Note: Descriptions are shown in the official language in which they were submitted.
7~5
HERMETIC WINDOW ASSEMBLY WITH
PRESSURE-EQ~ALIZATION SYSTEM
Background of the Invention
The invention relates to a system for selec-
tably equalizing an air pressure differential, relative
to ambient, in the airspace between the pair of glass
panes of double-glazed hermetically-sealed thermal
insulating window units (hereinafter referred to as
"hermetic window assemblies").
Hermetic window assemblies essentially consist
of two or more glass panes spaced apart and provided
with a hermetic seal about the entire perimeter of the
panes. Such assemblies are useful for ener~y conser-
vation purposes because the 'Idead air'l trapped in the
space between the glass panes serves as an effective
thermal insulator to reduce the amount of heat trans-
mitted through the window assembly. These window
assemblies can, in the normal course of use, be sub-
jected to a major change in ambient air pressure (for
example, if a mobile home containing such windows is
moved through a significant elevation gradient, or a
window assembled at a sea level manufacturing site is
used on the upper stories of a high-rise building). If
the ambient air pressure is significantly decreased, the
differential air pressure in the space between the panes
will cause them to deflect outwardly, producing dis~
tortion and stress on the hermetic seal at the window's
perimeter. On the other hand, if the window assembly
were assembled at a high elevation, then transported to
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a lower elevation, the panes would deflect inwardly,
similarly leading to stress on the perimeter's seal.
Over time this stress could breach the structural
integrity of the hermetic seal, thus allowing air and
moisture to enter into the airspace, causing foyging and
condensation on the interior surface of the glass panes
and rendering the window assembly unusable. If the
pressure differential of the ambient air pressure and
the airspace between the panes should become extreme,
the deflections of the panes may in time, particularly
if there are repeated air pressure variations such as
might occur in a mobile home transported to several
locations at differing elevations, even be severe enough
to fracture the panes.
Systems which automatically equalize the air
pressure differential of the airspace between the glass
panes of a hermetic window assembly and the ambient air
are known to the art. McCurdy et al. ~.S. Patent
3,60~,163 discloses a system for automatically equaliz-
ing the interior air pressure of a plurality of hermetic
window units by ducting the interiors of the window
units to a common manifold which is ported, in turn, to
the ambient air. The manifold is equipped with a means
for automatically releasing air when the manifold pres-
sure exceeds the ambient air pressure, and yet permitsair to enter into the manifold and thence the hermetic
window units if the ambient air pressure exceeds the
manifold air pressure.
~ elstharp U.S. Patent 2,062,7~7 d~scloses
another type of system for automatically equalizing
the air pressure in the interior of a hermetic window
assembly with the ambient air pressure. This systern
employs piping between the interiors of a plurality of
hermetic double-glazed window assemblies together with a
syphon which functions as a bellows and expands if the
interior air pressure of the window assemblies is
greater than ambient air pressure, and contracts if the
latter is greater.
Such prior art systems are relatively compli-
cated and costly because the equalization of the air
pressure differential, between the ambient air and the
interior of the window assemblies, is carried out auto-
matically, and continuously, on a plurality of windowunits.
Thus, what is needed is an economical, easy to
install and easy to operate system, for equalizing the
air pressure differential of the airspace between the
glass panes of an individual hermetic window assembly
and the ambient air, which can be selectably actuated,
as necessary, when this pressure differential becomes
significant.
Summary of the Invention
.
The present invention is directed to a low-
cost, readily installable and simple to use system for
equalizing the air pressure differential of the airspace
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between thç glass panes of a double-glazed hermetic
window assembly and the ambient air whereby this air
pressure differential is selectably, rather than auto-
matically or continuously, equalized.
A hermetic window as~embly, comprising a pair
of glass panes spaced apart and hermetically sealed
about their entire perimeter so as to form an airtight
airspace therebetween, is provided with a valve which is
selectably-actuated to open an air passageway from the
interior airspace to the ambient air. If it is desired
to equalize the air pressure differential between the
interior airspace and the ambient air, the valve can be
actuated by the user to open a connecting air passageway
and allow the interior air pressure to equalize.
The valve exemplarily is a manually operated,
spring-biased push-button type plunger valve, somewhat
similar to that shown in Peterson et al. U.S. Patent
4,014,365 and Hobbs U.S. Patent 2,820,475, although
other types of valves, capable of being actuated selec-
tably, may also be employed.
Therefore, it is an object of the present
invention to provide a means and system for selectably
equalizing the air pressure differential of the airspace
between the glass panes of a hermetic window assembly
and the ambient air.
It is a further object to provide a means and
system for selectably equalizing such air pressure dif-
ferential which is inexpensive, easy to manufacture and
install, and which can be manually operated.
7~i
The foregoing and other objective~, features,
and advantages of the invention will be mor~ readily
understood upon consideration of the following detailed
description of the invention, taken in conjunction with
the accompanying drawings~
Brief Description of the Drawings
FIG. 1 is a partially broken-away perspective
view of a hermetic window assembly incorporating the air
pressure equalization system of the persent invention.
FIG. 2 is an enlarged cross-sectional view of
a portion of the hermetic window assembly of FIG. 1,
showing the valve assembly in the closed position, taken
along the line 2-2 of FIG. 1.
FIG. 3 is a similar view to FIG. 2, but show-
ing the valve in the open position.
Detalled Descripton of the Drawings
Referring to FIG. 1, a hermetic do~hle-gla~ed
window assembly 20 of conventional construction is shown
comprising a frame 22, typically made of aluminum alloy
or other metal, and two glass panes 24 and 26 spaced
apart and sized so that their perimeters contact the
inner surface of the frame which is provided with a her-
metic caulking sealant 21 and 23 therebetween. (Ofcourse, other types of hermetic sealants suitable for
sealing the perimeters of glass panes 24 and 26 against
the inner surface of frame 22 could also be used.) One
of the panes of the window is provided at one of its
s
lower corners with a manually-actuated hermetic valve
28, the details of which are shown in FIGS. 2 and 3.
Turning now to the cross-sectional views of
FIGS. 2 and 3, hermetic valve ass~mbly 28 includes a
valve seat element 30 comprised of a central cylinder
34 and an interior hore 36. The ~ylinder 34 is
enlarged at one end to form an expanded outwardly-
tapered circular flange 38. At the other end the
cylinder is threaded to mate with a matching circular
flange member 42 on collar 40. When the valve asse~bly
is installed the two flanges 38 and 42 on valve seat 30
and collar 40 respectively are spac~d apart by the
thickness of the interposed glass pane 24, as
hereinafter described. The valve 28 also includes a
push-button plunger 44 comprising a cylindrical axial
member 46, having a button-type flange element 50
mounted by threading or other means onto its outer end
and a flared interior end portion 48. The flared end
48 is provided with an annular groove 55 in which ~-
ring 52 is seated.
Plunger 44 mates with valve seat 30 so thatthe major portion of its axial member 46 is located
inside the bore channel 36. The flared end 48 of the
plunger sits within the general confines of the
expanded portion 38 of the bore 36 and is designed to
make sealing contact therewith, as shown in FIG. 2. A
circular spring 54 passes around the outer portion of
the axial member 46 betwePn the button flange 50 and
the circular flange 42 so that spring 54 biases the
~21 3~745
plunger 44 outwardly, away from glass pane 24, when the
valve is installed. In this biased, or closed
position, flared end 48 of the plunger sealingly
contacts the expanded portion 38 o~ the cylindrical
member 34. A second 0-ring 52 is provided therebetween
to form an annular hermetic seal ~etween these two
elements.
The valve assembly 28 is installed in glass
pane 24, prior to the latter's assembly into a double-
glazed window unit, by first boring a hole just largeenough to accommodate the cylinder member 34, then
passing valve seat 30 through the hole from one side so
that the maior portion of cylinder 34 is positioned
within the pane opening. The outer circular flange
element 42 is then screwed on so that a snug fit is made
between the two flanges and the interposed pane, with the
0-rings 60 and 64 providing an annular he~metic seal.
The plunger 44 and its 0-ring member 52 are then
installed from the interior side, the spring applied from
the outer side and the button flange then fitted onto the
outer end of the plunger.
A~ shown in FIG. 3, when the plunger 44 is
pressed, its flared end 48 moves away from sealing
contact with the expanded channel portion 38 of the
central cylindrical member 34, thereby breaking the
hermetic seal and creating an air passageway in the
clearance between the plunger and the cylinder. Any air
pressure differential existing between the airspace in
the glass panes 24 and 26 o~ the assembled window unit
and the ambient air pressure will then equalize as this
newly opened air passageway allows the ambient air to
freely mix with the inside airspace. Hermetic valve 28
can thus be selectably actuated by a user as needed to
e~lalize the air pressure.
The terms and expressions which have been
employed in the foregoing specification are used therein
as terms of description and not of limitation and there
is no intention, in the use of such terms and
expressions, of excluding equivalents of the features
shown and described as portions thereof, it being
recognized that the scope of the invention is defined and
limited only by the claims which follow.
