Lighting fixture with rotatable glareshield

A lighting fixture is provided which includes a rotatable lamp and reflector system which can be adjusted to direct its maximum candlepower at a desired vertical angle. The lighting fixture also includes a rotatable glareshield which can be adjusted to vary the height of the top of the shield to change the degree of shielding provided. The glareshield and the housing of the lighting fixture form an interchangeable unit which can be installed after wiring. The glareshield may be adapted to provide diffused or patterned backlighting. A removable supplementary baffle may be employed to prevent glare or reflected light from being viewed by a person beneath the lighting fixture, or to prevent undesired backlighting beneath the lighting fixture.

BACKGROUND OF THE INVENTION 
The present invention relates to a lighting fixture. More particularly, it 
relates to a lighting fixture which can be adjusted to direct the maximum 
candlepower of the lamp and reflector system of the lighting fixture at a 
desired vertical angle, and which includes a rotatable glareshield which 
can be adjusted to prevent glare from the lamp and reflector system of the 
lighting fixture from being viewed by persons present in the space 
illuminated by the lighting fixture. 
A ceiling washer is a lighting fixture which is designed to uniformly 
illuminate the ceiling of a particular space by projecting light across 
the ceiling. The light is typically generated by a lamp, the output of 
which is intensified and directed by a system of reflectors. Several 
different designs have been employed to prevent glare from the lamp and 
reflector system from causing discomfort to those occupying the space lit 
by the ceiling washer. One such design involves concealing the lamp and 
reflector system in a buildin element, such as a cove located below the 
edges of the ceiling. Another approach has been to conceal the lamp and 
reflector system in a box which is mounted on a wall and provided with an 
open top. Yet another approach has been to provide a visor which protrudes 
from the bottom of the frame of the lamp and reflector system to shield 
the glare of the lamp and reflector system from the eyes of those 
occupying the illuminated space. 
The degree of shielding necessary to prevent glare from being seen by those 
occupying the space depends on the geometry of the space illuminated by 
the lighting fixture and the height at which the lighting fixture is 
positioned. For example, where a lighting fixture is mounted in a room 
with a low ceiling, and therefore must be mounted at a low height, the 
sightline of persons occupying the room is such that the shielding 
provided must block the glare from the lamp and reflector system at a 
greater vertical angle than would be required in a room with a high 
ceiling where the fixture can be mounted at a greater height. 
Likewise, the degree of shielding necessary depends on the size of the room 
to be illuminated, since the height at which glare is visible above the 
shield decreases as the horizontal distance between the viewer and the 
lighting fixture increases, assuming that at least some portion of the 
lamp and reflector system capable of creating glare is higher than the top 
of the shield. 
Greater shielding is of course achieved by increasing the height of the 
shield; however, the greater the height of the shield is, the less 
effective the lighting fixture is as a ceiling washer. This is because a 
ceiling washer illuminates the greatest area of ceiling most uniformly 
when the maximum candlepower of the lamp and reflector system is directed 
far out across the ceiling, i.e., when the angle at which maximum 
candlepower is directed, as measured from a vertical line drawn upward 
from the lighting fixture, is large. The optimum value of the angle varies 
depending on the area and shape of the ceiling to be illuminated and the 
vertical distance between the lighting fixture and the ceiling. When light 
is projected at such a large angle, a high shield may block some of the 
light which otherwise would shine on the ceiling. Therefore, the shield 
should be made only as high as is required to prevent visible glare. 
Nonetheless, in some cases, the height of the shield required in a 
particular space to shield a lamp and reflector system which is designed 
to project its maximum candlepower at the "optimum" angle for the same 
space may be such that the maximum candlepower of light projected by the 
lamp and reflector system is actually blocked by the shield. In such 
circumstances, greater efficiency would be achieved by projecting the 
maximum candlepower of the lamp and reflector system in a more vertical 
direction so that more of the projected light reaches the ceiling. 
In view of the foregoing, it would be desirable to be able to provide a 
lighting fixture which has an adjustable lamp and reflector system and an 
adjustable shield, both of which may be adjusted for use in various 
lighting arrangements to efficiently shield the glare created by the lamp 
and reflector system of the lighting fixture and to effectively light the 
surface desired. 
It would also be desirable to be able to provide a means for easily 
mounting and removing the adjustable shield such that the shield and 
associated housing for the lighting fixture can be installed after the 
lighting fixture has been wired in place, and such that the shield and 
housing may be changed at a later time. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide an improved 
lighting fixture which can be adjusted to direct the maximum candlepower 
of the lamp and reflector system at a desired vertical angle and which 
includes a rotatable glareshield which can be adjusted to vary the height 
of the top of the shield to tailor the degree of shielding provided 
thereby to the requirements imposed by the geometry of the illuminated 
space and the position of the lighting fixture. 
It is another object of the present invention to provide an improved 
lighting fixture having an adjustable shield and associated housing which 
can be installed after the lighting fixture is wired in place and which 
can be removed and replaced at a later time to effect a change in the 
style of the lighting fixture. 
It is another object of the present invention to provide an improved 
lighting fixture which is capable of projecting light outward and upward 
across a ceiling or other surface and which is capable of projecting 
diffused light back toward the wall or other surface on which the lighting 
fixture is mounted. 
It is another object of the present invention to provide an improved 
lighting fixture which is capable of projecting light outward and upward 
across a ceiling or other surface and which is capable of projecting light 
into specific solid angles in space to illuminate areas of the wall or 
other surface on which the lighting fixture as mounted above or below the 
lighting fixture as desired. 
It is another object of the present invention to provide an improved 
lighting fixture having a removable means for preventing glare or 
reflected light from being viewed from beneath the lighting fixture and/or 
preventing glare or reflected light from being projected downward and 
backward toward the wall or other surface on which the lighting fixture is 
mounted. 
It is another object of the present invention to provide an improved 
lighting fixture which can be employed in any one of the following 
configurations: (1) mounted on a wall or workstation partition to 
illuminate a ceiling; (2) mounted on a wall or workstation partition to 
illuminate a floor; (3) mounted on a wall or a workstation partition to 
illuminate a desk; or (4) mounted on a ceiling to illuminate a wall. 
These and other objects of the present invention are accomplished by a 
lighting fixture which comprises a lamp and reflector system and a 
partially cylindrical shield pivotally supported in a removable enclosure. 
The lamp and reflector system is pivotally supported and can be rotated to 
vary the direction of the projected beam of light. The shield can be 
rotated to expose a portion of the surface of the shield to the beam of 
light projected by the lamp and reflector system to shield a desired 
portion of the beam of light. The shield may also be used to reflect light 
onto the surface on which the lighting fixture is mounted, and a 
supplementary baffle is provided to prevent light from emitting beneath 
and between the lamp and reflector system and the shield.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIG. 1A, lighting fixture 100 in accordance with the present 
invention is shown, comprising lamp and reflector system 102, glareshield 
104, supporting structure 106, and mounting means 108 for mounting 
lighting fixture 100 to a surface. Lamp and reflector system 102 is 
enclosed by reflector frame 112 and glass door 114. Light is generated and 
focused by lamp and reflector system 102 and is projected through glass 
pane 116 of glass door 114. Glass pane 116 is held in place with respect 
to reflector frame 112 by door frame 118. 
Conventional designs for lamp and reflector system 102 which are in 
accordance with the principles of the present invention may be employed. 
Alternatively, a lamp and reflector system may be used of the type 
described in U.S. Pat. No. 3,679,893, issued on July 25, 1972 to Sylvan R. 
Shemitz and Benjamin L. Stahlheber, the disclosure of which is 
incorporated herein by reference. Reference is made to the disclosure of 
that patent for purposes of illustration only, and is not to be considered 
a limitation on the scope of the present invention. For example, the lamp 
employed in a lighting fixture designed in accordance with the present 
invention may be of various types, which may include incandescent lamps, 
tungsten halogen lamps, metal halide lamps, high pressure sodium lamps and 
fluorescent lamps. 
Referring to FIGS. 1A-1C, supporting structure 106 comprises two side 
plates 120, two decorative end plates 122 and yoke 124. Side plates 120 
are preferably made of steel or other material of suitable strength and 
extend along both sides of lighting fixture 100 to provide support for 
glareshield 104. Each side plate 120 has an L-shaped flange 126 which 
extends inwardly and rearwardly from the rear edge of the side plate. Each 
flange 126 has slots 140 and 142 for removably attaching the side plate to 
mounting means 108 by bolts 128 and 130. A decorative end plate 122 may be 
attached by screws or other conventional means to the outer surface of 
each side plate 120 to cover the plate and may be made of any material, 
and in any shape and color as desired by the designer. 
Yoke 124 comprises rear portion 132, flange 133 (not shown in FIG. 1A) and 
two side portions 134. Rear portion 132 of yoke 124 extends substantially 
across the rear of lighting fixture 100 and is adapted to be attached to 
mounting means 108. Flange 133 extends forwardly from the bottom of rear 
portion 132 beneath lamp and reflector system 102. Side portions 134 of 
yoke 124 extend forwardly along the sides of, and provide support for, 
lamp and reflector system 102. Lamp and reflector system 102 is pivotally 
attached at each end to a side portion 134 of yoke 124 by bolt 135. The 
pivot points provided by bolts 135 permit the direction of the light 
projected through glass pane 116 to be adjusted upward or downward, 
depending on the desired angle at which the maximum candlepower of the 
system is to be directed. These pivot points preferably coincide with the 
center of the lamp in lamp and reflector system 102. The range of rotation 
of lamp and reflector system 102, shown in FIG. 1B by arrow 117 and 
shadowed lamp and reflector system 103, may vary in accordance with the 
choice of the designer. 
Glareshield 104 is an open semi-cylindrical shell with enclosed ends. 
Preferably, the shell of glareshield 104 covers approximately 195 degrees 
of arc, and is pivotally mounted at each end to a side plate 120 by a bolt 
136 such that the outer convex surface of glareshield 104 is directed 
substantially away from lamp and reflector system 102. The pivot points 
provided by bolts 136 permit glareshield 104 to be rotated such that the 
front edge 138 of glareshield 104 may be adjusted upward or downward to 
shield a desired portion of the light projected through glass pane 116, to 
thereby prevent glare from glass pane 116 from being visible to a person 
occupying the space illuminated by lighting fixture 100, as is shown more 
clearly by FIGS. 2A and 2B. The range of rotation of glareshield 104, 
shown in FIG. 1B by arrow 119 and shadowed glareshield 105, like that of 
lamp and reflector system 102, may vary in accordance with tee choice of 
the designer. 
Mounting means 108 comprises bracket 144 and mounting plate 146. Bracket 
144 and mounting plate 146 are made of steel or other material of suitable 
strength. Bracket 144 has a rear portion 147 which abuts the surface on 
which lighting fixture 100 is to be mounted and is adapted to be fixedly 
attached to the mounting surface. The means of attachment may be any 
conventional means which is capable of holding bracket 144 against the 
surface when bracket 144 is loaded with the weight of lighting fixture 
100. Extending forwardly at a right angle from each side of rear portion 
147 is a side element 148 having threaded holes 150 and 152 for receiving 
bolts 128 and 130. Extending forwardly at a right angle from the bottom of 
rear portion 147 is lower lip 154. Lower lip 154 is substantially L-shaped 
and extends across the length of rear portion 147. Extending forwardly and 
downwardly from the top of rear portion 147 is upper lip 156, which 
extends across the length of rear portion 147. 
Mounting plate 146 has a front portion 15B which is adapted to be attached 
to rear portion 132 of yoke 124. Extending rearwardly at a right angle 
from the bottom of front portion 158 is lower member 160, which extends 
across the bottom of front portion 158. Lower member 160 is substantially 
U-shaped, and is designed to fit into the recess formed by lower lip 154 
of bracket 144, as shown in FIG. 1B. Extending rearwardly and upwardly 
from the top of front portion 158 is upper member 162, which rests flush 
against the top of upper lip 156 when lower member 160 is inserted into 
lower lip 154 and the top of mounting plate 146 is pressed against bracket 
144, as shown in FIG. 1B. Mounting plate 146 may have side portions which 
replace or fit inside of side elements 148 of bracket 144, and in which 
threaded holes are provided for receiving bolts 128 and 130. 
Mounting plate 146 is attached to yoke 124, which pivotally supports lamp 
and reflector system 102. Glareshield 104, side plates 120 and decorative 
end plates 122 form an independent and interchangeable cover unit for lamp 
and reflector system 102. During installation of lighting fixture 100, 
bracket 144 is first attached to the surface on which lighting fixture 100 
is to be mounted. The assembly of lamp and reflector system 102, yoke 124 
and mounting plate 146 is then mounted on bracket 144 by inserting lower 
member 160 into lower lip 154. The resulting interlock of lower member 160 
and lower lip 154 provides a hinge which facilitates the installation of 
lighting fixture 100 by allowing lamp and reflector system 102 to hang 
from bracket 144 while being wired by an electrician. 
Once wiring is complete, the top of mounting plate 146 is pressed against 
bracket 144 such that upper member 162 rests on top of upper lip 156. 
Mounting plate 146 and bracket 144 may then be fastened together by any 
conventional means, such as by screws or bolts. 
The interchangeable cover unit comprising glareshield 104, side plates 120 
and decorative end plates 122 is installed by positioning the unit such 
that the ends of slots 140 and 142 are aligned with the shafts of bolts 
128 and 130. The unit is then pressed against bracket 144 such that the 
shafts of bolts 128 and 130 slide along the lateral legs of slots 140 and 
142 and come to rest in the vertical legs of slots 140 and 142. Bolts 128 
and 130 are then tightened against flanges 126 to hold the cover unit in 
place. Bushings 170 and 172 may be employed to fill any gap between 
flanges 126 and bracket 144 to prevent distortion when bolts 128 and 130 
are tightened. The offset between the outer surfaces of decorative end 
plates 122 and bracket 144 conceals bolts 128 and 130 from normal viewing 
angles. Bolts 128 nnd 130 may be replaced by conventional threaded studs 
adapted to receive nuts for holding the cover unit in place. 
The interchangeable cover unit may be installed at any time. This makes the 
inventory of the manufacturer more flexible, and allows the 
interchangeable cover unit to be shipped and installed after the lamp and 
reflector system has been wired in place. It therefore reduces the 
manufacturer's inventory and shipping time, and can prevent jobsite damage 
to the unit caused by painters, movers, etc. It also permits a change in 
the style of the lighting fixture to be effected at a later time by simple 
replacement of the cover unit, without requiring that a new fixture be 
wired. 
FIG. 2A is a side view of lighting fixture 100 with lamp and reflector 
system 102 and glareshield 104 adjusted as shown in FIG. 1A. In this 
posture, lighting fixture 100 is best suited for use in circumstances 
where only a limited degree of shielding is necessary, e.g., where 
lighting fixture 100 is mounted high on the wall in a small room. Lamp and 
reflector system 102 is rotated downward and away from wall 202 to project 
its maximum candlepower, as shown by vector 204, far out across ceiling 
206. 
Since lighting fixture 100 shown in FIG. 2A is presumed to be mounted high 
on a wall in a room of short depth, the front edge 138 of glareshield 104 
need not be positioned very high to prevent persons occupying the room 
from viewing glare from glass pane 116 of lamp and reflector system 102. 
The angle subtended by glare zone 208, which represents the area in which 
glare from glass pane 116 can be viewed, is narrowed only as much as 
necessary by rotating the front edge 138 of glareshield 104 to a low 
position as shown in FIG. 2A to keep glare zone 208 from intersecting the 
line of sight of persons occupying the room (represented in FIG. 2A by 
vector 209). In this manner, the maximum candlepower of lamp and reflector 
system 102 is permitted to shine without impedance far out onto ceiling 
206 to wash ceiling 206 most efficiently and uniformly, and at the same 
time glare from lamp and reflector system 102 is shielded. 
In less favorable circumstances which require a greater degree of 
shielding, e.g., where lighting fixture 100 is mounted low on a wall in a 
large room, the positions of lamp and reflector system 102 and glareshield 
104 are adjusted as shown in FIG. 2B. Glareshield 104 is rotated to raise 
front edge 138 to the height necessary to prevent glare zone 213 from 
intersecting the line of sight of persons occupying the room illuminated 
by lighting fixture 100 (represented in FIG. 2B by vector 211). To 
minimize the amount of light which is lost by virtue of the raising of 
front edge 138 of glareshield 104, lamp and reflector system 102 is 
rotated backward toward wall 202 about the pivot points provided by bolts 
135. In this manner, the maximum candlepower of lamp and reflector system 
102 (represented in FIG. 2B by vector 212), is able to be projected 
unimpeded toward ceiling 206, and at the same time the glare from lamp and 
reflector system 102 is shielded. 
The inner surfaces of lighting fixture 100 are preferably painted black to 
reduce reflection. Alternatively, backlighting of the surface on which 
lighting fixture 100 is mounted can be accomplished by painting the inner 
concave surface of the cylindrical shell of glareshield 104 with a matte 
white or other light color finish. When glareshield 104 is rotated to the 
position shown in FIG. 2B, and lamp and reflector system 102 is rotated 
slightly downward from the position shown in FIG. 2B, the inner concave 
surface of glareshield 104 is illuminated by spill light from lamp and 
projector system 102 of less intensity than the maximum candlepower of the 
projected light. Preferably, the intensity of the spill light illuminating 
glareshield 104 is 60 percent or less of that of the maximum candlepower. 
This illumination is reflected by the white finish 10 of the inner concave 
surface of glareshield 104, causing the inside of glareshield 104 to 
become bright white, and making glareshield 104 a secondary light source 
which delivers diffused light back to the surface on which lighting 
fixture 100 is mounted, both above and below lighting fixture 100. 
If it is desired that the backlight be of a controlled distribution, rather 
than of the diffused distribution obtained by painting the inner concave 
surface of glareshield 104 matte white or another light color, reflective 
plate 302 may be provided as shown in FIG. 3 across open back aperture 303 
of glareshield 104 to cause spill light 304 from lamp and reflector system 
102 to be reflected in a desired pattern toward the surface on which 
lighting fixture 100 is mounted. Reflective plate 302 may be flat, concave 
or convex, and may be formed with smooth curves or flat facets to reflect 
spill light 304 into specific solid angles in space, depending on the 
choice of the designer. In this manner, the surface on which lighting 
fixture 100 is mounted may be illuminated with backlight above and/or 
below lighting fixture 100 as desired. 
An additional feature of the present invention is shown by removable 
supplementary baffle 402 in FIG. 4. Baffle 402 is a strip of opaque 
material, preferably painted black to reduce reflection, which extends 
substantially across the width of lighting fixture 100 between lamp and 
reflector system 102 and glareshield 104. Baffle 402 is supported by 
flange 133, to which it is removably attached by spring clips 406, 
although other conventional means of removably mounting baffle 402 to 
flange 133 may be employed. 
Baffle 402 prevents a person from seeing the glare or reflected light from 
lamp and reflector system 102 from a viewing position below lighting 
fixture 100. It is preferably installed when, as shown in FIG. 4, lamp and 
reflector system 102 is rotated downward away from the surface on which 
lighting fixture 100 is mounted and glareshield 104 is rotated to a 
relatively low position. Baffle 402 may also be employed to absorb or 
shield glare or light that might reflect off the outer convex surface of 
glareshield 104 and would otherwise be projected downward and backward 
toward the surface on which lighting fixture 100 is mounted. 
While preferred embodiments of the invention have been set forth for 
purposes of the disclosure, modification of the disclosed embodiments may 
occur to those skilled in the art. For example, while the lighting fixture 
of the present invention has been disclosed as a ceiling washer, the 
lighting fixture, as a whole assembly, can be used as other than the 
ceiling washer heretofore described. The lighting fixture of the present 
invention can be inverted and mounted on a wall or workstation partition 
to illuminate a floor, or mounted on a wall or a workstation partition to 
light a desk. The lighting fixture may also be mounted on a ceiling to 
wash a wall with light. 
Thus, a lighting fixture which includes a rotatable lamp and reflector 
system which can be adjusted to vary the angle at which its maximum 
candlepower is projected, and which includes a rotatable glareshield which 
can be adjusted to prevent glare from the lamp and reflector system of the 
lighting fixture from being viewed by persons occupying the space 
illuminated by the lighting fixture, has been disclosed. The lighting 
fixture of the present invention can readily be employed to illuminate a 
ceiling, wall, floor or desk, and may further include means for providing 
and controlling backlighting of the surface on which the lighting fixture 
is mounted. One skilled in the art will appreciate that the present 
invention can ee practiced by other than the described embodiments, and 
the present invention is limited only by the claims which follow