U.S. patent number RE35,120 [Application Number 08/116,729] was granted by the patent office on 1995-12-12 for display type refrigerator/freezer cabinet.
This patent grant is currently assigned to Anthony's Manufacturing Company, Inc.. Invention is credited to James J. Heaney.
United States Patent |
RE35,120 |
Heaney |
December 12, 1995 |
Display type refrigerator/freezer cabinet
Abstract
A substantially transparent single-pane insulating structure,
positionable between a warmer region and a colder region having a
substantially transparent pane wherein one surface is exposed in
use to the warmer region and the opposed surface in use facing the
cold region and a reflecting material applied to the surface of the
pane which faces the colder region for reflecting a substantial
portion of infrared radiation incident on the reflecting material
through the pane to the surface of the pane exposed in use to the
warmer region to restrict substantial transmission of infrared
radiation from the warmer region to the colder region and to heat
the surface of the pane exposed in use to the warmer region
sufficiently to prevent formation of a visibility-impeding layer
thereon without using electrical energy therefor and wherein the
reflected infrared radiation is reradiated into the warmer region
so as to inhibit reradiation thereof into the colder region and for
transmitting a substantial portion of visible light radiation
incident on the reflecting material to enable substantially clear
visibility therethrough is shown.
Inventors: |
Heaney; James J. (Glendale,
CA) |
Assignee: |
Anthony's Manufacturing Company,
Inc. (San Fernando, CA)
|
Family
ID: |
22689459 |
Appl.
No.: |
08/116,729 |
Filed: |
September 3, 1993 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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187558 |
Sep 15, 1980 |
4382177 |
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Reissue of: |
389675 |
Jun 18, 1982 |
04477129 |
Oct 16, 1984 |
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Current U.S.
Class: |
312/116;
52/171.1; 52/786.1 |
Current CPC
Class: |
A47F
3/0434 (20130101); E06B 3/6715 (20130101) |
Current International
Class: |
A47F
3/04 (20060101); E06B 3/67 (20060101); E06B
3/66 (20060101); A47F 003/04 () |
Field of
Search: |
;312/116
;52/171,788,178,811 ;428/34,913,432 ;350/1.6 ;62/248,255 ;219/218
;126/200 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2113876 |
|
Oct 1972 |
|
DE |
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1364712 |
|
Oct 1971 |
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GB |
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Primary Examiner: Dorner; Kenneth J.
Assistant Examiner: Anderson; Gerald A.
Attorney, Agent or Firm: Poms, Smith, Lande & Rose
Parent Case Text
This application is a division of Ser. No. 187,558, filed Sept. 15,
1980, now U.S. Pat. No. 4,382,177.
Claims
I claim:
1. In a display type refrigerated cabinet having a transparent
viewing area comprising a cabinet body for installation inside a
building and for containing merchandise required to be kept at
least colder than the ambient temperature in the region surrounding
the cabinet, apparatus for maintaining the temperature in the
region inside the cabinet at least colder than the ambient
temperature region surrounding the cabinet and including
transparent pane structure for viewing the contents inside the
cabinet, the improvement wherein .[.at least some of.]. the
transparent pane structure is a single pane having one surface
directly exposed in use to the warmer ambient region outside the
cabinet, and an opposed surface in use facing the colder region
inside the cabinet, and having an infrared reflecting visible light
transmitting coating applied to the surface facing the colder
region for reflecting a substantial portion of infrared radiation
incident on said coating from the warmer region, so as to restrict
substantial transmission of infrared radiation from the warmer
region to the colder region and so as to heat the surface of the
pane exposed in use to the warmer region sufficiently to prevent
formation of a visibility-impeding layer thereon by reradiation of
the reflected infrared radiation back through the pane toward the
warm region and for transmitting a substantial portion of visible
light radiation incident on said coating, to enable substantially
clear visibility therethrough.
2. The structure of claim 1 further comprising a second coating
over the said coating for protecting said coating.
3. The structure of claim 1 wherein the pane is embodied in a door
of said cabinet.
4. The structure of claim 3 wherein the door is oriented and
openable in a substantially horizontal plane. .[.
5. The structure of claim 1 further comprising a second transparent
pane, one surface being directly exposed in use to the colder
region and the other surface being substantially parallel to and
spaced from the first pane to form an airspace therebetween and
the infrared reflecting visible light transmitting coating is
applied to the surface of one of the panes facing into the
airspace..].
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is in the field of insulating devices and,
more particularly, a substantially transparent insulating
structure, having an infrared reflecting visible light transmitting
coating applied to one surface thereof.
2. Description of the Prior Art
It is presently known to provide a substantially transparent
multi-pane insulating structure, which functions so as to inhibit
transmission of infrared radiation from a warmer region to a colder
region. The structure may typically comprise two or more panes,
spaced apart by spacers which extend about the top, bottom, and
sides thereof so as to form at least one insulating airspace
therebetween. The panes may be bonded together, and a frame may
extend about the edges thereof. Such a multi-pane structure may
comprise a glass door for a refrigerated cabinet or freezer
compartment.
Generally, such multi-pane structures provide substantially more
insulation than single-pane structures. However, multi-pane
structures are also more expensive than single-pane structures. It
is therefore desirable to provide a single-pane structure which
provides substantial insulation so as to inhibit transmission of
infrared radiation from a warmer region to a colder region.
Further, there is a tendency in such insulating structures for the
temperature of the surface exposed in use to the warmer region to
attain the temperature at which a visibility-impeding layer may
form thereon, by virtue of the temperature differential between the
warmer region and the colder region. The visibility-impeding layer
may take the form of condensation on a refrigerated cabinet glass
door, or frost on a freezer compartment glass door. The formation
of such layer tends to occur as a consequence of the temperature
differential between the warmer and colder regions, by virtue of
the fact that the surface exposed in use to the warmer region is
generally at a cooler temperature than the ambient air in the
warmer region due to heat loss by radiation and conduction. Since
the door occupies a substantial portion of the front of the
cabinet, formation of the visibility-impeding layer therein
prevents customers from viewing products stored and displayed in
such cabinet or compartment, and is aesthetically unattractive and
unappealing.
To counter the tendency for condensation and frost to form on the
surface of the pane exposed in use to the warmer region, it is
known in the art to provide electrical heating means which heat
such surface. Various types of electrical heating means have been
used, including conductive coatings and resistive wires.
Preferably, the conductive coating is visible light transmitting,
to enable viewing of products stored and displayed in the cabinet
or compartment, and is applied to the surface of the pane facing
into the airspace for protection of the coating.
Electrical heating means use substantial quantities of electricity
in the operation thereof, which is expensive and inefficient.
Nevertheless, use of electricity is necessary in presently known
devices to prevent formation of the visibility-impeding layer, so
that customers may view products stored and displayed in the
cabinet or compartment, and to maintain the attractiveness of the
panes. Use of substantial quantities of electricity to heat the
pane is particularly necessary where the air in the warmer region
has a high moisture content.
It is presently further known to provide infrared filtering visible
light transmitting means in such structures, to prevent
transmission of infrared radiation therethrough while transmitting
visible light.
Transmitting infrared radiation into a colder region increases the
heat content thereof, necessitating use of substantial quantities
of electricity in operating the refrigeration system to remove such
heat from the colder region. These problems arise particularly with
respect to refrigerators and freezers.
Various types of infrared filtering visible light transmitting
means are presently known. One type of such means is an infrared
absorber shown, for example, in Brown U.S. Pat. No. 2,444,976.
Brown shows an absorption glass including a composition mixed in
the batch during manufacture of the glass, which composition
absorbs infrared radiation incident thereon. However, infrared
absorbing materials, as in Brown, increase the heat content of the
structure. A substantial portion of the absorbed infrared radiation
is released back therethrough by conduction and reradiation. This
substantially reduces the operating efficiency and utility of such
means.
Another type of infrared filtering visible light transmitting means
presently known comprises film or laminate applied to a surface of
a pane. Such means are shown, for example, in Edwards U.S. Pat. No.
3,499,697. Edwards shows a transparent laminate including a pair of
panels, a pair of thin plastic films, and multi-layer and
single-layer dielectric films, sandwiched together to provide a
laminate which selectively transmits visible light and reflects
infrared radiation. Here, as in Brown, the reflected infrared
radiation is released back by convection and reradiation.
Still another type of infrared filtering visible light transmitting
means presently known comprises a multi-pane insulating structure
with an infrared filtering film applied to one surface of one of
the panes. For example, U.S. Pat. No. 4,035,608, Stromquist, et
al., illustrates use of an infrared reflecting visible light
transmitting film applied to the inside surface of the second pane
from the warmer region, and a first pane adjacent the warmer region
electrically heated to prevent formation of a visibility-impeding
layer on the outside surface thereof. The heating means are
electrically operated, and are used to prevent formation of
condensation or frost. Since the heating means require use of
electrical energy for operation therefor, the expense of operation
thereof is substantial. This is particularly true with respect to
refrigerators and freezers, as there are normally substantial
temperature differentials between the ambient warmer region and the
colder region, and as the panes occupy a very substantial portion
of the selectively openable interface between the warmer region
which may include humid ambient air, and the colder region.
Further, the electrical heating means radiate heat to the second
pane, as well as the first, and such heat radiation interferes with
and reduces the efficiency of the coating in reflecting infrared
radiation.
It is further presently known to provide a guard for a fluorescent
lamp in a refrigerated cabinet. The guard extends substantially the
length of the fluorescent lamp and is spaced therefrom so as to
form an airspace thereabout. In operation of the cabinet, the
airspace constitutes a warmer region, and the surrounding
refrigerated air constitutes a colder region. The guard is
reusable, and typically need not be disposed of when the
fluorescent lamp is replaced.
Infrared radiation may be transmitted from the warmer region in the
guard-defined airspace to the colder region in the refrigerated
cabinet through the guard, heating the colder region and removing
heat from the warmer region. Loss of heat to the colder region
reduces the efficiency of operation of the fluorescent lamp and
increases the heat load in the colder region within the cabinet,
reducing the operating efficiency of the refrigerated system while
increasing its expense of operation. On the other hand, increased
heat in the warmer region within the guard could provide an
environment which would increase the efficiency of operation of the
fluorescent lamp.
The problems addressed by the present invention include preventing
transmission of infrared radiation from a warmer region to a colder
region, preventing formation of a visibility-impeding layer on a
surface of a structure exposed in use to a warmer region,
preventing reradiation of reflected infrared radiation, and
enabling transmission of visible light radiation.
It is normally necessary to use a multi-pane insulating structure
to provide insulation sufficient to enable efficient operation of a
refrigerated cabinet or freezer compartment. However, if a
single-pane insulating structure is used pursuant to presently
known devices, such structure is substantially less effective than
a multi-pane insulating structure in preventing transmission of
infrared radiation from the warmer region outside the cabinet or
compartment to the colder region inside the cabinet or compartment.
On the other hand, if such a multi-pane insulating structure is
used, it is substantially more expensive than a single-pane
structure.
It is further normally necessary, pursuant to presently known
devices, to use electrical heating means to heat the surface
exposed in use to the warmer region to a temperature above the
temperature at which a visibility-impeding layer forms. This
approach imposes expense and inefficiency upon the insulating
structure, particularly where there is a large temperature
differential between the warmer region and the colder region, and
where the warmer region may include humid ambient air.
Still further, presently known fluorescent lamp guard devices
transmit heat generated by the fluorescent lamp to the colder air
in a refrigerated cabinet, interfering with the most efficient
operation of the fluorescent lamp and of the refrigerated
cabinet.
Thus, particular problems arise. If a single-pane structure
pursuant to presently known devices is used, such structure is
substantially less effective than a multi-pane structure to prevent
transmission of infrared radiation from a warmer region to a colder
region. However, if a multi-pane structure is used, such structure
is substantially more expensive than a single-pane structure.
Further, if the surface of the insulating structure exposed in use
to the warmer region is not heated electrically pursuant to
presently known structures, a visibility-impeding layer forms,
which prevents customers from viewing merchandise stored and
displayed in the colder region. However, if the surface is heated
electrically, a substantial expense is incurred as a result of the
use of substantial quantities of electricity necessary for
operation thereof. Still further, if a guard is used pursuant to
presently known structures so as to protect a fluorescent lamp in a
refrigerated cabinet, heat in the airspace surrounding the
fluorescent lamp is dissipated by transmission thereof into the
colder region, which reduces the operating efficiency of the
fluorescent lamp. These are the particular problems for which the
present invention provides novel solutions.
SUMMARY OF THE INVENTION
The present invention provides a substantially transparent
insulating structure, which restricts substantial transmission of
infrared radiation from a warmer region to a colder region, which
inhibits formation of a visibility-impeding layer on the surface
thereof exposed in use to the warmer region without using
electricity therefor, and which inhibits reradiation of the
reflected infrared radiation, while enabling transmission of
visible light radiation.
The improvements in substantially transparent insulating structures
are provided by use of an infrared reflecting coating which
reflects a substantial portion of infrared radiation incident
thereon. The coating inhibits transmission of infrared radiation
from the warmer region to the colder region, thus reducing heat
transfer into the colder region. The coating transmits a
substantial portion of visible light radiation, thus enabling
customer viewing of products stored and displayed in the colder
region. The reflecting means reflect a substantial portion of
infrared radiation incident thereon, so as to heat the surface of
the pane exposed in use to the warmer region sufficiently to
prevent formation of the visibility-impeding layer thereon, without
using electricity therefor, thus substantially reducing operating
costs. The reflected infrared radiation is reradiated into the
warmer region, thereby inhibiting heat transfer into the colder
region. The reflecting means enable use of a single-pane structure
with insulating capabilities equal to or better than uncoated
multi-pane structures, while substantially reducing the cost of
such structures. The single pane structure preferably includes an
antiabrasion coating applied over the infrared reflecting coating,
to protect the infrared reflecting coating from abrasion which
might otherwise result from contact therewith. The antiabrasion
coating enables use of the single pane structure where contact may
occur, as in refrigerated cabinets or freezer compartments. A
multi-pane structure would otherwise be necessary to protect the
infrared reflecting coating from abrasion.
The substantially transparent insulating structure of the present
invention has utility in doors for refrigerated cabinets and
freezer compartments, particularly for commercial cabinets and
compartments used for storing and displaying food products in
retail food stores. The structure has further utility in a guard
for a fluorescent lamp in a refrigerated cabinet.
The novel features which are characteristic of the invention, both
as to structure and method of operation thereof, together with
further objects and advantages thereof, will be understood from the
following description, considered in connection with the
accompanying drawings in which several preferred embodiments of the
invention are illustrated by way of example. It is to be expressly
understood, however, that the drawings are for the purpose of
illustration and description only, and are not intended as a
definition of the limits of the invention.
DESCRIPTION OF THE DRAWINGS
The invention is illustrated, by way of example thereof, in the
accompanying drawings wherein:
FIG. 1 is a perspective view of a substantially transparent
insulating structure in a refrigerated cabinet door embodiment
thereof pursuant to the invention;
FIG. 2 is a perspective fragmentary view of the substantially
transparent insulating structure in a single-pane embodiment
pursuant to the invention;
FIG. 3 is a side cross-sectional elevational view of the
single-pane embodiment with electrical heating means applied
thereto in accordance with the invention;
FIG. 4 is a perspective fragmentary view of the substantially
transparent insulating structure in a double-pane embodiment
thereof pursuant to the invention;
FIG. 5 is a side cross-sectional elevational view thereof in
accordance with the invention;
FIG. 6 is a perspective fragmentary view of the substantially
transparent insulating structure in a triple-pane embodiment
thereof pursuant to the invention;
FIG. 7 is a side cross-sectional elevational view thereof in
accordance with the invention;
FIG. 8 is a perspective partly-exploded view of a substantially
transparent insulating structure in a single-pane freezer
compartment door embodiment pursuant to the invention;
FIG. 9 is a side cross-sectional elevational view thereof in
accordance with the invention;
FIG. 10 is a side cross-sectional elevational view of a
substantially transparent insulating structure in a double-pane
freezer compartment door embodiment pursuant to the invention;
FIG. 11 is a front elevational partly fragmentary view of a
substantially transparent or translucent insulating structure in a
fluorescent lamp guard embodiment thereof pursuant to the
invention;
FIG. 12 is a top view thereof; and
FIG. 13 is a side cross-sectional elevational view thereof in
accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, FIGS. 1-7 show a substantially
transparent insulating structure used as a door for a commercial
refrigerated cabinet. In this embodiment, as shown in FIG. 1, each
door 10, 10', 10" comprises a selectively openable interface
between a warmer region outside the cabinet and a colder region
inside the cabinet. Each door constitutes a substantial portion of
the front of the cabinet, and includes a pane which comprises a
substantial portion of the door, to enable customer viewing of
products displayed and stored in the refrigerated cabinet.
There are shown in FIGS. 2-3 perspective and cross-sectional views
of the insulating structure in a single-pane embodiment thereof. It
is necessary for use of such pane to prevent formation thereon of a
visibility-impeding layer, such as condensation or frost, in an
efficient and economical manner. This is particularly true where
the warmer region has a high moisture content.
The present invention enables such objectives to be satisfied by
means of a novel composite insulating structure. The substantially
transparent insulating structure is positionable between a warmer
region outside the refrigerated cabinet and a colder region inside
the refrigerated cabinet. The structure includes a substantially
transparent pane 20, one surface 21 of which is exposed in use to
the warmer region, the opposite surface 22 of which faces the
colder region in use.
Infrared radiation from the warmer region may be transmitted
through pane 10 to the colder region, if insulation is not
provided. To inhibit such transmission, it is presently known to
provide an insulating structure which includes at least two panes
of transparent material, such as glass. The panes of transparent
material are spaced from each other by spacers to form an airspace
therebetween. The airspace may be dead air or partially evacuated
to provide insulation. If the panes are separated by dead airspace,
it is presently known to fill such airspace with dry air and
include dessicant material therein. The structure is held together
by a surrounding U-shaped frame member and typically includes a
sealing gasket (not shown) to prevent leakage of air between the
inside and outside of the refrigerated cabinet.
Generally, a single-pane structure provides substantially less
insulation than a multi-pane configuration. Single-pane structures,
however, are less expensive than multipane structures. Thus, means
for insulating against the transmission of infrared radiation from
a warmer region to a colder region in a single-pane configuration
would provide substantial benefits. Further, such insulating means,
provided as a coating of a surface in a single-pane configuration,
must be protected from abrasion due to exposure thereof to
contact.
Further, the surface 22 of pane 20 exposed in use to the colder
region is no colder than the temperature of the colder region and
is generally warmer. Thus, no visibility-impeding layer, such as
condensation or frost, will normally form thereon. The warmer
region, on the other hand, particularly where it includes
humidity-bearing air, may generate formation of a
visibility-impeding layer, such as condensation, on surface 21 of
pane 20 exposed in use thereto. Pane 20 comprises a substantial
portion of the door, and the door occupies a substantial portion of
the front of the cabinet. Therefore, such visibility-impeding
layer, if formed on pane 20, would prevent customer viewing of
products stored and displayed in the colder region, and would be
unattractive and unappealing.
To prevent formation of the visibility-impeding layer it is
presently known, in a multi-pane configuration, to use electrical
heating means to heat the pane adjacent the warmer region, so that
the temperature of such pane is above the dew point temperature of
warmer ambient air adjacent the surface thereof exposed to the
warmer region. Electrical heating means consume substantial
quantities of electricity. Consumption of electricity is expensive
and inefficient. Further, the electrical heating means radiate heat
towards the colder region and into the refrigerated cabinet. Heat
transmitted into the colder region must be removed by the
refrigeration system, thus increasing the heat load and increasing
the expense of operation thereof. Thus, it is desirable to provide
means for preventing formation of a visibility-impeding layer on
surface 21 of pane 20 exposed in use to the warmer region, without
using electrical energy therefor, and while preventing reradiation
of such infrared radiation. It is further desirable to transmit
visible light radiation, to enable customers to clearly view
products stored and displayed in the refrigerated cabinet.
The present invention accomplishes these objectives by providing an
infrared reflecting visible light transmitting coating 30, applied
to surface 22 of pane 20 exposed in use to the colder region. By
virtue of such coating 30, a substantial portion of infrared
radiation incident thereon from the warmer legion is reflected
through pane 20 to surface 21 of pane 20 exposed in use to the
warmer region, preventing infrared radiation from entering the
colder region, and reducing the heat load on the refrigerating
system. A substantial portion of infrared radiation is reflected to
heat surface 21 of pane 20, sufficient to prevent formation of the
visibility-impeding layer thereon without using electricity
therefor. This eliminates the expense of use of electricity while
increasing the efficiency of operation. Coating 30 enables customer
viewing of products stored and displayed in the colder region by
transmitting visible light radiation sufficient to enable
substantially clear visibility therethrough. In using reflected
infrared radiation to heat surface 21 of pane 20 exposed in use to
the warmer region so as to prevent formation of a
visibility-impeding layer, reflected infrared radiation is
reradiated into the warmer region, thereby inhibiting reradiation
thereof into the colder region, further increasing the efficiency
of operation of the insulating structure. The use of the
single-pane configuration reduces the cost of the insulating
structure over double-pane configurations, while coating 30
provides such configuration with insulation capibilities equal to
or better than uncoated double-pane configurations. An antiabrasion
coating 31 is applied over coating 30 to protect coating 30 from
abrasion which might otherwise result from contact therewith.
A suitable infrared reflecting visible light transmitting coating
for use in the preferred embodiments of the invention is of the
type produced by Teijin Limited, Tokyo, Japan, under its
designation "Heat Reflection Film," having the characteristics of
95% infrared reflectance and 82% visible light transmittance. Such
coating includes a polyester film, on which multiple rare earth
depositions are performed, and is preferably thin, having a
thickness of 0.001", and flexible. The coating is substantially
transparent optically, and does not interfere with transmission of
visible light radiation, so as to provide substantially clear
visibility therethrough. The coating is highly efficient in
reflecting sufficient infrared radiation to prevent the formation
of condensation, without using electricity therefor, and in
reducing the temperature of products stored and displayed in the
colder region, while reducing use of electrical energy otherwise
necessary to remove additional heat from the colder region.
The materials used for antiabrasion coatings and processes for
depositing them are known in the art. Such materials and processes,
for example, are described in U.S. Pat. No. 3,806,462, issued to
Bloom.
FIG. 3 shows the single-pane embodiment of such insulating
structure, to which means for electrically heating the pane are
additionally applied. Such means comprise conductive coating 40,
applied to surface 22 of pane 20 which in use faces the colder
region, with coating 30 applied over coating 40. An antiabrasion
coating 31 is preferably applied over coating 30 to protect coating
30 from abrasion which might otherwise result from contact
therewith.
In such embodiment, coating 30 reflects a substantial portion of
infrared radiation incident thereon through pane 20 to surface 21
of pane 20 exposed in use to the warmer region, heating the surface
sufficiently, in combination with the heating provided by coating
40, to prevent formation of the visibility-impeding layer thereon,
while minimizing use of electrical energy therefor.
The materials used for conductive coatings and processes for
depositing them are known in the art. Such materials and processes,
for example, are described in U.S. Pat. No. 3,710,074, issued to
Stewart.
FIGS. 4-5 show perspective and cross-sectional views of such
insulating structure in a double-pane embodiment thereof. In this
embodiment, the structure includes a substantially transparent
first pane 50, one surface 51 thereof being exposed in use to the
warmer region, and a substantially transparent second pane 50', one
surface 52 thereof being exposed in use to the colder region,
spaced apart from the first pane 50' so as to form an airspace 53
therebetween. An infrared reflecting visible light transmitting
coating 54 is applied to the inside surface of pane 50 facing into
the airspace 53 between panes 50, 50'. Such coating 54 may
alternatively be applied to the inside surface of pane 50' facing
into the airspace between panes 50, 50'. Coating 54 functions in
the manner set forth above with respect to coating 30 in the
single-pane embodiment shown in FIG. 2.
In FIGS. 6-7 there are shown perspective and cross-sectional views
of such insulating structure in a triple-pane embodiment thereof.
The structure includes a substantially transparent first pane 70,
one surface 71 thereof being exposed in use to the warmer region, a
substantially transparent second pane 70', spaced apart from first
pane 70 so as to form airspace 72 therebetween, and a substantially
transparent third pane 70", one surface 73 thereof being exposed in
use to the colder region, spaced apart from the second pane 70' so
as to form an airspace 74 therebetween. An infrared reflecting
visible light transmitting coating 75 is applied to the surface of
pane 70' facing into the airspace 72 between panes 70, 70'.
Alternatively, such coating 75 may be applied to the inside surface
of pane 70' facing into the airspace 72 between panes 70, 70' or to
the inside surfaces of panes 70', 70" facing into airspace 74
therebetween. Coating 75 functions in the same manner set forth
above with respect to coating 30 shown in FIG. 2 in the single-pane
embodiment. FIGS. 8-9 illustrate a substantially transparent
insulating structure used as a door of a commercial freezer
compartment. In this embodiment, as shown in FIG. 8, the door is
oriented and operable in a substantially horizontal plane. The pane
100 comprises a substantial portion of the door between the warmer
region and the colder region, to enable customer viewing of
products displayed and stored therein.
In FIGS. 8-9, there are shown perspective and cross-sectional views
of such insulating structure in the single-pane embodiment thereof
for use in a freezer compartment. In FIG. 8, the structure is
positionable in use in a substantially horizontal plane between the
warmer region generally thereabove and the colder region generally
therebelow, and includes a substantially transparent pane 100, one
surface 101 being exposed in use to the warmer region, the other
surface 102 in use facing the colder region. An infrared reflecting
visible light transmitting coating 103 is applied to surface 102 of
pane 100. In such embodiment, coating 103 reflects a substantial
portion of infrared radiation incident thereon through pane 100 to
surface 101 of pane 100 exposed in use to the warmer region,
heating the surface sufficiently, in combination with infrared
radiation rising substantially vertically through the pane 100, to
prevent formation of the visibility-impeding layer thereon, without
using electricity. In FIG. 9, the single-pane embodiment of FIG. 8
is shown, to which means for electrically heating the pane is
additionally applied. The electrical heating means comprise
conductive coating 110 applied to the surface 102 of pane 100 in
use facing the colder region, with coating 103 applied over coating
110. An antiabrasion coating 111 is preferably applied over coating
103 to protect coating 103 from abrasion which might otherwise
result from contact therewith. Coating 110 functions as set forth
above with respect to the function of coating 30 in the single-pane
embodiment shown in FIG. 3.
In FIG. 10, there is shown a cross-sectional view of such
insulating structure in the multi-pane embodiment thereof for use
in a freezer compartment. The structure is positionable in use in a
substantially horizontal plane between the warmer region and the
colder region, and includes a substantially transparent pane 120,
one surface 121 being exposed in use to the warmer region, and a
substantially transparent second pane 120', one surface 122 of
which in use faces the colder region, spaced apart from the first
pane 120 so as to form an airspace 123 therebetween. An infrared
reflecting visible light transmitting coating 124 is applied to the
inside surface of pane 120 facing into the airspace 123 between
panes 120, 120'. In such embodiment, coating 124 reflects a
substantial portion of infrared radiation incident thereon through
first pane 120 to surface 121 of first pane 120 exposed in use to
the warmer region, heating the surface sufficiently, in combination
with infrared radiation rising substantially vertically through the
first pane 120, to prevent formation of the visibility-impeding
layer thereon, without using electricity.
FIGS. 11-13 show side, top and cross-sectional views of a
substantially transparent structure used as a guard for a
fluorescent lamp in a refrigerated cabinet. In this embodiment, as
shown in FIGS. 11-13, the guard 130 extends about the fluorescent
lamp substantially the length thereof and is spaced apart therefrom
so as to form an airspace 131 thereabout, and end caps 132 and 132'
retain the guard in position in the fixture and seal same from the
interior of the cabinet.
There are shown in FIGS. 11 and 12 elevational and top views of
such insulating structure, and in FIG. 13 a cross-sectional view
thereof. The guard structure 130 is substantially transparent or
translucent, one surface 136 being exposed to the interior of the
cabinet, the opposite surface 134 facing the fluorescent lamp. An
infrared reflecting visible light transmitting coating 135 is
applied to the surface 136 of guard 130 facing into the interior of
the cabinet. Alternatively, coating 135 may be applied to surface
134 of guard 130 facing the fluorescent lamp. In such embodiment,
coating 135 reflects a substantial portion of infrared radiation
incident thereon, to the fluorescent lamp in the warmer region,
heating the fluorescent lamp sufficiently to increase the operating
efficiency thereof, without using additional electrical energy
therefor, while transmitting a substantial portion of the visible
light radiation incident thereon. An antiabrasion coating 136 may
preferably be applied over coating 135, to protect same from
abrasion which might otherwise result from contact therewith.
Thus, there has been shown an insulating structure, substantially
transparent to visible light, having an infrared reflecting visible
light transmitting coating applied to a surface thereof. The
coating enables use of a single-pane or multi-pane structure having
substantial insulating capabilities. The coating further reflects a
substantial portion of infrared radiation incident thereon,
restricting substantial transmission of infrared radiation from the
warmer region to the colder region. The reflected infrared
radiation heats the surface of the structure exposed in use to the
warmer region sufficiently to inhibit formation of a
visibility-impeding layer thereon, without using electrical energy
therefor. The reflected infrared radiation is reradiated into the
warmer region, inhibiting reradiation thereof into the colder
region. The coating still further transmits a substantial portion
of visible light radiation, to enable substantially clear
visibility therethrough. In a single pane structure, the coating
provides insulating properties equal to or better than a double
pane uncoated structure. The single pane structure further includes
an anti-abrasion coating applied over the infrared reflecting
coating, to protect the infrared reflecting coating from abrasion
which might otherwise result from contact therewith. In a
multi-pane structure, the coating provides increased insulating
properties. In a structure positionable in use in a substantially
horizontal plane between a warmer region thereabove and a colder
region therebelow, infrared radiation reflected by the coating in
combination with infrared radiation rising substantially vertically
are sufficient to heat the surface exposed in use to the warmer
region so as to inhibit formation of a visibility-impeding layer
thereon without using electrical energy therefor. In a fluorescent
lamp guard structure, the coating enables heating of the
fluorescent lamp for more efficient operation thereof.
The foregoing description is illustrative of preferred embodiments
of the invention. It is to be understood that additional
embodiments thereof would be obvious to those skilled in the art.
Therefore, the embodiments described herein, together with such
additional embodiments, are within the scope of the invention.
Thus, the invention is to be broadly construed, within the scope
and spirit of the claims appended hereto.
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