US2060588A - Reflector - Google Patents

Description

NOV. 10, 1936. J. R QGDEN, JR 2,060,588

REFLECTOR Filed March 19, 1935 6/ FI Q 1a \Qq\ ATTORNEYS Patented Nov. 10,1936

UNITED. s A Es PATENT OFFICE 2 Claims.

The present application is a continuation in part of my prior application Serial No. 568,614, filed October 13, "1931.

The object of my invention is the provision of a reflector particularly adapted for use in vehicle headlights and for floodlighting, projecting a light beam having as its upper edge a substantially straight line, while its lower edge is formed of a spreading curved line when projected on a vertical screen, permitting a light beam to be projected forward a greater distance without the resultant upward spreading 3f light rays incident to the parabolic reflectors in common use on automobiles, thus eliminating glare while distributing the road lighting more emciently, the more concentrated light being projected directly in front of the vehicle, where it is most needed. In order to accomplish this, I use'two reflector sections, an upper and a lower. The upper reflector section being a curved reflector which has a semiparaboloid as its limiting surface within which the reflector surface may lie entirely, or partly within and partly coincident with the semiparaboloid, or coincident with the semi-paraboloid. The lower reflector section being a curved reflector which has a semi-paraboloid as its limiting surface outside which the reflector surface may lie entirely, or partly outside and partly coincident, or entirely coincident therewith. The lower semi-paraboloid has a greater focal length than the upper semi-paraboloid, while their axes are substantially common. The lighting filament is disposed with respect to the reflectors so that the common axis of the reflectors substantially coincides with a line axially disposed with respect to the wire or wires forming the said filament. The respective foci of the two semi-paraboloids are so disposed along their substantially common axis that the intersections of lines through the filament pillar end or ends with the common axis will lie between the feel or substantially coincide with the fool; the lines through the filament pillar ends being perpendicular to the axis of the paraboloids, thereby limiting the filament pillar lengths in relation to the distance between the foci.

The patterns,on a vertical screen, in all modifications of my device, of light beams from both the upper and lower reflector sections, are substantially concentric and superimposed one directly upon the other, each having an upper edge substantially a straight line, and a lower edge ranging substantially from a circle to an ellipse. Said upper. edges are substantially coincident. The lower edges spread to larger curves of the same forms, as the distance from the reflector increases. This results in the concentration of the strongest light directly in front of the vehicle, while the light becomes gradually less strong as it spreads to each side; in this way, the brightest light being concentrated in front, where needed most, and with somewhat dimmer light'at 'th'e sides of the road where it is of secondary importance, eflicient illumination is obtained. r My device may be used effectively with single 10 and multiple pillar filament lighting sources.

It is to be understood that the invention is not confined to the disclosure, as it is recognized that changes and modifications can be made therein without materially departing from the invention described and claimed.

In the drawing: a

Fig. 1 is a vertical section of a. reflector constructed in accordance with the principles of my invention.

Fig. 2 is a front view of a reflector constructed in accordance with the principles of my invention.

Fig. 3 shows the beam pattern projected upon a vertical screen by the reflector shown in Fig. 2.

Referring to the drawing,

In Figs. 1 and 2, the upper reflecting surface 5, is coincident in vertical section with the semiparaboloid III, which has its focus 3 substantially at the intersection of the line through the rear end or ends of the filament I and the substantially common axis of the lighting filament I and the semi-paraboloids Ill and II, and gradually comes within the semi-paraboloid II) as it approaches the horizontal plane through the axis of the semi-paraboloid I 0. The light ray 6 emanating from the focus 3 is projected horizontally, while the light ray 9 emanating from a source 2 forward of the focus 3 is projected downwardly. The farther the reflecting surface 5 comes within the semi-paraboloid III, the greater the angle becomes between the axis and light rays which are always projected horizontally or downwardly. The lower reflecting surface 4, is coincident in vertical section with the semi-paraboloid II, which has its focus 2 substantially at the, intersection of the line through the forward end or ends of the filament I and the substantially common axis of the lighting filament I and the semiparaboloids I 0 and II, and gradually goes outside the semi-paraboloid I I as it approaches the horizontal plane through the axis of the semiparaboloid II. The lightray I, emanating from the focus 2 is projected horizontally, while the ray 8 emanating from a source 3 rearwardly of the focus 2 is projected downwardly. The farther the reflecting surface 4 goes outside the semi-paraboloid II, the greater the angle becomes between the axis and light rays which are always projected horizontally or downwardly.

In Fig. 3, the upper reflector surface projects the beam pattern which is contained within and reaching to the substantially straight line I2, I, and the curve It, I1, II, with the small area I! lying above the line l2, l3. By a minor change in adjustment the small area It can be made to disappear. The lower reflector surface projects the beam pattern which is contained within and reaching to the substantially straight line 14, II, and the curve II, it, ll.

I claim: 1. In combination a reflector consisting of a upper and a lower reflector surface and a lighting filament, the lower reflector surface formed of a surface which substantially coincides in vertical section with a semi-paraboloid having its focus substantially at the intersection of its axis-with a line perpendicular thereto through the forward extremity of the said lighting filament, and forming a curve substantially outside said semi-paraboloid where a horizontal plane through the axis cuts the extension of the reflector surface, the intermediate surface being a transition from one section to the other; the upper reflector surface formed of a surface which substantially coincides in vertical section with a semi-paraboloid having its focus substantially at the intersection of its axis, with a line perpendicular thereto through the rear extremities of the said lighting filament; and forming a curve inside said semi-paraboloid-where a horizontal plane through the axis cuts the extension of the reflector surface, the intermediate surface being a transition from one section to the other.

2. A headlight construction consisting of an upper and a lower reflector section and a lighting filament, the lower reflector section formed of a surface which substantially coincides in vertical section with a semi-paraboloid having'its focus substantially at the intersection of the longitudinal axis of the lighting filament with a line Joining the front extremity of said filament perpendicular to said axes and forming a curve substantially outside said semi-paraboloid where a horizontal plane through the axis cuts'the extension of the reflector surface, the intermediate surface being a transition .from one section to the other; the upper reflector section formed of a surface which substantially coincides in vertical section with a semi-parabw loid having its focus substantially at the intersection of the longitudinal axis of the lighting filament with a line joining the rear extremities of said filament perpendicular to said axis and forming a curve substantially inside'said semiparaboloid where a horizontal plane through the axis cuts the extension of the reflector surface; the intermediate surface being a transition from one section to the other, the axes of the said semi-paraboloids and lighting filament being substantially coincident.

JOSEPH RICHARD OGDEN} JR.

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