US1449809A - Headlight lens - Google Patents

Description

Patented Mar. 27, 1923.

erre Ass FFEE.

HARRY J. W. BROOKS, OF VANCOUVER, BRITISH COLUMBIA, CANADA, ASSIGNOR I'O JOHN MOLELLAN GRAHAM, OF VANCOUVER, BRITISH COLUMBIA, CANADA..

HEADLIGHT LENS.

Application filed June 1, 1920. Serial No. 385,605.

To all w/iomz't may concern l Be it known that I, HARRY J. lV. BROOKS, a citizen of the Dominion of Canada, residing at Vancouver, in the Province of British Columbia, Canada, have invented certain new and useful Improvements in Headlight Lenses, of which the following is a specification.

This invention relates to a headlight lens for self-propelled vehicles and is particularly designed to obscure direct view of the lamp from the front and to project practically all the light forward and slightly downward to the road through a limited portion of the upper part of the lens.

The obscuration of the glass of the lens and the reflection of the light backward from the lower part of it into the reflector of the light is effected by prismatic ridges formed on the inner surface of the lens.

No opaque hoods or screens are thus used to supplementthe glass of the lens nor is any silvered surface applied thereto, which silvered surface is subject to deterioration in use.

The particular construction by which the several desired results are attained is fully set forth in the following specification, reference being made to the drawings by which it is accompanied, in which:

Fig. l is a vertical cross section of the lens showing its relation to the lamp, the lamp casing and the reflector.

Fig. 2 is a face View of the back of the lens,

and

Fig. 3, a horizontal section on the line 3-3 in Fig. 2 looking in the direction of the arrow 3.

In these drawings 2 represents the outer casing which encloses the lamp, 4 is the border frame which retains the lens and 5 the reiector.

The outer face-of the lens has a plane glazed surface and has a roughened border r 6 where it fits within the frame 4 of the casdisposed equi-angular base rightangle peak prismatic ridges to project all the light of the lamp 3, which falls on it, into the upper part of the reflector 5.

From the lower edge of this circular portion 7 a part 8 projects backward from the back face to beyond the filament of the lamp 3. Thisr part is shown in the drawing as the half frustum of a hollow cone, but may be semi-cylindrical with its axis inclined downward from the face of the lens.

The inner surface of this part 8 hasv a se,- ries of equi-angular prismatic ridges lengthwise disposed on it.

The annular space between the border 6 and the central portion 7 is divided horizontally, the general surface of the lower part 9 being parallel to the outer face of the lens and is formed with a series of vertically disposed equi-angular base rightangle peak prismatic ridges that will reflect all the i light backward into the reflector 5, and similar ridges are formed ina lune l0 around the upper part 11. this lune 10 is at the top of the lens and the horns terminate at the horizontal diameter.

The inner face of that portion l1 of the lens between the lune 10 and the lower part 9 and central part 8 is, as shownin Fig. l, formed as a flattened prismatic surface, the face of which is directed backward and downward, so that the horizontally disposed rays of light which pass through it are refracted slightly downward.

The prism-ridged central portion 7, obscures a direct view of the lamp 3 from the front and reflects its light backward into the upper part of the reflector 5. The prism ridged surface of the backwardly projecting and downwardly inclined part S also reiiects the light of the lamp to the upper half of the reiiector while the prism-ridged lower portion 9 shuts off from the front the glare of the light from the reflector, breaking it up and throwing it back on the reflector for final transmission through the upper part l1, which is the only part of the lens through which the light is clearly projected from the lamp. The slightly angled face of this clear portion 11 throws downward onto the road what light is projected. from the lamp at a distance of approximately two hundred (200) to two hundred and fifty (250) feet in advance of the car, which amount may be lessened or increased by the angle at which the lamp is set.

The larger dimension lof lVith this lens, while practically all the light of the lamp is projected forward, it is not thrown above the statutory limit of forty-two (42) inches and presents no glare of direct light to approaching' vehicles or pedestrians.

Having now particularly described my invention, l hereby declare that what l claim as new and desire to be protected in by Letters Patent, is:

l. A headlight lens, the outer' face of which has a plane glazed surface and the inner face has a hollow projection which is semi-circular in cross section and of relatively small radius below the horizontal diameter, the inner face of the lens'below the horizontal diameter' and the inner surface ol' the projection and the circle within the base of that projection being formed as prismatically ridged reflecting surfaces.

2. A headlight. lens, the outer face of which is a plane glazed surface and the inner face of which below the horizontal diameter and above that diameter in a concentric circular are of relatively small radius is formed as a reflecting surface of prismatic ridges, the inner face of the lens above the horizontal diameter being` angled slightly backward downward to form a flattened prism.

3. A headlight lens, the outer face of which is a plane glazed surface and the inner face of which below the horizontal diameter and above that diameter in a concentric circular are of relatively small radius is formed as a reflecting surface of prismatic ridges, which reflecting surface is carried also as a lune across the upper part of the lens, said inner face having also a hollow cylindrical projection from the horizontal diameter baclc ward and downward to beyond the filament of the lamp, the inner surface of which projection has a prismatically ridged reflecting surface, the remaining` portion of the lens between the horizontal diameter and the lune being uniformly angled slightly downward backward to form a flattened prism.

4L. A headlight lens, the outer face of which is a plain glazed surface and the inner face 0f which below the horizontal diameter and above that diameter in a concentric circular arc of relatively small radius is formed as a reflecting surface of prismatic ridges, the base angles of which are equal, the inner face of the lens above the horizontal diameter being angled slightly backward to form a flattened prism, the inner face of said lens having a hollow projection of relatively small radius and semi-circular in cross section located below the horizontal dia1n eter, the inner face of which projection be ing formed as a reflecting surface of prismatic ridges, substantially as shown and for the purposes described.

In testimony whereof I affix my signature.

HARRY J. W. BROOKS.

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