US2874271A - Indirect lighting fixture - Google Patents

Description

Feb. 17, 1959 w. LIPSCOMB INDIRECT LIGHTING FIXTURE Filed June 9. 1953 60 INVENTOR.

WILLIS L. LIPSCOMB 14311.01 & 15mm QGZNTS FOR APPl-JCANT 6 Fig.4

United States Patent INDIRECT LIGHTING FIXTURE Willis L. Lipscomb, San Diego, Calif. Application June 9, 1953, Serial No. 360,465

6 Claims. c1. 240-5111) The present invention relates generally to lighting fixtures and more particularly to an indirect lighting fixture, having novel cellular or lattice light control units and frame structure.

The primary object of this invention is to provide a lighting fixture in which the lamps are concealed from view below the level 'of the fixture so that the fixture has a high degree of efliciency while attaining a highly esthetic appearance.

Another object of this invention is to provide an indirect lighting fixture in which air may circulate freely, the moving air tending to prevent dust from settling on the fixture ,while the lamps are in operation.

terial can be according to the dictates of availability and price considerations, the exact sizes and proportions being matters easily determined to suit particular conditions and needs. i

Another object of this invention is to provide an indirect lighting fixture which is inexpensive and practicable i to manufacture. V

Finally, it is an object "to "provide an indirect lighting fixture of the aforementioned character which is simple, safe and convenient to operate, and which will give generally eflicient and durable service.

With these and other objects definitely in view, this invention consists in the novel construction, combination and arrangement of elements and portions, as will be hereinafter fully described in. the specification, particularly .pointed out in the claims, and illustrated in the drawing which forms a material part of this "disclosure and wherein similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawing, and in which:

Fig. 1 is a perspective view, from below, of the luminaire.

Fig. 2 is a lateral sectional view of the luminaire.

Fig. 3 is a longitudinal sectional view of the luminaire.

Fig. 4 is a lateral sectional view showing an alternative method of constructing the luminaire.

Referring now to the drawing, the fixture includes a basket 10, which constitutes the shielding portion of the luminaire, and a lamp supporting reflector 12 to which the basket is attached.

The reflector 12 is arcuate in cross section, the upper surface 14 thereof comprising the reflecting portion, above which the lamps 18 are disposed and upon which the lamp sockets 20 are mounted. The reflector may be domeshaped or generally upwardly arched and having poly- 2,874,271 Patented Feb. 17, 1959 hedral reflecting surfaces. The reflector 12 has downwardly turned flanges 22 along its longitudinal edges, and

.the complete reflector 12 is suspended from a ceiling or other suitable supporting structure by means of stem hangers 24 of conventional type.

The basket 10 comprises a pair of end plates 26 joined by side angle plate members 28 which are provided with inwardly turned flanges 30 on their lower edges. The basket also includes a center panel 32 which is depressed at the center and secured to the end plates 26 which are shaped to conform to the cross-sectional shape of said center panel. Fastened to the center panel 32 is a reinforcing channel member 34, extending substantially the full length thereof, and having angular flanges 36 along both edges. The width of the channel member 34 is such that the center panel 32 extends slightly on either side thereof to form support flanges 38.

The elongated spaces between the channel member 34 and the side angle plate members 28 accommodate egg crate type cellular lattices 40 which are-secured to the support flanges 38, the flanges 30 and the end plates 26. These cellular lattices 40 comprise a plurality of flat strips or slats arranged to form rows of rhomboid cells 42, open at both ends and having substantially vertical or slightly inclined walls. The two inner rows of cells 42 are covered at their upper ends by shield plates 44 so that the lamps 18 are shielded from below the fixture. The material of the luminaire may be plastic, metal, or a combination of both, the cellular lattices in particular being suited for plastic construction.

The basket 10 is attached to the reflector 12 by means of rivets or bolts 46 which pass through the flanges 22 and the innermost slats 48 of the lattices 40.

The electrical wiring and the ballasts 50 required for the tubular type lamps shown in the drawing, are attached to the channel 34 in the chamber between the reflector 12 and said channel. Access to the ballasts 50 and the wiring is obtained through an aperture 52 in the reflector 12, said aperture being covered by a removable panel 54.

It will be seen that the lamps 18 are easily replaced from above the fixture without dismantling any part of the structure. Thecellular lattices allow air to circulate freely around the lamps by convection, while shielding the lamps and preventing direct light falling below the fixture. The lattices may, of course, be constructed of translucent material so that the downward light will be effectively diffused.

The air moving by convection around the fixture, while the lamps are in operation, tends to prevent dust from settling on the structure, the vertical walls of the cells 42 further assisting by causing dust to gravitate out of the fixture. While the unit is not in operation, a certain amount of dust may accumulate on the various surfaces but this is limited.

An alternative structure for the luminaire is shown in Fig. 4, this particular structure including a basket 56 which is molded from plastic in two similar portions 58.

These basket portions 58 may be produced from the same mold and cemented or otherwise fastened together along their inner edges. It will be seen that each basket portion includes a cellular lattice 60, of the same characteristics as that previously described, and an integral center panel 62 which is shown flat for ease of manufacture, the end plate 64 also being integral with the structure. The inner edge of the center panel 62 is reinforced by a thickened rib 66 which also provides an increased bonding surface for fastening the halves together. Similarly the inner edge of each end plate 64 is reinforced by a rib 68. The assembled basket 56 is substantially V-shaped in cross section and is used with a reflector 70 similar in structure to the reflector 12 previously described.

It will be obvious that the purpose and functions of the modified luminaire are similar to those described for the primary structure. The use of molded plastics to produce a unitary structure will greatly reduce the cost of manufacture, while the division of the structure into two similar halves will also reduce the cost of the mold.

It should .be noted that the flat outer surfaces of the center panels 62 tend to reflect a considerable amount of the light which is reflected from the surrounding walls, thus increasing the illumination of the lower portions of the luminaire. Although the mid-portion of the curved center panel 32 is not illuminated as brightly as the flat sided center panels, the esthetic value of the curved surface may more than offset the advantage in prevention of a dark area on the underside of the fixture.

The operation of this invention will be clearly comprehended from a consideration of the foregoing description of the mechanical details thereof, taken in connection with the drawing and the above recited objects. It will be obvious that all said objects are amply achieved by this invention.

Further description would appear to be unnecessary.

It is understood that minor variation from the form of the invention disclosed herein may be made without departure from the spirit and scope of this invention, and that the specification and drawing are to be considered as merely illustrative rather than limiting.

I claim:

1. A structural element for a lighting fixture comprising a reflector panel having an elongated light-reflective upper surface, means to mount elongated fluorescent lamps in positions parallel to and immediately above said surface, lamp shielding lattice structure in positions laterally abutting and inclining upwardly from said surface on both sides thereof and extending the full length thereof, and said panel constituting the means to support said lattice structure in said positions, said surface being elongated and curved upwardly in the form of a segment of a hollow cylinder and said lattice structure being of unitary construction and having a multiplicity of cells with that vertical parallel walls.

2. A structural element for a lighting fixture comprising a panel having a light-reflective upper surface, means to mount lamps in positions immediately above said surface, lamp shielding lattice structure in positions laterally abutting said surface on both sides thereof and extending the full length thereof, and said panel constituting the means to support said lamp mounting means and said lattice structure in said positions, said surface being elongated and curved upwardly in the form of a segment of a hollow cylinder, said panel defining the upper boundaries of a wiring compartment, a plate fixed in relation to said panel and defining the lower boundaries of said compartment, said panel having means adjacent said end thereof for securement thereto of fixture suspension stems, said panel having an access opening extending throughout the major portion of the distance between the last mentioned means and a closure for said opening and said lattice structure being of unitary construction and having a multiplicity of cells with flat vertical parallel walls.

3. An indirect lighting fixture comprising an elongated reflector element of substantially inverted U-shape in cross section with depending laterally disposed flanges, means to mount a plurality of elongated tubular lamps above and parallel to said reflector, a basket attached to said flanges, said basket including a pair of end plates, side members interconnecting said end plates, a center panel secured to said end plates intermediate said side members, a pair of cellular lattice structures secured between said side members and said flanges, and shield plates covering portions of said lattice portions.

4-. An indirect lighting fixture according to claim 3 wherein said lattice portions comprise a plurality of. rhomboid cells having substantially vertical side walls.

5. An indirect lighting fixture comprising a reflector element comprising an elongated dome with a reflecting surface on its upper side, means for mounting a plurality of elongated tubular lamps above and parallel to said reflecting surface, a basket attached to said reflector element, said basket including a pair of end plates, a cellular lattice between and integral with said end plates, a shield plate integral with and covering a portion of said lattice, an imperforate center panel integral with said cellular lattice, and the center panels being joined together along the vertical central plane of the fixture.

6. An indirect lighting fixture comprising an elongated reflector element of substantially inverted U-shape in cross section with depending laterally disposed flanges, means to mount a plurality of elongated tubular lamps above and parallel to said reflector, a basket attached to said flanges, said basket including a pair of end plates, side members interconnecting said end plates, a center panel secured to said end plates intermediate said side members, a pair of cellular lattice structures secured between said side members and said flanges, shield plates covering portions of said lattice structures, said reflector element, said end plates and said center panel defining an enclosed chamber for electrical wiring, said reflector element being provided with an aperture permitting access to said chamber, and a closure for said aperture.

References Cited in the file of this patent UNITED STATES PATENTS 2,319,732 Guth May 18, 1943 2,341,895 Beck Feb. 15, 1944 2,421,967 Schepmoes June 10, 1947 2,490,191 Baker Dec. 6, 1949 2,597,739 Lacy et al. May 20, 1952 2,659,807 Wakefield Nov. 17, 1953 2,703,360 Lipscomb Mar. 1, 1955 2,732,484 Lipscomb Ian. 24, 1956 2,761,058 Lipscomb Aug. 28, 1956 2,777,053 Lipscomb Jan. 8, 1957

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