US2156087A - Illumination - Google Patents

Description

April 25, w H RR N ILLUMINATION Filed March 6,1936 2 Sheets-Sheet 1 Fig.1.

l2 l2 /3 5 W \J f /8 Inventor: Ward Harrison H is Attorn qy.

April 25, 1939. w. HARRISON ILLUMINATI ON Filed March 6, 1936 2 Sheets-Sheet 2 Inventor: I Ward Harrispn, b fla y His *3 5.19 torne y.

Patented Apr. 25, 1939 UNITED STATES PATENT OFFICE HLUMINATION New York Application March 6, 1936, Serial No. 67,451

1 Claim.

My invention relates to illumination generally and more particularly to a lighting arrangement for the interior of a building.

One of the objects of my invention is to provide a lighting arrangement which is substantially free from glare and has a high efficiency.

According to my invention, I provide one or more concave light concentrating reflecting surfaces, preferably in the shape of troughs, at the c'eiling of the room. One or more light sources are located adjacent the focus of each of said reflecting surfaces or troughs, and reflectors are preferably disposed under each of said light sources to direct the light upward to the adjacent trough from which it is redirected downward into the room. In this way each of the reflecting surfaces or troughs illuminates substantially only the area directly below! it so that the troughs will appear to be very dimly lighted except for that portion directly above the observers head which is normally out of the line of his vision. Since nearly all the light is directed straight down and very little toward the side walls, the efliciency of illumination is very high. Further features and advantages of my invention will appear from the following detailed description of species thereof.

In the drawings Fig. l is a plan view, looking upward, of a lighting arrangement comprising my invention; Fig. 2 is a section taken along lines 2--2 of Fig. 1; Fig. 3 is a section through one trough and its lighting unit on an enlarged scale; and Figs. 4 and 5 are sections through the troughs and lighting units of modified arrangements of my invention.

My invention is embodied in illuminators which are preferably built into the ceiling of a room or office, etc., as shown in Figs. 1, 2 and 3. In this instance three substantially parabolic troughs l0 form all but the extreme edges ll of the ceiling and a plurality of lighting units l2 are suspended at intervals so that each illuminates a portion of a trough. The lighting units, as shown in Fig. 3, each comprise a light source [3 which is preferably located at the focus or focal line of the parabola, and a reflector 14 which directs the light upward to the trough. Lips IS on the reflector l4 prevent the light from striking the trough at too sharp an angle so that the light is kept away from the side walls of the room as much as. possible. The light source l3 may consist of an incandescent lamp which is mounted in a socket l6 which in turn is mounted in an enclosure IT. The lamp bulb may be of clear or frosted glass and the reflector l4 and parabolic trough ID are preferably of brushed or oxidized aluminum. A polished trough is not desirable since sharp lines of light appear on the reflector. A metallic coating sprayed or brushed onto the trough may 5 also be used although the surface must give a limited amount of diffusion. White paint would not be satisfactory due to its excellent diffusing properties. The light unit i2 is supported by pipes l8 and IS, the latter of which is fastened to the ceiling adjacent to the trough. The edges of the parabolic trough l0 may extend above or below the. focus but in either case the reflector l4 must be formed so that the light strikes only the trough and is not projected into the room directly.

Obviously in the arrangement just described the trough In illuminates substantially only the area directly below it so that the troughs will all appear to be very dimly lighted except for H that portion directly above the observers head which is normally out of the line of his vision. In some instances it may be found desirable to illuminate the side wall in which case the lighting unit l2 can be moved sideward as shown in dotted lines in Fig. 3 so that the light is directed to one side rather than straight down.

Other types of lighting units such as those shown in Figs. 4 and 5 may also be used. In Fig. 4 the lamp I3 is mounted base upward in a socket 20 which is supported by a pipe 2| extending downward from the center of the trough ID. The reflector M is mounted below the lamp IS on arms 22 extending from the socket 29. In Fig. 5 the lighting unit is comprised of a :33 trough-shaped reflector 23 which is coextensive with the trough l0 and is supported by a pipe 24 which extends downward from the trough Ill and supports a plurality of. light sources l3.

What I claim as new and desire to secure by Letters Patent of the United States is:

A. room lighting arrangement comprising a concave light concentrating trough having a reflecting surface and located at the ceiling, a plurality of light sources dispose'd adjacent the focal line of said trough, and a reflector disposed under each of said light sources and adapted to direct light upward to said trough from which it is redirected downward each of said reflectors having an upwardly extending lip on each side thereof in the longitudinal direction of said trough for confining the light from the light source located therein to a definite portion of said trough.

WARD HARRISON.

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