U.S. patent number 3,835,606 [Application Number 05/255,652] was granted by the patent office on 1974-09-17 for combination ceiling tile and air duct structure.
Invention is credited to Milton Liberman.
United States Patent |
3,835,606 |
Liberman |
September 17, 1974 |
COMBINATION CEILING TILE AND AIR DUCT STRUCTURE
Abstract
A heating and air conditioning duct system for installation in
drop ceilings utilizing T-bar construction wherein ducts are formed
of a suitable insulating light weight material and secured to
ceiling tiles to provide the completed duct which can then be
placed in position on the T-bars as in the case of conventional
ceiling tiles. Bends and reducing sections may also be
pre-fabricated so that the entire air distribution system can be
installed in the course of installation of the ceiling and without
the need for special sheet metal work which involves considerable
time and expense.
Inventors: |
Liberman; Milton (East
Rockaway, NY) |
Family
ID: |
22969299 |
Appl.
No.: |
05/255,652 |
Filed: |
May 22, 1972 |
Current U.S.
Class: |
52/220.6;
52/506.07; 454/284; 138/149 |
Current CPC
Class: |
F24F
13/0263 (20130101); E04B 9/02 (20130101); E04F
17/04 (20130101); F24F 13/0227 (20130101) |
Current International
Class: |
E04F
17/00 (20060101); E04F 17/04 (20060101); F24F
13/02 (20060101); E04B 9/02 (20060101); E04f
017/08 (); F24f 013/06 () |
Field of
Search: |
;52/220,221,484 ;138/149
;98/4D |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Perham; Alfred C.
Claims
What is claimed is:
1. An air duct for drop ceilings having longitudinal and transverse
members for supporting ceiling tiles, a U-shaped channel having
outwardly extending legs, a sheet bridging said legs, said channel
and sheet being supported by said longitudinal and transverse
members.
2. An air duct for drop ceilings according to claim 1 wherein
successive sheet and channel combinations are joined in end-to-end
relationship and means are provided for sealing the abutting edges
of said combinations.
3. An air duct for drop ceilings according to claim 1 wherein said
channel is formed of a relatively dense plastic insulating material
having an aluminum sheet bonded to at least the inner side
thereof.
4. An air duct for drop ceilings according to claim 1 wherein said
channel extends upwardly from said sheet and said sheet is in the
form of a ceiling tile provided with openings extending
therethrough for the discharge of air from said duct.
5. An air duct for drop ceilings having longitudinal and transverse
members for supporting ceiling tiles, a U-shaped channel having
outwardly extending legs, a sheet bridging said legs, said channel
and sheet being supported by said longitudinal and transverse
members, the legs of said channel being cemented to said sheet and
said sheet is in the form of a ceiling tile mechanically secured to
said channel by fastening means.
6. An air duct for drop ceilings according to claim 5 wherein said
fastening means comprise clips secured to said channel legs and
said ceiling tile.
7. An air duct for drop ceilings according to claim 2 wherein the
sealing means for said abutting edges include strips bridging
adjoining channels and fixedly secured thereto.
8. An air duct for drop ceilings according to claim 5 wherein said
longitudinal and transverse members are inverted T-bars and said
fastening means include tabs engaging at least certain of said
T-bars.
9. An air duct for drop ceilings according to claim 1 wherein said
channel has a cross-sectional area in the plane of the ends of said
legs smaller than the area of said sheet and said legs are provided
with outwardly extending means defining an area substantially equal
to the area of said tile.
10. An air duct for drop ceilings according to claim 1 wherein said
channel is formed of a single sheet of compressed polyurethane foam
sheathed on at least one side with a continuous sheet of aluminum
foil.
11. An air duct for drop ceilings according to claim 10 wherein
said longitudinal and transverse members are inverted T-bars with
the upwardly extending portion of the longitudinal T-bars having a
height greater than the thickness of the tile and the transver
T-bars having a height approximately equal to the thickness of the
tile.
12. An air duct for drop ceilings according to claim 1 wherein said
channel is formed of glass fibers compressed into a sheet and
sheathed with metal foil.
13. An air duct for drop ceilings according to claim 12 wherein
said longitudinal and transverse members are inverted T-bars with
the upwardly extending portion of the longitudinal T-bars having a
height greater than the thickness of the tile and the transverse
T-bars having a height approximately equal to the thickness of the
tile.
14. An air duct according to claim 1 wherein said channel is of
non-uniform cross-sectional area.
15. An air duct according to claim 1 wherein said channel is curved
in the plane of the ends of said legs.
16. An air duct for drop ceilings according to claim 1 wherein said
channel depends from said longitudinal and transverse members.
17. An air duct for drop ceilings according to claim 1 wherein the
legs of said channels include outwardly extending flanges, said
sheet is secured to the outer surfaces of said flanges and said
flanges engage said longitudinal and transverse members with said
channel depending therefrom.
Description
This invention relates to drop ceiling structures and more
specifically to a novel and improved combination tile and air duct
structure for use in drop ceilings to facilitate the installation
for heating and air conditioning without the need for extensive
sheet metal operations prior to installation of the drop
ceiling.
Drop ceilings are widely utilized in building construction to
provide space for the accommodation of electric wiring, heating and
air conditioning ducts, communication circuits, recessed lighting
fixtures and the like. With reference to heating and air
conditioning ducts, known procedures have entailed the installation
of conventional sheet metal ducts prior to installation of the drop
ceiling. In such cases it is necessary to determine the precise
location of the air conditioning and heating outlets and, should it
be desirable to change the position of a hot or cold air outlet
after the ceiling is in position, a substantial amount of work is
entailed as it may be necessary to actually remove portions of the
drop ceiling to permit installation of additional sheet metal
ducts. This invention overcomes the difficulties heretofore
encountered in providing heating and air conditioning ducts and
provides a novel and improved structure wherein the air duct and
ceiling tile are combined so that the ducts are in effect supported
by the drop ceiling. This procedure greatly reduces the cost of
duct installation since pre-formed duct and tile structures can be
installed simply and quickly in the installation of the drop
ceiling. Furthermore, should any changes in the duct work be
required, the ducts can be simply and easily removed and relocated
in the ceiling to provide outlets in new desired locations.
Another object of the invention resides in the provision of a novel
and improved combination air duct and ceiling tile wherein the
pre-formed duct may be constructed either integrally with the tile
or secured to the tile at the site of the installation.
Still another object of the invention resides in the provision of a
novel and improved air duct and tile assembly which may be readily
fabricated of a lightweight insulating material which avoids the
need for insulation as required on metal ducts and which greatly
simplifies installation and maintenance.
A still further object of the invention resides in the provision of
a novel and improved air duct and tile combination for use in
connection with drop ceilings having T-bar supporting members and
wherein the duct and tile combinations are removably secured to the
T-bars.
The duct and tile assembly in accordance with the invention
consists of a pre-formed duct having dimensions coordinated with
conventional tile sizes as utilized with drop ceiling structures so
that the duct and tile can be readily assembled and secured one to
the other and also to the T-bars in the ceiling when the duct and
tile assembly is positioned therein. The invention further
contemplates the provision of duct sections for reducing the duct
area as well as curved sections so that air outlets can be
positioned in any location in the room. If desired, air outlets may
be readily provided by simply forming openings in the ceiling tile
at any location and which openings merely communicate with the
overlying duct.
The above and other objects of the invention will become more
apparent from the following description and accompanying drawings
forming part of this application.
In the Drawings:
FIG. 1 is a perspective view of a fragmentary portion of a drop
ceiling showing the installation of an air duct assembly in
accordance with the invention,
FIG. 2 is a perspective view of an air duct and tile assembly,
FIG. 3 is an exploded perspective view illustrating one mode of
attachment of a pre-formed duct to a ceiling tile,
FIG. 4 is a cross-sectional view of FIG. 1 taken along the line
4--4 thereof,
FIG. 5 is a plan view of a drop ceiling structure showing a
reducing section for reducing the duct area together with curved
and straight duct sections of reduced area,
FIG. 6 is a cross-sectional view of FIG. 5 taken along the line
6--6 thereof,
FIG. 7 is a cross-sectional view of FIG. 5 taken along the line
7--7 thereof,
FIG. 8 is a plan view of a modified embodiment of a duct structure
in accordance with the invention,
FIG. 9 is a perspective view of the means for attaching the duct to
the ceiling tile,
FIG. 10 is a cross-sectional view of the assembly of the duct of
FIG. 8 with a ceiling tile,
FIG. 11 is a cross-sectional view of FIG. 10 taken along the line
11--11 thereof,
FIG. 12 is a perspective view of a modified embodiment of an air
duct for installation in drop ceilings,
FIG. 13 is a cross-sectional view of FIG. 12 taken along the line
13--13 thereof, and
FIG. 14 is a perspective view of one embodiment of a clip for use
in the embodiment of the invention shown in FIGS. 12 and 13.
One embodiment of a combined ceiling tile and air duct structure in
accordance with the invention is illustrated in FIG. 1. The drop
ceiling is of conventional construction having a plurality of
longitudinal T-bars 10 at conventional 1 foot or 2 foot spacings as
the case may be, and transverse T-bar sections 11 spaced generally
at 4 foot intervals and interlocked with the longitudinal T-bars 10
in the conventional manner. Ceiling tiles 12, or in the alternative
a recessed lighting fixture, are positioned in the rectangular
openings formed by the T-bars 10 and 11. While the T-bar runners 12
are of conventional size with the center leg extending
substantially above the tile 12, the T-bars 11 preferably have
center legs of reduced height so that they do not extend materially
above the tile 12. The T-bar grid is generally supported by rods or
wires 13 which are connected to the T-bars and anchored in the
ceiling of the building.
The air duct sections 14 in accordance with the invention are
carried between adjoining longitudinal T-bars 10 and each duct
section 14 as shown in FIG. 1 preferably has a width corresponding
to the space between T-bars 10 and a length corresponding to the
distance between the transverse T-bars 11. Successive duct sections
14 are arranged to abut one another and the gap between successive
sections may be readily closed by a suitable sealing means 15 such
as metal straps cemented to the ducts, adhesive strips or the like.
The duct sections 14 and the associated tiles 12 may be held in
position between the T-bars by any suitable means as, for instance,
tabs 16 which extend through cooperating openings in the vertical
portions of the T-bars 10.
FIGS. 2, 3 and 4 illustrate one mode of attachment of a rectangular
ceiling tile 12. The duct 14 in the illustrated embodiment of the
invention is generally rectangular and has a top wall 17 and side
walls 18 and 19. While the duct is essentially rectangular, it is
of course evident that the duct may be made in other configurations
such as semi-circular, trapezoidal and the like. The lower edge of
each side wall 18 and 19 is provided with a metal channel denoted
by the numeral 20 which has a bottom portion 21 and upwardly
extending side walls 22 and 23. The upper edge of the side wall 23
has an inwardly formed flange 24 provided with a saw-toothed edge
25. The bottom wall 21 has a plurality of triangular tabs 26 which
may be cut from the metal forming the bottom wall and bend
downwardly as illustrated more clearly in FIGS. 3 and 4. The side
wall 23 also has at least two outwardly extending tabs 16 which may
be formed from the side wall material as illustrated and which
engage cooperating openings in the T-bars 10 as described in
connection with FIG. 1. A channel 20 is fastened to the lower edge
of each side wall 18 and 19 of the duct 14 by inserting the side
wall between the two upwardly extending walls 22 and 23 of the
channel 20 and then compressing the channel 20 to urge the
saw-toothed edge 25 into the side wall of the duct as shown in FIG.
4 to securely attach the channel to the duct. The duct 14 with the
channels 20 secured to the lower edges of the side walls thereof
may then be placed on a tile section 12 and the triangular tabs 26
forced into the tile. To seal duct 14 to the tile, the underside of
the channels 20 may be cemented to the tile or a suitable strip of
adhesive tape 27 may be adhered to the channel 20 and an adjoining
surface of the tile 12. In this way an air tight seal is provided
between the duct 14 and the tile 12.
The duct 14 may be made of any suitable material such as plastic or
the combination of plastic and metal and formed by a suitable
molding or other forming process and, if desired, lined with a thin
layer of aluminum or other suitable metal. Similarly, the top
surfaces of the tiles 12 which are to form part of the air duct may
also be covered with a thin metallic sheet of aluminum or other
suitable metal or, in the alternative, both the insides of the duct
14 and the top side of the tile 20 may be sprayed with a metallic
paint. Room outlets can be readily formed by cutting openings in
the tiles 12 such as the opening 28 as shown for instance in FIG.
2. If desired, a suitable louver may be inserted in the opening.
Particularly desirable materials for use in forming the ducts 14
are compressed polyurethane foam in the form of sheets and glass
fiber sheets of the desired density having layers of aluminum foil
14' and 14" on each side thereof. The sheets are light in weight,
can have any desired rigidity and can be cut easily to desired
sizes. With compressed sheets of polyurethane foam fiber glass or
other similar plastic material wherein the outer surfaces are
covered by aluminum foil, the sheets can be formed readily into
shaped ducts, such as ducts 14 at the installation site. The
compressed polyurethane foam or fiber glass sheathed in aluminum
can be bent to form relatively sharp corners by placing the
material on a surface with a portion extending beyond the surface
edge. Then by applying downward pressure on the overhanging portion
the material will fracture uniformly and precisely along the length
of the bend without fracturing or breaking the aluminum sheaths.
Moreover, bends substantially in excess of 90.degree. can be made
without damaging the material or even weakening those portions
adjacent to the bend. Accordingly, each duct length can be cut to
size at the factory and the "breaks" formed in the proper
locations. The material can then be shipped in flat form and be
shaped and installed quickly at the site. One form of compressed
polyurethane foam sheathed with aluminum foil is manufactured by
the celotex Corporation and marketed under the name "Technifoam"
and has a thickness of 9/16 inch.
In many instances it is necessary to reduce the area of the duct in
order to provide adequate distribution of air. For this purpose a
pre-formed reducing section such as the section generally denoted
by the numeral 29 may be provided as shown in FIGS. 5 and 6. The
reducing section may be formed in any desired manner and of any
desired material such as metal, plastic, and combinations thereof.
It is preferable however to use a suitable fireproof insulating
material such as those described with at least the inner surface
being sheathed with aluminum foil or other metal. The reduction in
area is effected in a conventional manner, namely, by providing a
duct section 30 which corresponds in area to a duct section 14 as
previously described, a tapered section 31, and a straight section
32 of the desired reduced area. The reducing section 29 may be
secured to a ceiling tile 12 in any suitable manner as, for
instance, by cementing the duct section to the tile or by providing
straps 33 which are shaped to engage a duct section and extend
outwardly to engage cooperating openings in the adjoining T-bars
10. Pre-formed curved ducts such as the duct 34 and cooperating
straight sections 35 may also be provided and secured in position
on the tiles 12 by transverse straps 33. While the transverse
straps may be formed in any desired manner and of either plastic or
metal, it may be desirable to provide reinforced straps such as the
strap shown for instance in FIG. 7 and denoted generally by the
numeral 36. The strap 36 includes a flat strip 37 which is formed
to fit the duct section 35 as shown in FIG. 7 and having end
portions lying flat against the tile portion 12. Webs 38 are
secured to at least one side edge of the strap 37 and, thus, afford
substantial rigidity to the strap 37 causing it to tightly engage
the duct 35. If desired, the duct sections 35 as shown in FIG. 7 as
well as the duct sections 34 and 29 may be sealed to the ceiling
tile by cement or strips of adhesive tape 39 as shown in FIG.
7.
A modified embodiment of the invention is shown in FIGS. 8 through
11. A duct section denoted by the numeral 40 and formed of
compressed polyurethane foam of 1/2 inch to 5/8 inch in thickness
is cut to size and the preliminary breaks 41 and 42 are formed
therein. Duct attaching means 43 and 44 each comprising a metal
angle 45 with an adhesively coated strip 46 attached to and
extending from one leg thereof is provided on each end of the duct
section 40. The adhesive strip 46 is attached to the underside of
the polyurethane board 40 as shown in FIG. 8 so that the edge of
the board is spaced from the upwardly extending leg 45' of the
angle 45, a distance equal to the thickness of the ceiling tile
47.
Each strip 43 has a pair of end lugs 48 of a light gauge material
and a plurality of intermediate lugs 49. In the instant embodiment
of the invention, the lugs are welded to the leg 45" of the angle
45 and the lugs 49 have a V-shaped portion with the ends thereof
extending through an opening 50. When the duct 14 is formed from
the sheet 40 as shown in FIG. 10, the lower edges 51 of the duct
are cemented to the ceiling tile 47 and then the angles 43 and 44
are moved into engagement with the tile 47 and with the legs 45'
underlying the tile. The lugs 48 and 49 are then forced into the
tile 47 to provide the completed assembly for installation in the
ceiling.
In the foregoing structure, adhesive tape is used to effect the
joinder of the tile 47 with the duct 14. It is evident that metal
clips may be used to engage both the ceiling tile 47 as well as the
walls of the duct 14 since the duct material can be pierced
readily. The ceiling tile 47 also preferably has an inner aluminum
layer 46' and an outer decorative layer 47".
FIGS. 12 through 14 illustrate a modified embodiment of the
invention which is particularly useful with drop ceilings wherein
the space between the supporting surface and the drop ceiling is
too shallow to accommodate a duct of the desired cross-sectional
area. In this case the duct in accordance with the invention
depends from the plane of the ceiling and is arranged so that its
outer surface has the same finish as the exposed surfaces of the
ceiling tile.
More specifically, the drop ceiling generally denoted by the
numeral 60 includes longitudinal and transverse T-bars 61 and 62 as
in a conventional drop ceiling. The T-bars form essentially
rectangular openings which are closed by ceiling tile 63, lighting
fixtures as previously described or by air duct sections 64 as
illustrated. Each air duct section 64 includes a depending channel
having a bottom wall 65 and upwardly extending side walls 66, the
latter terminating in outwardly extending flanges 67. The top side
of the channel is closed by a sheet 64' cemented or otherwise
secured to the flange portions 67. For instance, U-shaped strips 68
may be utilized to engage the sheet 64' with the flanges 67. Each
strip 68 includes a top wall 69, a side wall 70, and a bottom wall
71. The bottom wall 71 includes an upwardly extending toothed
flange 72 to firmly engage the underside of the associated flange
67.
The channels 64 and sheets 64' are preferably made of an insulating
material and in the same manner as described in connection with the
embodiment of the invention shown in FIGS. 1 and 2. In this case,
however, the lower surface of each sheet 64' and the inner surface
of each channel 64 should be coated with a metal foil, sprayed or
otherwise treated to render it substantially impervious to moisture
and dust and dirt particles. The exposed surfaces of channels 64
should be provided with the same decorative surfaces as the exposed
surfaces of the tiles 63. If desired, means such as tabs 73 may be
used to firmly engage the channels 64 with the T-bars.
With the invention as described above, ducts for heating and air
conditioning can be readily and easily installed in the course of
installation of the drop ceiling with the result that both the time
and cost for duct installation can be drastically reduced. By
forming the duct sections of an insulating material, additional
insulation is not required, and of course noise is materially
reduced. The invention also facilitates modification of duct
systems required as the duct sections can be readily removed and
replaced to provide outlets in any desired location in a room.
While only certain embodiments of the invention have been
illustrated and described, it is understood that alterations,
changes and modifications may be made without departing from the
true scope and spirit thereof as defined by the appended
claims.
* * * * *