Note: Descriptions are shown in the official language in which they were submitted.
CA 02253592 1998-11-04
FLUSH GLAZED DOOR
Field of the Invention
This invention relates to the field of door manufacture and more
particularly to the manufacturing of an insulated door having a glazing or
window
section installed therein, where the frame of said window section is installed
during
manufacture and is flush with both faces of the door.
1o Background of the Invention
The manufacture of decorative insulated doors for residential use is a
process that marries a coloured and decorative skin or sheathing to both sides
of a
perimeter frame. The frame usually constructed from wood, has specially formed
recesses into which the longitudinal edges of the decorative sheathing can be
inserted
after they have been in turn correspondingly bent to fit said recesses.
Frictional
engagement between the frame and sheathing components secure this assembly and
lend rigidity to the door structure. This door and frame unit is typically
insulated with
an expanding insulating foam material which is applied through very small
holes
drilled through the wooden frame to provide access to the internal void.
As the insulating foam expands to fill the internal door cavity, it is
likely to flow outwardly through any minute perimeter imperfections between
sheathing and frame resulting in time consuming cleanup by production
personnel.
As a result of the foregoing, frames for glazing or window units have
not generally been installed at the time of manufacture. It is common that a
portion of
an insulated door is cut out after manufacture to accommodate pre-made glazing
units
available in a variety of shapes and sizes. Said units comprise a frame,
having an
outer portion which is slipped into the cut out portion from the outside and
which
bears against the outer face of the door. An inner portion is installed in
opposed
facing relation so as to bear against the inner face of the door. The inner
and outer
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two portions are connected by screws passing from the inside portion to the
outer.
The two parts when assembled retain a separate thermally insulated glass
window
unit.
This process is typically not cost effective since the part cut out from
the door, once removed, have no further use and are scrapped. The insulating
value of
the door is obviously compromised since any retro-fitted frame will be subject
to
thermal transmission. Further, the window frame must be located on the outside
faces
of the door surrounding the window opening which can be susceptible to
moisture
1o infiltration. The door face loses the smooth linear expression by being
interrupted by
a bulky frame. U.S. Patent 4,897,975 discloses a door light which includes a
frame
incorporated structurally into the door and a glass removable from the frame.
Glazing
stops are provided to secure within the frame to allow for the insertion and
removal of
glass panels. While this patent does provide an integral door light frame, it
may not
adequately provide a weather-proof seal about the glass panel, nor does it
provide an
adequately insulated door where the insulation is continuous with the glass
support
portion of the door. There was therefore a need to develop a simple and
efficient
method for making an insulated door which is rigid and strong and can
accommodate
a suitable glass window that has a weather-proof seal. As will be evident, the
present
invention obviates the problems associated with the prior art methods.
Summarv of the Invention
In accordance with the present invention there is provided a method
and apparatus for manufacturing a door, wherein the door has a rigid wooden
frame
having interior and exterior faces, metal sheathing secured to the rigid
wooden frame
by means of preformed grooves or recesses therein which securely accept
suitably
formed edge portions of the sheathing, a window frame, which may be of a
suitable
extruded plastic, the window frame for placing within a window opening defined
by
the wooden frame and sheathing, that is, formed by interior and exterior
sheathing
assembled onto the wooden frame, the window frame for accepting for mounting
therein a thermally insulated window.
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The window frame has integral, outwardly facing recesses to accept
suitably formed edges of the interior and exterior sheathing, such as edges
bent at
right angles to the sheathing.
A resilient insulation seal is integrally formed at, or mounted to, the
extremity of each of the outwardly facing recesses such as along the distal
edge of the
recess. The seal engages the inner faces of the door sheathing thereby
preventing
expanding foam insulation from escaping around the perimeter of the window
frame.
The insulation seals may be components which are separate from the window
frame
and are installed around the inner and outer perimeter of the window frame
during
assembly. An integrally formed shoulder is formed around an exterior
perimeter,
parallel to the length of each window frame member, to retain a double glazed
window therein. The shoulder has a longitudinal internal void or thermal
break. The
interior perimeter of the window frame has formed therearound a slot or
channel. A
shoulder, notch or step is formed along at least one sidewall of the channel
for mating
engagement with a corresponding shoulder, notch or step in a mating resilient
clip.
The clip may be a channel member having opposed side walls, where a first side
wall
is mated into the slot or channel in the window frame to interlock the
corresponding
notches on the frame and clip. The second side wall is thereby pressed against
the
face of the double glazed window pane retained within the window frame.
Advantageously, the second side wall may be formed of a length to
allow double glazed window units of different thickness to be accommodated
within
window frames having the same dimensions. In order that the clip functions as
a
spring clip to urge the second side wall against the window pane, the first
side wall
and the web extending between the first and second side walls may be formed at
a
slightly acute included angle therebetween.
According to an object of the present invention there is provided a flush
glazed
door comprising;
- a rigid wooden frame having an opening for mounting an insulated window
therein;
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- a metal sheathing secured on each side of said frame;
- a window frame unit mounted within said wooden frame within said
opening;
- an insulated window positioned within said window frame unit; and
- means for retaining said window within said frame in an air-tight and
weatherproof manner.
The rigid wooden frame has a hollow internal cavity for the introduction of
insulating foam therein such that when the window frame unit is mounted within
said
opening it is partially embedded within the introduced insulating foam as it
cures.
According to another aspect of the present invention is a method for
assembling a flush glazed door, said method comprising the steps of
- constructing a rigid wooden perimeter frame having an internal cavity
therein;
- fitting an exterior and interior metal sheathing to said frame;
- securing a window frame within said perimeter frame;
- filling said interior cavity with expanding foam insulation such that said
window frame is partially embedded within said perimeter frame; and
- mounting a window within said window frame.
The present invention provides a flush glazed door that is durable and
thermally insulating and which allows one to manufacture the door without the
glass
insert therein such that no damage will occur to the glass as it can be easily
installed at
a job site. The door can acconunodate varying sizes and thickness of glass and
by
virtue of the design of the window frame, a window can be installed therein
and
tightly secured in an airtight and weatherproof manner.
Brief Description of the Drawings
A detailed description of the preferred embodiments are provided
herein below with reference to the following drawings in which:
Figure 1 is a perspective view of one embodiment of the flush glazed
door of the present invention;
Figure 2 is an enlarged view of one corner of the door assembly;
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Figure 3 is an enlarged sectional view along line 3 - 3 in Figure 1;
Figure 4 is an enlarged view of the exterior shoulder portion of a
window frame member of the present invention;
Figure 5 is an enlarged view cross-sectional through a window frame
member;
Figure 6 is a cross-sectional view of a retainer clip; and
Figure 7 is a view of the retainer clip installed against a window pane.
In the drawings, preferred embodiments of the invention are illustrated
by way of example. It is to be expressly understood that the description and
drawings
are only for the purpose of illustration and as an aid to understanding and
are not
intended as a definition of the limits of the invention.
Detailed Description of the Preferred Embodiment
As seen in Figures 1- 3, door 10 comprises perimeter frame members
12, exterior and interior faces 14 and 16 and a window unit 18. Frame 12 has
preformed vertical grooves 20 formed in both the exterior and interior faces
to accept
and securely retain suitably formed edge portions 22 of the sheathing. An
extruded
plastic window frame 24 is positioned within door frame 12 and sheathing
panels are
trimmed to a size that will permit their preformed edges 22 to engage both the
recesses in the perimeter frame 12 and corresponding recesses 26 formed around
the
exterior and interior perimeter of the window frame 24. It is preferred that
each
sheathing panel be made of a single piece of suitable steel that is punched
and flanged
to add rigidity and strength to the door. While the sheathing is fixed via
grooves it is
preferred that the sheath be bent at 90 angles to form lips 27 over the top
and bottom
edges of the door at either sides as desired.
It is understood by one skilled in the art, that the extruded plastic frame
can be made of any suitable material. Such materials may include but are not
restricted to plastic resin such as polyvinyl chloride of a suitable
weatherability
characteristic and of any suitable colour.
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As can be seen in Figures 3-7, the extruded plastic window frame 24 has an
integrally formed shoulder 28 formed around its exterior perimeter which
restrains
window 18 against outward movement. Shoulder 28 has a continuous cavity along
its
length to provide a thermal break. The interior face 30 of shoulder 28 is
formed at right
angles to window surround 32, as can be seen by angle A in Figure 5. Shoulder
28
terminates at its upper end in an inwardly projecting lip 34. Lip 34 contacts
the glass
pane of window unit 18 to provide a watertight seal when window unit 18 is
inserted into
the frame. Flanges 36 are integrally formed with window frame 24 to define
recesses 26
for securely retaining therein suitably formed edge portions 22 of the door
sheathing.
Flexible insulation seals 38 are formed along the free edge of flanges 36.
Seals 38 press tightly against the inner faces of the door sheathing when
installed in
recesses 26 to prevent escape of expanding foam insulation 39 injected into
the door
frame cavity around the perimeter of the window frame. Seals 38 may be of a
suitably
flexible resilient material which may be attached to, or formed as part of,
flanges 36 so as
to be cantilevered outwardly of the edges of flanges 36. After the door unit
is fully
assembled the internal cavity is completely filled with expanding foam
insulation 39.
As seen in Figure 5, the inner edge of window frame 24 has channel 40,
parallel to surround 32, and opening toward the inside face 16 of the door.
One or both
side walls of channel 40 may be notched to form shoulder 42, although in
Figure 5 only
the radially outer side wall (radially outer relative to the center of the
window and lying in
the plane of the window) is notched. Resilient retaining clip or strip 44,
illustrated in
Figure 6, resiliently snaps into place to mate step 50 with shoulder 42 as
side wall 46 is
slid into channel 40. The clip can be fabricated in any suitable resilient and
durable
material such as plastic. The clip is cut to a length to suit the window frame
dimensions.
Side wall 46 may also have a raised projection 48 on its inside surface,
opposite to step
50. Web 52 extends from the side wall 46 and is formed so as to be canted
slightly
toward the window when installed as indicated by angle B, that is, side wall
46 and web
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52 form a slightly acute angle between them. Web 52 extends from side wa1146
to side
wall 54, which also projects toward the window when clip 44 is installed.
Resilient
retaining clip 44 may be manufactured so as to provide clips having side walls
54 of
different lengths so as to accommodate double glazed window units of different
thickness. As will be noted from Figure 7, the retaining clip 44 cannot be
completely
seated within channel 40 so as to bring step 50 and shoulder 42 into locking
engagement
until side wall 54 engages the inner pane of glass 53 causing web 52 to be
resiliently
forced into a generally perpendicular orientation relative to side wall 46.
Clip 44 thus
acts as a spring clip in frictional engagement with glass 53, that is, with
the inside face of
the window unit. The glass for use in the present invention is preferably a
thermally
insulated glass.
The double glazed window is generally manufactured with dimensions
which are slightly undersize to that of the window frame. It is also
understood that the
window can be manufactured of varying widths and still be mounted within the
window
frame. Setting blocks 56 enable the window to be easily centred between the
upper and
lower portions of the frame.
Construction of an insulated door using the previously described process
requires only
that a rigid wooden perimeter frame be constructed, a window frame be
positioned within
said frame, exterior and interior sheathing strips be fitted thereto and the
internal cavity
be filled with expanding foam insulation. This method and the construction of
the
insulated door does not allow the expanding insulating foam to flow outwardly
from the
cavity. Thus the door of the present invention does not require any additional
cleanup of
any perimeters. The double glazed window need not be installed within the
frame until
the door is ready to be hung, thereby reducing damage of breakage during
shipping. The
method of manufacturing the door of the present invention does not compromise
the
insulating value of the finished door in any manner.
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Installation of the window within the frame simply requires that
double-sided glazing tape 60 as seen in Figure 4, similar to CascadeTM 2021
for
example, be applied to the inside perimeter of shoulder 28, and the protective
covering strip removed. Setting blocks 56 are then placed in the bottom
portion of the
window frame and the bottom of the double glazed window is positioned on the
blocks and the unit centred within the opening. The window is then pressed
firmly
against the glazing tape. Lengths of retaining clip 44 are then cut to suit
the frame
dimensions, side wall 46 is inserted into channel 40 formed in the frame and
step 50
snapped into position behind shoulder 42.
It is understood by those skilled in the art that the door of the present
invention can be fabricated in various dimensions to accommodate various sized
window units therein. The door has excellent insulating value and is not
susceptible
to moisture infiltration about the window.
As will be apparent to those skilled in the art in the light of the
foregoing disclosure, many alterations and modifications are possible in the
practice
of this invention without departing from the spirit or scope thereof.
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