U.S. patent application number 10/891226 was filed with the patent office on 2005-01-20 for exhaust fan.
Invention is credited to Goyetche, Michael E..
Application Number | 20050013711 10/891226 |
Document ID | / |
Family ID | 34069010 |
Filed Date | 2005-01-20 |
United States Patent
Application |
20050013711 |
Kind Code |
A1 |
Goyetche, Michael E. |
January 20, 2005 |
Exhaust fan
Abstract
In accordance with one aspect of the present invention, a
portable exhaust fan for removing airborne materials from a
localized area is disclosed. The portable exhaust fan comprises: a
housing having an inlet opening and a discharge opening and
configured so as to define an air passageway between said inlet and
discharge openings; a blower unit mounted within said housing such
that rotating blades of said blower unit are located within said
air passageway to draw air into said inlet opening and to cause
said drawn air to travel through said air passageway and to exit
through said discharge opening; a flexible tube having a proximate
end connected to said inlet opening of said exhaust fan and a
distal end for placement in the localized area such that air drawn
into said inlet opening is air located primarily in the localized
area and travels through said flexible tube; and an inlet filter
removably attached over said inlet opening of said tube such that
air drawn into said inlet opening travels through said inlet
filter, wherein said inlet filter is constructed and arranged to
remove airborne materials that can accumulate in said tube or said
housing unit.
Inventors: |
Goyetche, Michael E.;
(Nahant, MA) |
Correspondence
Address: |
JAGTIANI + GUTTAG
10363-A DEMOCRACY LANE
FAIRFAX
VA
22030
US
|
Family ID: |
34069010 |
Appl. No.: |
10/891226 |
Filed: |
July 15, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10891226 |
Jul 15, 2004 |
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10418413 |
Apr 18, 2003 |
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10418413 |
Apr 18, 2003 |
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10213676 |
Aug 6, 2002 |
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6599341 |
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10213676 |
Aug 6, 2002 |
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09639869 |
Aug 16, 2000 |
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6440190 |
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Current U.S.
Class: |
417/423.9 ;
417/313; 417/423.3 |
Current CPC
Class: |
B01D 2273/30 20130101;
B01D 46/10 20130101; B01D 46/0023 20130101 |
Class at
Publication: |
417/423.9 ;
417/313; 417/423.3 |
International
Class: |
F04B 023/00; F04B
039/00 |
Claims
What is claimed is:
1. A portable exhaust fan for removing airborne materials from a
localized area comprising: a housing having an inlet opening and a
discharge opening and configured so as to define an air passageway
between said inlet and discharge openings; a blower unit mounted
within said housing such that rotating blades of said blower unit
are located within said air passageway to draw air into said inlet
opening and to cause said drawn air to travel through said air
passageway and to exit through said discharge opening; a flexible
tube having a proximate end connected to said inlet opening of said
exhaust fan and a distal end for placement in the localized area
such that air drawn into said inlet opening is air located
primarily in the localized area and travels through said flexible
tube; and an inlet filter removably attached over said inlet
opening of said tube such that air drawn into said inlet opening
travels through said inlet filter, wherein said inlet filter is
constructed and arranged to remove airborne materials that can
accumulate in said tube or said housing.
2. The exhaust fan of claim 1, wherein said exhaust fan further
comprises: an electrical box for housing electrical components
mounted on said housing, said electrical box constructed and
arranged to be substantially impenetrable by the airborne
materials.
3. The exhaust fan of claim 2, wherein said electrical box is
secured within said housing.
4. The exhaust fan of claim 2, wherein said electrical box is
secured to an exterior surface of said housing.
5. The exhaust fan of claim 2, wherein said electrical box is an
explosion proof electrical box.
6. The exhaust fan of claim 2, further comprising: electrical
wiring to carry power to the blower unit; and a sealed conduit
through which said electrical wiring travels within said air
passageway, wherein said sealed conduit is substantially
impermeable to the airborne materials.
7. The exhaust fan of claim 1, wherein said airborne materials
comprise paint overspray.
8. The fan of claim 7, wherein said airborne materials comprise
hazardous airborne materials.
9. The fan of claim 7, wherein internal components of said exhaust
fan that are exposed to said air is accessible and removable.
10. The fan of claim 1, wherein said components comprise a blower
fan blade.
11. The fan of claim 1, wherein said exhaust fan is constructed and
arranged such that the exhaust path prevents air from coming into
contact with incendiary promoters.
12. The fan of claim 11, wherein said incendiary promoters
comprise: high temperature surfaces, and electrical components.
13. The fan of claim 12, wherein said electrical components are
further prevented from exposure to the localized environment.
14. The fan of claim 1, further comprising: a second inlet filter
located adjacent to an inlet opening of the in the exhaust path,
constructed and arranged to remove at least those airborne
materials that can accumulate on or otherwise damage the internal
fan components.
15. The fan of claim 14, further comprising: an exhaust filter
located adjacent to a discharge opening of the in the exhaust path,
constructed and arranged to remove said hazardous materials and
additional airborne hazardous materials that may damage the
environment.
16. The exhaust fan of claim 1, wherein the exhaust tube further
comprises an accessible filter compartment disposed at a distal end
of the tube.
17. The exhaust fan of claim 1, further comprising: kill switches
that monitor conditions in the exhaust fan and which prevent the
exhaust fan from operating unless said conditions are in a
particular state.
18. The exhaust fan of claim 17, wherein said kill switches monitor
the status of any doors on the exhaust fan.
19. The exhaust fan of claim 17, wherein the kill switches monitor
the status of the filters in the exhaust fan.
20. The exhaust fan of claim 1, further comprising: accordion doors
attached to opposing sides of the fan.
21. The exhaust fan of claim 20, wherein the accordion doors are
removably attached to the exhaust fan without the use of tools.
22. The exhaust fan of claim 21, wherein the exhaust fan further
comprises a compartment constructed and arranged to store said
removable accordion doors.
23. The fan of claim 1, further comprising: a control panel through
which a user controls the speed at which the blades of said blower
rotate.
24. The exhaust fan of claim 1, further comprising: an indicator
panel having one or more indicators which visually prevent to the
user the status of various conditions in the exhaust fan.
25. The fan of claim 24, wherein the conditions comprise the
operational status of the exhaust fan.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention is a continuation-in-part application
of U.S. patent application Ser. No. 10/418,413, filed Apr. 18, 2003
entitled EXHAUST FAN FOR REMOVING AIRBORNE MATERIALS and naming as
inventor Michael E. Goyetche, now pending, which is a continuation
of U.S. patent application Ser. No. 10/213,676, filed Aug. 6, 2002
entitled EXHAUST FAN FOR REMOVING AIRBORNE MATERIALS and naming as
inventor Michael E. Goyetche, now U.S. Pat. No. 6,599,341 B2,
issued on Jul. 19, 2003, which is a continuation of U.S. patent
application Ser. No. 09/639,869, filed Aug. 16, 2000 entitled
PORTABLE EXHAUST FAN FOR REMOVING AIRBORNE HAZARDOUS MATERIALS and
naming as inventor Michael E. Goyetche, now U.S. Pat. No. 6,440,190
B1, issued on Aug. 27, 2002.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates generally to exhaust fans and,
more particularly, to exhaust fans for removing airborne
materials.
[0004] 2. Related Art
[0005] Stationary and portable fans have been known for years and
have been used for numerous applications. One use of exhaust fans
of particular pertinence to the present invention is for the
removal of airborne materials from a localized area. As used
herein, the term airborne material refers to any particles, fumes,
dust, chemicals or other materials that are at least momentarily
suspended in the air.
[0006] There are many drawbacks to traditional exhaust fans used
for removing various airborne materials in different applications.
For example, there are significant drawbacks associated with
conventional exhaust fans that are used for removing from a
localized area overspray from spray painting, airborne dust from
surface sanding, and airborne chemicals from painting, varnishing,
staining and similar activities.
[0007] One such drawback is that certain conventional exhaust fans
expose the air traveling through the fan to events that can ignite
those airborne materials that are flammable or combustible. Thus,
conventional exhaust fans are generally inappropriate to remove
safely from a localized area air having flammable or combustible
airborne materials.
[0008] Another drawback is that many currently-available exhaust
fans do not protect the internal components of the fan from the air
passing therethrough, resulting in an accumulation of materials on
such internal components. Certain airborne materials such as paint
overspray readily accumulate on the internal components of the fan
such as the fan blade, blade shaft, grating, electrical components,
etc. This requires conventional fans to be periodically
disassembled and cleaned. Unfortunately, such conventional fans
cannot be disassembled. As a result, a conventional exhaust fan
used in such applications is replaced often due to the rapid
accumulation of material on the fan components which adversely
affects the operating performance of the fan.
[0009] Another drawback to some conventional exhaust fans is that
they often do not clean the air before releasing it into the
surrounding environment. That is, the airborne materials are not
sufficiently removed from the air. As a result, such conventional
exhaust fans are unsuitable for use in many communities in which
clean air standards have been established.
[0010] Another drawback to some conventional exhaust fans is that
they often cannot be placed in the localized area from which
airborne materials are to be removed. This may be due to, for
example, the localized area not having a window that opens to the
external environment or that the localized area has such a window
but that the window dimensions are not appropriate for receiving
the exhaust fan.
SUMMARY
[0011] In accordance with one aspect of the present invention, a
portable exhaust fan for removing airborne materials from a
localized area is disclosed. The portable exhaust fan comprises: a
housing having an inlet opening and a discharge opening and
configured so as to define an air passageway between the inlet and
discharge openings; a blower unit mounted within the housing such
that rotating blades of the blower unit are located within the air
passageway to draw air into the inlet opening and to cause the
drawn air to travel through the air passageway and to exit through
the discharge opening; a flexible tube having a proximate end
connected to the inlet opening of the exhaust fan and a distal end
for placement in the localized area such that air drawn into the
inlet opening is air located primarily in the localized area and
travels through the flexible tube; and an inlet filter removably
attached over the inlet opening of the tube such that air drawn
into the inlet opening travels through the inlet filter, wherein
the inlet filter is constructed and arranged to remove airborne
materials that can accumulate in the tube or the housing.
[0012] Various embodiments of the present invention provide certain
advantages and overcome certain drawbacks of conventional exhaust
fans. Not all embodiments of the invention share the same
advantages and those that do may not share them under all
circumstances. This being the, the present invention provides
numerous advantages including the noted advantages of providing
safe and efficient removal of airborne materials, including
hazardous materials, from the localized air. These and other
features and advantages of the present invention as well as the
structure and operation of various embodiments of the present
invention are described in detail below with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above and further advantages of the invention will be
more clearly appreciated from the following detailed description
when taken in conjunction with the accompanying drawings, in which
like reference numerals indicate like structures or method steps,
in which the left-most one or two numerals of a reference numeral
indicate the number of the figure in which the referenced element
first appears, and in which:
[0014] FIG. 1A is a side view of an exhaust fan in accordance with
one embodiment of the present invention.
[0015] FIG. 1B is a perspective view of the fan illustrated in FIG.
1 installed in a window having vertical adjusting sashes.
[0016] FIG. 2A is a front view of one embodiment of the exhaust fan
illustrated in FIGS. 1A and 1B.
[0017] FIG. 2B is a front view of another embodiment of the exhaust
fan illustrated in FIGS. 1A and 1B.
[0018] FIG. 3 is a perspective view of one embodiment of the
invention in which input filter is secured within tracks in the
exhaust fan housing.
[0019] FIG. 4 is a side view of another embodiment of the present
invention in which filters that are not standardized,
self-contained filters can be utilized.
[0020] FIG. 5 is a side view of one embodiment of the control
module illustrated in FIG. 1A.
[0021] FIG. 6A is a front view of an exemplary control panel that
can be implemented in the exhaust fan illustrated in FIG. 1 A in
accordance with one embodiment of the invention.
[0022] FIG. 6B is a high level schematic diagram of an exemplary
embodiment of a control circuit and control panel for use in the
exhaust fan of FIG. 1A in accordance with one embodiment of the
present invention.
[0023] FIG. 7A is a cross-sectional view of one embodiment of the
exhaust fan of the present invention including an exhaust tube
attached thereto to remove airborne materials from a localized area
without having to locate the exhaust fan in that localized
area.
[0024] FIG. 7B depicts side and end views of one embodiment of the
exhaust tube illustrated in FIG. 7A.
[0025] FIG. 8 is a side view of an alternative embodiment of the
exhaust fan of the present invention.
[0026] FIG. 9 is a rear view of the exhaust fan illustrated in FIG.
8.
DETAILED DESCRIPTION
[0027] Embodiments of the present invention are directed to an
exhaust fan that can easily and quickly be carried to and set up in
a localized area to safely and efficiently remove airborne
materials from the localized area. Exhaust fans in accordance with
some embodiments of the present invention may be used to ventilate
a localized area such as an enclosed room and may be placed in any
aperture such as a window or doorway to remove such airborne
materials and to exhaust filtered air directly or indirectly to the
external environment. One embodiment of the present invention is
directed generally to an exhaust fan constructed such that airborne
materials contained in air traveling along an exhaust path through
the fan are substantially prevented from contacting components of
the fan that can be damaged by exposure to such materials. This
enables the fan to efficiently remove airborne materials from a
localized area while preventing the material from accumulating
appreciably on exhaust fan components. This has particular utility
in applications wherein airborne materials such as paint overspray
adheres readily to surfaces. By preventing the accumulation of such
and other materials on internal fan components, the fan operates
with greater efficiency for longer periods of time, does not
require the extensive periodic cleaning that conventional exhaust
fans mandate, and has a significantly longer operational life. The
fan components that necessarily come into contact with the air; for
example, the interior surface of the exhaust chamber and the vanes
of the fan blade, are preferably accessible and/or removable.
[0028] The above and other embodiments of the present invention
prevent airborne materials from accumulating on the fan components
such as the motor, motor shaft, bearings, fan blade and the like.
Depending on the airborne materials, this may cause damage ranging
from corrosion of internal surfaces, interference with blade
rotation, physically impeding device operation, shorting or
otherwise interfering with electrical components, etc. For example,
accumulation of paint overspray can occur quickly and may severely
hamper the operation of the fan. Over what may be a very short
period of time such accumulation can reduce the efficiency of the
exhaust fan (that is, continually reducing the CFMs of the fan),
eventually rendering the exhaust fan inefficient or ineffective.
This can continue until the motor seizes, rendering the fan
inoperable. It is not uncommon for example, for painters to dispose
of conventional commercial exhaust fans after a few weeks of
continual use due to the accumulation of overspray on the motor,
blades, blade shaft and other components.
[0029] Preferably, some embodiments of the exhaust fan are
constructed and arranged such that the air does not come into
contact with incendiary promoters such as high temperature
surfaces, components that transport or are powered by electrical
current, and the like. This enables the fan to safely remove air
that includes airborne materials that are flammable or combustible.
In addition, such incendiary promoters are also shielded from the
localized environment to prevent ignition of localized air that has
not yet been drawn through the exhaust fan. For example, the
electrical components are preferably located in a sealed,
air-impermeable or explosion-proof boxes and conduits mounted to
the exterior or interior of the exhaust fan.
[0030] Embodiments of the fan may also comprise disposable or
permanent inlet and/or exhaust filters located in the exhaust path
on opposing sides of the fan blades. The inlet filter is preferably
constructed to remove at least those hazardous materials that can
accumulate on or otherwise damage the internal fan components. The
exhaust filter is preferably constructed to remove the same and/or
other airborne materials that may damage the environment.
Advantageously, only the disposable filters need be changed to
maintain the fan in operable condition, eliminating the need for
costly and time consuming cleaning processes or the disposal of the
fan due to a reduction in operating effectiveness. In certain
alternative embodiments the inlet and/or exhaust filters are
non-disposable filters which are designed to be periodically
removed and cleaned. In certain other alternative embodiments, kill
switches are provided to ensure the proper installation of the
inlet and/or exhaust filters and, preferably, to ensure that any
doors on the exhaust are properly closed before permitting the
exhaust fan to be operated.
[0031] For those localized areas that are enclosed and which lack a
window or other aperture directly connecting the localized area
with the outside environment, alternative embodiments of the
invention include a flexible exhaust tube that extends from the
localized area to the exhaust fan located in a remote aperture that
opens to the exterior environment. The conduit may be a flexible,
extendable pipe having a proximate end for attaching to the fan
inlet and a distal end for being located in the localized area. In
certain embodiments, the distal end of the conduit may also include
a filter to prevent accumulation of airborne materials on the
internal surface of the conduit. In one embodiment, the distal end
of the exhaust tube includes a compartment formed in the tube which
is designed to removable hold such an inlet filter. To limit any
obstruction to the flow of air through tube, such a compartment is
preferably formed by interior and exterior gratings secured
partially in and on the distal end of the exhaust tube. Such a
filter compartment is preferably accessible by, for example, having
the external grating hinged or otherwise adjustably or removably
attached to the distal end of the exhaust tube. This enables a user
to easily gain access to the filter compartment to install and/or
remove a filter.
[0032] Thus, as will be described in detail below, in one
embodiment, the exhaust fan of the present invention is a long
lasting, portable exhaust fan that can remove airborne materials
such as overspray, fumes and dust particle from painted or sanded
surfaces, flammable and combustible materials, etc., without
damaging or reducing the operating life of the fan itself and while
preventing the exhaust air from harming the environment.
[0033] FIG. 1A is a side view of an exhaust fan in accordance with
one embodiment of the present invention. FIG. 1B is a perspective
view of the fan illustrated in FIG. 1A installed in a window with
vertically adjustable sashes. FIG. 2A is a front view of the
exhaust fan as it would be deployed in an aperture in accordance
with one embodiment of the invention. Exhaust fan 100 generally
comprises a housing body 102 in which a motor 104 and fan blade
assembly 108 are housed. Together, motor 104 and fan blade unit 108
comprise fan assembly 151.
[0034] In this illustrative embodiment, exhaust fan 100 includes a
hinged housing front cover 128 and a hinged housing rear cover 136
attached to housing body 102. In accordance with one embodiment of
the invention, replaceable filters are utilized to capture airborne
materials before entering exhaust path 112 as well as before the
air exits output opening 130. In the illustrative embodiment, each
housing cover 128, 136 are configured to hold such filters.
Specifically, an inlet filter 122 is removably secured within
housing cover 128 and an outlet filter 132 is removably secured
within rear housing cover 136. As fan assembly 108 rotates, air 124
having airborne materials is drawn through inlet opening 118 and
inlet filter 122 to enter an exhaust path 112 defined by chamber
116. The filtered air then travels through output filter 132,
resulting in the release of dual-filtered air 134 to the
environment. In this illustrative embodiment, exhaust fan 100 is
configured to be operationally positioned within a window and is
controlled through a control module 114. Each of the components is
described in detail below.
[0035] Housing 101 includes housing body 102 and, in this
embodiment, front and rear doors or covers 128, 136. In accordance
with one embodiment of the present invention, kill switches are
provided to ensure that front and/or rear doors 128, 136 are
properly closed before the fan is permitted to operate. One example
of such a kill switch is illustrated in FIG. 1A. Kill switch 180A
is disposed on the interior surface of housing body 102 and is
connected to a conduit 182. Conduit 182 provides a closed path
through which the electrical wires of one or more kill switches
180A, 180B can travel. Conduit 182 prevents airborne materials or
other materials from coming into contact with such electrical
wires, ensuring the integrity of the electrical connections.
Housing rear cover 136 is properly latched to housing body 102, and
provides a signal of such status to control module 114. Similarly,
one or more kill switches 180B may be provided in exhaust fan 100
to detect the installation of inlet filter 122 and/or outlet filter
132. The wiring related to such kill switches preferable is
included in conduit 182 as described above. Accordingly, in those
embodiments which include kill switches 180A and 180B on both the
inlet and outlet sides of exhaust fan 100, the exhaust fan will not
operate unless both doors are closed and latched and have filters
installed therein.
[0036] Preferably, interior surface 103 of housing body 102 is
substantially smooth to prevent interference with the flow of air
through exhaust passageway 112, and to avoid providing surfaces to
which airborne materials can adhere. It is also preferable that
housing body 102 be a unitary member or includes appropriate seals
at any joints to provide a sealed exhaust path 112 that prevents
contaminated air 124 from escaping from chamber 116 to the
environment before passing through outlet filter 132.
[0037] Housing 101 has a substantially rectangular configuration in
the illustrative embodiment for placement in a window or other
aperture. However, it should be understood that housing 101 may
vary widely in form and shape depending on the anticipated
operational location of exhaust fan 100. Housing 101 may be a
fabricated metal, molded plastic construction, synthetic resins,
etc.
[0038] As noted, the configuration of exhaust fan 100 is one such
that the fan can be secured within a window having upper and lower
sashes. Secured to or formed with housing body 102 of such an
embodiment is an upper flange 138 extending from the top wall of
housing body 102 and a lower flange 140 extending from a bottom
wall of housing body 102. Lower flange 140 is configured to fit
behind a window sill while upper flange 138 is configured to fit
behind a lower window sash opened to receive exhaust fan 100. To
prevent exhaust fan 100 from falling out of the window, a channel
152 may be provided to receive the window sash. In the embodiment
shown in FIG. 1, the window sash fits in channel 152 formed, by
control module 114 and upper flange 130, although in alternative
embodiments channel 152 is defined by two substantially parallel
flanges 138. As such the window closes over fan 100 securing it in
place by entrapping the housing against the window sill. It should
be understood that alternative approaches may be used to secure
exhaust fan 100 in a window aperture, depending upon the
configuration of the window. In the illustrative embodiment, upper
flange 138 and control box 114 are spaced to receive sash 184. When
sash 184 is positioned between control box 114 and sash 184, with
exhaust fan 100 resting on window sill 182, fan 100 will remove
airborne materials from localized area 190 to surrounding
environment 192.
[0039] Referring to FIG. 2A, on at least one side, and preferably
both sides of exhaust fan housing body 102, is an accordion door.
In the illustrative example, a left accordion door 202 is secured
to the left side of housing body 102 while a right accordion door
204 is secured to a right side of housing body 102. The accordion
doors 202, 204 may be used to close off any portion of the aperture
that is not consumed by exhaust fan 100. This increases the
likelihood that airborne materials do not escape the localized area
without passing through exhaust fan 100. Preferably, accordion
doors 202, 204 have conforming seals along their edges to further
minimize or prevent airborne materials from escaping the localized
area.
[0040] FIG. 2B is a simplified front view of an alternative
embodiment of the exhaust fan of the present invention comprising
removable accordion doors 252. In certain applications, it is
preferable to be able to remove one or more accordion doors from
the sides of exhaust fan 100 to facilitate transportation and/or
installation of the exhaust fan. In the embodiment shown in FIG.
2B, exhaust fan 100 includes a channel 254 formed into or secured
to the left and right sides of exterior surface 113 of housing body
102. A removable accordion door 252 has an extension arm 256
configured to slide into channel 254. To install removable
accordion door 252, the door is placed over the opening of channel
254 at the top of exhaust fan 100 and then slid down channel 254
until extension arm 256 is fully inserted in channel 254. In such
an embodiment removable accordion doors 252 are held in place by
gravity. Such tooless attachment and detachment of removable
accordion door 252 facilitates easy configuration and
reconfiguration of exhaust fan 100 by an end user. One of ordinary
skill in the art would appreciate there are other mechanisms which
may be implemented in other embodiments of the exhaust fan which
permit tooless attachment and detachment of removable accordion
doors 254. For example, in one alternative embodiment, velcro
strips are securely attached to the exterior surface 113 of housing
body 102 and to the abutting surface of removable accordion doors
252. In further embodiments snaps, magnets and detachable hinges
may be used. In such embodiments, the user of exhaust fan 100 may
be able to attach and detach removable accordion doors 252 without
the use of tools.
[0041] As noted, fan assembly 151 includes fan blade unit 108
attached to and controlled by motor 104. Electric motor 104 is
disposed within a sealed motor box 106 that is suspended from and
supported by a support conduit 126 secured to one or more sidewalls
of housing body 102. As shown in FIG. 1A, support conduit 126 not
only provides structural support to motor 104, but also provides an
enclosed path through which electrical wires and ventilating air
can travel. This prevents airborne materials from coming into
contact with electrical wires 105 and from escaping exhaust fan 100
through component ventilation paths.
[0042] As noted, motor 104 is housed within sealed motor box 106 in
this illustrative embodiment. Such a box 106 prevents the
accumulation of airborne materials on motor 104, preventing
interference with the electrical connection with wires 105,
rotation of shaft 115, etc. In alternative embodiments, motor
manufacturers may provide a fully self-contained motor that can
withstand such exposure, thereby negating the need for such a
sealed box 106.
[0043] Motor 104 is secured within sealed box 106 through upper and
lower grommets 109 to avoid damage due to shock and to dampen
vibration from blade rotation. Shaft 110 exits sealed motor box 106
through an aperture on a downstream side of motor box 106. This
limits the exposure of shaft 110 to airborne contaminants due to
the airflow patterns around sealed motor box 106. A bearing seal
107 is provided at the aperture to rotationally support shaft 110
while maintaining the integrity of sealed motor box 106.
[0044] Removably attached to shaft 110 is fan blade assembly 108.
Fan blade assembly 108 includes any number of blades to provide the
desired air flow. A bolt 111 secures blade assembly 108 to shaft
118. Bolt 111 is also positioned at a location and orientation that
limits its exposure to the flow of air through chamber 116 to avoid
accumulation of airborne materials that may enter chamber 116.
Despite filtering of airborne materials by inlet filter 122, it may
be desirable to clean periodically fan blade assembly 108. This may
be accomplished by opening rear cover 136 and removing bolt 111. To
prevent combustion of air 124, in certain embodiments fan blade
assembly 108 is manufactured from a non-sparking material such as
aluminum. It is preferred that such a material also be capable of
withstanding chemical cleaning.
[0045] As one of ordinary skill in the relevant art would find
apparent, motor 104 may be any motor suitable for the overall size
of exhaust fan 100 and the requisite CFMs. For example, to delivery
500 CFMs or more, a fan having a blade diameter of at least 10
inches would be likely used in one embodiment. On the other hand,
if space is at a premium and significant CFMs are required, then
motor 104 should be capable of operating at sufficient RPMs to
deliver the requisite CFMs. In one particular embodiment, fan
assembly 151 is a Dayton 4C650 fan with a 10 inch diameter fan
blade and a motor 104 that can operate at 1550 RPM to deliver 520
CFMs. In an alternative embodiment, fan assembly 151 is a Dayton
4C650 fan with a 12 inch diameter fan blade and a motor 104 that
can operate at 1550 RPM to deliver 700 CFMs. In an alternative
embodiment, fan assembly 151 is a Dayton 4C658A fan with a 10 inch
diameter fan blade and a motor 104 that can operate at 1550 RPM to
deliver 595 CFMs. In one embodiment, sealed in motor box 106 as
described above is utilized to provide an exhaust fan 100 that can
be used to remove flammable airborne materials.
[0046] As noted, certain embodiments of exhaust fan 100 comprises a
dual filter system including an inlet filter 122 and an outlet
filter 132 located on opposing sides of fan blade assembly 108 in
exhaust path 112. Inlet filter 122 filters the air 124 to remove
certain materials from the air before the air impinges upon fan
blade 108 and other internal components. Outlet filter 132 filters
the filtered air to remove airborne materials that may be damaging
or otherwise undesirable to release into the external environment.
Thus, contaminated air 124 enters inlet duct 120 and passes through
inlet opening 118 to be filtered through inlet filter 122 before
entering chamber 116.
[0047] Inlet filter 122 and outlet filter 132 may be any type of
filter now or later developed that removed the particular airborne
materials that, in the case of inlet filter 122, may adhere to or
accumulate on internal components of exhaust fan 100, and in the
case of outlet filter 132 may be damaging to the external
environment. In one embodiment, inlet and output filters 122,132
are manufactured from a filter material of sufficient porosity to
permit a desired volume of air to pass therethrough while retaining
the desired materials which may be suspended in the mass of moving
air. For example, the filter material used in filters 122, 132 may
comprise a particulate filter made of fiberglass, etc., a sorbent
filter made of carbon, zeolite, etc, for absorption of gases and
odors. In one embodiment, the particulate filter may be
electrically charged; that is, an electret. In yet another
embodiment, an ion emitter is also utilized. The electret filter
material in combination with the ion emitter will enhance the
capturing of airborne particles which become charged when they
enter the electric field surrounding the fan. Any suitable porosity
and material for removing the particular airborne materials may be
used.
[0048] Filters 122, 132 may take different forms. In the
illustrative embodiment, filters 122, 132 include filter material
in a cardboard or disposable plastic container. Preferably the
filter container is self-supporting. In the illustrative
embodiment, filters 122, 132 are secured within corresponding
covers or doors 128 and 136, respectively. Filters 122, 132 may be
secured within the covers using any well-known technique. In the
example illustrated in FIGS. 1A-1B, adjustable latches 115 are
utilized to secure inlet filter 122 to front cover 128. As another
example, tracks 117 are formed in rear cover 136 to receive a
replaceable outlet filter 132. In one embodiment, filters 122, 132
are Binks Sames carton paint pocket filters, number 29-2372,
available from Binks Sames, Franklin Park, Ill. In another
embodiment, filters 122, 132 are Binks Sames single piece blanket
paint pocket filters, number 29-2359, available from Binks Sames,
Franklin Park, Ill. It should be understood, however, that filters
122, 132 can be any filter appropriate for capturing the intended
airborne materials.
[0049] To provide access to filters 122, 132 for cleaning and
replacement, housing front cover 128 and rear cover 136 are hinged
to housing body 102. Hinges 142 and 144 are provided for such
purposes, and the doors are latched to housing body 102 via latches
146, 148, respectively. As one of ordinary skill in the art would
appreciate, any well-known mechanism now or later developed may be
used to provide access to filters 122, 132 and to releasably secure
front and rear covers 128, 136 to housing body 102. For example,
latches 146, 148 may be magnetic latches, among others. As noted,
certain embodiments of exhaust fan 100 preferably include kill
switched 180A, 180B to ensure that rear cover 136 and/or front
cover 128 are properly latched to housing body 102 and/or include
properly installed filters 132 and/or 122.
[0050] FIG. 3 is a perspective view of one embodiment of the
invention in which input filter 122 is secured within tracks in
housing front cover 128. Inlet filter tracks 302 run along the
length of each of three sides of housing cover 128, with the fourth
side open to facilitate installation and removal of filter 122. As
shown in FIG. 3, this embodiment of filter 122 is self-contained in
a substantially rigid porous cardboard exterior surface. In the
embodiment illustrated in FIG. 1A, a filter retaining member in the
form of a grating is illustrated on the exterior sides of inlet and
outlet filters 122, 132. Specifically, inlet grating 119 is secured
in inlet opening 118 and outlet grating 150 is secured within
housing rear cover 136. This provides increased safety while not
interfering with the flow of air through chamber 116.
[0051] FIG. 4 is a side view of another embodiment of the present
invention in which standardized, self-contained filters 122, 132
are not available. Here, a filter bay 406 is formed on the interior
side of housing front cover 128. Filter bay 406 is defined by side
walls 402 mounted on interior surface of cover 128. A hinged grill,
grating or other filter retaining member is hingedly secured to
housing front cover 128. As such, any filter material may be placed
in filter bay 406 and held in place with grating 404. This
embodiment is particularly useful when either filter 122 or 132 is
in the form of a flexible package or several packages containing
the particulate filter material. To facilitate the use of such
filters, the embodiment illustrated in FIG. 4 provides filter bay
or enclosure 406 that retains such a filter in a flat operational
configuration regardless of the orientation of exhaust fan 100.
[0052] It should be understood that any filter retaining member can
be used to be attached to both sides of housing covers 128, 136 to
hold corresponding filter 122, 132. Such filter retaining members
are porous to enable air to pass therethrough. For example, the
filter retaining members may be gratings as illustrated in FIGS. 1A
and 1B. On the interior sides of the housing covers, the filter
retaining members includes fasteners, latches, adhesives, screws,
bolts and levers, magnetic catches and the like. Gratings may also
be used. Preferably, the filter retaining member that serves as
inlet grating 119 is of a construction and material that is easily
to clean since it has the greatest exposure to airborne materials.
As one skilled in the art would appreciate, other porous support
structures such as a screen mounted to the frame may be used.
[0053] Exhaust fan 100 is controlled by an operator through the
manipulation of power controls located on a control module 114. In
the illustrative embodiment, control module 114 is secured to an
exterior surface 113 of housing body 102. FIG. 5 is a side view of
one embodiment of control module 114. Control module 114 has a
front panel 506 through which the operator controls exhaust fan
100. In one embodiment, control module 114 receives external AC
power and applies the power to motor 104 in accordance with
operator control inputs. Control module 114 is preferably an
air-tight container that is substantially impervious to the
surrounding air. Thus, all electrical components and cables are
enclosed in an air-impermeable closed system. This enables
embodiments of the exhaust fan 100 to be used to remove air 124
having flammable or combustible airborne contaminants. Referring to
the illustrative embodiment shown in FIG. 5, for example, control
module 114 includes unitary sidewalls 502 secured to a base 504.
Control panel 506 is secured to sidewalls 502 such that the top
surface of control panel 506 is substantially flush with the top
surface of control module 114. Sealant material 508 is used to fill
any gaps between neighboring components. Control module 114
includes control circuitry 508 that is electrically connected to
motor 104 through passageways 510 in base 504 and housing body
102.
[0054] It should be understood that sealed electrical box 114 may
be secured directly or indirectly to the interior 103 or exterior
113 surface of fan housing body 102. In addition, and as will be
described below, all electrical contacts, switches and the like are
implemented with electrical components that minimize arcing and
other events that can cause combustion.
[0055] FIGS. 6A and 6B is a high level schematic diagrams of an
exemplary embodiment of control circuit 508 and control panel 506,
with related sensors. In the illustrative embodiment, control panel
506 includes a speed control 602 and an on-off control 604. The
type of manual control inputs implemented in control panel 506
should be selected based on the intended operating environment
and/or user. For example, in the particular embodiment described
herein, exhaust fan 100 is to be used to remove overspray, dust
created from sanding painted surfaces and the like. Such airborne
materials would accumulate on the typical knobs and buttons used on
conventional exhaust fans, eventually impairing the operation of
such knobs and buttons.
[0056] To prevent such damage from occurring, contact or touch
responsive switches operating by capacitance are preferably
provided. Such touch responsive switches are well known in the art,
and will therefore not be described in greater detail herein. In
the illustrative example, speed control selector 602 includes four
touch-responsive switches to enable the operator to select
direction of rotation and one of three speeds of rotation in the
selected direction. On-off control selector 604 includes 2 touch
sensitive switches to turn the fan on and off, respectively. It
should be appreciated that other techniques for providing control
inputs may also be provided, For example, wire or wireless remote
control, voice control, and other control approaches may be
implemented.
[0057] To insure the operator is aware of the operation of exhaust
fan 100 at any given time in the potentially noisy environment in
which fan 100 may be used, an array 606 of indicators is also
provided on control panel 506. The indicators may provide a visual
indication of, for example, the on/off status of exhaust fan 100,
the speed of rotation and alarm conditions described below.
[0058] Referring now to FIG. 6B, power is conducted to fan 100 from
a conventional power cord and electrical plug 610. Electrical plug
610 is configured to be connected to an exterior power source such
as a conventional AC outlet. However, as one of ordinary skill in
the art would appreciate, embodiments of the exhaust fan of the
present invention can operate in conjunction with other power
sources. For example, in one alternative embodiment the power
source is an internal power source such as a battery. Such
batteries may be lithium ion, NiCd and other chemistries. The
dimensions and quantity of the batteries can also vary in
alternative embodiments. For example, in one embodiment a single
lantern battery is used to power the exhaust fan. In an alternative
embodiment, a series of dry cell batteries are used. Furthermore,
such batteries may be chargeable or rechargeable depending on a
particular application. An on/off relay 612 controlled by on-off
control selector 604 includes one pole controlling a switch in
series with power plug 610 and motor 104. Speed control selector
602 is also connected in series with plug 610 and motor 104 as
shown in FIG. 6B.
[0059] As noted, certain embodiments of exhaust fan 100 may be
utilized in environments having hazardous airborne materials. In
particular, flammable airborne materials may be removed from a
localized area by exhaust fan 100. To insure safety, the
temperature and integrity of the electrical system are
monitored.
[0060] One or more temperature sensors 614 may be implemented in
exhaust fan 100 to sense the temperature of any component that may
come into contact with the air passing through the exhaust fan 100.
For example, temperature sensor(s) may be placed on chamber 116.
Additional sensors, for example, may be placed in control module
114 to monitor the temperature of the electrical components
contained therein.
[0061] The temperature sensor(s) control a safety relay 616 that
controls a switch 618 interposed between and in series with motor
104 and power 610. If a temperature greater than some predetermined
threshold value is sensed, temperature sensor 614 activates safety
relay 616 to open switch 618. Similarly, a fault detection sensor
620 may be included in control module 114. Fault detection 620
monitors the electrical integrity of control module 114, activating
safety relay 616 when an electrical fault is detected. Furthermore,
kill switches 180 may be provided in fan 100 to ensure the safe
operation of the fan, as described above. Such kill switches
monitor the position of the front and rear doors and filter as
described above, activating safety relay 616 when a desired door is
opened or a desired filter is not installed. As shown in FIG. 6B,
on-off relay 612 and safety relay 616 have a second pole 622, 624
that provides grounded inputs to indicators and alarms control
module 626. In addition, indicators and alarms control module 626
also receives inputs from temperature sensor(s) 614 and fault
detection sensor(s) 620. Based on these inputs, indicator and
control module 626 controls an audio alarm 628 and indicator array
606 to provide continual visual and audible operator feedback.
[0062] FIG. 7A is a side view of an alternative embodiment of the
present invention. An exhaust fan assembly 700 includes exhaust fan
100 and a flexible conduit or tube 702. Assembly 700 enables
exhaust fan 100 to remove airborne debris from a remote localized
area. Exhaust fan 100 is located in an aperture to exhaust filtered
air to the environment, as described elsewhere herein. Flexible
conduit 702 is secured to inlet duct 120 and extended to the
localized area in which the airborne materials are being generated.
Such an arrangement is necessary in those localized environments
that are lacking apertures to the outside environment.
[0063] Flexible conduit 702 includes a lining 704 reinforced with,
for example, helical wire to maintain its diameter. Conduit 702 is
secured to inlet duct 120 through the use of an adjustable metal
strap, although any approach may be used to secure conduit 702 to
fan 100. In an alternative embodiment, distal end 710 of conduit
702 includes an inlet filter secured therethrough. The construction
and operation of such an inlet filter can be similar to that
described above.
[0064] FIG. 7B is a side and end view of flexible conduit 702. In
the embodiment shown in FIG. 7B flexible conduits 702 includes an
inlet filter at its distal end 710. Such an inlet filter is
designed to prevent the accumulation of the above-noted airborne
materials on the interior surface of conduit 702 and ultimately,
the interior components of exhaust fan 100. The embodiment shown in
FIG. 7B a filter compartment 720 comprises an internal grating 714
secured to the interior surface of conduit 702 approximate to
distal end 710. An external grating 712 is hingedly secured to the
edge of conduit 702 by hinges 716. External grating 712 can be
opened to provide user access to the interior of filter compartment
720 to install or remove a filter (not shown). As one of ordinary
skill in the art would appreciate in alternative embodiments an
inlet filter can be securely retained at the distal end 710 of
conduit 702 by means other than grating 712, 714. Some such
alternative embodiments have been described above in connection
with inlet filter 122 and output filter 132. It should be
appreciated that still other alternatives are considered to be in
within the scope of the present invention. Furthermore, an
alternative embodiment, the external grating 712 is removably
attached to distal end 710 of conduit 702 by mechanisms other than
hinges 716. As one of ordinary skill in the art would appreciate,
filter compartment 720 may be the same or similar to the inlet
filter 122 and output filter 132 described above. In one
embodiment, the filter used in filter compartment 720 is circular
while in the filter 122 and output filter 132 have rectangular
dimensions. However, as one of ordinary skill would find apparent,
such filters can be modified to have any dimensions suitable for
their particular locations. It should also be appreciated that
should a filter be used in filter compartment 720 then an
additional inlet filter 122 may or may not be necessary in such
embodiments of exhaust fan 100.
[0065] In an alternative embodiment, filter compartment 720 may not
be defined by internal and external gratings 714, 712. For example,
in one embodiment, a mesh is glued or sown into the tube 702 at
some distance into the distal end 710 of the tube. A filter
inserted into the distal end of the tube would be held either by
virtue of the relative dimensions of tube 702 and the inserted
filter, or by clips or other retaining material such as Velcro
straps, or with an external cross-bar, grating, or other similar
means. In a further embodiment, two mesh material structures are
sown into the distal end of the tube to form a pouch which retains
a filter inserted into the tube."
[0066] FIG. 8 is a side view and FIG. 9 is a rear view of an
alternative embodiment of the present invention. In this
alternative embodiment, an exhaust fan 800 provides a sealed
exhaust path by segregating two exhaust chambers 818, 820 and a
mechanical compartment 802 having located therein substantially all
mechanical components of fan 800. In this particular embodiment,
exhaust chambers 818 and 820 are on different sides of mechanical
components 802 so that a fan blade 804 can extend into each such
chamber from mechanical compartment 802.
[0067] Mechanical compartment 802 has located therein a motor 814
secured to compartment 802 through one or more support members 806.
A ventilation fan 808 is optionally provided at the rear of fan 800
since mechanical compartment is essentially sealed. Fan blade
assembly is controlled b y motor 814 in response to control inputs
provided by an operator through control module 810. Control module
810 includes a user interface that is located at the face of
exhaust fan 800 to provide the operator with direct and easy access
to a user interface provided by control module 810, as well as to
provide an easily visualized array of indicators for operator
feedback. Electrical signals from control module 810 are provided
to motor 814 through electrical wiring that extends through the
shaft of fan blade assembly 804. Preferably, an electrical
connector 812 is provided to facilitate removal of control module
810 when necessary.
[0068] Individual blades of fan blade 804 extend through an opening
between mechanical compartment 802 and exhaust chambers 818, 820.
Such an opening preferably includes a seal that substantially
reduces the amount of air that it can prevent entering mechanical
chamber 802.
[0069] Surrounding central layer 902 is an exhaust duct 904 that
appears on both the top and bottom of mechanical layer 902 due to
the cross-sectional nature of the view provided. This duct layer
904 defines a sealed exhaust path through the fan. Finally above
and below duct layers 904 are support layers 906 and 908. These
functional layers include all mechanical support elements such as
window flanges, support legs, etc.
[0070] Inlet filters 824 are preferably a single filter that has an
aperture in its center. The aperture has a shape and size to
receive mechanical compartment 802. Outlet filter 822 has a similar
configuration. Alternatively, inlet and outlet filters 824, 822 may
each be configured as two filters, one for exhaust chamber 818 and
the other for exhaust chamber 820.
[0071] While various embodiments of the present invention have been
described above, it should be understood that they have been
presented by way of example only, and not limitation. Thus, the
breadth and scope of the present invention are not limited by any
of the above-described exemplary embodiments, but are defined only
in accordance with the following claims and their equivalents.
* * * * *