U.S. patent application number 09/817279 was filed with the patent office on 2001-08-30 for insulating air conduit.
Invention is credited to Lessard, Marc, Tremblay, Mona.
Application Number | 20010017165 09/817279 |
Document ID | / |
Family ID | 4155210 |
Filed Date | 2001-08-30 |
United States Patent
Application |
20010017165 |
Kind Code |
A1 |
Lessard, Marc ; et
al. |
August 30, 2001 |
Insulating air conduit
Abstract
This invention is related to ultra-light conduit for used air
and a method for construction of such a conduit with sandwich sheet
type of material such as "THERMO-FOIL.TM." permitting to avoid
losses of heat and humid air. The method of construction of a used
air rectangular conduit includes the following five (5) steps: 1)
cutting of a sandwich sheet 2) sealing around the sandwich sheet 3)
heat formation of lengthwise channels on the surface of sandwich
sheet 4) assembling the sandwich sheet into a conduit of a
predetermined length and 5) installing a lengthwise vertical
reinforcement into the conduit and providing a male adaptor to a
fore end of the conduit which could be adapted to an aft end of a
joining conduit.
Inventors: |
Lessard, Marc; (Chicoutimi,
CA) ; Tremblay, Mona; (Chicoutimi, CA) |
Correspondence
Address: |
SWABEY OGILVY RENAULT
SUITE 1600
1981 MCGILL COLLEGE AVENUE
MONTREAL
QC
H3A2Y3
CA
|
Family ID: |
4155210 |
Appl. No.: |
09/817279 |
Filed: |
March 27, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09817279 |
Mar 27, 2001 |
|
|
|
08547131 |
Oct 24, 1995 |
|
|
|
6230750 |
|
|
|
|
Current U.S.
Class: |
138/149 ;
138/151; 138/155; 138/158; 138/169 |
Current CPC
Class: |
F24F 13/0245 20130101;
Y10T 29/12 20150115; F24F 13/0263 20130101; F16L 59/021 20130101;
F24F 13/0209 20130101; Y10T 29/49879 20150115; E04F 17/04 20130101;
Y10T 29/49385 20150115; F24F 13/0281 20130101 |
Class at
Publication: |
138/149 ;
138/151; 138/155; 138/158; 138/169 |
International
Class: |
F16L 009/14 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 14, 1995 |
CA |
2,142,190 |
Claims
I claim:
1. An air duct comprising: one or more segments, each segment
disposed longitudinally relatively to a major axis 32 parallel to
the air flow, each segment comprising a wall defining an internal
space that permits flow of said air, said wall being uniformly
thick and made of a sandwich material comprising air cells
contained between a first external film and a second internal film,
said second internal film coinciding with an internal space, each
said segment comprising an upstream end 36 and a downstream end 34,
said upstream end 36 and said downstream end 34 being opened, each
segment comprising means for coupling fitted into said downstream
end and posing as a male end to join a segment to another segment,
and an evacuation conduit to a female end of another evacuation
conduit; said upstream end 34 to pose as female end to join with
said means for coupling.
2. An air duct as defined in claim 1 wherein said wall comprises: a
first end 88 longitudinal relatively to said segment and a second
end 89 also longitudinal, said first end 88 ending with a first
angular crushing 82, extended in a first flat end 60, said second
end 89 ending with a second angular crushing 86 extended in a
second flat end 62 to be folded on said second angular crushing 86,
said first angular crushing 82 leaning against said second flat end
62, said first end 60 setting itself beyond said second end 89,
along said first external film, said wall also comprising means for
adhesion to make said conduit airtight and to hold together said
first end and said second end.
3. An air duct as defined in claim 1 wherein said means for
coupling comprise an adaptor 42 with an external face 43 adjacent
to said second internal film 76 of said wall, said adaptor 42
partly extended outside of said downstream end 36 for inserting
into said upstream end 34 of an adjacent segment, said wall
comprising lateral crushed ends 64 to seal said sandwich material
at said upstream and downstream ends.
4. An air duct, as defined in claim 2 wherein said wall forms a
parallelepiped with a rectangular section comprising a top 24,
prolonged by said first flat end 60, a closed side 28, a bottom 26,
an opened side 30 prolonged by said second flat end 62, and at
least three longitudinal lines for folding of which one demarcating
a first limit 68, between said top 24 and said closed side 28,
another demarcating a second limit 70 between said closed side 28
and said bottom 26, and a third demarcating a third limit 72,
between said bottom 26 and said opened side 30, said parallelepiped
comprising means for reinforcement orientated along said major
axis, touching said top and bottom.
5. An air duct, as defined in claim 4, wherein said means for
coupling is a parallelepiped rigid adaptor comprising two opened
sides and a rectangular section adapted to lean onto an internal
side of an aperture defined by said top, closed side 28, bottom 26
and opened side 30.
6. An air duct, as defined in claim 4 wherein said means for
reinforcement is a C-reinforcement comprising a web and two wings
wherein each of said wings is respectively in contact with said top
and said bottom, said web serving as reinforcement, to avoid
collapsing of said top onto said bottom.
7. An air duct, as defined in claim 4, wherein said first flat end
is joined to said end of said opened side by means for adhesion
placed on all length of said opened side.
8. An air duct, as defined in claim 2, wherein said wall is
cylindrical, comprising a first end and a second end, said upstream
end and said downstream end being of circular section, said means
of coupling being a rigid adaptor 114 that will lean against an
internal side of said cylindrical wall of an adjacent segment.
9. An air duct, as defined in claim 7, wherein means for adhesion
is an aluminized band of the type Mactac.TM., located on all length
of said wall and joining said first flat end to said second
end.
10. A method of construction of air duct made with rigid insulating
material comprising a sandwich made of air cells contained between
a first external film and a second internal film, said air duct
comprising a wall placed around a major axis parallel to fluid flow
direction, said wall comprising a longitudinal union of a first
flat end and a second flat end, said air duct comprising opened
upstream and downstream ends, said method of construction
comprising the following steps: step of cutting said sandwich
insulating material demarcating a perimeter of predefined
dimension; step of sealing said perimeter to proof said sandwich to
prevent liquid or gaseous fluid exchanges between the interior of
said insulating material and the exterior, said step of sealing
comprising a step of crushing of said first flat end and said
second flat end; step of folding said sandwich around said major
axis according to a desired form of section; step of assembling of
said first flat end and said second flat end with means of
adhesion, to complete said form of section; step of installation of
a rigid adaptor fitting into said downstream end.
11. A method as defined in claim 10, for a parallelepiped air duct
of rectangular section comprising a top, a bottom and opened and
closed sides, said method comprising the following additional steps
of construction: step of folding by means for heating of said
sandwich to obtain said top, said bottom, said closed side and said
opened side required to form said rectangular air duct; step of
preparing a C-reinforcement, in shaping a web and two wings from
said insulating material; step of installation of said wings
respectively in contact with said top and said bottom, said web
serving as reinforcement joining said top to said bottom.
12. A method as defined in claim 10, wherein said sandwich is a
sheet comprising several layers of material, four sides, and said
perimeter, and wherein said step of sealing of said perimeter
consists in heating said perimeter with an angle iron in such a way
that the layers of said sandwich melt to create four thin bands
respectively on each of said four sides of said sheet, two of said
thin bands coinciding with said first flat end and said second flat
end, said first flat end, when installed, being joined to said
second flat end.
13. A method as defined in claim 11, wherein the width of said
first flat end is larger than the width of said second flat end to
cover completely any joint between said top and said opened side,
said first flat end being installed externally to said opened side,
and said second flat end of said opened side being placed under
said top side.
14. A method as defined in claim 11, wherein said step of folding
said sandwich consists in heating said sandwich with an angle iron
to produce three V grooves on said internal film of said sandwich,
said V grooves having 135.degree. sides to form a section of an
isosceles triangular form when said sandwich is placed on a flat
surface, said V grooves respectively demarcating a first limit
between said top and said closed side, a second limit between said
closed side and said bottom and a third limit between said bottom
and said opened side; when said sandwich is folded to form said
rectangular air duct, said 135.degree. sides join to define corners
of said rectangular air duct.
15. A method as defined in claim 11, wherein said step of
assembling consists in sticking said first flat end of said top
onto said opened side with said adhesive band on all length of said
first flat end.
16. A method as defined in claim 10, wherein said step of folding
comprises an additional step to circularize said air duct sandwich
sheet with a folding device.
17. A method as defined in claim 16 wherein said step of
installation comprises the jointing of a circular adaptor in said
upstream end, said adaptor being rigid and comprising a cylindrical
wall and two ends.
18. A method as defined in claim 10, wherein said means for
adhesion is an aluminized band of the Mactac.TM. type located on
all length of joining of said first flat end to said second flat
end.
19. A method as defined in claim 16 wherein said step of sealing of
said perimeter of said insulating material consists of heating said
perimeter by pressing a heated angle iron so that the layers of
sandwich that form the insulating material melt to create a thin
band and a 135.degree. side 134, this band being placed under said
cylindrical wall, said second flat end comprising said chamfered
135.degree. side 130 being placed outside of said cylindrical
wall.
20. A method as defined in claim 19 wherein said second flat end
124 leans against said interior face of said cylindrical wall to
form a continuous cylindrical wall.
Description
RELATED APPLICATION
[0001] This application is a Continuation of U.S. patent
application Ser. No. 08/547,131 filed on Oct. 24, 1995.
FIELD OF INVENTION
[0002] This invention belongs to the field of exhausting used air
from houses, apartments and commercial buildings and particularly
from kitchen hoods, bathroom fans and dryer conduits.
[0003] This invention is related to a new method of construction of
used air conduits that have a circular or a rectangular cross
section and made of a sandwich of reflective double wall air bubble
cushioned material, such as "THERMO-FOIL .TM." to prevent losses of
heat and humid air.
[0004] The method of construction comprises five steps of
transformation of a sandwich sheet, for a rectangular conduit or
for a conduit with a circular section. For a conduit with a
rectangular section 1) cutting of a sandwich sheet, 2) sealing the
periphery of the sandwich sheet 3) creating a heat formed channel
installed lengthwise to deliminate four sides of a segment 4)
assembling the mating ends of a sheet and 5) installing a male
adaptor in one end of a segment for joining another end of a second
segment.
[0005] Another method of construction is provided for used air
conduits with circular section by: 1) cutting a sandwich sheet 2)
sealing around the sandwich sheet 3) passing through a bender to
form a circular section 4) assembling the mating ends of a sheet
and 5) putting a male adaptor to join another conduit.
PRIOR ART
[0006] A review of prior art revealed some patents relating to
conduits comprising insulating material, sheet type or foam
type.
[0007] The following patents held my attention.
[0008] CN 2,049,198 Lutgen, Aug. 22, 1991, describes an insulator
of the sandwich type conceived to exactly fit the internal shape of
cryogenic containers. The sandwich includes successive layers of
thermal insulating materials such as polystyrene and foams of
different densities. To prevent liquid or gas exchanges, sheets
must be enclosed in impermeable and rigid walls such as the steel
walls of a cryogenic reservoir: this increases considerably the
construction costs.
[0009] CN 2,032,111 Cur et Al., Jun. 19, 1991, describes an
insulator of the sandwich sheet type conceived to be stuck onto a
flat face of a refrigeration unit. The sandwich, sealed at its
ends, includes superposed lamellae made of different insulating
materials and thin inter-lamellar spaces filled with air. The
insulating sandwich of Cur et Al. is held by a wall of plastic and
a wall of metal, this increasing considerably construction costs.
Moreover, Cur et Al. do not show joints between sheets that would
indicate how those could form independent structures without the
existence of plastic and metal walls. Also Cur et Al. do not use
air bubbles as a thermic insulation.
[0010] U.S. Pat. No. 5,014,753 Rossignol et Al., May 14, 1991,
describes a flexible and impermeable insulator to protect
electrical wires against radiant heating. The insulator comprises a
series of successive layers of polymers of which a first layer is
of dark particles and a second clear with particles of metal having
a reflecting surface. Rossignol et Al. do not use air bubbles as
thermic insulation, nor the principle of hermetic joint around an
empty structure.
[0011] U.S. Pat. No. 3,810,491 Hildebrandt, May 14, 1974, describes
a method of manufacturing insulating conduits of double-walling and
circular section. Conduits of double walling comprise an interior
pipe disposed in a coaxial way relatively to an exterior pipe and
are insulated in the space comprised between double-walling.
Insulators being constituted of many successive layers of
insulating materials are separated by air spacing. These are
obtained with an insulating method placing insulation in tension
rather than compression. The insulating method consists in laying
out insulating bands and spacers in a helicoidal way along the wall
of the internal pipe and to remove the spacers to create a tension
between the wall of the internal pipe and the wall of the external
pipe. This invention requires two conduits with rigid walls. Its
use seems less appropriate for bends or other brutal directional
changes or for conduits of rectangular section.
[0012] U.S. Pat. No. 3,397,720 Jones, Aug. 20, 1968, reveals an
insulation system for cryogenic structures made of a sandwich sheet
that has many successive layers of insulation material, such as
sheets of corrugated polyester and other layers of insulation
material. Sheets of corrugated polyester create space at the center
leaving room for air. This application requires a double-walling
pipe to avoid air losses through insulating sheets that seem
porous. Moreover, this type of corrugated material, in the
construction of sandwich sheets does not make them flexible enough
for directional changes such as bends.
[0013] Conventional used air conduits made for kitchen hoods are
built with galvanized steel and do not comprise any insulation to
prevent heat loss. This type of conduits is available on the market
in two L-shaped half-conduits to be joined to make a rectangular
conduit. The two parts are held together with ends that are not air
tight and the conduits do not comprise any adaptor to hold the ends
of conduits together, facilitating loss of humid air. This type of
conduit does not comprise any thermic insulator, thus favoring
humid air condensation in a conduit which passes through a cold
area of a building or in winter time. So, as the conduit is not
tight to fluid exchanges, humidity and condensing water may leak
into the structure of the building and bring nuisances such as
moisture or other problems needing repairs or replacement.
[0014] None of the inventions mentioned above has a combination of
a light material, not requiring rigid nor expensive walls, but on
which the joints and the perimeter are air-tight, to prevent losses
of warm and humid air.
Objectives
[0015] The first objective of this invention consists in building
vaportight used air conduits to prevent humid air losses in
buildings, a thermic insulator to avoid humid air condensation
within conduits, adaptors and means of joining such conduits.
[0016] An objective of this invention is to provide a combination
comprising a basic material with two external layers of a radiant
material, separated by at least two layers of air bubbles comprised
in between five films of plastic matter (as polyethylene), cut in
variable sizes, prefolded in desired shape and assembled by means
of adhesive bands and provided with rigid means of coupling at one
end of a conduit and at the center of a four foot long straight
conduit.
[0017] Another object of this invention is to create ventilation
conduits that are light, easy to install and at a lower cost than
uninsulated conduits requiring the addition of an insulator
available in present market.
[0018] Another objective is to make four foot long conduits that
permit union with multiangular bends or internal deflectors.
[0019] The last objective is to make used air conduits of
rectangular shape (10 inches.times.31/4 inches) for kitchen hoods,
used air conduits of circular shape for bathroom (generally 3
inches) and drying-machine conduits (usually 4 inches).
DRAWING FIGURE
[0020] I will describe hereinafter more precisely, a method of
construction consistent with the present invention by referring to
annexed drawings in which:
[0021] FIG. 1 is a perspective view of a used air conduct,
rectangular, with partial section.
[0022] FIG. 2A is a plan view of the conduit of FIG. 1
[0023] FIG. 2B is a side view of the conduit of FIG. 1
[0024] FIG. 2C is a view from the upstream end of the conduit of
FIG. 1
[0025] FIG. 3A is a top view of a conduit, in construction
[0026] FIG. 3B is a section according to line 3B-3B of FIG. 3A
[0027] FIG. 3C is a section according to line 3C-3C of FIG. 3A, in
assembly
[0028] FIG. 3D is a close-up view of region 3D of FIG. 3C in closed
position
[0029] FIG. 4A is a perspective view with a partial cut of a
bend
[0030] FIG. 4B is a perspective view with a partial cut of another
bend
[0031] FIG. 5 is a perspective view of a circular conduit with a
partial section
[0032] FIG. 6A is a partial section of a longitudinal junction of a
circular conduit in preparation
[0033] FIG. 6B is a partial section of the longitudinal joint of
FIG. 6A completed.
DESCRIPTION OF THE INVENTION
[0034] A preferred embodiment of the subject invention is
illustrated in FIG. 1 wherein like parts refer to like numbers and
which shows:
[0035] Air Duct, Rectangular
[0036] A rectangular air duct 20 particularly for evacuating used
air has a parallelepiped shape and is made of a sandwich sheet 22.
The air duct 20 comprises a top 24, a bottom 26, a closed side 28
and an opened side 30 all forming a rectangular shape, parallel to
the major axis 32 and in the direction of fluid flow. The air duct
20 also comprises opened upstream 34 and downstream 36 ends, it is
also of rectangular shape and is parallel to a minor axis 38 and
perpendicular to the fluid flow. The top 24 is joined to the closed
side 28 with an adhesive band 40 on all the length of the top 24
and of the opened side 30.
[0037] A rectangular adaptor 42 comprises two longer sides 44 and
two shorter sides 46; the rectangular adaptor 42 partly fits into
downstream end 36 to serve as male end to another air duct on which
the upstream end 34 serves as the female end.
[0038] An elongated C-reinforcement 48 comprises a web 50 and two
wings 52. Each wing 52 of the C reinforcement is respectively in
contact with the top 24 and the bottom 26, the web 50 serving as
support, the C-reinforcement 48 being near the center of the major
axis 32 and of the minor axis 38. The C-reinforcement 48 prevents
the collapse of the top 24 onto the bottom 26.
[0039] FIG. 2A illustrates a view of the top 24 and of the
rectangular adaptor 42. FIG. 2B is a view of the opened side 30, of
the adhesive band 40 and of the rectangular adaptor 42. FIG. 2C
illustrates a view of the upstream end 34, the rectangular adaptor
42 and the C-reinforcement 48.
[0040] FIGS. 3A, 3B and 3C illustrate different steps of the
construction of an air duct 20, 4 foot long, 31/4 foot tall, 10
inch wide. FIG. 3A shows the result of the first step of
construction, namely cutting the sandwich sheet 22 in such a way
that it has a rectangular shape with a perimeter 54 comprising two
sheet long sides 56 of 4 foot in length and two sheet short sides
58 of 30 inches.
[0041] The second step of construction is that of sealing the
perimeter 54 of the sandwich sheet 22 with a heated angle iron to
form a first flat end 60 prolonging the opened side 30 and two
lateral flat ends 64 prolonging the sheet short sides 58.
[0042] The third step of construction is that of creating V grooves
66 with a heated angle iron to form a first limit 68 between the
top 24 and the closed side 28, a second limit 70 between the closed
side 28 et the bottom 26 and a third limit 72 between the bottom
and the opened side 30.
[0043] FIG. 3B illustrates a detail of a side view of the sandwich
sheet 22, the first flat end 60, the second flat end 62 and the V
grooves 66 after the third step. The V grooves 66 have a 45.degree.
side 73 to form a isosceles triangle when the sandwich sheet is on
a flat surface.
[0044] The sandwich sheet 22 (FIG. 3D) is of THERMO-FOIL.TM. type
and comprises an external film 74, an internal film 76, two layers
of air cells 78, the first flat end 60 (FIG. 3C) prolonging the top
24 and the second flat end 62 prolonging the opened side 30. The
air cells 78 act as insulators while the external film 74 and the
internal film 76 act like radiant material to keep a gradient of
temperature between ambient air and used air circulating in the air
duct. There cannot be any heat loss between an environment with
ambient air and an environment with used air because the first flat
end 60 and the second flat end 62 seal a perimeter of the sandwich
sheet 22.
[0045] FIG. 1 illustrates a wall located longitudinally relatively
to a major axis parallel to the direction of fluid flow and of
which a side is shown on FIG. 3C and presents a rectangular shape
comprising a first end 88 extending in a first flat end 60 of a
long crushed prolonged surface 80 of a width of 11/2 inch, and a
first angular crushing 82 at 45.degree. relatively to the top
24.
[0046] A second end 89 extends in a second flat end 62 and
comprises a second angular crushing 86 at 45.degree. relatively to
the opened side 30. The second flat end 62 is crushed on a width of
1/2 inch and can comprise a small prolongated surface 84 that
overhangs the second angular crushing 86.
[0047] FIG. 3C illustrates the fourth step of construction, namely
to assemble the rectangular air duct 20. When the sandwich sheet 22
is folded to form the air duct 20, the first angular crushing 82
and the second angular crushing 86 join to make a corner of the air
duct.
[0048] The first flat end 60 located at the first end 88 is to be
stuck to the outside of the opened side 30 and the second flat end
62 located at a second end 89 is to be stuck on the second crushing
end 86 and on the small prolongated surface 84 on bottom 24 to form
the air duct 20.
[0049] FIG. 3D illustrates a detail of the location of the first
flat end 60 once assembled and held by the adhesive band 40.
[0050] The fifth step is that of fitting the rectangular adaptor 42
into the downstream end 36 and to fix the C-reinforcement 48 (FIG.
1) inside the air duct 20.
[0051] FIG. 4A is a perspective view of a vertical bend 90, made
for a ventilating network with a vertical change in direction.
[0052] FIG. 4B is a perspective view of a horizontal bend 92
designed for a ventilation network with a horizontal change in
direction.
[0053] Circular Air Duct
[0054] FIG. 5 is a perspective view of a circular air duct 100,
that has a cylindrical shape and made of a sandwich sheet 22. The
circular air duct 100 comprises a cylindrical wall 102 having a
first end for circle 88' and a second end for circle 89' which are
parallel to a major axis of circle 108, an upstream and a
downstream ends of circle 110 and 112, opened and with circular
sections, and a circular adaptor 114.
[0055] The first end for circle 88' is joined to the second end for
circle 89' with an adhesive band for circle 116 on all the length
of the circular duct 100.
[0056] The circular adaptor 114 is rigid, of cylindrical shape and
comprises two ends 120; the two ends 120 being opened and
comprising a circular section. The radius of the circular adaptor
114 is shorter than the radius of the circular section by an amount
equal to the width of the sandwich sheet 22. The circular adaptor
114 partially fits in the inside of the downstream end of circle
112 to serve as a male to a following air duct of which the
upstream end of circle 110 is used as a female.
[0057] To construct the circular duct 100, having a length of 4
feet and a diameter of 3 or 4 inches, there are four steps
equivalent to those needed to construct the air duct 20 with
rectangular section. A first step consists in cutting the sheet 22
into a rectangular shape having a perimeter 54 (FIG. 3A) and two
sheet long sides 56 of four feet and two sheet short sides 58 of
91/2 or 121/2 inches.
[0058] A second step of construction consists in sealing the
perimeter 54 of the sandwich sheet 22 with a heated angle iron to
form a first flat end for circle 122 (FIG. 6A) prolonging the first
end for circle 88', a second flat end for circle 124 prolonging the
second end for circle 89' and two lateral flat ends for circle 126
prolonging the sheet short sides 58.
[0059] FIG. 6A shows a detail of the first end for circle 88' that
comprises a first flat end 122 that comprises a 1/2 inch wide
prolongated external crushing and an angular side 130 angular
relatively to the cylindrical wall 102.
[0060] The second side 124 prolongs itself towards the interior,
over a width of 1/2 inch, and has a 135.degree. side 134.
[0061] A third step of construction is that of assembling the
circular duct 100. The first flat end 122 is to be stuck outside of
the second end 89 and the second flat end 124 is to be stuck under
the first end 88 to form a continuous circular duct 100.
[0062] FIG. 6B illustrates the location of the first and second
flat ends 122 and 124 with external and internal prolongations once
assembled and enforced with an adhesive band 116.
[0063] A fourth step of construction is to put the sheet for the
circular duct 100 through a bender to get a perfectly cylindrical
product. This step is optional.
[0064] A fifth step of construction is that of fitting the circular
adaptor 114 into the downstream end 112.
[0065] I have discovered that the condensation problem caused by
heat loss in used air conduit is resolved by using a sandwich sheet
such as THERMO-FOIL.TM. with thermic insulation properties superior
to those of foams or sandwiches made of lamellae of different
insulating materials. I have also discovered that the problem of
humid air loss caused by used air conduits that are not air-tight
is resolved by sealing the perimeter at each joint by material of
the sandwich sheet and in using an adaptor located judiciously in a
used air system.
[0066] The reflective sandwich sheet material is made of a sandwich
comprising two layers of air cells and serving as thermic insulator
and on which is superinposed on top and bottom a sheet of
impermeable and radiant material.
[0067] So the sandwich sheet may successively comprise an aluminum
sheet, two layers of air bubbles contained within three films of a
plastic sheet coated with a material that might be fireproof, and
another aluminum sheet; or comprise an external aluminum sheet, a
layer of air cells and an internal polyethylene sheet; or it might
also be constructed with an external polyethylene sheet, a layer of
air cells and an internal polyethylene sheet.
SUMMARY OF INVENTION
[0068] A general objective is to create an air duct comprising a
number of segments, each one longitudinally oriented relatively to
a major axis 32 parallel to the direction of used air flow and
comprising a wall delimiting an interior space which permits air
flow, the wall being of uniform thickness and made of a rectangular
sandwich sheet comprising air cells confined between a first
external film and a second internal film, the second internal film
coinciding with the wrapping of the internal space, each segment
comprising an opened downstream end 36 and an upstream end 34, and
means for coupling fitted into the downstream end 36 to become the
male end when joined with another segment, or to couple an used air
conduit to a female end of another type of conduit, the upstream
end being the female end receiving the above male end.
[0069] The sheet may comprise: a first end 88 coinciding with the
length of the rectangular sheet to form the longitudinal joint of
the segment with a corresponding second end 89, the first end
terminating by a first 45.degree. angular crushing 82 extended in a
first flat end 60 and a second end 89 ending with a second angular
45.degree. crushing 86 extended into a second flat end 62 that
folds up onto the second angular 45.degree. crushing 86, the first
45.degree. angular crushing 82 leaning on the second flat end 62,
the first flat end edge 60 settling onto the second end along the
first external film. The wall comprises means of adhesion to seal
and hold together the first and second ends.
[0070] The coupling means comprise an adaptor 42 with an external
face 43 adjacent to the second internal film 76 of the wall, partly
extended outside of the downstream end 36 of the segment and that
can be sled in the upstream end of an adjacent segment or series of
segments. The wall also comprises lateral flat ends to seal
sandwich material at upstream and downstream ends.
[0071] The wall may also form a parallelepiped that has a
rectangular section comprising a top 24 extended in the first flat
end 60, a closed side 28, a bottom 26, an opened side 30 extended
by the second flat end 62 and at least three longitudinal folding
lines of which one demarcating a first limit 68, between the top 24
and the closed side 28, another demarcating a second limit 70
between the closed side 28 and the bottom and a third one
demarcating a third limit, between the bottom and the opened side,
the parallelepiped comprising means of reinforcement orientated
along the major axis, in contact with top and bottom, to prevent
collapsing of the top onto the bottom.
[0072] The rigid adaptor may be of parallelepiped shape and
comprises two opened ends and a rectangular piece of length l and
width w both inferior by twice the thickness t of the wall,
relative to the length L and width W of the rectangular section of
the segment, according to the equations L=2t+l and W=2t+w. The
adaptor will lean against the internal side of an opening delimited
by the top, the closed side, the bottom and the opened side of the
segment.
[0073] Means of reinforcement is a C shaped reinforcement
comprising a web and two wings, each one respectfully touching top
and bottom. The wings of the C are placed parallel to the major
axis and the web serves as support.
[0074] The first flat end is joined to the end of the opened side
by means of adhesion located on the entire length of the opened
side. Means of adhesion of the air duct is an aluminum band of the
Mactac.TM. type located over the entire length of the wall, to join
the first flat end to the second one.
[0075] The wall may be cylindrical, in which case it comprises a
first and second ends, the upstream and downstream ends being a
circular section of radius R, means of coupling being a rigid
adaptor comprising a cylindrical wall and two opened ends of radius
r inferior by the amount of the thickness of the cylindrical wall,
relatively to the radius of upstream and downstream ends, namely
R=r+t.
Method of Construction
[0076] The air duct may be made with rigid insulation material and
involves the following steps:
[0077] a step of cutting the sandwich of insulating material
delimiting a perimeter of predetermined size.
[0078] a step of sealing the perimeter to prevent fluid exchanges,
gaseous or liquid, between the interior of the insulating material
and the surroundings, the sealing step comprising a step of
crushing the first and the second ends,
[0079] a step of folding the sandwich around the major axis
according to a desired shape,
[0080] a step of assembling of the first and second flat ends by
means of adhesives to complete the shape of the section,
[0081] a step of installing of a rigid adaptor fitted into the
downstream end.
[0082] If the air duct is of parallelepiped form with a rectangular
section comprising a top, a bottom, a closed and an opened sides,
the method comprises these additional steps of construction:
[0083] a step of folding by heating means the sandwich to obtain
the angles, top, bottom, closed and opened sides required to have a
rectangular air duct,
[0084] a step of preparation of a C-reinforcement in making a web
and two wings with the insulating material,
[0085] a step of installation of the C wings respectively in
contact with top and bottom, the web serving as reinforcement.
[0086] The sandwich may be a sheet comprising many layers of
material, four sides and a perimeter. The sealing steps of the
perimeter consists in heating the perimeter with an angled-iron in
such a way that the layers of the sandwich that form the insulation
material melt to make four thin bands on each of the four sides of
the sheet, of which two are respectively part of the first flat end
of top and the second flat end of the opened side, the first flat
end when installed, should be in front of the second flat end of
the folded sheet.
[0087] The width of the first flat end of the top is bigger than
the width of the second flat end of the opened side so as to
reinforce any joint between the top and the opened side, the first
flat end of the top is installed, against the outside face of the
opened side, the second flat end of the opened side being placed
under the bottom face of the top side.
[0088] The step of folding the sandwich consists in heating the
sandwich with an angle iron so it will produce three V grooves
within the wall of the sandwich. The V grooves having 135.degree.
sides form an isosceles triangle when the sandwich is flat on the
ground: the V grooves respectively define a first limit between top
and closed side, a second limit between closed side and bottom and
a third one between bottom and opened side. When the sandwich is
folded to built the rectangular air duct, the 135.degree. sides are
connecting, to create angles forming the rectangular air duct.
[0089] A further assembling step consists in sticking the first
flat end of the top against the outside of the opened side, with an
adhesive band on all the length of the first flat end. Means of
adhesives may be an aluminized adhesive band of the Mactac.TM. type
installed on the full length of a joint, between the first and
second flat end.
[0090] The sealing step of the perimeter of the insulating material
consists in heating the perimeter with a hot angle iron in such a
way that the layers of the sandwich that form the insulation
material melt to create a thin band and a 135.degree. side, the
first flat end with the 135.degree. side 134 being set inside the
cylindrical wall, the second flat end with the 135.degree. angled
side being set outside the cylindrical wall.
[0091] The folding step requires an additional step of circulating
the air duct with the assistance of a roll folding device. The
second flat end 124 leans against the interior of the cylindrical
wall to obtain a continuous cylindrical wall.
[0092] The installation step comprises the jointing of a circular
adaptor inside a downstream end, the adaptor being rigid and
comprising a cylindrical wall and two ends.
[0093] It is clear that the method of realization of the present
invention being described above, referring to annexed figures is
provided as an indication and not limiting. Modifications and
adaptations may be made without parting with the objectives of the
present invention.
[0094] Other embodiments of the above invention are also possible
and not limited to the scope of the following claims:
1 PARTS LIST 20 air duct 22 sheet 24 top 26 bottom 28 closed side
30 opened side 32 major axis 34 upstream end 36 downstream end 38
minor axis 40 adhesive band 42 rectangular adaptor 43 external face
44 longer side 46 shorter side 48 C reinforcement 50 web 52 wing 54
perimeter 56 sheet long side 58 sheet short side 60 first flat end
62 second flat end 64 lateral flat end 66 V groove 68 first limit
70 second limit 72 third limit 73 45.degree. side 74 external film
76 internal film 78 air cell 80 long prolonged surface 82 first
angular crushing 84 small prolonged surface 86 second angular 450
crushing 88 first end for rectangle 88.sup.1 first end for circle
89 second end for rectangle 89.sup.1 second end for circle 90
vertical bend 92 horizontal bend 100 circular duct 102 cylindrical
wall 108 major axis of circle 110 upstream end of circle 112
downstream end of circle 114 circular adaptor 116 adhesive band for
circle 120 ends 122 first flat end for circle 124 second flat end
for circle 126 lateral flat end for circle 130 angled side 134
135.degree. side
* * * * *