U.S. patent application number 11/637841 was filed with the patent office on 2007-07-26 for electronics enclosure with solar shield.
Invention is credited to Albert Pedoeem, Kriss K. Replogle.
Application Number | 20070171600 11/637841 |
Document ID | / |
Family ID | 38163474 |
Filed Date | 2007-07-26 |
United States Patent
Application |
20070171600 |
Kind Code |
A1 |
Pedoeem; Albert ; et
al. |
July 26, 2007 |
Electronics enclosure with solar shield
Abstract
An apparatus for shielding an electronics enclosure is
disclosed. The apparatus includes an inner enclosure that houses
electronic components. An outer enclosure surrounds the inner
enclosure, and is separated from the inner enclosure by a gap. The
outer enclosure preferably comprises plastic, and comprises a
plurality of perforations uniformly distributed over its surface.
The plurality of perforations allow air to flow into the gap
between the outer enclosure and the inner enclosure. At the same
time, the perforations are configured and dimensioned such that
they substantially prevent sunlight from directly striking the
surface of the inner enclosure. In this manner, the apparatus
prevents overheating of the electronic components while minimizing
the space taken up by the enclosure.
Inventors: |
Pedoeem; Albert; (West
Orange, NJ) ; Replogle; Kriss K.; (Brookside,
NJ) |
Correspondence
Address: |
BINGHAM MCCUTCHEN LLP
2020 K Street, N.W.
Intellectual Property Department
WASHINGTON
DC
20006
US
|
Family ID: |
38163474 |
Appl. No.: |
11/637841 |
Filed: |
December 13, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60749577 |
Dec 13, 2005 |
|
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|
Current U.S.
Class: |
361/600 |
Current CPC
Class: |
H04J 3/1694 20130101;
H04Q 11/0062 20130101; Y04S 40/168 20130101; H04L 41/024 20130101;
Y04S 40/162 20130101; H04L 49/1523 20130101; H04L 41/042 20130101;
H04L 41/5054 20130101; H04L 49/50 20130101; H05K 7/202 20130101;
H04L 12/18 20130101; H04L 41/0856 20130101; H04L 45/16 20130101;
H04Q 2011/0084 20130101; H04Q 11/0067 20130101; H04L 41/0806
20130101; H04Q 2011/0079 20130101; H04L 49/351 20130101; H05K
7/20009 20130101; H04L 41/0213 20130101; H04L 43/50 20130101; H04L
41/509 20130101; H04L 49/357 20130101; H04Q 2011/0083 20130101;
H04L 49/30 20130101; H04Q 11/0071 20130101; Y04S 40/00 20130101;
H04L 49/15 20130101; H04L 49/352 20130101; H04J 2203/0094
20130101 |
Class at
Publication: |
361/600 |
International
Class: |
H02B 1/00 20060101
H02B001/00 |
Claims
1. An apparatus for enclosing electronics, comprising: an outer
enclosure having a plurality of perforations substantially
uniformly distributed about its surface; and an inner enclosure
positioned within the outer enclosure, wherein the inner enclosure
has one or more electronic components selectively positioned
inside; wherein the outer enclosure is configured and dimensioned
to be spaced from the inner enclosure.
2. The apparatus of claim 1, wherein each of the plurality of
perforations substantially prevent sunlight from directly striking
an outer surface of the inner enclosure.
3. The apparatus of claim 1, wherein each of the plurality of
perforations allow air to pass to the space between the inner and
outer enclosure.
4. The apparatus of claim 1, wherein about 95% or more of the
sunlight that strikes each of the plurality of perforations from an
angle of about 45 degrees or more, relative to normal, are
substantially prevented from striking a surface of the inner
enclosure.
5. The apparatus of claim 1, wherein the outer enclosure comprises
plastic.
6. The apparatus of claim 1, wherein the width of the perforations
is between about 5.5 mm and about 6.5 mm.
7. The apparatus of claim 1, wherein the height of the perforations
between about 2.5 mm and about 3.5 mm.
8. An apparatus for enclosing electronic components, comprising: a
first housing having one or more electronic components selectively
positioned therein; and a second housing configured and dimensioned
to enclose the first housing; wherein the second housing includes a
plurality of perforations that substantially prevent sunlight from
directly striking the first housing.
9. The apparatus of claim 8, wherein the plurality of perforations
are uniformly distributed about the surface of the second
housing.
10. The apparatus of claim 8, wherein the second housing comprises
plastic.
11. The apparatus of claim 8, wherein the thickness of the second
housing is between about 2.5 mm and about 3.5 mm.
12. The apparatus of claim 8, wherein the second housing is spaced
from the first housing.
13. The apparatus of claim 12, wherein the space between the second
housing and the first housing is between about 10 mm and about 14
mm.
14. The apparatus of claim 8, wherein: the height of the
perforations is between about 2 mm and about 4 mm; and the width of
the perforations is between about 4 mm and about 8 mm.
15. An apparatus for enclosing electronic devices, comprising: an
inner enclosure having one or more electronic devices positioned
inside; and an outer enclosure configured and dimensioned to
surround the inner enclosure; wherein the inner enclosure is
separated from the outer enclosure by a gap; and wherein the outer
enclosure comprises a plurality of perforations, wherein each of
the plurality of perforations allow air to enter the gap.
16. The apparatus of claim 15, wherein the outer enclosure
comprises plastic.
17. The apparatus of claim 15, wherein the plurality of
perforations are uniformly distributed on the surface of the outer
enclosure.
18. The apparatus of claim 15, wherein the plurality of
perforations substantially prevent sunlight from directly striking
a surface of the inner enclosure.
19. The apparatus of claim 15, wherein between about 80% and about
100% of the sunlight that strikes the outer enclosure from an angle
of about 45.degree. or more relative to normal is prevented from
directly striking a surface of the inner enclosure.
20. The apparatus of claim 15, wherein the gap is between about 8
mm and about 16 mm.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention claims priority to Provisional Patent
Application Ser. No. 60/749,577, filed Dec. 13, 2005, the entirety
of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to enclosures for electronic
equipment. More specifically, the present invention relates to an
enclosure for electronic equipment that effectively dissipates the
internally generated heat of the electronic equipment.
BACKGROUND OF THE INVENTION
[0003] Over the past 50 years, electronic equipment has become more
and more prevalent in the average person's everyday life. With the
invention of the transistor, electronics have rapidly become more
and more powerful and sophisticated. At the same time, advances in
technology have allowed electronics to penetrate nearly every
aspect of our everyday lives. The home is no exception.
[0004] Increasingly, electronic equipment has allowed us to
communicate with one another, or to receive other types of media
services such as television, telephone service, internet, and
satellite service. To provide these services, media providers often
run cables of varying types from remote locations to individual
homes. The cables, of varying types, allow individuals to receive
telephone, internet, and cable service.
[0005] Each individual home or unit has an interface, referred to
as a Network Interface Device (NID), located outside that allows a
home's internal wiring to communicate with the cables from the
media providers. The interface typically includes electronic
equipment and circuitry. The nature of electrical circuitry
requires that it be protected from the outside environment in order
to function properly. As such, different enclosures have been
devised in order to protect this equipment from the elements, such
as wind, water, dust, and heat.
[0006] Overheating of equipment due to solar radiation, and heat
generated by the electrical equipment itself, is the source of
significant problems. Electrical equipment that overheats can
malfunction, which results in costly repairs. To avoid overheating,
enclosures employ a wide variety of techniques in an attempt to
maintain an ambient temperature within an enclosure. This problem
is not as prevalent with indoor electrical enclosures, which are
currently more widespread, because these enclosures do not need to
be sealed and are not exposed to solar radiation.
[0007] Although the outdoor Network Interface Device (NID), the
housing for the demarcation point, is a mature technology, the
inclusion of heat-dissipating and environmentally sensitive
electronics and opto-electronics in particular in outdoor NID-like
applications is a relatively new application. Previous outdoor
applications have addressed the cooling problem by packaging the
electronics in an enclosure that is larger in surface area, and
hence less desirable by the customer, than is otherwise necessary
for the physical packaging of the electronics and associated
hardware. Prior art enclosures have also been designed to limit air
intake to the bottom surface of an enclosure, and air exhaust to
the top of the enclosure.
[0008] A drawback of more compact enclosures currently available is
that they result in operating conditions for the electronic devices
that are hotter than desirable under worst case environmental
conditions and will reduce the life and reliability of the system
below desirable levels. Higher power applications typically employ
expensive and power-hungry cooling fans.
[0009] A continuing need exists for a low cost electrical enclosure
that is capable of efficiently cooling electronic equipment.
Moreover, a continuing need also exists for an electrical enclosure
that can shield sensitive electronic equipment from solar
radiation.
SUMMARY OF THE INVENTION
[0010] The present invention comprises a method and apparatus for
mounting and cooling electronic equipment in a low-cost, preferably
plastic, environmentally protected enclosure that is protected from
excessive solar heating by a ventilated shield. The solar shield
intercepts the solar radiation and allows the ambient environment
on its outside surfaces and near ambient conditions on its inside
surface. The surface temperature of the environmentally protected
enclosure is reduced significantly relative to an enclosure without
a solar shield. The invention takes advantage of the fact that the
surfaces of the sealed electronics enclosure are not exposed to
solar radiation and yet, with adequate ventilation of the solar
shield, can be exposed to cooling air near the outdoor ambient
temperature. The ventilation openings in the solar shield, though
they may admit rain and dust along with cooling air, are sized to
exclude bees and wasps which are particularly troublesome in
outdoor enclosures.
[0011] According to one aspect, the present invention comprises an
apparatus for enclosing electronics. The apparatus includes an
outer enclosure having a plurality of perforations substantially
uniformly distributed about its surface, and an inner enclosure
positioned within the outer enclosure. Preferably, the inner
enclosure has one or more electronic components selectively
positioned inside. It is desirable for the outer enclosure to be
configured and dimensioned to be spaced from the inner
enclosure.
[0012] According to this embodiment, each of the plurality of
perforations substantially prevent sunlight from directly striking
an outer surface of the inner enclosure. At the same time, each of
the plurality of perforations allow air to pass to the space
between the inner and outer enclosure. The perforations are
configured and dimensioned such that about 95% or more of the
sunlight that strikes each of the plurality of perforations from an
angle of about 45 degrees or more relative to normal are
substantially prevented from striking the surface of the inner
enclosure.
[0013] In one embodiment the outer enclosure preferably comprises
plastic that has a thickness of between about 2.5 mm and about 3.5
mm. The width of the perforations may be between about 5.5 mm and
about 6.5 mm. Finally, the height of the perforations is preferably
between about 2.5 mm and about 3.5 mm.
[0014] According to another embodiment, the present invention
comprises an apparatus for enclosing electronic components. The
apparatus includes a first housing having one or more electronic
components selectively positioned therein, and a second housing
configured and dimensioned to enclose the first housing. It is
desirable for the second housing to include a plurality of
perforations that substantially prevent sunlight from directly
striking the first housing. The second housing is preferably spaced
from the first housing by a distance of between about 10 mm and
about 14 mm. Preferably, the height of the perforations is between
about 2 mm and about 4 mm, and the width of the perforations is
between about 4 mm and about 8 mm.
[0015] According to yet another embodiment, the present invention
comprises an apparatus for enclosing electronic devices. The
apparatus includes an inner enclosure having one or more electronic
devices positioned inside, and an outer enclosure configured and
dimensioned to surround the inner enclosure. The inner enclosure is
preferably separated from the outer enclosure by a gap that is
between about 8 mm and about 16 mm. The outer enclosure comprises a
plurality of perforations, each of which allow air to enter the
gap.
[0016] According to this embodiment, the outer enclosure comprises
plastic, and the plurality of perforations are uniformly
distributed on the surface of the outer enclosure. The plurality of
perforations substantially prevent sunlight from directly striking
a surface of the inner enclosure. For instance, between about 80%
and about 100% of the sunlight that strikes the outer enclosure
from an angle of about 45.degree. or more relative to normal is
prevented from directly striking the surface of the inner
enclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Further features and advantages of the invention can be
ascertained from the following detailed description that is
provided in connection with the drawings described below:
[0018] FIG. 1 shows an exemplary embodiment of the present
invention;
[0019] FIG. 2 shows a side view of one embodiment of the present
invention; and
[0020] FIG. 3 shows a cross-section of a ventilation hole according
to one aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Manufacturers of electrical enclosures prefer to produce the
enclosures in high volume in order to reduce their cost. This
requirement tends to favor a molded plastic enclosure cooled by
natural convection, although such a design does not dissipate the
internally generated heat of the electronics effectively enough for
a compact design with long life. The housing of electronic
equipment on the exterior of a residence for applications such as
fiber to the premises introduces a cooling problem due to the
following requirements: (i) compact packaging; (ii) sealing against
contamination; (iii) additional thermal loading from solar
radiation; (iv) low cost due to widespread deployment; and (v) low
maximum device temperatures for maximum life and reliability.
Temperature rise due to solar heating is particularly problematic
in sealed enclosures. In enclosures that hold electronics that have
a low operating power, temperature rise due to solar loading can
far exceed temperature rise due to self-heating of the
electronics.
[0022] To overcome this and other disadvantages, the present
invention provides an electronics enclosure that comprises a solar
shield. Generally, the enclosure comprises an inner enclosure that
isolates the electronics from the outside environment. The inner
enclosure, in turn, is surrounded by an outer enclosure that
includes perforations over at least a portion of its surface area.
The perforations are configured and dimensioned such that air is
capable of passing into a space between the inner and outer
enclosures. The flow of air around the inner enclosure allows heat
to be dissipated, cooling the electronics positioned within it. At
the same time, the perforations are configured and dimensioned such
that the inner enclosure is shielded from solar radiation.
Preferably, the perforations prevent the entry of insects, such as
bees and wasps, into the space between the inner enclosure and the
outer enclosure.
[0023] The enclosure may house any type of equipment. Preferably,
electronic equipment is housed within the enclosure. However, it is
contemplated that other non-electronic hardware may also be
enclosed. The non-electronic equipment may comprise materials that
support or otherwise interact with the electronic equipment. The
present invention may be used in combination with other elements,
e.g., heat sinks. An example of a heat sink that may be used is
disclosed in a co-pending U.S. Application filed on Dec. 13, 2006,
entitled "Heat Sinks for Electronic Enclosures," Attorney Docket
No. 19546.0005, the entirety of which is incorporated herein by
reference.
[0024] In one embodiment, the inner and outer enclosures comprise
the same material. In other embodiments, however, the inner and
outer enclosures may comprise different materials. It is desirable
for the enclosures to comprise a material that reduces cost and is
lightweight. As such, the enclosures are preferably comprised of a
plastic. However, the enclosures, or portions thereof, may comprise
a variety of materials other than plastic. These materials may
include, for example, metal, alloys, wood, glass, composites,
fiberglass, and the like.
[0025] Each enclosure may have any desired dimensions, as will be
appreciated by those skilled in the art. In other words, the
height, width, and depth of each enclosure may be chosen according
to a particular application. Factors that may be considered
include, but are not limited to, the type of electronic equipment
enclosed, the dimensions of the electronic equipment and/or
hardware enclosed, the space available outside a residence, and the
like.
[0026] FIG. 1 is a diagram showing one exemplary embodiment of the
present invention. FIG. 1 shows the enclosure of the present
invention in an unassembled position in order to facilitate the
explanation of this embodiment of the present invention. It is
desirable for the outer enclosure to include two parts, e.g., a
solar shield 10 and a mounting bracket 12. Similarly, the inner
enclosure includes a first portion 14 and a second portion 16.
[0027] The solar shield 10 and the mounting bracket 12 may comprise
any desired dimensions. Preferably, however, the dimensions of the
two parts 10, 12 are selected such that they are able to enclose
the inner enclosure. An example of this is shown in FIG. 2, which
is a side view of the FIG. 1 embodiment in the assembled position.
Similarly, the dimensions of the first portion 14 and the second
portion 16 of the inner enclosure may be selected such that the
electronics and/or other non-electronic hardware may be fully
enclosed.
[0028] In one embodiment, the outer enclosure of the present
invention is mounted to the wall, or another portion, of a
residence. As such, the mounting bracket 12 preferably includes one
or more mounting feet that enable the mounting bracket 12 to rest
flush against the surface of the wall of the residence. Optionally,
the mounting bracket 12 may include a fastener, e.g., a screw,
bolt, and the like, that passes from the inside of the mounting
bracket 12, through the back wall of the bracket 12 (facing the
wall), in order to fasten the mounting bracket 12 to the surface of
the wall. Skilled artisans will recognize that other fastening
mechanisms may be employed as desired. For instance, the fasteners
may pass through the mounting feet 18, or alternately the surface
of the mounting feet 18 that contacts the wall may include an
adhesive. In other embodiments, combinations of these and other
fastening mechanisms known to those skilled in the art may be
used.
[0029] The solar shield 10 and the mounting bracket 12 may be
connected in any desirable manner, using an fastening mechanism
known to those skilled in the art. Preferably, the solar shield 10
and the mounting bracket 12 are connected through selectively
engageable parts. For example, in one embodiment the solar shield
10 may include a protrusion, and the mounting bracket 12 may
include a corresponding recess. In order to connect the solar
shield 10 and the mounting bracket 12, the protrusion may be
inserted into the recess. At least a portion of the protrusion may
be configured and dimensioned such that it is slightly larger than
the opening of the recess, such that friction forces provide
resistance against disengagement. Alternately, the solar shield 10
and the mounting bracket 12 may comprise a "lock and key" mechanism
that prevents their disengagement. In still other embodiments,
adhesives, Velcro, hinges, or the like may be employed. Apparatus
and methods for connecting two portions of an enclosure are well
known to skilled artisans, any of which may be used, and the
present invention is not intended to be limited to any particular
apparatus or method of engagement.
[0030] In a manner similar to the outer enclosure, the inner
enclosure may also employ any of the apparatus and methods of
engagement described above. In one embodiment, however, it is
desirable for the inner enclosure to be tightly sealed when it is
engaged. This provides the advantage of isolating the electrical
components within the inner enclosure from any environmental
factors that may affects its operation, e.g., dust, wind, moisture,
and the like. An example of a sealed engagement 30 is illustrated
in FIG. 2. The inner enclosure, according to one embodiment, may be
configured and adapted to receive wires 32, cables, and the like
that may be connected to the electronic components, as shown in
FIG. 2.
[0031] The sealed engagement 30 of the inner enclosure may be
formed in a similar manner as the engagement described above.
Skilled artisans will recognize that additional materials may be
necessary to form a seal, such as rubber, metal, and the like. Both
the inner and outer enclosure, despite the engagement of its parts,
should be capable of being separated to allow access to both the
area between the inner and outer enclosure as well as the
electrical components positioned within the inner enclosure. To
facilitate the engagement of the outer enclosure and the inner
enclosure, the inner enclosure preferably includes hinges 20 that
are capable of engagement with the parts of the outer
enclosure.
[0032] As shown in FIG. 1, solar shield 10 and the mounting bracket
12 of the outer enclosure include a plurality of ventilation holes
22, or perforations. The present invention is not intended to be
limited to any number of ventilation holes 22. The ventilation
holes 22 may be selectively positioned in any desirable manner.
According to one aspect, the ventilation holes 22 may be positioned
such that the air flow results in a maximum amount of cooling of
the electronic components located within the inner enclosure. The
ventilation holes 22 are preferably located on both parts of the
outer enclosure, i.e., the solar shield 10 and the mounting bracket
12. In other embodiments, however, the ventilation holes 22 may
only be located on one part of the outer enclosure. It is desirable
for the ventilation holes 22 to be uniformly located over the
surface of the outer enclosure. One advantage of uniformly
positioning the ventilation holes 22 is that cooling may be
improved by maximizing air intake.
[0033] FIG. 3 is a diagram showing a cross-sectional view of an
exemplary ventilation hole 22 of FIG. 1. The ventilation holes 22
are preferably configured and dimensioned such that they are able
to admit air while preventing the entry of larger debris and even
insects, e.g., bees and wasps, that are often troublesome in
outdoor enclosures. The ventilation holes 22 may comprise any
desired shape known to those skilled in the art including, but not
limited to, circular, oval, any polygon, or even an irregular
shape. Preferably, however, the ventilation holes 22 are
rectangular. Furthermore, each of the plurality of ventilation
holes 22 may have the substantially same dimensions and shape, or
alternately the ventilation holes 22 may have substantially
different dimensions and shape.
[0034] In one embodiment, the height 24 of the ventilation hole 22
may be varied. Preferably, the height 24 of the ventilation hole 22
is between about 1.5 mm and about 4.5 mm. More preferably, the
height 24 of the ventilation hole 22 is between about 2.5 mm and
about 3.5 mm. Most preferably, the height 24 of the ventilation
hole 22 is between about 2.85 and about 3.15 mm.
[0035] In another embodiment, the height 24 of the ventilation hole
22 is preferably about 5 mm or less. More preferably, the height 24
of the ventilation hole 22 is about 4 mm or less. Most preferably,
the height 24 of the ventilation hole 22 is about 3 mm or less. In
yet another embodiment, the height 24 of the ventilation hole 22 is
preferably about 2 mm or greater. More preferably, the height 24 of
the ventilation hole 22 is about 3 mm or greater. Most preferably,
the height 24 of the ventilation hole 22 is about 4 mm or
greater.
[0036] The width 26 of the ventilation hole 22 may also be varied
as desired. In one embodiment, the width 26 of the ventilation hole
22 is preferably between about 3 mm and about 9 mm. More
preferably, the width 26 of the ventilation hole 22 is between
about 4 mm and about 8 mm. Most preferably, the width 26 of the
ventilation hole 22 is between about 5 mm and about 7 mm.
[0037] According to another aspect of the present invention, the
width 26 of the ventilation hole 22 is about 12 mm or less. More
preferably, the width 26 of the ventilation hole 22 is about 8 mm
or less. Most preferably, the width 26 of the ventilation hole 22
is about 6 mm or less. According to still another embodiment, the
width 26 of the ventilation hole 22 is preferably about 3 mm or
greater. More preferably, the width 26 of the ventilation hole 22
is about 6 mm or greater. Most preferably, the width 26 of the
ventilation hole 22 is about 8 mm or greater.
[0038] As shown in FIG. 3, the depth 28 of the ventilation hole 22,
and thus the thickness of the outer enclosure, may also be varied
as desired. In one embodiment, the depth 28 of the ventilation hole
22 is preferably between about 1.5 mm and 4.5 mm. More preferably,
the depth 28 of the ventilation hole 22 is between about 2 mm and
about 4 mm. Most preferably, the depth 28 of the ventilation hole
22 is between about 2.5 mm and about 3.5 mm.
[0039] In another aspect of the present invention, the depth 28 of
the ventilation hole 22 is preferably less then about 10 mm. More
preferably, the depth 28 of the ventilation hole 22 is less than
about 6 mm. Most preferably, the depth 28 of the ventilation hole
22 is less than about 3 mm. According to another embodiment, the
depth 28 of the ventilation hole 22 is preferably greater than 2
mm. More preferably, the depth 28 of the ventilation hole 22 is
greater than about 3 mm. Most preferably, the depth 28 of the
ventilation hole 22 is greater than about 6 mm.
[0040] To facilitate movement of air, the outer enclosure is spaced
a sufficient distance away from the inner enclosure, as illustrated
in the FIG. 3 embodiment. At the same time, it is desirable to
minimize the distance of between the inner and outer enclosure in
order to reduce the amount of space that the enclosure occupies. In
one embodiment, the distance between the outer enclosure and the
inner enclosure is preferably between about 6 mm and about 18 mm.
More preferably, the distance between the outer enclosure and the
inner enclosure is between about 9 mm and about 15 mm. Most
preferably, the distance between the outer enclosure and the inner
enclosure is between about 11 mm and about 13 mm.
[0041] In another embodiment, the distance between the outer and
inner enclosures is preferably about 25 mm or less. More
preferably, the distance between the outer and inner enclosures is
about 20 mm or less. Most preferably, the distance between the
outer and inner enclosures is about 15 mm or less. According to
other embodiments, the distance between the outer and inner
enclosures is preferably about 8 mm or greater. More preferably,
the distance between the outer and inner enclosures is about 15 mm
or greater. Most preferably, the distance between the outer and
inner enclosures is about 25 mm or greater.
[0042] One advantage of configuring and dimensioning the
ventilation holes 22 in the manner described above is that sunlight
can be prevented from directly striking the surface of the inner
enclosure, reducing the amount of heat to which the electronic
components are exposed. In other words, the ventilation holes 22
are preferably configured and dimensioned such that they
substantially minimize the amount of sunlight that strikes the
inner enclosure.
[0043] Those skilled in the art will recognize that sunlight
strikes the horizontal and vertical surfaces of the shield at
angles of about 45.degree. or more, relative to normal, during much
of the day. As illustrated in FIG. 3, sunlight that strikes the
ventilation holes 22 of the solar shield 10 from these angles
(about 45.degree. or more relative to normal) is substantially
prevented from passing through to the inner enclosure. Preferably,
about 80% or more of the sunlight that strikes the outer enclosure
is prevented from directly striking the surface of the inner
enclosure. More preferably, about 90% or more of the sunlight that
strikes the outer enclosure is prevented from directly striking the
surface of the inner enclosure. Most preferably, about 95% or more
of the sunlight that strikes the outer enclosure is prevented from
directly striking the surface of the inner enclosure.
[0044] According to another embodiment, between about 80% and about
100% of the sunlight that strikes the outer enclosure is prevented
from directly striking the surface of the inner enclosure. More
preferably, between about 90% and about 100% of the sunlight that
strikes the outer enclosure is prevented from directly striking the
surface of the inner enclosure. Most preferably, between about 99%
and about 100% of the sunlight that strikes the outer enclosure is
prevented from directly striking the surface of the inner
enclosure.
[0045] As shown in FIG. 2 and described above, one embodiment of
the present invention may be mounted or otherwise attached and/or
secured to the exterior of a residence, preferably a wall of the
residence. In its sealed configuration, the present invention
allows air to pass through the ventilation holes 22 of the outer
enclosure. The selectively positioned ventilation holes 22 allow
air to pass through the outer enclosure. At the same time, the
ventilation holes 22 are configured and dimensioned such that most
of the sunlight that strikes the outer enclosure does not directly
strike the inner enclosure. Moreover, the ventilation holes 22
substantially prevent the entry of insects and other objects of
similar dimensions. As the air enters the space between the inner
and outer enclosure, heat is effectively removed by natural
convection. One advantage of the present invention, therefore, is
that the surface temperature of the inner enclosure is reduced
significantly.
[0046] Although the present invention has been described with
reference to particular embodiments, it will be understood to those
skilled in the art that the invention is capable of a variety of
alternative embodiments within the spirit of the appended
claims.
* * * * *