US1514551A

US1514551A - Chusetts

Info

Publication number: US1514551A
Authority: US
Publication date: 1924-11-04
Anticipated expiration: 1941-11-04

Description

Nov. 4 1924.

' F. w. LYLE ET AL REFLECTOR FOR USE IN HEADLIGHTS Filed Aug. 15 1 1916 l n .n

n Ma m WITNESS:

Patented Nov. 4, 1924.

U NlTE-D stares :FATEN'T! OFFICE.

FREDERICK W. LYLROF LYNN, AND N. TU 013 BOSTON, -MASSAGHUSETTS,

ASSIGNORS 'TO'BEACQN AGGEESORIES COIRPQRATIUIT, A CORPORATION OF MASSA- REFLECTOR FOR USE IN HEADLIGHTS.

Application filed August 15, 1916. Serial No. 115,009,

T 0 all whom it may concern: I Be it'known that we, FREDERICK WV. LYLE, a citizen of the United States, residing at Lynn, inthe county of Essex, in the State of Massachusetts, and JAMES N. TUTTLE, a citizen of the I-lnitedStates, residingat Boston,in the county of Sufl'ollr, in the State of ,lVIassachusetts, have jointly invented a new and useful Improvement in Reflectors for Use in Headlighta of which the follow :ing is a specification, reference being had to theaccompanying drawings. H The object of this invention is to pro- ,Vide a headlight for vehicles from which there. shall beno objectionable glare in the eyes, of; approaching pedestrians or drivers. This is accomplished by so shaping the re fiedtor that the glaring rays of lightare wholly confined to-space below a certain predetermined level.

In Figure 1 of the attached drawingsuch afheadlight is shown mounted in the usual position on-an automobile, the proj ected rays ofnlight being represented by dotted lines. Figure 2 shows a vertical, longitudinal, mid section of this headlight. Figure 3shows a front view.

In-Figures 2 and 3the letter a denotes-the casing of such a headlight, the letter F) the,

reflector and the letter 0 an electric light bulb, located near the focal point thereof. The light source is preferably located forwardlytof at least thefocus of the upper half of the reflector, and in Fig. 2 we have illustratedthe two foci as being coincidentally disposed at f immediately in the rear of the light source.

Heretofore headlight reflectors have been formed as surfaces of revolution, ordinarily hyperboloids or paraboloids, about an axial line such a lineconstituting an axis of symmetry therefor- :Inpractice the headlights are, so mounted that their axis is substantially horizontal; furthermore, .the light 'beam forms a cone, themarginal rays of which diverge at a considerable angle from :the'axis. It therefore comesabout that the, light o constituting the ,upper half of this coneis. thrown upward at so great an angle :that-it is i'not onlylost but it produces a blinding-glare in the eyes of approaching pedestrians or drivers of vehicles. Thisobjeotionable efi'ect weeliminate by forming reflectors-0f the headlights as described ,1 e 0w."

Ordinarily the light source is solocated with respect to the reflector that the objectionable light constituting the upper portion of the conical beam emanates fromthe lower half ofthe reflector, that is, the light source is usually positioned in front of the focus. We therefore form the reflector of what might be considered two segments, an'upper and a lower, the axis of the upper segment bein subs'tantially horizontal and the axis of the lower being inclined forward and being horizontal and the lamp focused as above described, the rays 0]al reflected by it are thrown out, some horizontally and others slightly tipped downward as shown.

If the axis of the :lower segment were also horizontal it would reflect rays forward and upward. It is however tipped downward at such anangle as to throw light forward and downward only, as indicated by the dotted lines 0m-,n. Thus no rays emanating from either segment of the reflector rise above the level of the headlight. The-gem eral appearance of the light beam is indicated by the dotted lines of Figure 1.

The attainment of this result may, of course, bebrought about either by combining the two segments integrally ina single reflector or by making the lower segmentsepvarate from the upper and placing it in the above described position l with reference thereto.- The glare fromxa reflector of the kindnow commonly used may therefore be I eliminated by attaching within it a segment of asurface ofrevolution so asto cover its lower half and soplaced thatit shall take up a position, with reference to the light source and the upper segmentysimilarto that of the lower segment above described.

From the above description it will be apparent that the present. invention is intended to be applied to headlights in whichithe light. source is disposed substantially in the focus or forwardly ofthe focus ofthe reand by orientating the lower flector. With the light source so disposed substantially all light striking the upper half of the reflector is reflected in or below a horizontal direction and, in the absence of our invention, substantially all light striking the lower half of the reflector would be reflected in and above a hor1zontal direction in such manner as to produce upward glare.

can be swung substantially wholly below the horizontal plane through the light source. The lower half of the reflector may be disposed in such angular relationship to the upper half that the light therefrom is directed to the nearerportionsof the roadway. However, we prefer to arrange the two reflector so that the angle between the axes is relatively small, and so that the light from the lower half of the reflector is directed into substantiallythe same space as the light from the upper half, thereby not only eliminating upward glare but also intensifying theillumination of .the roadway.

Instead of true paraboloidal reflectorswe may use reflectors having other contours, such as that of a hyperboloid, and indeed we preferably use a hyperboloidal contour differing slightly from a paraboloidal contour so that light is reflected from each half reflector in the form of a half cone, thereby to secure better distribution of. light throughout near and distant'portions of the roadway and along the sides of the roadway. However, the cardinal features of the invention comprise the orientated position of the lower half reflector relatively to the upper half and the orientation of the lower half substantially about'a transverse axis through V the region of the light source and focus.

3 In theappended claims the expressions horizontally, upwardly downwardly,etc. are

used merely in a relative sense in order more conveniently to refer to relative positions, and theseterms are not tobe construed as necessarily being employed with reference to the earths surface. The word axis. is

employed to signify a line ofsymmetry of a reflector and is not intended to refer solely to the major axis of'a surface of revolution. On the contrary it is intended also to apply I to thecentral axis of a surfacewhich has a I Patent cross-sectional contour other than circular as, for example, an elliptical contour.

claim as new and wish to secure by Letters l. light projection apparatus for projectinga concentrated beam of light horizontally without producing appreciable upward glare, the combination of a light source, an upper reflecting surface adapted to project a concentrated beam of light along its axis, the upper surface being disposed predominantly above the horizontal plane of the light source with its focus in the region of the light sourc and its axis disposed substantially horizontally, so as to project light substantially horizontally without projecting appreciable light upwardly, and a lower reflecting surface disposed predominantly below said horizontal plane with its focus in the region of the light source and its axis directed downwardly, so as to project light downwardly Without projecting light upwardly, said surfaces meeting in the region of the horizontal plane passing through the light source.

2. In light projection apparatus for projecting a concentrated beam of light horizontally without producing appreciable upward glare, the combination of upper and lower reflecting surfaces adapted respectively to project beams of light along their axes, the reflecting surfaces being arranged in opposition with their foci coincident, and a light source disposed in the focal region of the reflecting surfaces, the upper reflecting surface having its axis disposed substantially horizontally and the lower reflecting surface having its axis directed downwardly, and'the light source being so disposed with relation to the respective foci that light is projected in and below a horizontal direction without projecting substantially any light upwardly, said surfaces meeting in the re.- gion of the horizontal plane passing through the light source. v

3. In light projection apparatus for pro jecting a concentrated beam of light longi tudinally without producing appreciable up ward glare, the combination of upper and lower reflecting surfaces adapted respectively to project beams of lightalong their axes, the reflecting surfaces being arranged in opposition with their foci approximately coincident, and a light source disposed in the focal region of the reflecting surfaces, the upper reflecting surface. having its axis disposed substantially horizontally and the lower reflecting surface having its axis orientated downwardly with respect to the other axis about a transverse axis passing through the focal region. 7 4. In light projection apparatus for projecting. a concentrated beam of light longitudinally without producing appreciable upward glare, the combination of upper and lower reflecting surfaces adapted respectively upper reflecting surface having its axis disrespective foci, forwardly of the'focus of the posed substantially horizontally and the upper reflecting surface, that light is pro-. lower reflecting surface having its axis orijected in and below a horizontal direction 10 entated downwardly with respect to the without projecting substantially any light other axis about a transverse axis passing upwardly.

through the focal region, and the light FREDERICK W. LYLE. source being so disposed with relation to the JAMES N. TUTTLE.