Dual lighting lens panel

Information

  • Patent Grant
  • 6402349
  • Patent Number
    6,402,349
  • Date Filed
    Monday, July 30, 2001
    24 years ago
  • Date Issued
    Tuesday, June 11, 2002
    23 years ago
Abstract
A dual-surface lens for light fixtures and T-bar ceilings includes a first lens panel having a planar perimeter around a decorative or optical control area and a second lens panel having a planar perimeter resting on the planar perimeter of the first lens panel. In a preferred embodiment the first lens panel depends below the planar perimeter and the second lens panel extends above the planar perimeter at an angle of from 5° to 15°.
Description




BACKGROUND OF THE INVENTION




This invention applies to the field of light fixture lenses and more particularly to the square or rectangular lens panels used as diffusers on fluorescent light fixtures. Such lenses are often installed into recessed or surface-mounted fluorescent light fixtures, or are made to rest on the flanges of the T-bar grid openings that are illuminated from above.




DESCRIPTION OF THE PRIOR ART




Some prior art light fixture lenses are simply white opal translucent plastic sheets or prismatic light control patterns. All such prior art lenses have three short-comings.




First, all fluorescent lamps emit significant UV (ultraviolet radiation) that is harmful to humans, as well as damaging to photosensitive materials, such as textiles, documents and other organic materials. Most prior-art fluorescent lenses do not have enough thickness to stop such radiation.




Second, all fluorescent lamps emit significant IR (infrared radiation) that is uncomfortable to humans, as well as damaging to heat sensitive materials, such as paintings, painted wood, animal specimens and other organic materials that are subject to being dried out. Most prior-art fluorescent lenses do not have enough thickness to stop such radiation.




Third, prior-art lenses tend to accumulate internal dirt and dead insects that are attracted to the light and remain trapped in the fixture until they die and fall onto the inner surface of the lenses, making the fixtures look dirty and unsightly.




PURPOSE OF THE PRESENT INVENTION




The first purpose of the present invention is to provide a lighting lens capable of blocking UV radiation. The second purpose of the invention is to provide a lighting lens capable of blocking IR radiation. The third purpose of the invention is to provide a lens in which trapped debris particles and dead insects are not visible.




BRIEF DESCRIPTION OF THE INVENTION




The foregoing purposes are achieved by a dual-surface lens for light fixtures and T-bar ceilings in which a first lens panel has a planar perimeter around a central area of decorative or optical control and a second lens panel has a planar perimeter resting on the planar perimeter of the first lens panel. In a preferred embodiment the central area of the first lens panel is flush with or depending below the planar perimeter and the second lens panel is pyramidal and extending above the planar perimeter at an angle of 5° to 15°.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a cross-sectional elevation view of a prior-art lens, shown in a typical fluorescent light fixture with a flat, prismatic lens;





FIG. 2

is a cross-sectional elevation view of a prior-art lens, shown in a typical T-bar suspended ceiling, with a sculpted, decorative lens;





FIG. 3

is a cross-sectional elevation view of a prior-art lens, shown in a typical fluorescent light fixture with a flat, prismatic lens;





FIG. 4

is a cross-sectional elevation view of a prior-art lens, shown in a typical T-bar suspended ceiling, with a sculpted, decorative lens;





FIG. 5

is an enlarged cross-sectional elevation view of detail


5


of

FIG. 4

, showing a preferred embodiment of the invention; and





FIG. 6

is an enlarged cross-sectional elevation view of a second preferred embodiment of the invention











REFERENCE NUMERALS IN THE DRAWINGS





















1 prismatic lens




2 fluorescent fixture flange







3 fluorescent light fixture




4 insects







5 debris




6 fluorescent lamp







8 decorative embossed lens




9 T-bar flanges







10 T-bar




12 fluorescent lamp







15 dual-surface lens




16 first lens panel







17 first lens perimeter




18 light fixture flanges







19 optical control area




20 fluorescent lighting fixture







21 perimeter of second lens




22 raised pyramid area







23 pyramid peak




24 second lens panel







26 first lens panel




27 planar perimeter







29 T-bar flange




30 T-bars







32 bonding




35 fasteners















DETAILED DESCRIPTION OF THE DRAWINGS




In

FIG. 1

a prior art prismatic lens


1


is shown installed on flanges


2


of a fluorescent light fixture


3


. Insects


4


and debris particles


5


have found their way into the fixture are clearly visible on the lens, normally right under lamps


6


.




In

FIG. 2

a prior art decorative embossed lens


8


is shown installed on flanges


9


of suspended ceiling T-bars


10


under fluorescent lamps


12


. Insects


4


and debris particles


5


have found their way onto the lens, normally right under lamps


12


.




In

FIG. 3

a dual-surface lens


15


is shown having a first lens panel


16


having a planar perimeter


17


adapted to rest on a flanges


18


of a light fixture


20


, said planar perimeter enclosing an optical control area


19


. A second lens panel


24


has a planar perimeter


21


adapted to rest on the planar perimeter


17


of the first lens panel. Said second lens panel planar perimeter


21


encloses a raised pyramid area


22


with a central peak


23


and edges contiguous with the planar perimeter


21


. Pyramid area


22


may be comprised of any clear or translucent diffusing material common in the lighting industry. Insects


4


and debris particles


5


have found their way onto the lens, normally right under lamps


6


. However, the pyramid area, having angle “A” slope angles from 5° to 15° between the peak


23


and the perimeter


17


, causes insects


4


and debris particles


5


to migrate to the perimeter


17


. The migration is facilitated by the buzzing of dying insects and natural ballast and ceiling vibrations. The result is that the insects and debris end up out if sight.




In

FIG. 4

a dual-surface lens


25


is shown having a first lens panel


26


having a planar perimeter


27


adapted to rest on a flanges


29


of suspended ceiling T-bars


30


. The lenses are illuminated by ceiling-mounted fluorescent lamps


12


. Planar perimeter


27


encloses an optical control area


26


having depending decorative patterns


29


. A second lens panel


24


is identical to panel


24


of

FIG. 3

, having a planar perimeter


21


adapted to rest on the planar perimeter


27


of the first lens panel


26


. Second lens planar perimeter


21


encloses a raised pyramid area


22


with a central peak


23


and edges contiguous with the planar perimeter


27


of first lens


26


. The pyramid area


22


may be comprised of any clear or translucent diffusing material common in the lighting industry. Insects


4


and dirt particles


5


may find their way onto the lens, normally right under a lamp


12


. However, the pyramid area


22


, having angle “A” slope angles from 5° to 15° between the peak


22


and the perimeter


21


, causes insects


4


and dirt particles


5


to migrate to the perimeter


21


. The migration is facilitated by the buzzing of dying insects and natural ballast and ceiling vibrations. The result is that the insects and debris do not remain under the lamps, but end up out if sight on the perimeter


21


of the second lens


24


.




In

FIG. 5

a dual-surface lens


25


is shown having a first lens panel


26


attached to second lens panel


24


with bonding


32


selected from the group including solvent adhesive bonding, thermal bonding, double-sided adhesive tape. This forms a rigid hollow structure that prevents the lens from bending or warping in service.




In

FIG. 6

dual-surface lens


25


is shown having a first lens panel


26


attached to second lens panel


24


with fasteners


35


selected from the group including integral snap fasteners and hook-and-loop fasteners.




Lens material thicknesses of lenses


16


and


26


are usually insufficient to stop al UV and IR from lamps, but they are economical to form in complex patterns. However, the simple shape of the pyramidal second lens panel may be made of thicker material to better absorb UV and IR.




SUMMARY, RAMIFICATIONS AND SCOPE




The purposes of the present invention are achieved and in practice provides a practical and inexpensive method for a flat, rigid lens capable of filtering UV and IR out of the transmitted light and causing Insects and debris particles to migrate to the perimeter of a lighting and end up out if sight. I will be obvious to anyone skilled in the art to employ other shapes and angles that will perform the same functions within the scope and spirit of the present invention.



Claims
  • 1. A dual-surface lens (15, 25) for light fixtures and T-bar ceilings including:a first lens panel (16, 26) having a planar perimeter (17, 27) adapted to rest on a light fixture flange (18) or T-bar ceiling flange (29), said planar perimeter enclosing a decorative or optical control area (16, 29); and a second lens panel (24 ) having a planar perimeter (21) adapted to rest on the planar perimeter (17, 27) of the first lens panel, said second lens panel planar perimeter enclosing a raised pyramid area (22) with a central peak (23) and edges contiguous with the planar perimeter (21), said pyramid area comprising clear or translucent diffusing material.
  • 2. A dual-surface lens for light fixtures and T-bar ceilings according to claim 1 in which the second lens panel pyramid has sides (22) extending from the perimeter flange (21) to the peak (23) at an angle from 5° to 15°.
  • 3. A dual-surface lens for light fixtures and T-bar ceilings according to claim 1 in which the first lens panel (16) optical or control area (19) is selected from the group including clear or translucent prismatic or irregular patterns.
  • 4. A dual-surface lens for light fixtures and T-bar ceilings according to claim 1 in which the first (16, 26) and second (24) lens panels are joined together with fasteners (32, 35) selected from the group including solvent adhesive bonding, thermal bonding, double-sided adhesive tape, integral snap fasteners and hook-and-loop fasteners.
  • 5. A dual-surface lens for light fixtures and T-bar ceilings according to claim 1 in which the second lens panel (24) pyramid area (22) is generally polygonal.
US Referenced Citations (4)
Number Name Date Kind
3117729 Silvers et al. Jan 1964 A
5025349 Gow Jun 1991 A
5791764 Jaksich Aug 1998 A
5863114 Nagatani et al. Jan 1999 A