US841799A - Lamp, &c. - Google Patents

Description

No. 841,799. y PATENTED JAN. 22, 1907.

' G.'MARIS.

LAMP, 5w.' APPLICATION FILED APR. 1 0. 1905.

UNTFB- STATES-l PATENT. UFFCE.

suonerie MARIS, or PARIS, FRANCE, AssIGNoR To LA socir BnsNAan,A

MARIS a ANTOINE, or PARIS, FRANCE.

LAMP, ae, l j

apprenante@ Aprilia, 1965. sentirti. 254,733. n j j T0 @ZZ whom, it fit/.ty concern: u

Be it known that l, Gnoneiis MARIS, a citizen of the French Republic, residing at Boulevard Beaumarchais, Paris, France, have invented certain new and useful .lmprovements in Lamps or Devices for Projecting Light; and. l do hereby declare the following to be a full, clear, and exact-description of the invention, such will enable others skilled in the art to which itrappertains to make and use the same.

This invention consists in the employment of an optical system in connection with lamps used for projecting, under certain conditions, the rays proceeding from a source of light.

The following description shows, by way of example, the manner of applying this system to a projector containing an acetylene-gas flame and intended for 'automobile-vehicles, locomotives, boats, te., With the object of lighting the route to be traveled over to a' sufflicient extent infront and to right. and .e t. I

ln the accompanying drawings, Figure 1 is the front view of a projector; Fig. 2, a section of the same. Figs. 3, 4, and 5, are diagrams illustrating the o )tical system.

l is an acety ene-gas flame arranged between a lens 2 and a reflector 3 placed behind the llame.

This invention. is essentially distinguished by the combination of a lens and a reflector forming, with the source of light l, an optical system diagrammatically illustrated in Fig. fi.

The lens 2 is a converging plano-convex lens, the focus of which is at F.

The reflector 3 is in the form of a hyperboloid, the meridian section of which is the hyperbola 72r 7L', the focus of which, on the one hand, is in the point F, which is common to the. lens, and, on the other hand., in thefpoint A the geometrical center of the flame on the axis a: y of the projector.

in examining Fig. 3 it will be seen that all the luminous rays proceeding from the point A and comprised in the pencil of rays h Ahh" are reflected by the 4hyperbolic reflector in the form of a conical pencil of rays the apex of which is the point F, the virtual focusof the hyperbola. The reflected pencil of rays `comes onto the lens as if it. proceeded from a luminous point placed at. F. Under these conditions, In accordance with the proper tieso'f the convergmg lens, all the rays of this pencil of. rays are lrefracted parallel to proceedingI from the point yA and directly reaching the lens are refracted therebyand` in issuing therefrom form a more condensed pencil of rays than the initial pencil of ,I'aysh This refracted pencil of rays has its apex ,in the point c, which is` in conjunction with the: point VA in relation to the lens. As the point c is always behind the point A, the intensity of the pencil of rays projected outside is much greater under this system. This conical and powerful pencil of rays is intended to effectively light the route near the rojector and over a larger extent than that ighted by the first pencil of rays intended for lighting at a distance. Y The hyperbolic form can only be obtained with suflicient precision by means of metallic reflectors; but when acetylene is employed as a source of light the metallic reflectors are soon tarnished. The hyperbolic metallic reflectors may be replaced by a spherical mir ror, Fig. 4, the reflecting-surface of which is protectedagainst external changes. The meridian section of this surfaceis an arc of 'a circle which coincides with the hyperbolic arc.

and proceeding from the incident raysissuing from the point A inclose a virtually caustic surface, the meridianof which is a curve n mp.

if the focal distance of the lens be so determined that its focus F is situated in the interior of the apex of the caustic surface and' at a distance slightly removed from the tangents to this caustic surface, the pencil of rays refr-acted by the lens will be sufficiently cylindrical and homogeneous. The aberrations, which, `moreover, are but slight, are utilized for illuminating the route in thel diratented Jansz, 1907.

j Iii Vthis case the extensions of the rays lreflected by the spherical concave surface rection of its width. These aberrations do not diminish the range in the distance, which is insured by the employment of the hyper! bolic refiector, as account must be taken of the superior reflecting and uniform power of IOC the optical mirror compared with that of mej tallic reflectors and of the practical difliculf spherical mirror is much more simply kept up an such a system frnished with a metallic reflector, Whichis with diflicnlty in a polished condition.

The casing which forms-the body of the preserved 'pro`ector and connects the back reflector -Wit the lens may be of a, form suited to the purpose of the projector.

the rays parallel to the exis x y. In this cese the projector may be' formed in front by en annular glass plate 5, through which the rays y can pass.' The lens 2, combined with they 'mirror 3, isset in the center of the glass plate for the purpose of forming the optical system that distinguishes this invention.

' What I claim, and desire to secure by Letters Patent, is-

A light-projector for eutomobiles and the like, distinguished bythe combination of a hyperbolic reflector with e converging lens having a, focus in cornmon with the external focus of the reflector', the source of light beT ing placed in the internal focus of the hyper# bolic reflector between the re-Hector and the lens, for the purpose described,

In testimony whereof I have affixed inyv signature in presence of two witnesses.

GEORGES MARIS.

Witnesses:

CHARLES FABER, HENRI GABY.

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