US1375418A - Dimming device for headlights - Google Patents

Description

W ASCHESDEH. Duin/UNG DEveCE WR HEADUGHTS.

APFUCATION FILED SET. 27, 1919.

92 2 SHEETS-SHEET I.

XYZ/Veni@ @ed ef' W. A. SGHROEDER. DIMMING DEVICE FOR HEADLIGHTS. APPLICATION man SEPT. 2?. 1919.

Paented Apr. 19, 1921.

` 2 SHEETS-SHEET 2.

reflector and form a part of t surface thereof, and when brought into UNITED WILLIAM A. SCHROEQDER, 0F SEATTLE, WASHINGTDN'.

DIMMING DEVICE FOR HADLIGETS.

I -Specication of Letterslatent. Patented Apr, 19, 192i ppn-cation sied september 27, 191e.V semi No; 32am.

To all whmt may conceyn:

Be it known that I, ,'fLLiAM A. ScHRoii- DER, a citizen of the United States, residing at Seattle, in the county of King and State of Washington, have invented certain new and useful Improvements in Dimming vices for Headlights, of which the followin is a specification.

his invention is intended :primarily for use on automobile headlights. The object of this invention is to provide a pair of screens disposed within 'the space vembraced bythe reflector and configured, when open, to.lie within the. pllane of the screening .positionv to cut off from the main 'reiiector .the rays' of light emanating from the lamp, and at the same time subserve the function 'of reflecting the rays laterally, with the result -that t e forwardly project'- ing glare of the headlight will be eliminate( and rays of light laterally diffused in such a manner as to illuminate the road immediately in front of the automobileand on each side thereof. This manipulation of. the device subserves a two-fold function, in that it destroys the glaring effect which tends to dazzle the eyes of the driver of an on-coming machine, while at the same time diffusing ample radiance immediately in front oi the headlight and atl each side.

` thereof, so that vthe road will be amp-ly illuminated while the lightsqare dimmed.' to? permit safe driving while passing the'f'on-'' coming machine.

While it was old in the art to provide screens* or the like for obstructing the passage of light from the source of illumination to the surrounding reiiector, some of such devices have in themselves subserved no refiecting function, so that a dimming or screening of the headlight has resulted in darkening the road immediately in advance of the machine, so that safe riding is rendered diiii'c'ult or impossible. will be appreciated when it is realized that the powerful headlights commonly usedwill, cast a glaring radiance to a very considerable'distance, and that safe driving demands a dimming of these lights while apare quite distant from one another, so that obstructions in advancc of a machine cannot be readily detected during the relatively long period of time hiring which the lights are dimmed.

e reflecting" .So that the source o Such danger Further objects and characteristics o f the present invention will be apparent from a detailed description of the invention which consists in the features of constructions hereinafter described and claimed.

In the drawings:

f Figure l is a front elevationof an automobile headlight with the screens in closed or screening position;

Figxj 2 is -a similar View showing the screens laid back in normal or open position.;

Fig. 3 is a vertical sectional view of the headlight with the screens closed; and

'Fig'. i is asimilar horizontal section.

The headlight, as va whole, comprises an outer shell 10 of the'usual dished formation, which shell provides a' housing for the. main reflector 11 which is preferably a parabolic reflector or one approachingthat formation. rilhe characteristic feature of Asuch a reflector, as well known, is found in the fact that rays of light emanating from the focal point to any portion of the 'refiectorwill be thrown forward in substantially parallel lines, with the result that the radiance will be projected to a great distance in the form of a narrow intense but slightly diffused column of light.

The reflector 11 has entered therethrough a lighting device preferably in the form of an incandescent electric bulb 12 carried by asocket 13 which is' referably adjustable, illumination vcan be brought to' the exactfocal point or to varyfing. distances therefrom the customary adjustment being one which diffuses the light `to some extent and gives to the beam an elngated,'narrow, conical formation. The

main reflector 11 on opposite sides of its vertical center plane is provided with^ depressions 14 adapted to receive apair of screens 15 which, when open or laid back,- will occupy the recessed portions of the main reflector, and these screens are so configured that when laid back they will constitute portions of the parabolic reflecting surface comprising, in'etlect,`a Portion of the main re'iiector. Each of the screens is of dished or concave formation being parabolically curved with the exception, however, that uniform configuration of 4the screen is'interrupted at its lower edge 16 which is more abruptly inturned to afford a lip 17 which, when the screen is in closed position. extends fore and aft in a line subm notatie i outer brightened sui-tace at the sides of the reflector, and similarly the upper and lower edges oit the two screens occupy positions in such close proximity to one another as toV l bstantially .screen the niain reflector at points above and below the source o'l illumination. It is desirable that the lower lips 17 shall almost, if not completely, close the gap below the source ol. illumination in order to prevent thelorward or upward projection of any light from the lower portion of the main reflector, but like considerations do not apply to the upper portions ot the screens, which may be separated slightly since light striking` through this opening will, in the main, be projected downwardly on the road and hence notvin the eyes ot the driver ot' an ori-coming machine.

ln order to prevent any glare from the surface of the main relectm'below and irninediately behind thesource of illumination,

`the rellector at this point 18 is preferably drilled Within the space subtended between the lov/er .rear edges of the screens, hut this` slight diminution in the reflecting suit/tace area oit the main reflector is negligible.

i In order to provide means for adjustinfr the screens to open or closed positions, eacn ot' the screens has secured to its rear Surface a bracket 19 "which extends through a slot 2O in the adjacent portion o'l' the recess 14, and the rear end ol the bracket is pivoted at the point 21. An arm or lever 22 is also pivoted to the bracket tor operating the screen, and suitable means, not shown, either manually or electrically-operated, are. provided for impartinfr the necessary movement to the parts. Since, however, the present invention is in no sense concerned with the specific means lemployed for effecting this result, it is notdeemed necessary to refer to the same, although mechanism of the character set forth 1n my Patent No. 1,305,498 issued June 3, 1919, may be einployed for this purpose.

In use, with the screens laid back into open or normal position, the main reflector will preferably present a substantially parabolic reflecting surface broken only by the slight protuberances caused by the lips 17, so that with the light positioned at or `near the Jfocal point an intense substantially parallel beam of light 1will be projected :tor-

distance in advance of 'the machine.

"When it is desired to dim the lights in' the presence oit an oli-coming machine-,fthe

screens will be closed, and this closing will obstruct the passage oi" light to the outer relier-,tor `and center the rellectingjfunctionin the screens, .themselves which lare, of course, silvered ou. their inner surfaces. These innersurifaces, being brought into close proitiinityto the source o' illumina#` tion, and standillp,i in hut slightly divergent relation to one another, will relect the light laterally, thus serving to illuminate the road in the immediate vicinityoi the machine Without projecting` any of the light forwardly in a manner to cause a glare in the eyes of the oncomingA driver.` The. road will thus loe brightly illuniinated.immediately in advance, so that no diliiculty will be experienced in driving the machine forward during the interval of time' prior to thepas-, sage of the ori-coming machine.

The manner in which this lateral dilliusion" of light is elected is 'well illustrated in Fig. Ll, in which the rays ot light are indicated` hy dotted lines, and it will be noted thatv all ot the reflected light isthrown atfa Widely divergent angle, and that no reflecico tion is thrown forwardly; The only4 lightwhich will be visible to the oli-coming driver will be that afforded by the electric bulb.. itself which is ample for I the purposeV of indicating the position of the machine but Wholly inadequate to occasion any glare inw the eyes ot' the oncoming' driver.

ln Fig. 3, the functioning' of the lip 17 isv indicated by the dotted lines, 'from Tvhich it will he noted that the rays ot light A are caught on the abruptly turned upper surface of the lipof one of the screens, and thrown back against Clie upper reflecting surface ot,v

are reflected from the upper inner surfaces of the screen which, being of constantly; varying curvature, will throw. the rays in' varying directions, hut always in a lateral rather than a forward direction. 0f course, the upperinner surfaces of the screens will' reflect a certain amount of light forvmrdly, hut this light is retlected in adoivnward israele direction so that it will not create a glare at a point substantially in advance of the machine.

The main reflector at the point D will be exposed to receive the rays from the source of illumination, but with the bulb adjusted slightly in front of the focal point as iscustomary this light will be projected 1n a slightly downward direction, so that no glare will be occasioned. The inner portions of the screens will reflect the light back and forth from one screen to another, thereby intensifying the light ultimately rellected from one of the screens past the edge of the other and toward the side of the road` The configuration of the screens is made to conform to the curvature of a parabolic reflector, but it will be understood that strict compliance with such a formation is not essential, since the use of such screens with the reflectors involving a departure from true parabolic form is contemplated, and it is understood that the description given is by way of preference rather than limitation. l claim:

1. In Va headlight, the combination of a source of illumination, an outerreflector, and a plurality of adjustable screens brightcned on their inner surfaces to constitute reflectors, adapted when in open position to constitute a portion of the outer reflecting surface and adapted when in closed position to screen the light of the outer reflector and l reflect the rays of light laterally, each of -the screens at its lower portion being configured to reflectrays of light upwardly toward the companion screen, substantially A. v as described.

B 2. In a headlight, the combination of a source of illumination, an outer reflector, and a pair of adjustable screens brightened on their inner surfaces, adapted when in open position to lie substantially flush with and constitute a portion of the outer reflecting surface and adapted when moved to closed position to present their forward. edges in position to intercept rays of light and screen the major portion of the outer reflecting surface, said screens being concavely formed to reflect rays of light back ject rays of light laterally and downwardly j" to afford illumination at a point closely inf advance of'the headlight, the lower edge of each screen being more abruptly rounded to relect'ra'ys' of light upwardly tothe companion screen and prevent the forward projection of rays from the lower surface of the screen, substantially as described.

3.1m a headlight, the combination of a source of illumination, an outer reflector of substantially parabolic formation, and a pair of adjustable screens of generallmparabolic curvature,- adapted when in open position to lie substantially Hush with the face and constitute reflectors adapted to diffuse the'light laterally, the lower edges of Ithe 4forward projection of light from the lower screen surfaces, substantially as described.

e. In a headlight, the combination of a4 source of illumination, an outer reflector of substantially arabolic formation, and a pair of-adjusta le screens of generally parabolic curvature, adapted when in open position-to lie'substantially flush with the outer o reflector and brightened to constitute a portion of the outer reflecting surface on opposite sides of the source of illumination, and adapted when in closed position to screen off rays of light from the outer reflecting sureach screen being more abruptly curved to relie/ct the light upwardly to the companion screen and prevent the forward projection of light from the lower screen surfaces, the surface of the outer reflector being exposed between the screens when closed at a point immediately above the source of illumination, substantiallyas described.

5; ln a headlight, the combination of a source of illumination, an outer reflector provided with recessed portions, and a pair of adjustable screens adapted when in open positionto lie within the recessed portions of the outer reflector and brightened on their surfaces to constitute a portion ofthe outer-reflecting surface, and curved to conforni tothe curvature of the -outer reflector, said/screens when closed being adapted to screen oli the rays of light from the major portion of the outer reflector and'toproject raysof llghtlaterally, the lower portion of each being more abruptly curved to provide as lip adapted to project rays-of'light up- ,fwardly to the companion screen and prevent 115 and forth from one to the other, and to prothe forward projection of rays of light, substantially as described.

6. 1n. a headlight, the combination of a source of illumination, an outer reflector providcdwlth recessed portions, and a pair 12 of adjustable screensadapted when in open positionwto lie within the recessed portions or the outer reflector and brightenedv on their surfaces to constitute a portion of the outer reflecting surface, and curved to con- 12 t raysof light laterally, the lower portion of 13t each being more abruptly curved t0 provide a lip adapted to project rays of light up wardly to the companion screen and prevent'the forward projection of rays of light, the surface of the outer reiector intermediate the screens when closed end above the source of illumination being exposed to project rays of light forwardly and doWnwardly;'substantially as described.

7. In a headlight, the combination of a source o illumination, and a pair of screens adjustably mounted with respect to the source of illumination, said screens being of riser/mie dished or concave configuration, adapted when in open position to :project rays of light forwardly, and adapted When closed to occupy positions closely contiguous to the source of`i,lluinination, and to reflect rays of light laterally, the lower edge of each of the screens being more abruptly curved to reflect the light upwardly to the companion screen and prevent the forward projection of the rays of light, substantially as described. v

I WILLIAM A. SCHROEDER. i

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