Note: Descriptions are shown in the official language in which they were submitted.
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1 FIELD OF THE INVENTION
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The present invention relates to an evacuated glass
tile which is particularly useful as a wall insulator.
BACKGROUND OF THE INVENTION
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In the recent past there has been a substantial move
to increased building insulation as a result of the ever
increasing cost of energy resources. One method of
providing insulation is through the use of glass blocks.
However the insulating factor of these glass blocks is
not at a maximum because the blocks are generally filled
with air which prevents convection of heat energy across
each block. A glass structure has been proposed in
~anadian Patent 798,079 issued November 5, 1968 to
Lessings Ltd. Inc. in which a double glazed unit is
evacuated for maximizing insulation of the unit.
However, this double glazed unit which is in the order of
1 square meter requires an internal supporting structure
to prevent the unit from crushing inwardly under
atmospheric pressure. The unit is made from two separate
pieces to permit the insertion of the internal support.
After the support has been located in position the tvo
pieces are fused to one another and the unit is then
~- evacuated. Accordingly the Lessings structure is
expensive from a material standpoint in that extra
material in the form of the internal support must be
added. It is also expensive from the labour standpoint
required for inserting the support within the unit and
thereafter fusing the unit sections to one another. No
mention is made in the patent as to how the vacuum is
formed within the unit.
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1 SUMMARY OF T8E PRESENT INVENTION
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The present invention provides a glass tile which is
highly effecient as an insulator while at the same time
being relatively simple and ine~pensive to construct.
The tile which is formed by a glass blowing method is
evacuated and blown only to a size such that the tile
will withstand atmospheric pressure without requiring
supplementary internal supports~ The tile includes a
common orifice through which it is both blown and
evacuated and a cap at the orifice for maintaining the
vacuum within the tile.
The tile is Eormed in a limited number of extremely
easy steps and can be both blown and evacuated by a
single machine adapted to perform both functions.
Therefore the cost of the tile is kept to a minimum even
though it is e~tremely efficient as an insulator due to
its substantial evacuation. Furthermore without the
inclusion of internal supports within the tile there is
very little conduction of heat energy across the tile
other than at its edge regions which are small in
proportion to the remainder of the tile. This of course
is in contrast to prior art structure in which heat
; energy is rapidly conducted via the internal supports
from one side of the tile to the other.
BRIEF DISCUSSION OF THE DRAWINGS
The above as well as other advantages and features
of the present invention will be described in greater
detail according to the preferred embodiments of the
present invention in which:
Figure 1 is a perspective view showing a glass
3 1 ~
1 formed evacuated tile according to a preferred embodiment
of the present invention;
Figure 2 is a sectional view along the lines 10-10
of Figure l; and
Figures 3 and 4 are exploded plan views showing the
use of the tile of Figure 1 in the formation of
insulating surfaces.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Tile 21 shown in Figure 1 is formed by a glass
blowing process. After the tile has been formed it is
then evacuated. The tile itself is of a size such that
it will withstand atmospheric pressure without requiring
any internal supports within the tile as can be seen in
Figure 1. A typical tile size is 4" by 8" although this
size may vary slightly. However the size of the tile
cannot increase to the extent that it will collapse
inwardly under normal atmospheric pressures. On the
other hand it is not practical to make the tile so small
that it loses most of its insulating properties.
A plurality of evacuated tiles may be set up as
shown in Figures 3 and 4 to insulate an entire wall or
ceiling surface. Furthermore the two layers formed in
Figures 3 and 4 may be overlaid with one another to
increase the overall insulation at the wall or ceiling
surface.
Tiles formed according to the preferred embodiments
of the present invention are both blown and evacuated
through a common opening in the tile wall. According to
the embodiment shown in the drawings, this opening takes
the form of a glass nipple although the tile may be
31~2
1 formed without a nipple. Regardless of whether or not
the tile has a nipple, it may be formed according to a
particularly efficient method which involves the heating
of a source of material such as sulphur from the solid
state to a temperature at which the source vapourizes to
form a gas. This gas which is under pressure is used in
blowing molten glass preferably into a mold for the
formation of the tile body. The vapourization point of
the gas forming source should be something below the
melting temperature of the glass which is about 600
degrees ~elcius. Sulphur for example has a vapourization
point of about 400 degress celcius. After the tile is
completely formed in the mold it is cooled and sealed and
as the tile cools the glass which hardens below 600
degrees celcius returns to the solid state while the gas
used in blowing the gas maintains pressure within the
tile to hold its shape in the mold. Vpon further cooling
and after the glass has hardened, the gas returns to its
solid state at which time a vacuum is formed within the
now sealed tile body with a small residue of source
material being left in the tile.
Gases other than sulphur with a vapourization point
below 600 degrees celcius can also be used with the same
effectiveness. Furthermore in order to reduce the
pressure required to blow the molten glass into the mold,
the mold itself may be partially or totally evacuated so
that only a small amount of gas is needed to hold the
shape of the tile within the mold.
Returning now to Figure 1, tile 21 includes a pair
of large faces 23, one on either side of the tile and a
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1 rectangular frame 25 bordering the faces. As shown in
Figure 2, faces 23 are bowed slightly outwardly, i.e.
they have a convex configuration to add to the strength
of the tile body which is particularly important in view
of the fact that the tile is evacuated and free of any
supplemental internal supports. The outward bowing of
the wall therefore helps the tile to withstand
atmospheric pressures.
In order to assure that these convex tiles properly
seat against one another, when two or more layers are
used in insulating a wall or the like, the oter frame 25
enables flat contact between adjacent tiles laid over one
another. As can be seen in Figure 2, the frame 25
extends laterally outwardly beyond the convex tile faces
so that there is no contact between the faces of abutting
tiles.
Tile 21 includes a nipple 27 at one end of the tile
through which the tile is both blown and evacuated. ~his
nipple after being sealed, remains exposed along the edge
of the tile. However, as can be seen in Figure 1 the
tile is additionally provided with a cavity or recess 29
at the opposite end of the tile as well as a pair of
~ recesses 31 and 33 along one side of the tile. The tile
; could of course be provided with corresponding recesses
on the opposite side of the tile in addition to or in
lieu of recesses 31 and 33.
The cavities on tile 21 are adapted to receive an
exposed nipple of an identical tile to that shown in
Figure 1. Accoringly cavity 29 is positioned centrally
of the endwall of the tile so that two or more tiles will
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1 mate flushly when fitted end to end with one another.
However, with some arrangements it may be necessary to
position tiles in something other than an end to end
relationship whereby cavities 31 and 33 along the side of
the tile are used for receiving nipples of two side by
side tiles at right angles to tile 21. Accordingly tile
21 in the embodiment shown has, as described above, a
length double to that of its width, e.g. 4" by 8" and if
the tile body were divided into two equal halves,
cavities 31 and 33 would be positioned centrally of those
halves so that the two side by side tiles would fit
flushly with the side edge of the frame of tile 21.
Figures 3 and 4 show the formation of two layers of
insuating surfaces using a plurality of tiles identical
to tile 21. As will be seen in these Figures, when the
tiles are properly positioned all of the exposed nipples
are covered and a combination of 8 tiles forms a square
which can be aligned with or overlaid by a second layer
of similarly arranged tiles. It will be noted that the
layers shown in Figures 3 and 4 are positioned such that
all of the tiles forming the second layer are turned at
90 degrees to the tiles forming the first layer to
maximize the strength of the arrangement and at the same
time to block any small gaps that might appear between
the individual tiles from one layer to the next. It will
furthermore be appreciated that the frames rather than
the tile faces will be in contact with one another at the
interface between the two layers.
Although various preferred embodiments of the
invention have been described herein in detail it will be
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1 appreciated by those skilled in the art that variati~ns
may be made thereto without departing from the spirit of
the invention or the scope of the appended claims.
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