Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGRO[1ND OF TH~ INVENTI ON
The present invention relates generally to ceiling
structures and more particularly to a ceiling structure of the
type which comprises a grid of supporting strut members for
supporting lighting fixtures, air handling outlets, ceiling
panels and the like.
The arrangement of electrical wiring conduits in
office and light industrial buildings varies considerably. For
example, such ducts are sometimes laid in the flooring or in
the air space between the ceiling and the next upwardl~
adjacent floor.
In order to achieve maximum flexibility in the use
and partition of such office, lighting industrial space and
commercial space, it is desirable that the wiring be capable
of being arranged across the space in parallel lines with
provision for tapping into the electrical conduits at various
points as may be required from time to time.
Various systems have heretofore been proposed for
satisfying ~hese objectives.
However, such known systems have suffered from a
variety of defects, being either undul~ complex or expensive or,
in some cases, failing to provide for the facility for maximum
electrical wiring distribution in the most efficient and
economical way.
The erection of a suspended ceiling in such commercial,
office or industrial space often employs a rectangular grid of
supporting struts suspended from the floor above. Ceiling panels,
lighting fixtures and air handling facilities are also incorporated
in or supported on such a grid. In some cases, electrical
services, conduits and the like have been located in the space
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between such a ~eilin~ qrid, and the Eloor above. Electrical
services are then led through the ceiling to the working area
, below by vertical posts or columns.
This known system permits a highly flexible and
convenient electrical distribution system but results in a
complex network of wires, conduits, air ducts and the like,
occupying the limited space between the ceiling and the floor
above.
In addition installation and servicing of facilities
in such a limited space involves various trades which may some-
times cause difficulty.
SUMMARY OF THE INVENTION
.. . _ .. . .
The present invention seeks to combine the function
of a ceiling strut grid with that of electrical distribution
in a single ceiling structure.
~ Broadly a ceiling structure in accordance with this inven-
- tion comprises a plurality of mutually parallel, mutually spaced
apart, hollow longitudinal members a plurality of transverse members,
~ terminally connected by junction means to said longitudinal
; 20 members and extending therebetween to form a grid-like structure
including open spaces, and said longitudinal members being
adapted to receive insulated electrical cables within at
least some of said longitudinal members, and electrical connec-
tion boxes releasably attached on top of the longitudinal members,
whereby electrical connections may be made at various locations
in the ceiling.
In accordance with a preferred feature of this inven-
tion, a ceiling structure in accordance therewith is provided
with a plurality of electrical receptacle fittings and fastener
means for fastening such receptacles in position on the longitudinal
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members at spaced intervals therealong.
In accordance with another features of this invention,
a ceiling structure in accordance therewith may be sombined with
vertically extending electrical supply posts extending down-
wardly to the floor from the ceiling and provided with electrical
outlets so to provide for electrical distribution in the working
space beneath the ceiling.
The various features of novelty which characterize
the inv~ntion are pointed out with particularity in the claims
annexed to and forming a part of this disclosure. For a better
understanding of the invention, its operating advantages and
specific objects attained by its use, reference should be had
to the accompanying drawings and descriptive matter in which
there are illustrated and described preferred embodiments of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
_
The invention will now be described merely by way of
illu~tration in the accompanying drawings in which:
Figure 1 is a fragmentary and somewhat schematic per-
spective view from above of one embodiment of a ceiling structureaccording to the invention, and showing various optional features
provided pursuant to preferred features of this invention;
Figure 2 is an exploded and fragmentary perspective
view of two longitudinal members forming part of the ceiling
structure shown in Figure;
Figure 3 is an enlargsd exploded perspective view showing
one systçm for interconnecting th~ longitudinal and transverse
members of the ceiling structure shown in Figure l;
Figure 4 is an enlarged exploded and fragmentary per-
spective view showing how an electrical junction box can be mounted
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on a ~ struct~lre accorAins to the invention, and,
Figure 5 is a cut-away perspective of a detail of
Figure 3.
DESCRIPTION OF THE PREFERRED ~MBODIMENT
. .
Referring first to Figure 1, it will be seen that the
invention is illustrated therein as comprising a rectangular
grid-like structure generally indicated at 8 for supporting a
ceiling. Known rectangular grid type ceilings have in the past
usually comprised simple T~shaped strut members for supporting
ceiling panels, accoustic panels, lighting fixtures, air handling
fixtures and the like.
In the present in~ention, similar ceiling panels or
accoustic panels illustrated as P are shown for closing off the
openings in the grid-like structure. In addition, two lighting
fixtures indicated at F in ~he form of fluorescent lighting
troffers are also shown.
While specific air handling fixtures such as inlets,
outlets, duct work and the like are not shown, it will of course
be appreciated and well understood by those in the art that such
fixtures can readily be placed in position, as desired, in the
ceiling structure 8 in generallv the same way as in known forms
of rectangular grid type ceilings.
Th,e ceiling structure 8 comprises mutually spaced
apart longitudinal members or struts 10 and mutually spaced apart
transverse members or struts 12 terminally secured to the longi-
tudinal struts 10 to form a grid-like structure including the
aforementioned openings. The ceiling structure 8 is supported
from an overhead structure at suitably spaced intervals by means
such as the support wires indicated at 14.
In accordance with well known practice, the support
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wires 14 are attached to any suitable portions of the building
fabric typically to the underside of the floor above (not shown).
Referring now in more detai.l to Figure 2, it will be
seen that two of the longitudinal struts 10 are show~ therein
in exploded or spaced apart relationship.
Each of such struts 10 will be seen to comprise a
generally hollow tubular section of sheet metal having a flat
bottom wall 16 (Figure 3), vertical and flat side walls 18, and
two partial horizontal top wall portions 20.
Spaced apart and upwardly extending flanges or lips
22 are formed along the free or inner edges of the top wall
portions 20~
Mechanical connection of the ends of adjacent lengths
~ of the struts 10 is achieved by means of sheet metal junction
.: plat~ members 24 which are fastened to the struts 10 by any
: suitable means such as sheet metal screws or rivets 25 as shown.
It is to be noted that the junction plate members 24 are omitted
from Figure 1 and 4.
The junction plates 24 are formed along their side
edges with flanges 26 for attachment of the transverse struts 12
in the manner yet to be described. It is to be noted that the
free edges of the flanges 26 are positioned outwardly of the side
: walls 18.
Electrical ground continuity between adjacent ones of
the longitudinal struts 10 is provided by means of tongue members
28 which are spot welded to one end of each such longitudinal
strut 10 so as to extend longitudinally therefrom. Each such
tongue member 28 has a width which is less than the interior
width of the strut 10 so that it will fit between the side walls
18 of an adjacent strut 10 as will be readily understood from
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Figure 2.
The ton~ue members 28 are provided with suitable
electrical fastening means such as a bolt 30 to which ground
wires G are attached for a reason yet to be explained.
Suitable electrical plug-receiving receptacles
generally indicated at 32 are also usefully provided. Each
such receptacle 32 comprises a face plate 34, an electrical
plug-receiving portion 36 mounted in the face plate 34 and a
plurality, in this case, four spring steel leg portions 38.
The legs 38 are dimensioned so as to make a snap-fit
between the upstanding lips 22 of the top wall portions 20 and
to ground the cover plates 34 to the struts 10. The ground
terminals of the plug-receiving portions 36 are connected by the
ground wires G to a respective one of the bolts 30.
In accordance with the invention, the longitudinal
struts 10 are provided with a suitable decorative exterior
coating such as paint or the like on their outwardly directed
surfaces but their inwardly directed surfaces, at least along the ~ -
opposed faces of the lips 22, are left free of any coating which
would inhibit good electrical contact between such lips 22 for
example and the aforementioned legs 38.
Wiring harnesses H (Figure 2) are laid within at least
some of the longitudinal struts 10 to supply electrical power to
the receptacles 32. To facilitate the introduction of such
harnesses H the longitudinal struts 10 are provided with removable
cover plates ~0 which are provided in turn, with a plurality of
spring legs 42 depending downwardly therefrom at suitably spaced
intervals therealong for holding them in position on the longi-
tudinal struts 10.
The cover plate members 40 may be made in different
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lengths and may~ for example, be made with weakened portions at
predetermined spaced points therealon(~ so that they may be readily
broken off to desired lengths to fit any particular modular
arrangement.
It will be seen from Figure 3 that the strut 10
shown therein is supported by means of the wire 14 which is
attached to a narrow strap 44 extending across the width of the
interior of the strut 10 between its side walls 18, and fastened
in position by any suitable means such as by the same rive,ts
(not shown) which secure the ~unction plate 24 in position ox
by separate rivets 45 as shown in Figure 4.
One of the tran~verse struts 12 is shown in more detail
in Figure 3, from which it will be seen that it comprises a
bottom wall 16, side walls 18 and top wall portions 20 with lips
22, in the same manner as the longitudinal struts 10.
For joining the ends of transverse struts 12 at right
angles to the longitudinal strut~ 10, end connectors 46 are
secured to the interior surfaces of the side walls 18 of the
transverse struts 12 by any suitable means, for example, by spot
2Q welding or the like. ~he connectors 46 are formed with connector
ribs 47 which are arranged to make a sliding interfitting engage-
ment with the edge flanges 26 on the junction plate 24 and are
locked in assembled position by means of locking clips 48 formed
on the flanges 26 and interlocking with holes 49 provided in
the members 46.
Once assembled in the form of the grid as shown in
Figure 1 and with that grid suspended in position, ceiling panels
or accoustic panels P may simply be laid on the top surfaces of
the top wall portions 20 of the struts 10 and 12 generally in
edge abutment with the flanges 22.
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L)epending on the size and shape of such ceiling panels
P, additional dummy struts S (Figure 1) may be secured between
adjacent struts 10 or 12 to support such panels.
Similarly, lighting troffer fixtures F may simply be
laid in position longitudinally or transversely with ceiling
panels laid on either or both sides thereof in accordance with
well known practice. In the same way, air handling fixtures
may also simply be laid so that they rest upon the top wall
portions 20 of the struts 10 and 12. Usefully, the open spaces
between adjacent pairs of the longitudinal and transverse struts
10 and 12 respectively are square in plan so facilitating the
positioning of a lighting troffer fixture F in either direction.
Usefully, the electrical power harnesses H are arranged
in the longitudinal struts 10 so that they eXtend from one side
to the other of the ceiling thereby providing for a fully flexible
system of electxical distribution throughout a given building
space.
Electrical power may be supplied to such harnesses ~ by
electrical cables C terminating at connection boxes 50 ~Figure 4).
Such connection boxes 50 will be of any suitable sheet
metal construction having side walls 52, end walls 54 and a
removable top cover 56. Suitable knock outs 58 may be provided
for introduction of the wiring in a conventional manner.
Each connection box 50 has an open base, the lower edges
of its side walls 52 being spaced apart a distance such that they
will fit snugly around the outer faces of the upstanding flanges
22 of the struts 10.
The end walls 54 of the boxes 50 are dimensioned so
that they can extend downwardly between such flanges 22, and so
that the aforem~ntioned cover plates 40 will thus abut against
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the outer faces of the end w~lls 54 so -to provide a completely
closed off system.
Notches 60 are formed between the lower portions
of the side walls 52 and the end walls 54 so as to permit the
former to straddle the upstanding flanges 22 in the manner
described.
Within the connection box 50, there is provided a
mounting plate 62 which is spot welded or fastened in any other
suitable manner to the inner faces of the side walls 52.
A mounting screw 64 extends do~nwardly from the plate
62 and is threaded into an oversize locking plate 66 which has
an elongated rectanqular shape, its narrower dimension being
such that it will fit between the lips 22, and can then be rotated
(arrows A) so as then to underlie the top wall portions 20 of the
struts 10. Consequently, when the screw 64 is tightened, it will
clamp the connection box S0 to the strut 10. A ground wire G
ensures ground continuity between the connection box 50 and the
strut 10.
In order to simplify installation of lightinq fixtures
such as the lighting troffers F, such fixtures will preferably
be provided with suitable electrical wiring or cables W provided
with conventional two or three pin plugs, which can be plugged
into the sockets or receptacles 32 so avoiding the need for time-
consuming stripping of c~bles and connectinq of wires.
At the same time, if one such lighting troffer should
require servicing, then it is a simple matter for maintenance
personnel in the building to simply remove the entire troffer
by unplugging it from its receptacle and replacing it with a new'
one.
As shown in Figure 1, a ceiling structure according
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to the invention may, and preferably will be combined with a
plurality of vertical posts or co]umn.s 70, extendinq vertically
downwardly to the floor below the ceiling. Such posts can be
provided therein with electrical cables extending upwardly
as at Y to a conventional electrical plug, for example, a three-
pin plug, which can be inserted in a convenient one of the
receptacles 32. Such a post 70 can then be provided with one
or more electrical receptacles at suitable heights for connection
of various appliances requiring electrical power.
It will, of course, be understood that some of the
services will require different voltages. For example, conven-
tional office equipment requires a supply voltage of 120V, while
other equipment may require a higher voltage. For example, the
lighting troffer fixtures F may require a supply voltage from
340 to 350 volts. Accordingly, alternate ones of the struts 10
are preferably wired with harnesses providing diferent voltages
so that one such strut 10 will be a power strut and the next one
will be lighting strut and so on. Other combinations of different
voltage supplies may also be provided.
The invention also envisages the manufacture of
complete strut assemblies in the factory complete with wiring
harnesses and receptacles. Plug connection means may be provided
at one end of each strut for simplified connection into the main
electrical supply system. Receptacles can also be located at
regularly spaced in ervals along the struts and closed off or
covered and sealed, until such time as they are required.
.. ..
~aving described what is believed to be the best
mode by which the invention may be pertormed, it will be
seen that the invention may be particularly defined as fol-
3~ lows:
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A ceilin~ structure adapted for the receipt of
electrical wiring therein, said ceiling structure comprising,
a plurality of longitudinal hollow parallel channel members each
such member havin~ a bottom wall and side walls, and flanges
along the upper edges of their side walls, a plurality of
transverse hollow channel members adapted to extend between
said longitudinal members, each said transverse member having
a bot~om wall, and side walls, junction means for connecting said
transverse channel members in end abutting relation with said
side walls of said longitudinal channel members, suspension
means on at least some of said members, whereby the same may
be suspended in position, and, a plurality of releasably
attachable electrical connection boxes, each having side walls,
end walls,and a top wall,and having downwardly directed edge
portions defining an access opening, said edge portions being
spaced apart a distance to fit over said flanges on said
channel members, and enclose the same along a portion of their
length, with said access opening registering with said opening
between said flanges.
The invention further comprises such a ceiling structure
wherein said edge portions comprise lower edges of said side and
end walls including notch means cut in at least one of said side
walls and end walls.
- The invention further comprises such a ceiling structureincluding notch means cut in at least one of said side walls and
end walls, and registering with said flanges, whereby said side
walls may fit downwardly over said flanges, with said flanges
extending upwardly into said notch means.
The invention further comprises such a ceiling structure
including box attachment means for each said box, said attachment
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means beln~ dimensioned to extend into said channel member beneath
said box, and being attachahle thereto.
The foregoing is a description of a preferred
embodiment of the invention which is given here by way of example
only. The invention is not to be taken as limited to any of the
specific features as described, but comprehends all such variations
thereof as come within the scope of the appended claims.
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