US3433941A - Lighting unit - Google Patents

Description

March 18, 1969 W. B. HALL LIGHTING UNIT Filed D80. 30, 1966 Sheet INVENTOR WILLIAM B. HALL.

ATTORNEY.

W. B. HALL LIGHTING UNIT mm p I ll/ a 3 H H T. \I

March 18, 1969 Filed Dec. 30, 1966 ems I NVEN TOR.

WILLIAM B. HALL ATTORNEY.

FIG.3

FIG.4

United States Patent 6 Claims ABSTRACT OF THE DISCLOSURE A luminaire employing a mercury vapor light source for illuminating large areas is disclosed wherein the fixture is fabricated of a tier of discrete bands of reflectors each formed in the configuration of a rectangular fence of substantially equal height but of increasing length and width from top to bottom of the fixture in stepped array, the bands being joined exteriorly by a plurality of stepped brackets such that the top of each band is spaced horizontally from the bottom of the band above to provide for the free circulation of air, and each band is increasingly inclined from the vertical proceeding from the bottom of the fixture such that a light source mounted centrally of the reflector at the top thereof has its rays directed downwardly by the tiered reflector surfaces and by an upper reflector disposed above the light source and joining with the top band.

This invention relates to lighting units for illuminating areas of substantial dimension. At present, such lighting units employ lamps of the fluorescent tube type for a light source. Such lamps have a relatively short life, requiring replacement at frequent intervals. Also, such lamps are adversely affected in their operation at low ambient temperature, as where the units are employed outdoors. In order to obtain desired density of light for the illumination of a large area, a plurality of the fluorescent tube lamps must be employed in each unit and, because of the form of the fluorescent tube lamp, the unit must only be of rectangular configuration.

This invention has as an object a lighting unit embodying a light weight vertically compact structural arrangement which is particularly economical to fabricate in different sizes and different shapes, the unit employing a high intensity mercury vapor lamp as a light source. The unit employing a high intensity mercury vapor lamp as a light source. The unit functions to give illumination of uniform intensity over an area of substantial dimension.

The lighting unit of my invention also provides extreme flexibility in the production of the units in different sizes and shapes, and in providing diiferent types of light distribution, the main reflecting surfaces being in the form of strips of reflecting material not requiring any forming, or other types of tooling, for their production.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

In the drawings:

FIGURE 1 is a perspective view of a lighting unit embodying my invention.

FIGURE 2 is a central cross sectional view of the unit.

FIGURE 3 is a bottom plan view of the unit, and

FIGURE 4 is a view, similar to FIGURE 2, showing the unit mounted in a ceiling structure.

The lighting unit consists generally of a frame having downwardly diverging side members. An upper reflector is mounted at the top of the frame, and a light source is positioned below the upper reflector. A plurality of strips of reflecting material are mounted on the inner surface of the side members, the strips being arranged in step on opposite tiers that surround the vertical axis extending through the light source.

The embodiment of the light unit, as shown in the drawings, is of rectangular configuration wherein the side members are in the form ofribs 10 located at the corners of the unit, and havingflanges 12, 13, 14 and 15, extending laterally from the ribs in right angular relationship. If the unit is of large dimension, it may also includeintermediate ribs 20 formed withflat flanges 21, 22, 23 and 24. These latter flanges may extend from one side of theribs 20, or fro-m both'sides, the flanges being arranged in registration with the flanges 12-15 respectively, on thecorner ribs 10.

The frame may be formed with a top member integral with theribs 10, 20. Preferably, the top member is formed separately and the ribs attached thereto. In the drawings, the top member is in the form of aplate 27, to the peripheral portion of which the ribs .10, 20, are attached, as being riveted, or otherwise aflixed, thereto. Anupper reflector 28 is mounted immediately below thetop member 27, and alight source 29 is mounted centrally in the frame below thereflector 28.

Reflecting strips 30, 31, 32 and 33, are fixed to the flanges 12-15 and 21-24. The rib flanges are arranged in step formation, whereby the reflecting strips 3033 are arranged in tiers one above the other, with the strips of each tier being located outwardly from the axis of the unit in relation to the strips in the tier next above, see FIGURES 2 and 4. The reflecting strips 30-33 are formed of flat sheet material, such as aluminum, or the like, processes to provide an eflicient reflecting inner surface. The reflecting strips are simply cut to the proper length for a given frame structure and affixed to the rib flanges, as by rivets, adhesive, or the like.

Referring again to FIGURES 2 and 4, the rib flanges 12-15 and 21-24 and accordingly, the reflecting strips aflixed thereto, incline at an angle upwardly and inwardly toward the vertical axis of the unit extending through thelight source 29. The angle of inclination of the strips 30-33 in each tier is greater than the angle of inclination of the strips in the next lower tier. The outward spacing and inclination of the reflecting strips in the respective tiers is determined by the size of the lighting unit and the desired light distribution. The reflecting strips are located and arranged to simulate sections of a selected type of reflector, such as spherical, parabolic, or elliptical.

It will be observed, referring to FIGURES 2, 3 and 4, that there is an open space of substantial dimension laterally between the lower edges of the reflecting strips in each tier and the upper edges of the strips in the next lower tier. This provides for exceptional ventilation for the reflecting strips, whereby they are maintained at substantially ambient temperatures regardless of the heat generated by the high intensity mercury vapor lamp.

Abezel 40 of channel formation is fixed to the lower ends of theribs 10, 20, for the reception of a drop inlens 41. In FIGURE 2, the unit is mounted by being suspended from a chain arrangement. For outdoor lighting, the unit may be enclosed by acasing 43. In FIGURE 4, the unit is illustrated as being mounted in a ceiling opening, as by means ofscrews 45. The upper edges of the reflectingstrips 30, 31, 32, terminate at or above the plane of the lower edges of the strips next above, whereby the light beams emitted laterally from thelamp 29 only strike the reflecting surfaces of the reflecting strips, whereby with the step arrangement there is no loss of light.

What I claim is:

1. A lighting unit comprising a frame having downwardly diverging side members, an upper reflector mounted in the frame, alight source mounted below said reflector, a plurality of discrete reflecting strips mounted on the inner surfaces of said side members, said strips being arranged in a plurality of tiers surrounding the vertical axis extending through said light source, said reflecting strips in each tier being located outwardly from said axis in relation to the strips in the tier next above and the top of each strip being horizontally spaced from the bottom of the higher strip, and said reflecting strips in each tier being inclined at an angle upwardly and inwardly toward said axis.

2. A lighting unit as defined inclaim 1, wherein the angle of inclination of the reflecting strips in each tier is greater than the angle of inclination of said strip in the next lower tier.

3. A lighting unit comprising a frame including a plurality of downwardly diverging stepped rib members,.an upper reflector positioned within said rib members at the upper ends thereof, a light source positioned below said reflector, a plurality of flat reflecting strips mounted on the inner surfaces of said ribs, said strips being arranged in a plurality of tiers surrounding the vertical axis extending through said light source, said reflecting strips in each tier being located outwardly from said axis in relation to the strips in the tier next above with the top of each strip being spaced horizontally from the bottom of the strip next above, and said reflecting strips in each tier being inclined at an angle upwardly and inwardly toward said axis wherein the angle of inclination of the reflecting strips in each tier is greater than the angle of inclination of said strip in the next lower tier.

4. A lighting unit as defined in claim 3, including a bezel attached to the lower ends of said ribs, and a lens carried by said bezel.

5. A lighting unit as defined in claim 3, wherein said frame includes a top member attached to the upper ends of said ribs.

6. A lighting unit as defined in claim 5, wherein said top member consists of a flat plate.

References Cited UNITED STATES PATENTS 972,328 10/1910 Browne 240l03 1,030,910 7/1911 Myer 240-103 2,323,073 6/1943 Netting 240103 NORTON ANSHER, Primary Examiner.

R. P. GREINER, Assistant Examiner.

US. Cl. X.R. 24011.4

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