Configurable furniture integrated ambient lighting system and method

A configurable furniture integrated lighting system has a plurality of interchangeable symmetric and asymmetric fixture heads for indirect lighting and a plurality of different supporting structures for supporting any one of the fixture heads at a predetermined mounting height from a variety of different support surfaces associated with the furniture system, including floor level support surfaces, desk top surfaces, book shelf surfaces, and binder bins. The described invention can be mounted virtually anywhere along the partition walls of almost any open office arrangement, with different alignments with respect to the walls being possible. Free-standing fixtures can additionally be placed as required to achieve an optimum ambient lighting distribution.

BACKGROUND OF THE INVENTION 
The present invention generally relates to office lighting; it particularly 
relates to providing and positioning sources of ambient lighting in an 
open office having office systems furniture. 
Modular systems furniture are widely used to create open office 
arrangements that are both flexible and efficient. A modular office system 
will typically include partition walls for creating suitably private 
office spaces or other work areas. However, much more than a desk 
surrounded by partitions, a modern office furniture system provides a 
coordinated set of elements that can be aesthetically integrated into an 
appropriate layout of offices and connecting spaces which can include, at 
the option of the designer, a variety a working surfaces, counter tops, 
book selves, storage cabinets, binders bins, and the like. As business 
needs change, the open office normally can be added to or reconfigured at 
a relatively modest cost. 
However, the very flexibility in placing and configuring modular office 
systems furniture leads to problems in terms of the quality of the open 
office's ambient lighting environment. Conventional sources of ambient 
lighting are relatively inflexible in terms of their placement. Thus, a 
layout of modular offices and connecting areas optimized to meet 
particular business needs may produce a poor lighting environment, that 
is, an environment where the ambient lighting (as opposed to specific task 
lighting) is not well distributed in relation to the work spaces of the 
open office. For example, ambient light might be produced in a typical 
office by direct lighting fixtures, such as conventional 2 foot by 4 foot 
recessed parabolic troffers evenly distributed about an overhead ceiling 
surface. Modular offices placed between fixtures would likely be poorly 
lit as compared to modular office placed directly underneath a lighting 
fixture. Where the office ambient lighting is provided by indirect 
lighting fixtures, the situation is improved since indirect light tends to 
be more evenly distributed. Nonetheless, the quality of the lighting 
environment in the modular office will still depend to a large degree on 
the placement of the systems furniture in relation to the normally fixed 
placement of the sources of indirect lighting. 
While moveable indirect lighting fixtures have been devised for use in open 
offices, such fixtures are very limited as to where they can be placed. 
Such existing moveable fixtures include floor standing indirect HID and 
fluorescent fixtures and indirect HID and fluorescent fixtures designed to 
simply rest on top of a furniture system's binder bin. 
The above-mentioned deficiencies of conventional sources of ambient 
lighting in the open office environment can have a great impact on the 
quality of the work environment and employee efficiency. An adequate and 
even distribution of ambient lighting which does not produce glare plays 
an important role in preventing employee fatigue, eye strain, and other 
health problems related to poor lighting. The present invention overcomes 
these problems by making it possible to provide an open office with 
optimally distributed ambient lighting from indirect lighting sources. 
Specifically, the present invention provides a furniture integrated 
ambient lighting system that is fully configurable within the modular 
office furniture system for which it is designed. Using the furniture 
integrated ambient lighting system of the invention, sources of indirect 
light can be easily and interchangeably placed in a wide variety of 
locations on or about the modular office furniture system for providing an 
ambient light distribution that is specifically tailored to a particular 
modular office layout. The result is the efficient illumination of all 
work areas and other areas such as connecting walkways, meeting areas and 
the like. Moreover, the below described invention permits the ambient 
lighting of an open office to be easily changed with changes in the office 
configuration. 
Thus, the ambient lighting system of the invention overcomes the present 
inflexibility of the above-described conventional direct and indirect 
lighting systems; it also provides a system that can be fully integrated 
into the furniture system and made to aesthetically compliment the 
system's structural elements. Furthermore, the elements of the lighting 
system are portable, and not architectural fixtures. Thus, ownership of 
the fixtures may be with the tenant who can move them from location to 
location and depreciate them over a shorter depreciation period. 
SUMMARY OF THE INVENTION 
Briefly, the furniture integrated ambient lighting system of the invention 
provides for a plurality of fixture heads for indirect lighting which are 
detachably mountable to and fully interchangeable with a plurality of 
different mounting structures for mounting the fixture heads from 
different support surfaces associated with a modular office furniture 
system. The mounting structures provide variously for mounting the 
detachable fixture heads from a low floor level surface, from an 
intermediate level surface such as a desk top or counter top, or from an 
elevated surface, such as the top of a binder bin, all using 
interchangeable parts which permit the fixture heads to be easily 
installed at a predetermined mounting height near or above eye level. 
While it is contemplated, indeed preferred, that all fixture heads will be 
in the same mounting plane, it is understood that, within a given open 
office plan, the mounting structures could, if desired, provide the 
flexibility of mounting the fixture heads at varied mounting heights. 
The interchangeable mounting structures of the invention include an upright 
stem element for providing the desired elevation for the fixture head, and 
a yoke which laterally extend from the stem to detachably support a 
selected one of the interchangeable fixture heads. The mounting structures 
additionally include stem support means for holding the stem element in an 
upright position from a variety of support surfaces and structures 
associated with a modular office furniture system. Examples of the stem 
support means include flat support bases of suitable dimensions for 
supporting fixture heads from a floor level surface or, at the other 
extreme, from the top of a high binder bin. Another example includes 
clamping structures for clamping the stem to the edge of a desk top or 
elevated counter top. Yet another stem support means might include cleats 
on the stem for hanging the stem element to slotted joiner strips 
connecting adjacent wall partition panels. The wide variety of support 
structures will permit the fixture heads to be located virtually anywhere 
within an arrangement of systems furniture to achieve an optimum ambient 
lighting environment. 
The stem of the mounting structure will preferably have a uniform 
cross-section and will be an extruded part cut to a desired length which 
provides a desired elevation. Attachment means, such as threaded ends of 
an extruded hole, are provided in the top and the bottom of the extruded 
stem such that the support yoke for the fixture head can removably be 
attached to one end of the stem, and the stem support attached to the 
other. Separate attachments, such as screw attachments, are provided in 
the yoke for detachably mounting the fixture head to the yoke. Thus, the 
fixture head and the parts of the mounting structure for the fixture head 
can be easily shipped and stored in a disassembled state. Also, the 
extruded stem can be conveniently cut to length at the factory, or even at 
the installation site, to meet varied requirements of a particular modular 
office installation. It is also a feature of the preferred embodiment of 
the invention that the yoke and stem of the mounting structure include 
wire chases to permit out of sight wiring of the fixture head. 
In a further aspect of the invention, the interchangeable fixture heads are 
provided in both a symmetric and asymmetric version. Specifically, each 
fixture head will have a characteristic geometric shape and will include a 
bottom support surface shaped to substantially match the characteristic 
shape of the yoke: when the fixture head is mounted to the yoke it is 
mounted to the yoke along and in a mating relationship with its bottom 
support surface. In the symmetric version of the fixture head, the head 
extends symmetrically about its bottom support surface and thus will lie 
symmetrically about the yoke. In the asymmetric version, the fixture head 
extends asymmetrically about its bottom support surface such that its 
relation to the yoke is asymmetric. This will permit different placement 
opportunities for the fixture heads such as placing symmetric heads in 
unbounded spaces while placing asymmetric heads next to vertical wall 
surfaces. 
It is a further feature of the invention that the yoke can be made to 
extend laterally outward and in asymmetric relation to the upright stem of 
the mounting structure such that the mounting structure can be reversed by 
180 degrees to obtain a different alignment of fixtures. For example, one 
or more symmetric fixture heads can be centered over a wall partition of a 
furniture system such that the fixtures straddle two work areas, or by 
reversing the direction of the yoke, the fixtures can for reasons of 
aesthetic design be aligned in off-set relation to the wall partitions 
such that the fixture heads are located within the perimeter of a defined 
office or connecting area. It will be seen that the unique mounting 
structures of the invention provide for maximum flexibility in locating 
the fixture heads in and about the modular office furniture system for not 
only achieving desired ambient light distributions but also for realizing 
aesthetic goals. 
Another aspect of the invention is that the housing of the fixture head can 
be fabricated in two sections which are joined together with a reveal 
along the joined edges of the housing sections. The sectional construction 
of the housing permits the housing parts to be fabricated from thinner 
walled extrusions and also importantly permits the symmetric and 
asymmetric versions of the fixture head to be readily assembled by simply 
selecting and joining, as required, two identical halves or two 
non-identical halves of the housing. The necessary inventory of parts for 
constructing symmetric and asymmetric fixture heads will thereby be 
greatly reduced since only two standard parts will need to be stocked for 
producing either version of the fixture head. 
Therefore, it can be seen that it is a primary object of the invention to 
provide a configurable furniture integrated ambient lighting system which 
can be used to optimize the distribution of ambient lighting in an open 
office environment by providing sources of indirect lighting that are 
readily located at a wide variety of positions in or about modular office 
systems furniture. In accordance with the invention, the quality of 
indirect ambient lighting in the open office can be greatly improved. This 
will include the ability to improve brightness uniformity on overhead 
ceiling surfaces thereby reducing glare producing contrast brightness. 
Other objects of the invention will be apparent from the following 
specification and claims.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
Referring now to the drawings, FIGS. 1 and 2 show the basic ambient 
lighting system of the invention mounted to different height surfaces 
associated with a modular office furniture system. A plurality of fixture 
heads 11A, 11B, 11C, 11D, 11E for indirect lighting are supported by a 
plurality of mounting structures 13A, 13B, 13C, 13D, 13E, each of which 
includes a yoke 15A, 15B, 15C, 15D, 15E, an upright stem 17A, 17B, 17C, 
17D, 17E, and a stem support means, the structure of which depends on the 
nature of the surface from which the fixture head is supported. As shown 
in FIG. 2, by providing suitable length stems 17 all fixture heads are 
preferably supported at the same mounting height. Generally speaking, the 
mounting heights of the fixture heads can be said to define an ambient 
lighting mounting plane as denoted in FIG. 2 by the letter "A". 
FIGS. 1 and 2A more specifically illustrate a fixture head 11A supported 
from a floor level surface on a full height stem 17A by a stem support 
means consisting of a relatively large flat support stand 19; in FIGS. 2B 
and 2C the fixture heads 11B and 11C are supported next to partition walls 
21 and 23 on intermediate height stems 17B and 17C from first intermediate 
height desk top surfaces 25 and 27 by means of clamping structures 29 and 
31 that clamp to the edge of the desk tops; FIG. 2D shows a fixture head 
11D supported next to a partition wall 33 from a second intermediate 
height bookshelf surface 35 on a second intermediate height stem 17D by 
means of a flat base 37 and partition retaining hook 38; and in FIG. 2E 
the fixture head 11E which has a flat stand 39 is freestanding on a short 
stem 17E on the high support surface 41 of a binder bin 43. It is 
understood that the interchangeable fixture heads 11 could be supported 
from other types of surfaces associated with office systems furniture in a 
manner not specifically illustrated in the drawings. For example, the stem 
17 of the mounting structure could be provided with a vertical row of 
mounting cleats adapted to be inserted in corresponding slots in vertical 
joiner strips connecting adjacent wall partition panels. Other stem 
support means could be devised to fit particular mounting criteria. 
It is further understood that while in FIG. 2 the fixture heads are 
illustrated as being mounted at the same mounting height, it is possible 
within the scope of the invention to mount the fixture heads at different 
mounting heights. Generally speaking, the mounting height of each fixture 
head will be at least at eye level and preferably above eye level. The 
heights of the fixture heads, even if at varied heights, will generally 
define a horizontal ambient lighting mounting plane, such as mounting 
plane A in FIG. 2, within which the fixture heads can be positioned and 
repositioned for achieving an optimum ambient light distribution pattern. 
The interchangeable fixture heads 11 each have a generally pan-shaped 
opaque housing 45 of a characteristic rectangular geometry. A visible side 
lens 47 extends along the top of the housing side wall 51 to provide a low 
brightness element visible to employees within the open offices. The 
psychological benefits of providing a source of observable low brightness 
in an indirect lighting environment are described in U.S. Pat. No. 
4,390,930. The housing also includes a shaped channel portion 53 which 
protrudes from and longitudinally extends along the bottom of the housing 
to provide a bottom support surface 55 by which the fixture head is 
supported on the yoke 15 of on of plurality of the mounting structures. As 
can be seen, both the yoke and the bottom surface of the fixture head's 
channel portion have corresponding curved shapes such that they nest 
together when the fixture head engages the yoke. As hereinafter described, 
attachment means are provided for easily securing the fixture head to and 
releasing it from the yoke when a furniture integrated lighting system is 
assembled and disassembled. 
It is noted that two versions of the fixture heads 11 are illustrated in 
FIG. 2: an asymmetric version that is asymmetric about the channel portion 
53 of the housing as shown in FIGS. 2A, 2B, 2D, and 2E; and a symmetric 
version that is symmetric about the housing's bottom channel portion as 
shown in FIG. 2C. It is also noted that, in the illustrated embodiment, 
the yoke 15 is seen to laterally extend to the side of the stem 17 such 
that the center of the yoke is offset in relation to the stem axis. By 
providing a symmetric and asymmetric version of the fixture head and an 
offset yoke and stem configuration as described and shown, a wide variety 
of mounting configurations can be created within the plan of an office 
furniture system. 
Examples of such mounting configurations are illustrated in FIG. 3. 
Specifically, three different basic floor plans are separately shown in 
FIGS. 3A, 3B, and 3C for an open office arrangement formed by partition 
walls 61, 62, 63 and having, among other things, surrounding floor level 
surfaces 65, 66, 67, desk top surfaces 69, 70, 71 and book shelf height 
surfaces 74, 75. Possible configurations of fixture heads include 
placement of the fixture heads within the perimeter of the partition wall 
as is the case with fixture heads 77 and 78 in FIGS. 3A and 3B, or 
centering the fixture heads over the partition walls so that the fixture 
heads span adjacent work areas, such as illustrated in connection with 
fixture heads 81, 82, 83 in all three floor plans. Alignment of the 
fixture heads within the perimeter of the partition walls or on center 
with the walls can be achieved by simply reversing the stem and yoke 
assembly as illustrated in FIGS. 2B and 2C. 
As above described, by interchanging mounting structures and fixture heads, 
the fixture heads can be mounted to a variety of different height support 
surfaces adjacent the wall partitions. Thus, as can be seen in FIG. 3, the 
fixture heads can be mounted virtually anywhere along the length of any 
partition wall regardless of adjacent structure. This includes mounting a 
fixture head from an adjacent floor surface, an adjacent desk top surface, 
or from a high adjacent book shelf or binder bin surface. Whatever the 
case, the fixture heads can be distributed about the wall partitions to 
produce the best possible distribution of ambient lighting within the open 
office. 
Free-standing fixture heads can additionally be distributed about the 
furniture system as required using a mounting structure as shown in FIG. 
2A. Also, using the asymmetric version of the fixture head, such 
free-standing fixtures can be placed so that the mounting structure and 
fixture head are substantially flush against a vertical wall. 
FIGS. 4-8 show a fixture head and a selected mounting structure in greater 
detail. In FIG. 4 an asymmetric fixture head 85 is shown in connection 
with a mounting structure comprised of yoke 87, stem 89, and a base clamp 
structure 87 for mounting the fixture head to the edge of a desk top 89. 
FIG. 5 shows further detail of the yoke, and FIGS. 6 and 7 show further 
detail of the fixture head. 
As shown in FIG. 4, the fixture head housing 91, in this case an asymmetric 
housing, contains a light source in the form of two high intensity 
discharge lamps 93, suitably Biax lamps, plugged into two closely adjacent 
lamp sockets 95, 96 mounted near the short side 97 of the housing. The 
lamp sockets are physically attached to reflector 99 which extends over 
the bottom of the housing and which reflects source light up through the 
housing's top opening 101. The lamp ballast 103 is physically attached by 
suitable pan screws to the reverse side of the bottom reflector 99 so that 
the reflector, ballast, and lamp sockets form an easily installable 
subassembly. The ballast is seen to be positioned on this subassembly so 
that it extends down into the bottom cavity 105 formed by the housing 
bottom channel 107. 
The fixture head housing 91 further contains a secondary reflector 
structure 109 having a diffuse reflector surface 111, which in conjunction 
with the angled side reflector portion 11 of the bottom reflector provides 
an indirect light path between the lamps 93 and the visible side lens 
element 11 mounted to the top of the housing's side wall 117. The 
secondary reflector structure, which extends the full length of the 
housing and which shields the side lens element from receiving light 
directly from the light source, permits greater control over the level and 
uniformity brightness induced in the side lens by the light source. 
FIG. 8 of the drawing shows, in a top plan view, a symmetric version of the 
fixture head shown in FIG. 4. The fixture head in FIG. 8 is in most 
respects identical to the fixture head of FIG. 4 except for the symmetry 
of the fixture and the fact that the FIG. 8 fixture is a three lamp 
fixture instead of a two lamp fixture and that the lamps 127 are 
symmetrically mounted over the larger bottom reflector 121 rather than off 
center as shown in FIG. 4. FIG. 8 further shows lamp retention brackets 
123 mounted to the bottom reflector opposite the lamp sockets 125 for 
holding the free end of the U-shaped high discharge lamps 127. Similar 
retention brackets suitably placed would be used in connection with the 
FIG. 4 asymmetric embodiment. Also, due to the symmetry of the FIG. 8 
fixture head, the FIG. 8 fixture head, unlike the FIG. 4 fixture head, has 
two visible lens elements 129, 131, one mounted to either side of the 
fixture housing, and two secondary lens structures 133, 135 extending the 
length of the fixture housing to ensure that both lens elements receive 
indirect source light only. 
Referring again to FIG. 4 and to FIG. 5 the yoke 87 of the mounting 
structure has a curved shape with opposed side walls 139, 140 and interior 
walls 140, 142, each of which has curved top edges which provide cradling 
surfaces 141 for the fixture head. The bottom surface 107 of the channel 
and the cradling surfaces of the yoke should have the same radius of 
curvature so that they closely nest together when the fixture head is 
placed on the yoke. The yoke additionally includes both a neck portion 143 
and screw attachment holes at its stem support end 145 for securing the 
yoke to the top of the stem 89. Additional screw holes 149 provided in 
bosses 151 formed in the middle of the yoke receive exterior accessible 
head attachment screws 191 for releasably attaching the fixture head to 
the yoke. 
The mounting structure stem 89 is preferably an extruded part having a 
uniform cross section including a wire chase 153 and internal extruded 
longitudinal ribs (not shown), the ends of which are threaded to permit 
screw attachment of the yoke to the top of the stem through the yoke stem 
attachment holes; similar screw attachment means are provided at the other 
end of the stem for attaching a bottom support structure, such as the 
clamp shown in FIG. 4, to the bottom of the stem. 
As shown in FIG. 4, the wire chase 153 in the stem communicates through the 
neck of the yoke to a wire chase area 157 in the yoke to permit wiring of 
the fixture head through the stem and yoke. Specifically, the fixture head 
is electrically wired by means of an insulated three-wire cord 159 having 
a plug end 161 extending from the bottom of the stem, and a quick connect 
end 163 for connecting to a corresponding quick connect plug 165 extending 
from the bottom channel 107 of the fixture housing. 
The stem support means of the stem structure shown in FIG. 4 includes a 
C-shaped clamp body 167 having a top plate 169 which rests on the desk top 
89, a downwardly extending side wall 171 to extend the clamp down behind 
the desk top, and a bottom leg 173 extending inwardly from below the desk 
top. The clamp body should be suitably massive and of a suitably heavy 
material to provide a weighted base that can hold the weight of the 
fixture head at the top of the support stem. 
The clamping force is provided at the bottom of the desk top by means of a 
relatively large clamping block 175 which is retractably engaged against a 
pivot hole 177 in the bottom leg of the clamp body by means of a threaded 
turn bolt element 179. The clamping surface of the clamping block should 
be sufficiently large to prevent damage to the desk top. Also, the clamp 
body should be suitably sized, and particularly the bottom leg of the 
clamp body should be of suitable length, to accommodate any wire channels 
that may exist under the desk top surface. 
The ease of on-site assembly of the fixture head to the mounting structure 
of the invention can be described with further reference to the FIG. 4 
embodiment. The quick connect end 163 of the electrical cord 159, without 
the quick connect housing attached, can first be threaded through a 
suitable wire hole 160 drilled in the top plate 169 of the clamp body 167. 
After a stabilizing washer 181 is placed over the quick connect end of the 
cord, the cord can then be threaded through the wire chase 153 of the stem 
89, after which the bottom of the stem can then be attached to the top 
plate of the clamp body by means of base attachment screws 183 inserted 
through suitable screw holes (not shown) formed on either side of the wire 
hole in the top plate of the clamp body. The quick connect end of the cord 
can then be threaded through the neck 143 of the yoke as the yoke's neck 
is inserted into the top opening of the stem, whereupon the yoke is 
screwed to the stem by means of yoke attachment screws 185. It should be 
noted that the cord is preferably pulled through the neck of the yoke 
before the yoke is screwed to the stem. This will prevent the end of the 
cord from becoming jammed in the stem's wire chase against the yoke's 
neck. 
Once the base clamp, stem and yoke have been assembled with the cord 
threaded through it, the plastic housing of the quick connect can then be 
snapped onto the quick connect end of the cord, the quick connect end of 
the cord connected to the connecting plug 165 from the lamp ballast, and 
the ground wire 187 attached to the housing at 189. With the loose wiring 
and connectors nestled in the yoke's wire chase area 157, the fixture head 
can thereafter be screwed onto the yoke by means of head attachment screws 
191. 
FIGS. 6 and 7 further illustrate the manner of attaching the yoke to the 
bottom of the fixture housing and the wiring of the housing ballast and 
internal slide switch. FIGS. 6 and 7 also illustrate the nature of the 
sectional construction of the housing which permits asymmetric and 
symmetric housings to be produced from an inventory of only two cast 
aluminum parts. 
With reference FIGS. 6 and 7, an asymmetric housing 201 is fabricated from 
a first housing section 203 and a second housing section 205, with the 
second housing section which supports the side lens element 207 having a 
wider dimension than the first housing section. The two sections ar joined 
along identical mating interior stepped edges 209 which are formed to 
produce a reveal 211 along the entire visible portion of the joined edges. 
(FIG. 1, for example, shows the reveal in the end of the housing.) Such a 
reveal construction permits the first and second sections of the housing 
to be joined together, such as by tack welds 213 shown in FIG. 7, such 
that otherwise apparent and unsightly mismatches in structure at the 
abutting edges of the housing sections will be hidden from view. Unique 
advantage is also taken of the reveal construction by providing 
unobtrusive slide switch slots 215, 217 in the reveal at opposite ends of 
the housing bottom channel 219. A slide switch 221 having a thin slide tab 
223 that accessibly projects from the reveal through one of the slots can 
thus be placed at either end of the channel. The slide switch 221 is held 
in place by spring clips 225, and the unused slot is covered by a blanking 
plate 227 which is similarly held in place by spring clips 229. 
FIGS. 6 and 7 also generally show the manner of wiring the slide switch 
221. Specifically, a three-wire cord having positive and negative wires 
233, 235 and ground wire 237, extend through a wire hole in the bottom 
mounting plate 231 which also receives the head attachment screws 197 
which are secured by nuts 198. As would be readily apparent to a person 
skilled in the art, the slide switch would be wired in series with the 
ballast and lamp sockets forming part of the reflector sub-assembly. In 
the case of the two lamp version of the fixture head shown in FIG. 4, a 
three-position slide switch having two micro switches can be provided for 
switching both the lamps 93. Thus, the slide tab projecting from the 
reveal at the bottom of the housing can be moved in a sliding action 
within the reveal to one of three switch positions for activating or 
deactivating the luminaire head. 
With further reference to FIG. 7, it can be seen that the individual lamp 
sockets can be wired from different micro switches (not shown) within the 
slide switch by means of separate wire pairs 239, 241. 
The present invention therefore provides an easily assembled, and versatile 
furniture integrated lighting system without the normal physical 
constraints as to location normally associated with conventional fixture 
designs. Although an illustrated embodiment of the invention has been 
described in considerable detail in the foregoing specification, it is 
understood that it is not intended that the invention be limited to such 
detail, except as may be necessitated by the following claims.