US2564373A - Recessed fluorescent lighting fixture having means to direct the light rays close tothe fixture supporting wall - Google Patents

Description

8- 4, 1951 A. POTTER RECESSED FLUORESCENT LIGHTING FIXTURE HAVING MEANS T0 DIRECT THE LIGHT RAYS CLOSE TO THE FIXTURE SUPPORTING WALL 2 Sheets-Sheet 1 Filed Feb. 15. 1946 INVENTOR 6 0. 15

Aug. 14, 1951 A. POTTER RECESSED FLUORESCENT LIGHTING FIXTURE HAVING MEANS TO DIRECT THE LIGHT RAYS CLOSE TO THE FIXTURE SUPPORTING WALL 2 Sheets-Sheet 2 Filed Feb. 15. 1946 I INVENTOR Aoaz as? POTTER Patented Aug. 14, 1951 RECESSED FLUORESCENT LIGHTING FIX- TURE HAVING MEANS TO DIRECT THE LIGHT RAYS CLOSE TO THE SUPPORTING WALL Adelbert Potter, New York, N. 'Y., assignor t Edwd. F. Caldwell & Co. Inc., New York, N. 1., a corporation of New York Application February '15, 1946, Serial No. 647,843

3 Claims. 1

This invention relates to lighting fixtures, and particularly to lighting fixtures which are designed for use with fluorescent lamps.

Because of the special structural and functional characteristics of fluorescent lamps, difficulty has been experienced heretofore in designing fixtures therefor which will both produce the desired illuminating effects, take full advantage of the overall economy incidental to the use of fluorescent lamps and at the same time -present an artistic appearance. Ceiling fixtures :for fluorescent lamps, as heretofore designed, which depend to any substantial extent below the ceiling, in addition to the fact that they usually do not present a'very artistic appearance if designed to'give the best illuminating effects, are also difficult to keep clean because of the extensive dust collecting surfaces which they expose. Attempts heretofore to recess fluorescent lighting fixtures into the ceiling have been unsatisfactory because of the inefiicient illumination produced by such fixtures.

A general object of the present invention, therefore, is to provide a fluorescent lighting fixture which not only is artistic in appearance but is also 'eflicient from the standpoint of economical overall illumination of the space in which it is located. To this end the invention aims to provide a fluorescent lighting fixture which may be recessed into its supporting wall until the light-emitting side thereof is substantially flush with said wall, which is so designed that the individual lamps held by the fixture will not be noticeable and yet which so emits the light therefrom that a substantial portion of the light rays from the lamps are emitted from said fixture in zones close to said fixture-supporting wall, whereb walls transverse to said supporting wall may be illuminated approximately to their intersection with said fixture supporting wall.

An important feature of the invention is the arrangement of the fluorescent lamps in the recessed casing in such manner that a reentrant lens may be sed to cover the light-emitting side of the casing. Further important features are the location of the lamps at substantially equal distances from the inner faces of the reentrant lens, the provision of a lens which is both formed of a light-difi'using glass and, in addition, has one of its surfaces so pebbled as to add refracting e'ifects to the difiusing effects, and the provision, in some cases, of specially arranged light reflecting surfaces near the light-emitting side of the casing further to insure reflection of a substantial portion of the light rays in zones close to the fixture-supporting wall, whereby illumination of Walls transverse to said fixture-supporting wall, approximately to their intersection with said fixture-supporting wall, may be obtained.

Other important features, objects and advan- FIXTURE cages of the present inventionto which reference has not specifically been made hereinabove, will appear hereinafter when the following descri-ption and claims are considered in connection with the accompanying drawings in which- Figure '1 shows the outside appearance of fixtures embodying the present invention when recessed into the ceiling 'of a room to be illuminated;

Figure 2 is a section through the recessed fixture on the line 2-2 "of Figure 1;

Figure 3 is a partial sect-ion similar to Figure 2 showing a two-part lens "arrangement;

Figure 4 is a section, similar to Figure 2,, of a modified structure in whicha transversely'curved lens and a transversely curved reflecting surface are incorporated;

Figures 5 and 6 show modified 'lens structures.

In the illustrative embodiment-of the invention an elongated 'casin'g 2, pre-"ferairily stamped up out of sheet metal and of a length and crosssection sufficient to receive and support in the desired relation to "each other fluorescent tubes 4 of the desired length and section, for example four foot tubes, has attached to the lateral lower edges of its light-emitting side, in any suitable manner, lens-supporting bracket strips 6 and 8 which provide ledges upon which the lateral edges of the reentrant lens I 0 are supported. The term lens is used herein to indicate any suitable light directing or light dispersing reentrant glass closure for the light emittin side of the fixture of the present invention.

In the illustrative embodiment of the invention the casing 2 is shown as provided with inturned lips 12 to which angle strips M, having lips is turned over into parallelism with the lips I 2, maybe connected in any suitable manner, as b bolts 18. The lens-supporting bracket strips 6 and -8 may be welded to the angle strips 14 and thus secured to the main body of the casing '2 through the connections above described. The outturned horizontal flanges of the angle strips it which overlap the fixture supporting wall alon the sides -of the fixture recess l5 therein, may be used to secure the fixture to the supporting wall in any suitable manner.

The space in the casing '2 between its bottom and the lens t'll is divided into two chambers by means of a partition wall 20 which may be secured to the side walls of the'casing 2 in any suitable manner. As herein shown, bracket strips 22 are riveted or spot-welded to the side walls of the casing '2 and the partition 20 is attached to these bracket strips by means of machine screws 24 tapped into the inwardly projecting arms of the brackets 2t.

As shown "in Figure "2, the partition 20, which has the side exposed to the fluorescent tubes I treated in such manner as to provide good light reflecting surfaces, has a horizontal top portion carrying the end contact supports 26 for the middle tube 4 of the three fluorescent tubes carried by the fixture, and two integral inclined portions carrying the end contact supports 28 and 30 for the other two tubes. The inclined portions of the partition 20 are preferably substantially parallel to the sides of the dihedral angle formed by the reentrant lens I0. The inner wall surface of the casing 2 that lies within the chamber 32 which is bounded by the lateral casing walls, the partition 20 and the lens are also preferably so treated that their surfaces act as good reflectors for the light rays from the tubes 4.

The chamber 34 above the partition 20 may receive the transformer 35 and any other adjuncts of the fixture, such as the wires (not shown) connecting the transformer with the end contact supports 26, 28 and 30 for the tubes 4.

The glass of which the lens I 0 is formed is preferably of one of the light-diffusing compositions which, while it transmits a high proportion of the light, nevertheless sufficiently conceals the tubes 4 so that the individual tubes are not visible through the lens I'll. In order that a portion of the light emitted from the fixture through the lens I0 may strike the walls which lie transverse to the fixture-supporting wall 36, for example, the walls 38 and 40 shown in Figure 1, as closely as possible to the points of intersection of these transverse walls with the fixturesupporting wall, the lens l0 shown in Figure 2 is preferably so pebbled on its outer surface, as shown at 42, that light rays striking this lens, particularly those reflected from the side walls of the chamber 32, will be refracted sufficiently, as they pass through pebbled portions 42 of the lens ID, to cause them to travel in zones close to the fixture-supporting wall 36.

The proportion of the light thus caused to travel in zones close to the fixture-supporting wall may be augmented, as shown in Figure 2, by providing auxiliary reflectors 44, so inclined to the vertical, as shown in Figure 3, that light rays from the fluorescent tubes 4 striking these reflectors are reflected through the lens IDA and B in directions which cause them to travel, without refraction, in zones close to the fixture-supporting wall 36. In the modified form of the structure shown in Figure 3, in which the reentrant lens is made in two parts [0A and MB, supported at their center by angle strips 46 and 48 held in spaced relation by rivets or screws 50, each of the parts IDA and [0B is shown as a plain translucent glass, without pebbling, to illustrate the fact that, with the reflectors 44, an illuminating effect approximating that obtained with the pebbled lenses may likewise be obtained.

Although the pebbling 42 is shown as located upon the outer surfaces of the lenses H1 in the various forms of the invention illustrated in the drawings, in order to avoid liability to accumulation of dust in the valley between the pebbled portions of the lens, it will be understood that the invention is not restricted to having the pebbling on the outer surface of the lens.

In the modification of the invention shown in Figure 4, both the partition 20 and the lens I0 are shown as arc-shaped in section. It will be seen that the illuminating effect with this arrangement will be substantially equivalent to that of the embodiment shown in Figure 2.

In Figure 6 a lens l0 having a sectional contour corresponding to a segment of a many-sided polygon is shown, A lens of this character, when In Figure 5 a lens I0 is shown having a crosspebbled as shown, tends to efiect an even greater diffusion and distribution of the light than some of the simpler forms shown in the previous figures.

From the foregoing description it will be seen that the lighting fixture of the present invention has the advantage of combining an artistic exterior appearance with efficient illuminating characteristics and with the possibility of a marked overall economy in current consumption in proportion to the effective illumination obtained.

What I claim as new is:

1. A lighting fixture for fluorescent lamps adapted to be recessed into its supporting wall until the light-emitting side thereof is substantially flush with said wall, said fixture comprising an elongated casing having elongated transversely reentrant and transversely uninterrupted reflecting surfaces on its inside and having its otherwise open light-emitting side covered by a correspondingly elongated transversely reentrant lens, said fixture having fluorescent lamps extending lengthwise of said casing and spaced transversely in a shallow, obtuse-angled reentrant arrangement which corresponds substantially both to that of the reflecting surface and to that of the inner face of said reentrant lens, so that a large portion of the light rays from said lamps, reflected from the reflecting surfaces in said casing, are emitted from said fixture through said lens at relatively small angles to the normals to said lens at the points of incidence and in zones close to said fixture-supporting wall, whereby walls transverse to said fixture-supporting wall may be illuminated approximately to their intersection with said fixture-supporting wall.

2. A lighting fixture according to claim 1 in which the casing has lateral reflecting surfaces adjacent to its light-emitting side which are inclined inwardly from vertical planes through the respective lateral boundaries of the casing.

3. A lighting fixture according to claim 1 in which a plurality of fluorescent lamps are spaced substantially equal distances from the inner surface of the reentrant lens and in which said plurality of fluorescent lamps comprise three parallel fluorescent tubes extending lengthwise of the casme. one being located midway between the side walls of the casing and the other two being equally spaced from said first mentioned tube and being located in a plane parallel to and below a horizontal plane through the axis of said first-mentioned tube.

ADELBERT POTTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,258,006 Hess Mar. 5, 1918 1,699,692 Ecker Jan. 22, 1929 1,718,560 Hollnagel June 25, 1929 1,784,171 Bertling Dec. 9, 1930 2,028,453 Hoffman Jan. 21, 1936 2,192,019 Schepmoes Feb. 27, 1940 2,232,499 Waterbury Feb. 18, 1941 2,291,494 Lorenz July 28, 1942 2,311,444 Kellogg Feb. 16, 1943 2,312,618 Beck Mar. 2, 1943 2,338,077 Schibner Dec. 28, 1943

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