U.S. patent number 3,854,248 [Application Number 05/362,043] was granted by the patent office on 1974-12-17 for duct access door.
Invention is credited to Lloyd Giddis Dayus.
United States Patent |
3,854,248 |
Dayus |
December 17, 1974 |
DUCT ACCESS DOOR
Abstract
Apparatus for manufacturing door frames for insertion into a
door opening, for example in air handling ducts and the like and
comprising a door frame forming member having at least one bendable
corner, and corner fastening means at a fourth corner whereby the
frame member can be formed into a rectangular frame. The apparatus
may include door latching means fastened to the frame member, and
means for sealing the frame to a duct opening. In conjunction with
the door frame apparatus the invention further comprises a door
border apparatus, for use with door forming members such as
rectangular metal door panels and the like, for making a door
border channel member having at least one bendable corner, and a
corner fastening means at a fourth corner whereby the channel can
be formed into a rectangular border around such rectangular panels
or the like, and including door securing means fastened to the
channel for co-operation with the door latching means on the door
frame.
Inventors: |
Dayus; Lloyd Giddis
(Mississauga, Ontario, CA) |
Family
ID: |
23424457 |
Appl.
No.: |
05/362,043 |
Filed: |
May 21, 1973 |
Current U.S.
Class: |
49/504; 49/465;
52/658 |
Current CPC
Class: |
B21D
53/74 (20130101); F24F 13/029 (20130101); F24F
13/02 (20130101) |
Current International
Class: |
F24F
13/02 (20060101); B21D 53/74 (20060101); B21D
53/00 (20060101); E06b 001/04 () |
Field of
Search: |
;49/465,466,464,463,501,503,504 ;160/1,381 ;52/658,627 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gilliam; Paul R.
Assistant Examiner: Kannan; Philip C.
Claims
What I claim is:
1. Apparatus for manufacturing door frames for insertion into a
door opening in a wall, for example in air handling ducts and the
like, and comprising;
a door frame forming member adapted to form a rectangular door
frame having four corners and defining a frame sidewall which may
be set up into a rectangular frame, a frame facing wall extending
from said frame sidewall in a generally L-shaped manner whereby to
lie within the frame when the same is set up, channel means formed
alongside the facing wall and remote from the sidewall and oriented
to receive a portion of the wall surrounding the opening therewith,
and,
notch means formed in said frame facing wall and said channel means
at spaced intervals to permit bending of said frame sidewall for
setting up as aforesaid, and,
means at at least one end of said frame forming member whereby the
ends thereof may be fastened together when the same is in its
rectangular position as aforesaid.
2. Apparatus for manufacturing door frames as claimed in claim 1
including door latching means fastened to the frame member,
engagable with a door, when the same is seated in said frame.
3. Apparatus as claimed in claim 1 including sealing means arranged
around said channel means for sealing between the same and said
wall.
4. Apparatus as claimed in claim 1 wherein said frame forming
member comprises a continuous strip of material formed with a frame
side wall, a frame facing wall, and a channel means as aforesaid,
and including;
notch means cut from said frame facing wall at three spaced
intervals therealong defining three corners;
and wherein the notch means in said channel means comprises
discontinuities in said channel means in registration will said
notch means in said facing wall;
sealing means arranged around said channel whereby to make a good
airtight seal between said frame forming member and said wall
defining the opening and,
door latching means fastened to said frame side wall, and
engageable with a door when the same is seated in said frame.
5. Apparatus as claimed in claim 4 including door forming means for
forming a door to be seated in said frame against said frame facing
wall, and door securing means on said door forming means for
interengagement with said door latching means.
6. Apparatus as claimed in claim 1 wherein said channel is formed
by an inner wall lying alongside said facing wall, and web means
joining the same along the free edge of said facing wall thereby
directing said channel outwardly with respect to the frame when the
same is set up.
7. Apparatus as claimed in claim 1 including door sealing means on
said facing wall.
8. Apparatus as claimed in claim 6 including notch means formed in
said webs at spaced intervals, and wherein said inner wall is cut
away at spaced intervals, to facilitate bending of said side
wall.
9. Apparatus as claimed in claim 1 including edge means on the edge
of said side wall remote from said facing wall, folded over said
side wall and including notch means cut therefrom at spaced
intervals to facilitate bending thereof.
Description
The present invention relates to inspection doors and frames for
use in air conditioning ducts and the like, and in particular, to a
kit for building such a door, and for building a door frame to
accommodate the door, for installation in a duct.
BACKGROUND OF THE INVENTION
Air conditioning ducts are installed with a variety of internal
controls such as dampers, and other equipment such as heating and
cooling coils, air filters, etc., and frequently are equipped with
so called "fire dampers" which are designed to close off the ducts
in the event of a fire. This equipment must be inspected and
serviced from time to time, and of course, in the case of fire
dampers, if the damper should be released by overheating, or by a
fire then it must be reset once the condition has passed, so that
the duct can be used once more.
In order to have access to the interior of the duct for these
reasons it is necessary to provide some form of inspection door or
trap door installed in the duct along side the damper or other
control. Such doors may be thermally insulated, and are often
sealed sufficiently well to withstand a certain predetermined
elevated pressure. In the past, such doors have been made more or
less or a custom basis by the installer of the duct work. As a
result, it was a relatively time consuming procedure, and was
unduly expensive.
Standardised doors and door frames have been manufactured which can
be applied to ducts and simply fastened in position by the duct
installer. However, these are not entirely satisfactory. In the
first place, the installer will require doors of different sizes.
In addition, the fastening of the frame to the duct work the
fastening and the sealing of the door frame to the duct must be
carried out with great care in order to achieve satisfactory
results. Such door frames as are available are cumbersome and
clumsy and require much time-consuming labour to fasten them in
position.
The manufacturing of standardized door and door frames, is also
open to a more serious drawback, in that the cost of stocking and
shipping the variety of sizes of doors and frames which may be
required for any particular job will be so great as to render the
doors and door frames unduly expensive except where local market
conditions are favourable.
BRIEF SUMMARY OF THE INVENTION
The invention therefore seeks to provide apparatus for
manufacturing door frames for insertion into door openings, for
example, in air handling ducts comprising a door frame forming
member adapted to form a rectangular door frame having four
corners; bendable means forming part of at least one of said four
corners whereby said means may be bent into an acute angle for
insertion of said frame forming member into a door opening, and,
corner fastening means at a fourth corner whereby the frame member
can be formed into a rectangular frame. The invention may also
provide door latching means fastened to the frame member, and means
for sealing the frame to a door opening. In conjunction with the
door frame apparatus the invention further comprises a door border
apparatus, for use with door forming members such as rectangular
metal door panels and the like, for making a door to fit the door
frame, the door border apparatus including a door border channel
member having three bendable corners, and a corner fastening means
at the fourth corner whereby the channel can be formed into a
rectangular border around such rectangular panels or the like, and
including door securing means fastened to the channel for
co-operation with the door latching means on the door frame.
The invention also seeks to provide a door frame, and door, when
made and assembled as aforesaid.
More particularly, it is an objective of the invention to provide a
door frame angle member formed out of a continuous roll formed
angle strip, the strip defining a frame sidewall, a frame facing
wall, and a channel formed along side the facing wall for
inter-engagement with the edges of the door opening in the air
handling duct for example, to form a good air tight seal.
More particularly, it is an objective of the invention to provide
apparatus for manufacturing door frames having the foregoing
advantages in which the angle member is formed with three spaced
apart notched portions, whereby the same may be bent at three
corners to form a rectangular frame, and including slotted means
formed at said corners whereby the corners may be bent into acute
angles to facilitate insertion of the frame into a door opening, as
in an air handling duct.
The foregoing and other advantages will become apparent from the
following description of a preferred embodiment of the invention
which is given here by way of example only with reference to the
following drawings in which like reference devises refer to like
parts thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective illustration of an air handling duct,
partially cut away, and showing a door and door frame, in
accordance with the invention, fastened in position therein;
FIG. 2 is a perspective illustration of a portion of the door and
door frame, partially cut away to show its construction;
FIG. 3 is a perspective illustration of an angle member for forming
the door frame according to the invention, shown prior to bending
into its rectangular shape;
FIG. 4 is a perspective illustration of the border channel for
forming the door according to the invention, shown prior to bending
into its rectangular shape, and,
FIGS. 5, 6, and 7 are schematic diagrams showing various stages of
the insertion of the door frame into a rectangular opening in a
duct, and,
FIG. 8 shows an alternate embodiment of the invention.
BRIEF DESCRIPTION OF A SPECIFIC EMBODIMENT
Referring to FIG. 1, a wall of an air duct 10 is shown which duct
may be of rectangular shape in section. The duct 10 may incorporate
some form of control means or damper means such as for example a
fire damper, (not shown) and access may be required to the interior
of the duct to service such control means or damper from time to
time.
For this purpose, the door unit shown generally as 12 is provided
in the sidewall of the duct by means of which access may be
obtained to the interior of the duct as desired.
The door unit 12 will consist of a door shown generally as 14 and a
door frame 16 which is fastened to the duct 10. It will of course
be understood that a rectangular opening is formed in the duct 10,
and the frame 16 is attached to the duct 10 around the rectangular
opening therein so as to enable the door 14 to be positioned in the
door frame 16 to close the same off.
Any suitable form of fastening means such as the latching members
18 and the door securing members 20 are provided by means of which
the door 14 may be secured in the door frame 16. A safety chain 22
may be attached between the door frame 16 and the door securing
member 20 so that when the door 14 is removed it will hang from the
chain 22.
Referring now to FIG. 2, it will be seen that the door 14 according
to the invention comprises inner and outer rectangular metalic door
panels 24 and 26, and sandwiched therebetween, a layer of thermal
insulation material such as spun fibre glass 28, or other suitable
material. The inner and outer panels 24 and 26 are held in their
sandwiching relation by means of the door forming chanel 30 which
comprises the central web 32, and the inner and outer side wall 34.
Notch means are formed at the corners 36 whereby the channel 30 can
be bent in to a rectangular shape as shown. Any suitable means may
be provided at the fourth corner for fastening the same and
securing it in its rectangular shape. Such means may comprise the
fastening lip 38 as shown in FIG. 4, which is adapted to overlap
the free end of the channel 30, and fastened for example by means
of a rivet or the like through the hole 40 (see FIG. 4).
As shown in FIGS. 1 and 4, door securing means 20 may be fastened
to opposite sides of the door forming channel 30, the door securing
members 20 having inturned flanges 42 whereby the same may be
grasped for manual removal of the door 14. In addition, the members
20 will preferably include some form of fastening means such as the
L-shaped tongue members 44 struck out of the members 20. A hole 46
may be provided in one or both of the inturned flanges 42 for
attachment of the chain 22 thereto.
The door frame 16 will preferably comprise a continuous angle
member having a sidewall 50, and a facing wall 52 arranged at right
angles thereto. Preferably, the outer edge of the side wall 50 is
turned inwardly at 54. Along side the facing wall 52 is formed a
narrow U-shaped channel, by means of the web 56 and inner wall 58.
Preferably, the inner wall 58 and the facing wall 52 define a
channel therebetween which is sufficient to receive the wall of the
duct 10 therein for securing the door frame 16 in position in a
rectangular opening in the duct. In order to provide a good air
tight seal, a strip or bead of a suitable sealant material 60 is
provided between the facing wall 52 and inner wall 58 which is of a
suitable consistancy to remain relatively soft, and to flow around
the edges of the opening formed in the duct 10 and make a good air
tight seal therewith.
Butyl rubber is a particularly suitable sealant material and has
the added advantage of providing a good adhesive bond to the walls
52 and 58 and also to the edges of the duct. This material
therefore acts as a space-filling adhesive and aids in securing the
frame to the duct.
Other sealant materials can also be employed such as foam plastic
material.
Alternatively, a seal may be achieved by applying a suitable
sealant to the edge of the ductwork itself. Such a sealant may be
some form of adhesive tape, with a foam plastic or rubber backing,
sufficient to fill the space between the duct work and the walls 52
and 58.
In order that the door frame 16 can be shipped flat and readily set
up in position at a work site, it is provided with three readily
bendable corners. These corners are formed by cutting notches 62 in
the facing wall 52 and the inner wall 58 and also by forming
notches 64 in the inturned outer edge 54 of the side wall 50. In
this way, the side wall 50 provides bendable means which can
readily be bent into a right-angle or an acute angle without
difficulty.
In order to permit the corners of the door frame 16 to be bent into
an acute angle, for insertion in the opening in the duct,
additional slots 66 are formed in the web 56 so that the adjacent
portions of the facing walls 52 and inner walls 58 may interleave
with one another when the corners are bent to acute angles.
The latching members 18 are rotatably fastened to the side wall 50
of the door frames 16, and will be seen to be of a more or less
irregular four-sided shape, roughly in the shape of a diamond, and
are provided with a curved slotted opening 72, and a finger portion
74 whereby the member may be swung to and fro. Preferably, the
curved slotted opening 72 is arranged so that its radius of
curvature shortens slightly from its open end to its closed end so
as to provide a slight camming action as it is closed around the
tongue 44 of its respective member 20.
In order to close and lock the fourth corner of the door frame 16,
an upturned locking member 76 is provided preferably indented as at
78, and the other end of the door frame 16 is preferably provided
with an opening as at 80 to receive the indentation 78.
A strip 82 may be struck out of a portion of the side wall 50 of
the frame 16 for attachment of the other end of the chain.
In operation, the duct work installer will receive the door frame
member 16 and the door border channel member 30 shipped flat as
shown in FIGS. 3 and 4. After having cut a suitable size of access
opening in the duct, he will then bend the door frame member 16 at
its three corners into acute angles as shown in FIG. 5. Having bent
the door frame member 16 into this position, it can then be
inserted into the opening in the duct, and the edge of the duct can
be pushed into the channel formed between the facing wall 52 and
the inner wall 58. The installer then gradually bends the various
portions of the frame 16 outwardly as shown in FIG. 6, until all
four sides are seated firmly around the edges of the duct as shown
in FIG. 7.
In order to fasten the frame 16 in position he then simply flexes
the wall 50, adjacent to the tongue 76 and twists it slightly so
that the tongue 76 can be introduced between the adjacent end
portions of the wall 50, and the turned-over edge portion 54, and
slipped into position. The struck-out portion 78 will then engage
with the hole 80, and the frame will then be secured in
position.
In order to make the door 14 itself, he will simply cut two pieces
of sheet metal into rectangular portions 24 and 26 as shown and
take a portion of insulation material 28 and cut it into a similar
rectangular shape and form it into a sandwich as shown in FIG. 2.
He will then take the door forming channel 30 and bend it around
the sandwich comprising the sheet metal portions 26 and 24 and the
thermal insulation panel 28, and fasten the two ends of the channel
by means of passing a rivet or self-tapping screw through the
tongue 38 and through the opening 40.
All that is then necessary is to fasten the chain in postion.
In this way, a simple apparatus is provided for forming door frames
and doors to fit the door frames, which may be supplied to the duct
installer in a compact form, and yet in a form in which it is
readily assembled in position at the site with a minimum of tools
or special forming being required.
It will be understood that where market conditions are suitable,
the door frames can be set up in the plant and shipped out already
bent as shown, for insertion into a duct opening. The doors can
also be completed and assembled in the factory and shipped out
ready for installation.
In the case of larger door sizes additional fastening means may be
provided where required on the frame and on the door to hold the
same secure against the air pressure in the duct.
In some cases, it may be possible to provide a satisfactory frame
with only a single bendable corner. Such a modified frame is shown
in FIG. 8. The two corners shown as 90 will be simple mitred
corners fastened into a right angle as shown and the third corner
92 will be of the flexible type as described above. Such a modified
frame can also be inserted into a duct opening in essentially the
manner shown in FIGS. 5, 6, and 7.
In either case, the invention provides a door frame having corners,
at least one of which incorporates bendable means whereby it can be
bent into an acute angle to permit insertion into a door opening.
Clearly, such opening can be in ductwork, or can be required in any
other location where such a door may be installed, such as in any
sheet metal, plastic, glass or wall panel of suitable
thickness.
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.
* * * * *