Note: Descriptions are shown in the official language in which they were submitted.
CA 02471104 2004-06-29
AIR TREATMENT SYSTEM
This application is a divisional of Canadian Patent Application No. 2,256,443,
filed
June 3, 1997.
FIELD OF THE INVENTION
The present invention relates to air treatment systems, and more particularly
to a
portable room air filtering system.
BACKGROUND ART
Air treatment systems have grown in popularity in recent years. A growing
concern
for health and an increased recognition of the risks associated with unclear
air are largely
responsible for this trend. For example, airborne pollutants can cause or
contribute to a
number of respiratory problems, including respiratory infections, asthma, and
allergies.
Additionally, some airborne pollutants can cause undesirable odors. While air
treatment
systems are available in a wide variety of designs, a conventional air
treatment system
includes a blower that moves air through a filter element. The blower and
filter element
are typically contained in a unitary housing and are arranged with the blower
either
drawing or pushing air through the filter element. A number of different
filter elements
with different filtering characteristics are commercially available. For
example, particulate
filters are available to remove particulate matter from air. A conventional
particulate filter
includes a substance, such as fiberglass or electret-type media, that traps
particulate matter
as air is passed therethrough. Another example, odor filters are available to
remove odors
from the air. A conventional odor filter includes activated carbon, or
activated charcoal,
which removes pollutants from the air primarily by adsorption.
Conventional air treatment systems suffer from a nuz~nber of problems. First,
the
systems are inherently noisy. The sound of air moving through the system and
the noise
generated by the blower motor are primary contributors to the noise level of
the system.
The noise level of the blower can be reduced by utilizing a quieter motor.
However,
quieter motors typically increase the cost of the system. The noise level of
the moving air
can be reduced by lowering the velocity at which it moves through the system.
This can be
done by increasing the size of the air flow path or by lowering the volume of
air moved
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CA 02471104 2004-06-29
through the system. Larger air flow paths require larger housings and
therefore increase
the overall size of the system. Lower air volumes can reduce the overall
effectiveness of
the system. Second, conventional air treatment systems are often difficult to
incorporate
into the home or office. To obtain acceptable treatment capacity, air
treatment systems are
typically relatively large. Due to their size, it is often difficult to find
room for an air
treatment system. In some rooms, it is desirable for the system to rest upon
the floor and in
others it is desirable for the system to mount to the wall. Conventional
systems do not
have the ability to meet both of these desires. Third, filter elements require
periodic
replacement. Consumers often forget when it is time to replace the filter and
may find it
difficult to replace the filter when they do remember.
SUMMARY OF THE INVENTION
The aforementioned problems are overcome or at least mitigated by the present
invention which provides an air treatment system having a relatively large
capacity while
maintaining a relatively small footprint and a relatively low sound level. The
system
includes a housing defining stacked, vertically extending inlet and outlet
chambers. The
stacked, vertically extending chambers reduce the footprint of the system. The
inlet
chamber houses a blower that circulates air through the system by moving air
from the
inlet chamber into the outlet chamber. The blower is positioned within the
inlet chamber
such that its inlets are facing away from the inlet grill. This :reduces the
sound level of the
system. A foam prefilter extends over the inlet grill to remove coarse
particulate matter
from the entering air. The foam prefilter is easily removed for periodic
washing.
The system includes a particulate filter and an odor filter that are installed
within
the outlet chamber. The two filters are secured within the outlet chamber by
spring biased
retainers that positively and firmly seat the filters within the housing to
prevent air
leakage. The filters are spaced away from the rear wall of the housing to
define a plenum.
The rear wall of the housing is curved to progressively reduce the cross-
sectional area of
the plenum away from the blower outlet, thereby providing uniform air pressure
over the
face of the filter. The system includes a large outlet opening that reduces
discharge
velocity and consequently the sound level of the system. The system also
includes a
louvered outlet grill covering the outlet opening. The outlet grill includes
angled laths
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which hide the filter and direct the discharge stream. The outlet grill is
reversible allowing
the consumer to select the desired air flow direction.
The system is adapted to rest upon the floor or mount to a wall. The system
includes removable feet which support the system at a reversely inclined angle
to reduce
the likelihood of tip over. The feet extend rearwardly a sufficient distance
to prevent the
system from engaging the wall. The system also includes a wall mounting
bracket and
receptacle that allow the system to be mounted to a wall in either a vertical
or horizontal
orientation.
The system also includes a control system having a high volume filtration
setting
that can be selectable for a specified period of time after which the system
automatically
returns to its prior setting. The control system also provides uniform volume
air flow by
increasing the blower speed as the filter becomes filled.
The present invention provides an air treatment system comprising: a housing;
a
filter mounted within the housing; a blower mounted within the housing to move
air
through the filter; and a control means for controlling operation of the
blower in one of a
plurality of normal modes of filtration operation. The control means includes
timing
circuitry for recording passage of time and blower speed control circuitry for
controlling
operation of the blower at one of a plurality of normal blower speeds. The
control means
also includes input means for allowing selection of one of the plurality of
the normal
modes of operation and one of the plurality of the normal blower speeds. The
control
means has a current made of operation, including a selected normal mode of
operation,
and a blower speed selected from the plurality of blower speeds. The control
means further
includes a high-speed mode of operation, selected by depression of a single
button, in
which the control means operates the blower at a maximum speed in excess of
any of the
normal blower speeds for a fixed period of time, following which the control
system
returns directly and solely to the current mode of operation.
In embodiments of the present invention, the control means includes uniform
volume control circuitry for monitoring a status of the filter, and for
providing uniform air
flow volume over the life of the filter by progressively increasing blower
speed as a
function of the status. The blower can include a direct current motor. In this
case, the
control means controls the speed of the blower by varying a command voltage
supplied to
the motor. The input means can include a control panel mounted to the housing.
The input
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means can further include a remote control for providing remote operation of
the control
means. The uniform volume control circuitry can include pressure sensing means
for
sensing air pressure within the housing, current draw sensing means for
sensing current
draw of the blower, air flow speed sensing means for sensing air flow speed
within the
housing, blower speed sensing means for sensing blower speed, and/or time
monitoring
means for monitoring and recording time elapse.
These and other advantages and features of the invention will be readily
understood and appreciated by reference to the detailed description of the
preferred
embodiment and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of the air treatment system resting on the floor;
Fig. 2 is a perspective view of the rear of the air treatment system with the
prefilter
removed;
Fig. 3 is an exploded perspective view of the air treatment system with a
portion
removed to show the blower and control system;
Fig. 4 is a side elevational view of the air treatment system resting on the
floor;
Fig. 5 is a perspective view of the air treatment system with the outlet grill
removed and the retainer in the secure position;
Fig. 6 is a perspective view of the air treatment system with the outlet grill
removed and the retainer in the release position;
Fig. 7 is an enlarged perspective view of a portion of the air treatment
system with
the outlet grill removed and the retainer in the secure position;
Fig. 8 is a sectional side elevational view of the air treatment system;
Fig. 9 is a sectional view of the air treatment system taken along line 9-9 of
Fig. 8;
Fig. 10 is a perspective view of a portion of rear of the air treatment system
showing the cord storage compartment;
Fig. 11 is a perspective view of the air treatment system mounted to the wall
in a
vertical position;
Fig. 12 is a perspective view of the air treatment system mounted to the wall
in a
horizontal position;
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Fig. 13 is a side elevational view showing the air treatment system being
installed
in a vertical position;
Fig. 14 is a side elevational view showing the air treatment system being
installed
in a horizontal position; and
Fig. 15 is a perspective view of the remote control.
DETAILED DESCRIPTION
An air treatment system according to a preferred embodiment is illustrated in
Fig.
1, and generally designated 10. The air treatment system 10 is shown resting
upon the
floor in an upright position. However, as described below, the system 10 is
also adapted to
mount to a wall. The air treatment system 10 includes a housing 12 having an
inlet grill
14, an outlet grill 16, and a blower 18 (See Figs. 1-3). The blower 18
circulates external air
through the housing 12 by drawing it in through the inlet grill 14 and forcing
it out through
the outlet grill 16. A prefilter 20, particulate filter 22, and odor filter 24
are positioned
along the air flow path to treat the air as it is moved through the housing
12. The system
is operated by an electronic control system 122.
The housing 12 includes front and rear halves 26 and 28, respectively. As
perhaps
best illustrated in Figs. 8 and 9, the housing 12 defines stacl~ed inlet and
outlet chambers
30 and 32. The inlet chamber 30 is located at the top of the system and is
cooperatively
defined by the top portions of the front and rear halves 26 and 28. The outlet
chamber 32
is positioned below the inlet charriber 30 and is defined primarily by the
front half 26. The
front half 26 of the housing 12 includes a gently curved front wall 34 that
defines a large,
generally rectangular outlet opening 36 and a smaller, generally rectangular
panel opening.
A plurality of screw bosses 35 extend rearwardly from the front wall 34 for
intersecuring
the two housing halves. The front half 26 also includes top 38, bottom 40, and
opposed
side walls 42 that extend rearwardly from the peripheral edges of the front
wall 34 to mate
with the rear half 28. The front half 26 further includes a top chamber wall
44, a bottom
chamber wall 46, opposed side chamber walls 48, and a rear chamber wall 50.
Together,
these chamber walls define the outlet chamber 32. The top 44, bottom 46, and
side 48
chamber walls extend rearwardly from the front wall 34 along the periphery of
outlet
opening 36, and are stepped to provide a first bearing surface 52 for engaging
the outlet
grill 16 and a second bearing surface 54 for engaging the particulate filter
22. The top
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chamber wall 44 also defines a pair of generally rectangular blower openings
60, 61.
These openings 60 allow the blower 18 to blow air into the outlet chamber 32.
The top 44
and bottom 46 chamber walls each include a pair of retainer catches 62 to hold
the
retainers 142 in the release position as described below. The catches 62 also
guide and
support the filters 22 and 24. The side walls 48 define top 56 and bottom 58
recesses
which receive the retainers 142. Tine rear chamber wall 50 is curved to
control the flow of
air in the outlet chamber and provide uniform air pressure over the face of
the filters 22
and 24.
The curve of the rear chamber wall 50 preferably follows the formula d=2.45-
0.032x for the first 54% of the length of the wall and d=-1.53+0.66x-0.03x2
for the final
46% of the length of the wall.
The retainers 142 are mounted to the front half 26 within outlet chamber 32
for
positively and firmly securing the particulate 22 and odor 24 filters. Each
retainer 142 is
movable between a securing position in which the retainer 142 engages and
positively
secures the filters 22 and 24 (See Fig. 5), and a release position in which
the retainer 142
is hooked onto catch 62 to allow removal of an old filter and installation of
a new one (See
Fig. 6). In Fig. 7, the lower retainer 142 is shown in the securing position
in solid lines and
in the release position in broken lines. Each retainer 142 is a generally U-
shaped wire
having free ends 143 that extend through bearing surface 54 and a cross member
145 that
engages the odor filter 24. A spring 144 is fitted over each free end 143 and
secured in
place by a snap ring 146. The springs bias the retainer 142 toward the rear of
the system
10. A thumb tab 148 is attached to the center of each cross member 145 making
it easier to
move the retainer 142 between the securing and release positions.
A panel bracket (not shown) is mounted to the rear of front wall 34. The panel
bracket is generally rectangular and functions to support the components of
the control
panel, including control buttons 166, LEDs (not shown), and infrared receiver
(not
shown). The panel bracket is preferably molded from a conventional filtering
material
used with conventional infrared systems. This allows the panel bracket to
function as a
filtering lens for the infrared receiver.
The rear half 28 of the housing 12 includes top 64, bottom 66, rear 70, and
opposed
side 68 walls. The top 64, bottom 66, and side 68 walls extend forwardly from
the
peripheral edges of the rear wall 70 and are shaped to mate with the
corresponding walls
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CA 02471104 2004-06-29
of the front half 26. The rear wall 70 is generally planar and defines a
centrally located,
mounting bracket opening 80. This opening 80 is generally square and is
surrounded by a
peripheral wall 84 that extends toward and engages the rear chamber wall 50 of
the front
half 26. The peripheral wall 84 defines a pair of recesses 88 in its top 91
and left side 93
sections. The recesses 88 is the top section 91 are adapted to received the
mounting
bracket flanges 90 when the system is mounted vertically (See Figs. 11 and 13)
while the
recesses 88 in the right side section 93 are adapted to receive the flanges 90
when the
system 10 is mounted horizontally (See Figs. 12 and 14). The rear wall 70 also
defines a
cord recess 74 (See Figs. 2 and 10) surrounded by a peripheral wall 86. The
peripheral
wall 86 extends toward and engages the front half 26. As perhaps best
illustrated in Fig.
10, the power cord 76 is stored in a storage compartment 7 l defined between
the front 26
and rear 28 halves. The cord recess 74 is positioned at the top of the cord
storage
compartment 77 and defines a cord opening 79 through which the cord passes out
of the
housing 12 and a V-shaped notch 78 into which the cord 76 can be wedged to
hold it in
place. The rear wall 70 includes a curved, protruding handle 72 defining an
open bottom
(not shown) into which the user's Fngers can be placed to lift the system 10.
The rear wall
also includes a plurality of forwardly extending screw bosses 73 that mate
with screw
bosses 35 for intersecuring the front and rear halves.
The top 64 and rear 70 walls cooperate to define a recessed inlet grill 14
having a
series of openings for allowing air to enter the inlet chamber 30 (See Fig.
2). The inlet grill
14 extends around the back and top of the system to allow adequate air intake
even when
the system 10 is situated against a wall. A mounting slot (not shown) is
defined at the
upper end of the inlet grill 14 to receive the prefilter mounting tab (not
shown) as
described below.
The mounting bracket 82 is generally square and is adapted to fit within
mounting
bracket opening 80. The bracket 82 includes a screw boss 92 for securing the
bracket 82 to
the housing 12. As noted above, the bracket 82 also includes a pair of
upwardly extending
flanges 90. The flanges 90 are adapted to interfit with recesses 88 in the
housing 12 and
firmly support the housing 12 when the system 10 is wall mounted. The bracket
82 further
includes four generally spherical protrusions 94 positioned in the four
corners of the
bracket 82. The protrusions 94 extend rearwardly and the outermost extent of
each
protrusion is flat to provide increased surface area for engaging a wall. The
top two
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CA 02471104 2004-06-29
protrusions 94 define screw holes 96 which allow the bracket 82 to be secured
to a wall.
The bracket 82 also defines an arcuate recess 98 which provides easy access to
the
opening (not shown) in the bottom of handle 72.
The system 10 further inchudes a pair of feet 150 that support the housing 12
when
resting upon the floor. The feet 150 are detachable so that they can be
removed when wall
mounting is desired. As perhaps best illustrated in Fig. 4, the feet 150
support the housing
12 at a reversely included angle to reduce the chance of the system 10 tipping
over. Also,
the feet 150 extend rearwardly beyond the housing 12 to prevent the housing 12
from
engaging a wall. Referring now to Fig. 3, each foot 150 includes a peripheral
side wall 152
forming a pedestal and a contoured top wall I 54 adapted to engage the housing
12. As
shown, the top wall 154 is contoured to match the shape of the bottom of the
housing 12
and includes an installation flange 156. The flange 156 is adapted to fit with
a slot (not
shown) defined in the housing 12. Each top wall 154 also defines a screw hole
158
through which a screw (not shown) is installed to mount the foot 150 to the
housing 12.
The blower 18 is mounted in the inlet chamber 30 to top chamber wall 44, and
includes a pair of centrifugal blower wheels 108 and 110 mounted on opposite
sides of a
conventional, external control DC motor 112. The blower 18 is mounted upon
conventional rubber motor mounts (not shown) to reduce the transmission of
vibration
from the blower to the housing 12. Each wheel 108, 110 includes a single
bellmouth inlet
114, 116 facing approximately ninety degrees away from the inlet grill 14.
This orientation
reduces the sound level of the system 10. Each wheel 108, 110 also includes a
single outlet
duct 118, 120 that communicates with blower opening 60 and 61, respectively.
The blower
18 is controlled by an external, electronic control system 122 as described
below.
As noted above, the prefilter 20 fits over the inlet grill 14 to remove
relatively
coarse particles from the air as it enters the inlet chamber 30. By removing
coarse
particulate matter, the prefilter 20 protects the blower I8 and extends the
life of the
particulate filter 22 and odor filter 24. The prefilter 20 includes a layer of
washable foam
100 secured to a polymeric support structure 102. The support structure 102
defines a
plurality of vents 104 through which air flows as it passes into the inlet
chamber 30. The
vents 104 preferably extend substantially vertically in correspondence with
the inlet grill
openings 71. The support structure 102 includes a lip 106 extending along its
upper end.
The lip 106 is useful in removing the prefilter 20 from the inlet grill 14.
The support
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CA 02471104 2004-06-29
structure 102 also includes a mounting tab (not shown) adapted to fit within
the mounting
slot (not shown) to secure the prefilter 20 in place over the inlet grill 14.
The particulate filter 22 is installed within the outlet chamber 32 to remove
fme
particulate matter from the air. The particulate filter 22 is seated against
bearing surface 54
in spaced-relation with the rear chamber wall 70. This creates a plenum 180
between the
particulate filter 22 and the rear chamber wall 70. The particulate filter 22
is generally
rectangular and includes a conventional die-cut paperboard frame 124. The
filtering media
(not visible) is preferably a meltdown polypropylene medium. This filtering
media can be
replaced by electret-type, fiberglass or other conventional media. The
particulate filter 22
also includes a protective cover 126, such as plastic mesh, which protects the
filter media
from damage. The particulate filter 22 further includes an open-cell foam
gasket 128 that
is secured to the rear of the filter 22 by conventional adhesives. The gasket
128 is
compressed between the filter 22 and bearing surface 54 to seal the filter 22.
The odor filter 24 is seated in the outlet chamber 32 adjacent to the
particulate
filter 22. The odor filter 24 is generally rectangular and is substantially
coextensive with
the particulate filter 22. The odor filter 24 preferably includes a die-cut
paperboard frame
130, an activated carbon medium (not visible), and a protective scrim 132 to
prevent
release of carbon dust from the filter 24. The activated carbon is preferably
applied to a
supportive substrate and/or is provided in a granular form contained within a
honeycomb
support.
The outlet grill 16 is generally rectangular and includes a peripheral frame
134
having a plurality of angled laths 136 that direct air exiting the system 10.
Support ribs
138 extend between the laths to strengthen the grill 16. A pair of tabs 140
extend
rearwardly from the top and bottom of the frame 134. The tabs 140 are fitted
within slots
(not shown) in the housing 12 to secure the outlet grill 16 in place. The tabs
and slots are
adapted so that the outlet grill 16 can be installed upside down thereby
reversing the
direction of air flow from the system 10.
Control System
As noted above, the system 10 is operated by an electronic control system 122.
The
control system 122 is mounted within the inlet chamber 30 upon top chamber
wall 44, and
includes a conventional circuit board having conventional L~C motor control
circuitry (not
shown) that controls operation of the blower 18, conventional timing and
recording
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circuitry (not shown) that monitors the life of the particulate and odor
filters, conventional
non-volatile memory (e.g. EPROM) (not shown) in which filter data is stored in
the event
of a power failure, and conventional input circuitry (not shown) that allows
the user to
select the desired operating parameters. The user operates the control system
122 by
manipulation of a control panel 164 on the face of the housing 12 or a
wireless remote
control 160 (See Fig. 15). The control panel 164 and remote control 160
includes a
plurality of control buttons 166 and 162, respectively. All information on the
face of the
control panel 164 is printed at an approximately forty five degree angle so
that the
information can be read when the system 10 is mounted either vertically or
horizontally.
While not illustrated, the control panel 164 also includes a plurality of
motor speed LEDs
that indicate the motor speed, a plurality of timer LEDs that indicate the
time remaining
before automatic shut off, a bicolor turbo LED that indicates when the system
10 is in
turbo mode, and a plurality of filter LEDs that indicate the status of the
particulate and
odor filters. As noted above, the components of the control panel 164 are
mounted to a
panel bracket. The control system also 122 includes a conventional infrared
receiver (not
shown) for receiving command signals from the infrared remote control 160 and
a
conventional annunciator that provides an audible response each time a control
panel
button 166 or remote control button 162 is depressed.
The control system 122 is capable of both manual and timed operation. With
manual operation the system 10 is turned on and off manually by the touch of a
power
button. With timed operation, the system 10 runs for a specified period of
time and then
shuts off automatically. The desired time period is specified by repeatedly
depressing a
timer button to cycle through the various options. Timer LEDs provide a visual
indication
of the time remaining before automatic shut off: In the presently preferred
embodiment,
the control system 122 provides two, four, eight, and twelve hour time
periods.
Additionally, the user can cycle through "high", °'medium°',
and "low" motor
speeds by the touch of a button. Each time the speed button is depressed, the
control
circuitry varies the command voltage to the motor 112 causing the motor speed
to adjust
accordingly. Motor speed LEDs provide a visual indication of the selected
speed level of
the motor.
The control system 122 also includes a "turbo" mode that operates the blower
18 at
"extra-high" speed. The "turbo" mode can be operated in several different
modes: (1)
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CA 02471104 2004-06-29
temporary, (2) timed, and (3) continuous. In temporary mode, the blower 18
operates at
extra-high speed for a predetermined period of time, preferably thirty
minutes. When the
predetermined period of time is over, the system 10 reverts to its previous
mode of
operation. Temporary mode is selected by depressing the turbo button once. The
bicolor
turbo LED is turned on amber to indicate that the system 10 is in temporary
turbo mode.
In timed mode, the blower I 8 operates at extra-high speed for a specified
period of time
and then the system is shut off. Timed mode is selected by depressing the
turbo button
once and then depressing the timer button repeatedly to select the desired
time period. The
bicolor turbo LED is turned on green and the appropriate timer LEDs are turned
on when
the system I O is in the timed turbo mode. And finally, in continuous mode the
blower 18
operates at extra-high speed continuously until the system l0 is shut off
manually.
Continuous mode is selected by depressing and holding the turbo button for at
least three
seconds. The bicolor turbo LED is turned on green and the timer LEDs are
turned off to
indicate that the system 10 is in the continuous turbo mode.
The control system 122 monitors the status of the particulate and odor filters
and
provides a visual indication when either filter needs to be replaced. The
control system
122 accumulates and records (a) the length of time that each filter 22, 24 is
installed in the
system I O ("filter age") and (b) the length of time that the system 10 is
operating while
that filter 22, 24 is installed ("filter life"). This data is maintained in
separate age and life
registers for each filter. The age and life data is moved to non-volatile
storage in the event
of a power failure. The control panel 166 includes two LEDs for each filter 22
and 24. The
first LED is green turned on green when the filter does not need to be
replaced. The
second LED is a bicolor LED that is amber when the filter approaches (e.g. two
weeks)
the end of its life and blinks red when the life of the filter is exceeded.
When the
cumulative time of either the life or age of the filter exceeds or approaches
the maximum
allowable time for that filter, the appropriate filter LED is illuminated.
When a filter is
replaced, the corresponding age and life registers are reset by the user by
pressing the
appropriate reset button.
The control system 122 also includes uniform volume control circuitry that
provides uniform air flow through the system 10 over the entire life cycle of
the particulate
filter 22. Conventionally, the volume of air flowing through the system at any
given motor
speed will decrease over time as the filter 22 becomes filled with particulate
matter. The
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CA 02471104 2004-06-29
uniform volume control circuitry monitors filter status and automatically
increases blower
speed to compensate for this effect. Various apparatus and techniques can be
used for
monitoring filter status. First, the system 10 can determine filter status
solely on the time
that the filter 22 has been in use in the system (i.e. filter life). Second,
the system 10 can
include a conventional pressure sensor for sensing variations in pressure
within the
plenum. As the filter becomes clogged, the pressure within the plenum at any
given
command voltage will increase. Third, the system 10 can include conventional
current
sensing apparatus for sensing the current draw of the blower motor. As the
filter becomes
clogged, the blower moves less air and therefore its load decreases. The
decreased load
decreases the current draw of the motor at any given command voltage. Fourth,
the system
can include a conventional rotations-per-minute (RPMs) gauge for determining
the RPMs
of the motor. As the filter becomes clogged, the blower moves less air and its
RPMs
increase at any given command voltage. And fifth, the system 10 can include
conventional
air flow speed sensing apparatus for determining the speed o:f air flowing
through the
system. As the filter becomes clogged, the air flow speed will decrease at any
given
command voltage.
As noted above, the system 10 also includes a battery-operated, infrared
remote
control 160 allowing remote operation. The remote control I60 is generally
conventional
and, as illustrated in Fig. 15, includes a plurality of control buttons 162
that allow full
operation of the system 10. The design and layout of the remote control 160
preferably
matches that of the control pad 164 so that the user is not required to Learn
two different
layouts. A conventional infrared receiver (not shown) is located in the
control panel 164
for receiving control signals from the remote control 160.
Assembly and Installation
The system 10 is manufactured and assembled using conventional techniques and
apparatus. The front half 26, rear half 28, outlet grill 16, mounting bracket
82, and feet 150
are injection molded from a polymeric material. The panel bracket is molded
from any of
a number of conventional material that are transparent only to infrared light
waves. The
blower 18, control circuitry 122, retainers 142, panel bracket, and control
panel
components are manufactured and mounted to the front half 26 before the two
halves are
intersecured. Once these components are installed, the front and rear halves
26 and 28 are
intersecured by screws (not shown) extending through screw bosses 35 and 73.
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Additionally, the rear chamber wall SO can be secured to rear wall 70 by a
plurality of
screws (not shown) to strengthen the housing 12 and provide the rigidity
necessary for
wall mounting. The wall mounting bracket 82 is installed within the mounting
bracket
opening 80 by a screw 93 that extends through the rear chamber wall SO into
screw boss
92.
The system 10 can rest upon the floor (See Fig. 1) or mount to a wall (See
Figs. 11
and 12). If the system is intended to rest on the floor, feet 1S0 are mounted
to the bottom
of the housing 12. The feet 1 SO are installed by inserting tabs 1 S6 into
corresponding slots
(not shown) in the rear half 28 of the housing 12 and then installing screws
(not shown)
through screw holes 1S8 into corresponding screw bosses (not shown) in the
rear half 28
of the housing 12. If the system 10 is intended for wall mounting, the feet 1
SO are not
installed. Instead, the mounting bracket 82 is removed from the housing 12 and
secured to
the wall at the desired location with the flanges 90 extending upwardly. The
bracket 82 is
preferably secured to the wall by screws extending through screw holes 96. The
housing
12 is then hung over the bracket 82 in either a horizontal (Fig. 12) or
vertical (Fig. 11)
orientation. To vertically mount the system 10, recesses 88 in top section 91
of the
peripheral wall 84 are fitted over the flanges 90 (See Fig. 13). To
horizontally mount the
system 10, recesses 88 in right side section 93 of the peripheral wall 84 are
fitted over the
flanges 90 (See Fig. 14). The housing 12 is then secured to the bracket 82 by
installing
screw 93 through the rear chamber wall 50 into screw boss 92.
The various filters are manufactured using conventional techniques and
apparatus.
The prefilter 20 is assembled by securing a layer of open cell foam 100 to an
injection
molded support structure 102 using conventional adhesives. A foam gasket 128
is secured
to the rear of the particulate filter 22 using conventional adhesives. The
prefilter 20 is
installed on the housing 12 by inserting a mounting tab (not shown) extending
from the
support structure 102 into a mounting slot (not shown) defined in the housing
12. The
particulate filter 22 and odor filter 24 are installed by first moving the
retainers 142 into
the release position by hooking them onto catches 62 (See Fig. 6). Next, the
particulate
filter 22 is inserted into the outlet chamber 32 with the foam gasket 128
facing rearwardly.
The gasket 128 will engage bearing surface 54 to provide a seal around the
filter 22. The
odor filter 24 is then inserted into the outlet chamber 32 against the
particulate filter 22.
The retainers 142 are then moved into the secure position by pulling them out
from
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CA 02471104 2004-06-29
catches 62 and placing them over tye top and bottom edges of the odor filter
24 (See Fig.
5). Because the retainers I42 are spring-biased toward the rear of the housing
12, then
positively and firmly secure the filters 22 and 24 in place. The outlet grill
16 is then
installed in the outlet opening 36 by fitting tabs 140 into corresponding
slots (not shown)
in the housing I2. The outlet grill 16 hides and protects the filters, and
directs the air
flowing from the system. The outlet grill 16 is reversible so that the user
can select the
direction of air flow.
The system 10 operates by circulating external air through the housing 12. The
blower 18 draws air in from inlet chamber 30 through inlets '114 and 116 and
expels it into
outlet chamber 32 through ducts I 18 and 120. As the blower 18 draws air out
of the inlet
chamber 30, new air enters through inlet grill 14 and prefilter 20. The
prefilter 20 removes
coarse particulate matter from the air. The blower 18 forces the air into the
plenum 180
defined in the rear of the outlet chamber 32. The plenum 180 is defined by the
rear of the
outlet chamber 32 and the rear face of the particulate filter 22. Because the
rear chamber
wall 50 is curved, the cross-sectional area of the plenum decreases away from
the blower
openings 60 and 61. This provides uniform air pressure over the particulate
filter 22. As
the pressure builds in the plenum 180, air is forced through the particulate
filter 22 and the
odor filter 24. The air then flows out of the system 10 through outlet grill
16.
The control system 122 monitors the Iife of the particulate and odor filters.
As
described above, the appropriate filter LED blinks red when either filter must
be replaced.
Replacement of filters 22 and 24 will be described in conjunction with Figs. 5
and 6.
Initially, the outlet grill 16 is removed from the outlet opening 36. Next,
the retainers 142
are moved into the release position by pulling them outwardly and swinging
them away
from the filter 24 as illustrated by the arrows in Fig. S. The retainers 142
are held in the
release position by catches 62. (See Fig.6). After, the expired filter is
removed from the
outlet chamber 32 as illustrated by the arrows in Fig. 6. A new filter is then
inserted in
place of the old filter and the retainers 142 are returned to the secured
position. The outlet
grill 16 is reinstalled to complete the process. The age and life registers
for the new filter
are reset by pressing the appropriate reset button for approximately three
seconds.
The above description is that of a preferred embodiment of the invention.
Various
alterations and changes can be made without departing from the spirit and
broader aspects
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CA 02471104 2004-06-29
of the invention as defined in the appended claims, which are to be
interpreted in
accordance with the principles of patent law including the doctrine of
equivalents.
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