US1614939A - Headlight - Google Patents

Description

1,614,939 Jan. 18, 1927- wooD HEADLIGHT Filed No v. 23; 1921 In ven tor. Mlliam 6. W601 v fltior'neyq.

Patented Jan. 18, 1927.

1 1,614,939 PATENT, OFFICE.

WILLIAM WOOD OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO AMERICAN WOODLITE CORPORATION, OF SAN FRANCISCO, CALIFOR- NIA, CORPORATION OF CALIFORNIA.

HEADLIGHT.

Application filed November 23,1921; Serial No. 517,194.

This invention relates to headlights and more particularly to improvements on headlights of the type shown in my copending applications entitled Headlight filed August 5, 1918, Serial Numbers 248,302 and 248,303.

In a headlight such as described in the foregoing, a cone-shaped beam is projected through an aperture in the lamp housing. The projected beam is of sharp definition and is lacking entirely in the usual scattercd and diffused rays occurring in other headlights. l/Vhen used on an automobile there is no light thrown out to the sides of the road immediately in front of the vehicle.

Of course, it is desirable to slightly illuminate the road side immediately in front of the automobile, especially when making a turn or traveling on narrow and winding roads. Therefore, I provide auxiliary or secondary reflectors to project a narrow beam preferably cone-shaped through the said aperture in the lamp housing. This secondary beam is directed downwardly and obliquely. It does not interfere with the main forward directed beam and does not in any way detract from the anti-glaring character of the headlight.

In the drawing Fig. 1 is a central vertical longitudinal sectional View through the headlight.

Fig. 2 is a plan view of the headlight partly broken away.

Referring to the drawing in detail, A mdicates in general a lamp casing constructed of two sections 2 and 3 which are adapted to be secured together by means of a collar 4 and a set screw 5. Formed in the for-.

ward portion of the casing is a centrally disposed transparent opening 6 WlllCll is relatively narrow and substantially arcuate The collar' conforms to the configuration of and surrounds the'opening 6 and it is secured to the sections 2 and 3 by suitable fastening devices 4 and 4. Mounted within the arcuate opening is a pair of lenses which are secured in the central portion 8 of the collar 4.

Suitably secured within the lower half of the casing is a reflector cage 9. This cage is substantially cylindrical in shape and carries at its lower end a parabolic reflector 10 and at its-upper end a section of a parabolic reflector shown at 11. The cage is ter of the reflector 10, this longitudinal adjustment being provided to eliminate the projection of converging rays and simultaneously to permit projection of substantially parallel rays against the projecting reflector 11.

The reflector 11 is a section of a comparatively large parabolic reflector and therefore serves the function of concentrating the parallel rays received from the reflector 10; that is, all the rays projected by the reflector 11 form a cone-shaped beam and cross eachothe'r at a common focal point, which is located directly in the transparent aperture 6. The rays diverge or spread after leaving or passing through the aperture. 1

The lenses 7 employed are small when compared with most standard types of-headlights employing parabolic reflectors and therefore glarin or blinding efl'ects generally produced by ordinary lleadliglitsare eliminated. This is for the reason that diffusion of light rays is largely reduced and neither the source of light nor the apparent source of light is in evidence.

F orthe purpose of' illuminating the sides of a roadway I provide means for projecting beams on each side of the lamp. Such means comprises a pair of reflectors such as shown at 17 and 18 which reflectors are sections of ellipsoidal reflectors of which the source of light or filament 16 is one focus of each and the end portions of the arcuate aperture 6 are the other foci, said foci being located on a line drawn through thelongitudinal axes of the ellipsoids.

' The rays. of light emanating from the filament 16 and strikin the parabolic reflector 10 are projecte Y in parallel lines against the sectional parabolic reflector 11. This reflector concentrates the parallel rays and rojects a cone-shaped beam such as indicated by the dotted lines shown in Fig. 1, the rays of said beam crossing while passing through the arcuate aperture '6 and then spreading after leaving the same. The reflectors 17 and 18 are not in any way affected by the parabolic reflector 10 or the sectional barabolic reflector 11 nor do they in any way lower the lighting efliciency of the main beam projected by the latter reflectors as no portion of the light required by these reflectors is consumed by the sectional ellipsoidal reflectors 17 and 18, the only, light projected by said reflectors 17 and 18 being the direct rays emanating from the filament These reflectors l7 and 18 receive radially projected rays from the filament and they have the function of reconcentrating said rays and projecting the same through the end portions of the arcuate opening. A

beam separate and distinct from the main beam is in this manner projected to each side of the road, thereby clearly illuminating the road side without in any way producing glare or blinding effect upon pedestrians or drivers of approaching vehicles. The reflec tors 17 and 18 are supported by arms 22, and are secured directly to the sectional parabolic reflector 11 but they may be mounted in any other desired manner. The position of the sectional ellipsoidal reflectors are fixed with relation to the filament and the ends of iliary reflectors it becomes possible to gather a large portion of the direct light rays emanating from the filament and to concentrate (them at the ends of the arcuate aperture. The side reflectors utilize that portion of the light which would otherwise be 4 wasted. They do not disturb tlie rays of the reflected light projected by the parabolic reflector but utilize only the'di'rect rays from the filament,. as they are positioned outside of the cylindrical beam of reflected light projected by the parabolic reflector 10 and also outside of the conical beam of light projected by the sectional parabolic reflector indicated at 11.

The axis of the ellipsoidis, of course, a straight line connecting the light filament and an end of the arcuate aperture,.the curve of the ellipsoid being laid off with these points as foci. The lenses 7 are merely provided for clearing the light field and for spreading or contracting the cone-shaped beam projected by the main reflector.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

A headlight comprising an outer casing having a relatively narrow substantially arcuate aperture formed therein, a lamp casing mounted within the outer casing and having a source of light and provided with a parabolic reflector surrounding said light and adapted to project a beam of substantially parallel rays, a projecting reflector carried by the lamp casing and intercepting the said beam and arranged to project a. convergent beam centrally through'the said arcuate aperture and auxiliary reflectors mounted on the lamp casing at opposite sides thereof and arranged to project separate and distinct beams through the end portions of the said aperture.

WILLIAM G. WOOD.

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