflector being at greater distances from said light source than the vertices or points of intersection with said axis of the curves of the upper portion of the reflector, said conic being guided in its revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is aplane figure which has upper segments and lower segments whose radii pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout successive fractional parts of the total angle of the downward rotation of the radius of an upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to a lower segment, which latter increases occur for and throughout like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

'7. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, a material portion of the reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing the distance from said light source of its vertex or point of intersection with said axis, and the radial distances from said axis of the curves of the lower portion of the reflector being greater than the radial distances from said axis of the curves of the upper portion of the reflector, said conic being guided in its revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure which has upper segments and lower segments whose radii pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout successive fractional parts of the total angle of the downward rotation of the radius of an upper segment there are accempanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to a lower segment, which latter increases occur for and throughout like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

8. A headlight set for approximately horizontal projection and comprising a reiiGCLOl and a light source therein, a material portion of the reflector having a surface substantially corresponding to a surface I nerated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis, and the vertices or points of in section with said axis of the curves of the lower portion of the reflector being at greater distances from said light source than thevvertices or points of intersection with said axis of the curves of the upper portion of the reflector, said conic being guided in its revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately l10li. zontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure which has upper segments and lower segments whose radii pass through and rotate on the point of intersection of said approximately hori zontal axis with said plane, and for and throughout successive fractional parts of the total angle of the downward rotation of the radius of an upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages rez-ipectively of the increases of the angle between the radius and its normal to a lower segment, which latter increases occur for and throughout like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

9. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, a material portion of the reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis 'of' the conic while increasing, at the same time, both itsradial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis, and the radial distances from said axis of the curves of the lower portion of the reflector being greater than the radial distances from said axis of the curves of the upperportion of the reflector, said conic being guided in its revolution by passing through successive points of a direciting line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resultingprojection is a plane figure which has upper segments and lower segments whose radii pass through and rotate on the point of intersection of' said approximately horizontal axiswith said plane, and for and throughout successive fractional partsof the'total angle of the downward rotation of the radius of an upper segment there: are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentagesrespectively of the increases of the angle between the radius and its normal to a lower segment, which latter increasesoccur for and throughout like and corresponding fractional parts of the total angle of the upward" rotation of the radius of said lower segment.

10. A headlight set for approximately horizontal projection and comprising a re flector and a light source therein, said reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while varying, at the same time, both its radial distance from said axis and the distance from said light source of its vertex orpoint of intersection with. said axis, and the radial distances from said axis of the conics of the terminal portions of the surface thus generated being greater than the radial distances from said axis of the conics 'of the initial portions of the surface thus generated, said conic being guided in its revoluY- tion by passing throughsuccessive points of a directing line. so designed that when said directing line is projected onto a plane which is substantially perpeirdicular to-sa-id approximately horizontal axis, by mea-ns'of lines parallel to said approximately horizontal'axis, tl-1e resulting projection is a plane figure which "has upper segments and lower segments Whose radii ;pass through and creases of the angle between the radiusand its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of theincreases of the anglebetween the radius and its normal to a: lower segment, which latter increases occur for and throughout li-lze and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

11. A headlight set for approximately horizontal projection and comprising a reflector and a light source. therein, said reflector having a surface substantially corresponding toa surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while varying the distance from said light source of its vertex or point of intersection with said axis, and the vertices or points of intersection with said axis of the conics of the terminal portions of thesurface thus generated being at greater distances from said light source than the vertic'es or points of intersection with said axis of the conics of the initial portions of the surface thus generated, said conic being guided in its revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the. resulting projection is a plane figure which has upper segments and lower segments whose radii pass through and rotate on the point of in 'tersection of said approximately horizontal axis with said plane, and for and throughout successive fractional parts of the total angle 7 o f the downward rotation of the radius of an upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle betweenthe radius and its normal to aelower' segment, which latter increases occur for and throughout like and corresponding fractional partsof the total angle of the upward rotation of the radius of said lower segment.

headlight set for approximately directions, on the approximately horizontal axis of the conic while continuously increasing the distance from said light source of its vertex or point of intersection with said axis, said conic being guided in its revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure which has upper segments and lower segments whose radii pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout successive fractional parts of the total angle of the downward rotation of the radius of an upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to a lower segment, which latter increases occur for and throughout like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

121A headlight set for approxiu'iately horizontal projection and comprising a reflector and a light source therein, said reflector having its entire surface substan tially corresponding to a surface generated by a conic revolved downwardly, in opposite directions, on the approximately horizontal axis of the conic while continuously increasing, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis, said conic being guided in its revolution by passing through successive points of a dire ting line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines par allel to said approximately horizontal axis, the resulting projection is a plane figure which has upper segments and lower segments whose radii pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout successive fractional parts of the total angle of the downward rotation of the radius of an upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to a lower segment, which latter increases occur for and throughout like and corresponding fractional parts of the total angle of the upward rotation of the radius of said sponding to a surface generated by a conicrevolved downwardly, on the approximately horizontal axis of the conic while continuously increasing its radial distance from said axis, and the vertices or points of intersection with said axis of the conics of the lower portion of the reflector thus generated being at greater distances from said light source than the vertices or points of intersection with said axis of the conics of the upper portion of the reflector thus generated, said conic being guided in its revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure which has upper segments and lower segments whose radii pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout successive fractional parts of the total angle of the downward rotation of the radius of an upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of th increases of the angle between the radius and its normal to a lower segment, which latter increases occur for and throughout like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

15. A headlight set for approxii'natey horizontal projection and comprising a re flector and a light source therein, said rcflector having a surface substantially cor-- responding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing the distance from said light source of its vertex or point of intersection with said axis, said conic being guided in its revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane which is sul'istantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure having an upper segment and a lower segment which together constitute the major portion ifs-refers of said plane figure and the radii. of said segmentspass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout all the successive fractional parts of the total angle" of the downward rotation of the'radiusof said upper 'segn'ient there are accompanying increases of the an gle between the radius and its normal tosaid upper segment, which increases of said latter angle are substantially constant percentages respectively of theincreases of the angle between the radius and its normal to said lower segment, which latter increases occur for anc'lthroughout all the like and corresponding fractional parts of the total angle or" the upward rotation of the radius ofsaid lower segment.

1,6. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, said re flector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with saidaxis, said conic being guided its revolution by pass ing through successive points of a directing line so designed that when said directing line isprojected onto a plane which is sub stantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approxiii'rately horizontal axis, the resulting projection is a plane figure having an upper segment and a lower segment which togetherconstitute the major portion of said plane figure and the radii of said segments pass through and 'rolate on the point of intersection of said approximately horizontal axis with said plane, a

and for and throughout all the successive fractional parts of the total angle of th downward rotation oifthe radius of said upper segment there are accompanying increases of the angle between t'he'radius and its normal to said upper segment, which increases of said latter angle are 'substantially constant percentages respectively of the incrcases'o'f the angle between the radius and its normal to said lower segment, which latter increases occur for and throughout all y the like andcorresponding fractional parts or the total angle of tlie upward rotation of the radius of said lower segment.

,17. A headlight set for approximately horizontal projection and comprising a reheater and a light source therein, a material port-ion of the reflector having asurface substantially corresponding to asurface generated by a conic revolved in a clownward direction on the approximately horiz'ontal axis of the conic while increasing the distance from said light source of its vertex or point oi 'intersection with said axis, and'the' verti'ces or points of intersection with said axis of the curves of the lower portion of the reflector being at greater distances from said light source 0 segment which together constitute the major portion of said plane figure sand the radii of said segments pass through and r=o tate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout all the successive fractional parts of the total angle of the downward rotation of the radius otsaid upper segmen-t there are accompanying in creases of the angle between the radius and its normal to said upper segment, whichin- V creases of said latter angle are substantially constant percentages respectively of the increases oi the angle between the" radius and its normal to said lower segment,- which latter increases occur for and throughout all the like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

18; A headlight set for approximately horizontal proj-ection and comprising a reflector and a light source therein, a material portion of the reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis o'frthe conic while increasing the distance from said light source of its vertex or point of intersection with; said axis, and the radial distances from said axis of the curves of the lower portion of the reflector being greater than the radial distances from said axis of the curves of theupper portion of the reflector, said conic being guided in its-revolution by passing through successive points of a directing line sodesigned that when said directing line is projected onto a 'plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure having an upper segment and a lower segment which together constitute the major portion of said plane figure and the radii of said'segn'ients pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout all the successive fractional parts of the total angle of the downward rotation of the radius of said upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to said lower segment, which latter increases occur for and throughout all the like and corre sponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

19. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, a material portion of the reflector having a surface substantially corresponding to a surface generator by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection withsaid axis, and the vertices or points of intersection with said axis of the curves of the lower portion of the reflector being at greater distances from said light source than the vertices or points of intersection with said axis of the curves of the upper portion of the reflector, said conic being guided in its revolution by passing through successive points of a directing line so designed that when saiddirecting line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure having an upper segment and a lower segment which together constitute the major portion of said plane figure and the radii of said segments pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout all the successive fractional parts of the total angle of the downward rotation of the radius of said upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to said lower segment, which latter increases occur for and throughout all the like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

20. A headlight set for approximately horizontal projection and comprising a refiector and a light source therein, a material portion of the reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing, at the same time, both its radial distance from said axis and the distance from said light source of it's vertex or point of intersection with said axis, and the radial distances from said axis of the curves of the lower portion of the reflector being greater than the radial distances from said axis of the curves of the upper portion of the reflector, said conic being guided in its revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane which is substan tially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure having an upper segment and a lower segment which together constitute the major portion of said plane figure and the radii of said seg ments pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout all the successive fractional parts of the total angle, of the downward rotation of the radius of said upper segment there are accompanying increases of ,the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to said lower segment, which latter increases occur for and throughout all the like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

21. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, said reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while varying, at the same time, both its radial distance from said axis and, the distance from said light source of its vertex r point of intersection with said axis, and the radial distances from said axis of the conics of the terminal portions of the surface thus generated being greater than the radial distances from said axis of the conics of the initial portions of the surface thus generated, said conic being guided in its revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis. the resulting projection is a plan figure having an upper segment and a lower segment which together constitute the major portion of saidpl'ane figure-and the radii of said segments pass through; and. rotate onth'e point of intersection of said approx-- unately hor zontal ax sw th said plane, and

for and tlfiroughout allfthe successive fractional fpai' tsof; the total angle of the downward {rotation o-f-the radius of said upper segment there are accompanying increase-s oft-he anglebetween the radius and its normal to said upper segment, which increases of said'latter angle are substantially constant percentages respectively of the increases of the angle between, the radius and. its normal to, said lower segment, which latter, increases occur for throughout all thelilre and corresponding fractional parts ofthe total angle ofthc upward rotation of the radius of said lowerlseg'ment'. a

22;. A' headlight-v set. for approximately horizontal projection and comp-risinga reflector and a light source therein, said, reflector having a surface substantially corresponding to a; surface generated by a conic revolved in a downward;direction on the approximately horizontal axis of the conic Zwhile varying the distance from said light source of its vertex or point of intersection with said, axis, and thevertices or points of intersectionwith said axis of the "conics of the-terminalportions of "the, surface thus generated being at greater 3 distances from said light source .thanth'e vertices. or points of intersection wltli' sa'iclaxis ofthe comes of the, initial portions of thesurface thus generated, said conic being guided in its revolution by passing through successive points of a'directinglineso designed that when saiddirectin'g line is projected onto a plane which is substantiallyperpendicular to said approximatelyhorizontal axis, by

said plane, and for and throughout all the successive fractional parts of; the total angle of the downward rotation of-the radiusof said upper segment there are accompanying increases; of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substan tially, constant, percentages respectively of the increasesof the angle between the radius and its normal to said lower s'egment,'which latter increases occur for and throughout all the like and corresponding fractional parts of the total angle of the upward rotation of the radius ofsaid lower segment.

23; A headlight set for approximately horizontal projection and comprising a retle 'torand a light source therein, said refl e ha i g i nti e sur e s bst ntiallyc rrsspnd o. w se rated y. a s ni ev lv wnward m. i OPPO- si re t ons. 9. he arp at y. i-

zontal of the conic fwhile continuously increasing the i; distance... from said, light source of its'vertexor point of intersection with said-axis, said conic being guided in its. revolution by passing through successive pointsof a directing line so designed that when. said directing line is. projected onto a planewhiclris substantiall perpendicular to said approximately hor zontal axis, by

'rneans fof lines parallel to said approximate;

'and' a lower segment which togethergconstitute thermajor portion ofsaidplane figare substantially constant percentages re spectively'of the increases ofthe angle between the radius and its normal to; said lowersegment, which latter increases occur for and throughout all thelike and] corresponding fractional parts ofthe total angle of the" upward. rotation of the radius of said lower segment.

24. A headlight. set for approximately horizontal projection and comprising a reflector and alight source therein," said re fiector having its entire surface substantiallycorresponding to a surface generated by va conic revolved downwardly, in opposite direc tions, on the approximately hori zontal axis of the conic while continuously increasing, at the same time, both its radial distance from said axis alld the distance from said light source of itsvertex or point of intersection with said axis, said conic being guided inits revolution bypassing through successive points of a directing line so designed that when said directing line is projected onto, a plane which is substantially perpendicular tosaid approximately horizontal axis, by means of lines parallel to said approximatelyhorizontal axis, the resulting projectionis a plane figure having. an upper segmentand alower segment which together constitute the major portion of said plane figure and the radii of said segments pass through and rotate on the pointof intersection of said approximately horizontal axis with said plane, and for and .throughout all the successive fractional parts, of the total angle of the downward rotation of the radius of said upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to said lower segment, which latter increases occur for and throughout all the like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

25. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, the surface of said reflector substantially corresponding to a surface generated by a conic revolved downwardly, on the approximately horizontal axis of the conic while continuously increasing its radial distance from said axis, and the vertices or points of intersection with said axis of the conics of the lower portion of the reflector thus generated being at greater distances from said light source than the vertices or points of intersection with said axis of the conics of the upper portion of the reflector thus generated, said conic being guided in its revolution by passing through successive points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure having an upper segment and a lower segment which together constitute the major portion of said plane figure and the radii of said segments pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout all the successive fractional parts of the total angle of the downward rotation of the radius of said upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its'normal to said lower segment, which latter increases occur for and throughout all the like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

26. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, said reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing the distance from said light source of its vertex or point of intersection with said axis, said conic being guided in its revolution by passing through the successlve points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure having an upper segment and a lower segment which together constitute substantially the entire portion of said plane figure and the radii of said segments pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout all the successive fractional parts of the total angle of the downward rotation of the radius of said upper'segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to said lower segment, which latter increases occur for and throughout all the like and corresponding fractional parts of thetotal angle of the upward rotation of the radius of said lower segment.

27. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein,-said refiector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis, said conic being guided in its revolution by passing through the successive points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure having an upper segment and a lower segment which together constitute substantially the entire portion of said plane figure and the radii of said segments pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout all the successive fractional parts of the total angle of the downward rotation of the radius of said upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to said lowersegment, which latter-increases 000111 for: and throughout all-the like andcorrespending fractionalpartsa'of the total angle of the "upward rotation of the "radiusof said T lower segment. i v

28: A headlight set for" approximately horizontal projection and-con1pr1s1ng a re-* flector'and a light source therein, amaterial portion of the reflector having a surface substantially corresponding to a surface generated by a conic revolved in 'a downward direction on the approximately horizontal axis of the conic whileincreasing the distance fioinsaid light source'of its vertex or point:

said light' sourcethanthe vertices or points ofinterse'ction with said axis of the'curves oftheupperportiont of the reflector, said conic being guided in its revolution by pass ing through the'successive points of a di-' recting line so designed that when said directing lineis 'projected'onto a'planew which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure having aniupper segment and a lower segmentfwhich together constitute substantiallythe entire portion of'sald plane figure and-the radii of said segments pass I through'and rotate onthe point of intersection of'said approximately horizontal,

axis with said plane, andfor and through out all the successive fractional'parts of the total angle of the downward rotation ofthe radius of 'said upper segment there are ac; companying increases of the angle between the radius andit's normalto saidupper segment, which increases of saidlatter angle are substantially constant percentages respectively of theincreasesof-ithe' angle" between the radiusandits normal to said lower segment; which latter increases occur for and throughout all the like and co responding fractional parts of the total'angle of the upward rotation of the radius ofsaidlower segment. i

29. A headlight set for approximately horizontal projection and comprising a -reflector and a-light'source therein, a material portion of the-reflector havinga surface" substantially. corresponding. to a surface generated by aconic revolved in a downward direction on the approximately horizontal-- axis ofthe conic whilellncreasing: the d1S-' tance from saidlight source ofl its vertex or point of intersection withsaid axis, an-dthe' radial distances from said axis ofthe curves of the lower portion i of. the reflector being greater-than therachal distancesfrom said 7 axis of the curves ofthe upper: portion of the reflector, said conic beirr guided in its revolution by" passing through the successive points' of" a directing line so designed that when'said directing line-isprojectedmnto a plane which is substantially perpendicular to 1 said approximately horizontal axis; by me-ansof lines parallel to said approximately horizontal 5 axis, the resulting proj eotionis aplane figure having an upper segment and a lower segment which together constitute substantially the entire portion of' said planefigure andflth'e radii ofjsaid segments pass through and rotateon thepoint ofint'erseotion of said approximately horizontal axi s with said plane, and for and throughout *all the successivefraetional parts of the total angle of the downward rotation of the radius of said upper segment there are ac-' companying increases of the angle between the radius and its normal to" said upper segment, which increases "of'said latter angle are substantially constant percentages" respectively of the increasesofthe angle be tween the radius and its normalto said lower segment, which latter increases occur tor and throughout all the-likeandcorre spondingfractional parts ofthe'total angle" of the upward rotation ofthe" radius of-saidlower segment. v

30. A headlight set for" approximately horizontal projection and comprisinga re= flector' and a light source "therein", a material portion of the reflector having a surface substantially corresponding to a surface generated by a" conic revolved iI1" a downwarddirection' on the approximately hori+ zontal axis of' the' conic while increasing, at the same time, both its 'radialdistance' from said'ax'is an'd the distance fr'om' said light source of its'vertex or point of intersection; with said axis, and the verticesfor" points of intersection with said axis of theicurves of the lower portion of" the reflector being. at greater distances from-said lightsour'ce than the vertices or points of intersection with said axis of the curves of the "upper portion o'f the reflector, said conicbeingjguidedrin it's'revolution by passing through the successive points of'a directing lineso designed that when said'directinmline' is ro'ect'ed onto a plane which is substantially perpendicular to said approximatelyhorizontali axis, by "means of'lines parallel to said approximately ho'rizontal'axis, the resulting projection is a plane figure having an upper segment and a lower segment which together constitute substantially the entire portionofsaidplane figure'and the radii of said segments passthrough and-rotate on the point otintersectionof' said approximately horizontalaxis with said plane, and for and throughout all the successive fractional-parts of the total angle of- 'the downward rotation of the radius ofsaidup'per segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of creases occur for and throughout all the like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

31. A headlight set for ap Jroximately horizontal projection and comprising a reflector and a light source therein, a material portion of the reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis, and the radial distances from said axis of the curves of the lower portion of the reflector being greater than the radial distances from said axis of the curves of the upper portion of the reflector, said conic being guided in its revolution by passing through the successive points of a directing line so designed that when said directing line is projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure having an upper segment and a lower segment which together constitute substantially the entire portion of said plane figure and the radii of said segments pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout all the successive fractional parts of the total angle of the downward rotation of the radius of said upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to said lower segment, which latter increases occur for and throughout all the like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lower segment.

32. A headlight set for approximately horizontal projection and comprising a retlector and a light source therein, said reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while varying, at the same time, both its radial distance from said axis and the disance from said light source of its vertex or point of intersection with said axis, and the radial distances from said axis of the conics of the terminal portions of the surface thus generated being greater than the radial distances from said axis of the conics of the initial portions of the surface thus generated, said conic being guided in its revolution by passing through the successsive points of a directing line so designed that when said directing lineis projected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting pro ection is a plane figure having an upper Seglililllt andalower segment which together constitute substantially the entire portion of said plane figure and the radii of said segments pass through and rotate on the point of intersection of said approximately horizontal axis with said plane, and for and throughout all the successive fractional parts of the total angle of the downward rotation of the radius of said upper segment there are accompanying increases of the angle between the radius and its normal to said upper segment, which increases of said latter angle are substantially constant percentages respectively of the increases of the angle between the radius and its normal to said lower segment, which latter increases occur for and throughout all the like and corresponding fractional parts of the total angle of the upward rotation of the radius of said lowersegment.

88. A headlight set for approximately horizontal projection and comprising a re- Elector and a light source therein, said reflector having a surface substantially corresponding to a surface'generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while varying the distance from said light source of its vertex or point of intersection with said axis, and the vertices or points of intersection with said axis of the conics of the terminal portions of the surface thus generated being at greater distances from said light source than the vertices or points of intersection with said axis of the conics of the initial portions of the surface thus generated, said conic being guided in its revolution bypassing through the successive points of a directing line so designed that when said directing line is )rojected onto a plane which is substantially perpendicular to said approximately horizontal axis, by means of lines parallel to said approximately horizontal axis, the resulting projection is a plane figure having an upper segment and a lower segment which together constitute substantially the entire portion of said plane figure and the radii of saidsegments pass through and