Patent Application
20050146867
The present invention relates indoor lighting with controlled uplight capability.
In order to make a large area visually comfortable, downlight fixtures often include some uptight capabilities, to reduce the “cave” effect caused by ceiling fixtures being too intense for the viewer to see the ceiling beyond the fixtures. The cave effect causes a glare-filled, enclosed effect, which increases eyestrain.
However, too much uplighting is inefficient and wasteful, not reflecting a large portion of emitted light back to the space below the fixture.
To provide uptight, it is known to have an open top, which wastes light usage, as much of the light is not reflected back to the space below the fixture. In addition, in general, however, lamp fixtures with open tops have a susceptibility to dirt accumulation.
Among related patents include U.S. Pat. No. 2,281,377 of Ohm, which has a slanted transparent/translucent wall but no reflector, which does not control uplight to a preferable maximum of 5-19% (by bent and concave angles of the reflector). Ohm's wall 13 is convex, so most light is not controlled. If a fixture were made similar to that of Ohm '377, wherein it would be fabricated without the lens, the fluorescent lamps would extend beyond the plane of the side of the fixture, allowing for excessive dirt accumulation thereon. Furthermore, if one would make a fixture similar to that of Ohm '377 with a non-translucent wall, the fixture efficiency would be greatly diminished. In addition, the lack of a photometrically designed reflector would diminish the obtainable efficiency of the fixture.
U.S. Pat. No. 2,534,182 of Schwartz has different angles for reflectors 31, 32, 33 that don't control uplighting. Their rounded lenses are not as efficient as using a flat lens.
In U.S. Pat. No. 2,548,500 of Sachs, the position of the reflector 15 beneath the fluorescent lamp tubes causes 50% of light up and 50% down, not a preferable controlled 5-19% as uptight. Also, if one removes the item 15 of Sachs, one accumulates dirt within the fixture.
U.S. Pat. No. 6,428,183B1 of McAlpin gets 100 percent of light up with visual waste and needs extra upper lamps 32,33 with separate mounts. These upper lamps are exposed and subject to dirt accumulation.
U.S. Pat. No. 5,806,967 of Soorus is mainly a V-shaped uptight fixture open at top, so dirt will invariably accumulate therein.
U.S. Pat. No. 2,545,058 of Walsh has an open top with susceptibility to dirt accumulation. Walsh is mainly uptight only as in
U.S. Pat. No. 2,474,341 of Wince doesn't have a reflector.
U.S. Pat. No. 2,348,930 of Shepmoes has a V-shape end view configuration of lamp fixtures. Downward light is less than 70%.
U.S. Pat. No. 2,327,230 of Weber is only concerned with access removal of the lens portion 27. Lighting inefficiency is similar to Shepnoes.
U.S. Pat. No. 2,320,829 of Naysmith and U.S. Pat. No. 2,323,002 of Baker both describe V-shaped arrangement of lamps, which does not control uplight.
Therefore, there is a need to provide a fluorescent lamp fixture which controls uptight to a desirable level, without wasting excess light, while significantly reducing an undesirable cave effect and without the tendency to accumulate dirt within the fixture.
It is therefore an object of the present invention to provide a fluorescent lamp fixture which controls uptight to a desirable level, without wasting excess light, while significantly reduces an undesirable cave effect and without the tendency to accumulate dirt within the fixture.
In keeping with these objects and others, which may become apparent, the fixtures of this invention accommodate straight fluorescent tube lamps of a variety of lengths and electrical design, for example popular four foot sizes. These fixtures have a full upper housing protecting all lamps from the accumulation of dust and debris while providing a controlled amount (5 to 19%) of total light output to uplighting, thereby lighting ceiling and wall areas above the fixture, to negate the so-called “cave effect”. The percentage range of 5 to 19 percent of total uplighting is controlled relative to the quantity of lamps utilized, the angle of the reflector and the height of the outside section of the fixture, which also impacts the angle of the outboard reflector.
The fixtures of this invention have a central section (from an end view) aimed directly below the fixture with lamp or lamps within a concave reflector or reflectors. Wing sections at an oblique angle extend sideways from the central section, carrying their own lamps and reflectors with totally or largely open distal ends, thereby accommodating uplighting in a controlled fashion. The uplighting provided is at an oblique angle from the fixture, as contrasted from prior-art fixtures with dedicated uptight lamps, or direct vertical upward lenses or windows, which would reflect uptight directly down from the ceiling surface.
These lighting fixtures preferably incorporate a trapezoidal pendant bracket, which accurately positions the fixture with respect to the pendant pipe and prevents any tendency of the fixture from deviating from orthogonal orientation. However, the pendant bracket of the present invention is usable on any type of suspended light fixture, to stabilize the fixture in place.
In one embodiment the fixture has no lens and the oblique housing sides are shortened to accommodate uplighting. In a second embodiment, a high efficiency lens is used for downlighting. Then the oblique housing sides are fitted with windows also, which are glazed with flat high efficiency lens panels to accommodate uplighting. Each of these embodiments can accommodate a variety of lamp configurations ranging from three to eight fluorescent lamps per fixture.
The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which:
Pendant pipe 11 is used to attach fixture 1 to a ceiling structure; it also carries wiring within. It is mounted in hub 8 and is located accurately by trapezoidal pendant bracket 10 and secured by pendant screw 12. However, pendant bracket 10 is usable on any type of suspended light fixture, to stabilize the fixture in place.
In a second embodiment, fixture 20 of
A variety of lamp configurations for the fixtures of this invention are shown in the end views of
For example,
For example,
Besides the differences in the configuration of reflector 42 and in the variations in angle X shown in
In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention.
It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims.
