US1385570A - Lens - Google Patents

Description

A. G. MILLER AND C. McMULLEN.

LENS.

APPLiCATION FILED JAN. 12, I920.

Patented July 26, 1921.

UNITED STATES PATENT ;-o 1 cE.

LENS.

To all whom it may concern:

Be it known that we, ALPHoNs Ur. MILLER and CHARLES MOMULLEN, citizens of the United States, both residing at F lemington, in the county of Hunterdon and State of New Jersey, have invented certain new and useful Improvements in Lenses, of which the following is a specification.

Our invention relates to a new and improved lens to be used in combination with a parabolic reflector and a source of llght located at the focus of the said reflector, for obtaining a diffuse and non-glaring illumination.

As is well known and as has been illustrated in many patents, automobile headlights are usually made of a combination of a parabolic reflector and an electric bulb located with its filament substantially at the focus of the said reflector.

For example, this is illustrated in U. S. Patent No. 1,308,431 in Figure 8 thereof.

It has also been well known for many years that the light provided by such combination of parts is glaring and dangerous in that it dazzles the eyes of pedestrians and also automobilists, and many lenses have been proposed which when placed at the mouth of such a parabolic reflector as shown in the said U. S. Patent No. 1,308,431, and more particularly in Fig. 8 thereof, will concentrate the illumination on the ground ahead of the automobile and prevent the light from dazzling the eyes of other people.

Our invention is devoted to such a lens and other objects of our invention will be disclosed in the following description and drawings which illustrate a preferred enibodiment thereof.

Figure 1 is a front view thereof.

Fig. 2 is a section along the line 2-2 of Fig. 1.

F ig. 3 is a section along the line 3-3 of Fig. 1. v

In Fig. 2, the source of light and the parabolic reflector are supposed to be located at the right of the lens. The periphery of the lens is preferably of a circular shape so that it can fit across the mouth of the reflector and be at right angles to the axis thereof.

The periphery is provided with a portion 1 whose inner boundary is substantially parallel tothe periphery of the lens. This portion 1 is made of glass produced by various Specification of Letters Patent. Patented l Application filed January 12, 1920; 'seriarivo. 350,790.

formulae-and methods well known to the art of glass making which diffuse or break up the light without materially diminishing the amount of illumination. Some ofthe glasses which produce this effect have numerous fine particles embedded therein which diffuse the light, but any suitable glass known'to be adapted for this purpose may be used.

The interior of the lens is provided with a series of intermediate segments 2 which have arcuate sidos,and which define a series of prismatic lenses 3 which are made of transparent glass. V

The portions 2 are preferably made of the same glass as the peripheral portion 1.

As is seen more particularly in Fig. 2, each lens-like portion 3 has a vertical cross section similar to that of a vertical prism.

This vertical formation of the said lenslike portions 3 causes all the beams reflected .by the parabolic reflector to be bent downwardly so as to minimize the danger of aberrant rays from dazzling a pedestrian or another automobilist.

In horizontal cross section and as seen more particularly in Fig. 3, the lens-like portions 3 are concave so that they spread out or diffuse the light in a horizontal direction.

It will be noted upon reference to Fig. 1-

and practically surround the said depressions, so that the lens-like portions not only each separately refract. downwardly all the light passing therethrough but also diffuse it laterally.

The horizontal curvature of the lens-like portions 3 may also be varied in the various layers being preferably greatest in the said central layers of lens-like portions, that the light is diffused more in the horizontal direction in the said central layers than in the upper andlower layers.

Practical tests have shown that because of the combination of prismatic lenses made of transparentor clear glass and the intermediate portions made-of glass which may be termed diffusing glass for the purpose of this specificatioinour invention givesa light which is non-glaring and at the same time does not substantially diminish the illuminating power of the source of light.

Theperipheries of the said lens-like portions viewed in the vertical plan, are substantially circular in shape, but other shapes might be given thereto.

.NVe claim A lens of the type described having a series of substantially semi-circular depressions forming lens-like portions arranged facin downwardl said de ressions bein r, a i r:

wise arranged in rows both vertically-"and.

horizontally, whereby each lens-like portion separately refracts the light downwardly and also diffuses it laterally.

In testimony whereof we hereunto aifix 20 our signatures; Y L s ALPHONS o. MILLER. I CHARLES McMULLEN.

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