Note: Descriptions are shown in the official language in which they were submitted.
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AIR PURIFIER
BACKGROUND OF THE INVENT10N
I. Field of the Invention
The field of the invention relates to air purifiers, particularly to portable
air
purifiers including HEPA filters.
2. Brief Description of the Prior Art
Portable air purifiers for removing airborne particles are used in many homes
and offices. Such purifiers often include a fine particle high efficiency
particulate air
(HEPA) filter. In addition to a HEPA filter, some purifiers include a carbon
filter to
remove odors. The carbon may he incorporated within a fibrous matrix. A filter
for
trapping relatively large particles may also be found in portable air
purifiers. In
operation, one or more fans cause air to be drawn through the filters) and
emitted
through an outlet.
HEPA filters have gained increasing acceptance for use in purifiers directed
to
consumers as they remove 99.97% of particles having a size equal to or greater
than
0.3 microns. In order to take full advantage of a HEPA filter or any other
type of filter
used in an air purifier, it is important to ensure that substantially all of
the air emitted
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by the air purifier has indeed first passed through the filters) provided in
the purifier.
Where a filter includes both a HEPA component and filter component, the
lifespan of
the filter is generally dependent upon the carbon component. This is because
the
trapping capacity of the carbon component is generally exhausted prior to that
of the
HEPA component.
As the filters) employed in air purifiers require replacement when spent, the
ability to easily remove and replace the filters) is important. A replaced
filter must be
properly installed if it is to function properly. Disposable filter assemblies
have
accordingly been designed to facilitate user convenience.
Currently portable air purifiers are manufactured in various sizes with
different
capacities to suit a consumer's particular needs. The larger capacity air
purifiers
generally require larger sized filters. This generally requires retailers to
stock a
plurality of different size filter elements to satisfy the demands of all
consumers.
Replacement HEPA filter elements are traditionally bulky and expensive
inventory for
retailers to maintain. The retailer must stock the replacement filters for
every air
purifier that is sold, but the filters generally do not need replacement very
frequently.
The retailers that carry air purifiers are required out of necessity to offer
a line of
different size units that are expensive to purchase, do not turn over very
often, and take
up a lot of shelf space. In addition, to exacerbate the problem it has been
found that by
the time the consumer needs to replace the filter element, the inventory is
old and
looks beat up.
A general problem associated with air purifiers is that the devices create
noise
which can be disturbing to the user. Most of the noise attributed to the air
purifier is
attributed to the airflow through the unit. Generally the noise levels
generated by the
unit will increase with the volume of airflow passing through the unit. In
addition, the
overall size of the unit is important too because it is also known that if
portable
purifiers could be made larger (while remaining portable) the unit would be
quieter.
Accordingly when assessing the performance characteristics of an air purifier
the
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volume or Clean Air Delivery Rate ("CADR"), size and noise generated must all
be
considered.
A number of patents have issued which disclose air purifiers including HEPA
filters, carbon filters, and/or other filters. U.S. Patent Nos. 3,928,008;
4,3?8,983;
4,21,234; 4,629,482; 4,737,173; 4,778,496; x,078,764; 5,102,435; 5,131,932;
5,230,723; 5,259,84; 5,290,330; 5,~ 12,086; and 5,893,939 disclose air
purifiers of
various constructions.
SUMMARY OF THE INVENTION
A portable air purifying device is provided for removing airborne particles.
The device includes a housing including an exterior surface formed with an air
inlet
and an air outlet. The air outlet is formed as a plurality of openings. A
scroll is
located within the housing and has walls formed with an intake opening and an
exhaust port. The exterior surface and the walls define a cavity. The cavity
has a first
portion and a second portion. The first portion is in communication between
the
exhaust port and the air outlet. A fan is positioned within the intake opening
for
drawing air in through the air inlet to pass through the scroll and the first
poriion of the
cavity to be expelled through the air outlet while the second portion of the
cavit<~ is
under a positive pressure. A filter assembly is positioned within the housing
between
the air inlet and the fan.
2~ In a first preferred embodirnentl the plurality of openings of the air
outlet are
formed as a Drill. The scroll preferablj ~ includes an exhaust duct portion
havin; a first
end and a second end with the walls defining a cross section of the exhaust
duct
portion. The first end is in fluid communication with the intake opening and
the
second end terminates at the exhaust port. Preferably the cross section
increases
between the first end and the second end. Preferably the walls of the scroll
are
configured to form a reducer at the intake opening having a cross section. The
fan
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preferably includes a motor mount assembly connected to one of the housing or
the
scroll; and a fan blade coupled to the motor mount assembly and positioned
within the
scroll adjacent to the reducer. Preferably the cross section of the reducer is
circular
and decreases from the intake opening towards the fan blade. The motor mount
assembly preferably includes a motor, a motor mount ring, and a plurality of
brackets.
The motor preferably has a shaft for coupling to the fan blade. The motor
mount ring
is preferably attached to the motor and has a center. Each of the brackets
preferably
has a pronged end attached to the motor mount ring and extending radially from
the
center, and a curved end for connecting to one of the housing or the scroll.
Preferably
a wire ring is connected to at least two of the plurality of brackets adjacent
to the
curved end. Preferably a grommet is located at the curved end of each bracket.
In an alternative embodiment, a portable air purifying device includes a
housing, a fan, and at least two filter assemblies. The housing includes an
air inlet and
an air outlet. The fan is positioned within the housing for drawing air into
the housing
through the air inlet and expelling air through the air outlet. The modular
filter
assemblies are positioned within the housing in parallel between the air inlet
and the
fan. Each of the filter assemblies include a frame and a filter element
mounted to the
frame. Preferably the housing includes a door configured to engage the filter
assemblies. Preferably each of the filter assemblies has a second filter
element in
series with the filter element. Most preferably the filter element is a HEPA
filter and
the second filter element is a removably attached carbon filter.
A family of portable air purifying devices is also presented in accordance
with
the present invention. The family includes a plurality of portable air
purifying devices.
Each of the plurality of portable air purifying devices include a housing, a
fan, and a
number of modular filter assemblies. The housing includes an air inlet and an
air
outlet. The fan is positioned within the housing for drawing air into the
housing
through the air inlet and expelling air through the air outlet. The number of
modular
filter assemblies are positioned within the housing in parallel between the
air inlet and
the fan. The filter assemblies have a frame and a filter element mounted to
the frame.
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The number for at least one of the plurality of portable air purifying devices
is different
from the number for another of the plurality of portable air purifying
devices.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a front perspective view of a preferred embodiment of the present
invention;
Figure 2 is a rear perspective view of the preferred embodiment of the present
invention shown in Figure 1;
Figure 3 is a cross-sectional view taken along line 3-3 as shown in Figures 1
and 2 of the preferred embodiment of the present invention shown therein;
Figure 4 is a partially exploded rear view of the preferred embodiment of the
present invention shown in Figure 1 with the filter assembly cover removed;
Figure S is a rear perspective view of the filter assembly of the preferred
embodiment of the present invention shown in Figure 1;
Figure 6 is a partially exploded rear perspective view of an alternative
embodiment of the present invention;
Figure 7 is a partially exploded rear perspective view of an alternative
preferred
embodiment of the present invention showing the hanger and elongate hanger
supports
located at the side of the filter assembly;
Figure 8 is a partially exploded rear perspective view of another alternative
embodiment of the present invention that include the hangers and elongate
hanger
supports shown in Figures 26 and 29.
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Figure 9 is a partially exploded rear view of another alternative embodiment
of
the present invention that includes the hanger and elongate hanger supports
shown in
Figures 30 and 31;
Figure 10 is a front perspective view of a first member of a family of air
purifiers in accordance with the present invention;
Figure 11 is an exploded perspective view of the air purifier shown in Figure
10;
Figure 12 is a cross-sectional view taken along line 12-12 as shown in Figure
10;
Figure 12A is an open view of the air purifier shown in Figure 10 looking at
the
fan and scroll relationship with the rear panel and top grill removed;
Figure 12B is a perspective view of the motor mount assembly of the air
purifiers shown in both Figures 10 and 19;
Figure 12C is a partially exploded perspective view of the motor mount
assembly shown in Figure 12B illustrating the relationship of the boss caps to
the
assembly;
Figure 12D is a front elevational view of the motor mount assembly shown in
Figure 12B;
Figure 12E is a side elevational view of the motor mount assembly shown in
Figure 12B;
Figure 12F is a perspective view of the fan blade of the air purifiers shown
in
both Figures 10 and 19;
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Figure 13 is a front perspective view of a second member of a family of air
purifiers in accordance with the present invention;
Figure 14 is an exploded perspective view of the air purifier shown in Figure
13;
Figure 15 is a cross-sectional view taken along line 15-15 as shown in Figure
13;
Figure 1 SA is an open view of the air purifier shown in Figure 13 looking at
the
fan and scroll relationship with the rear panel and top grill removed;
Figure 15B is a perspective view of the motor mount assembly of the air
purifier shown in Figure 13;
Figure 15C is a partially exploded perspective view of the motor mount
assembly showing the relationship of the boss caps to the assembly of the air
purifier
shown in Figure 13;
Figure 1 SD is a front elevational view of the motor mount assembly of the air
purifier shown in Figure 13;
Figure 1 SE is a side elevational view of the motor mount assembly of the air
purifier shown in Figure 13;
Figure 1 SF is a perspective view of the fan blade of the air purifier shown
in
Figure 13;
Figure 16 is a front perspective view of a third member of a family of air
purifiers in accordance with the present invention;
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Figure 17 is an exploded perspective view of the air purifier shown in Figure
16;
Figure 18 is a cross-sectional view taken along line 18-18 as shown in Figure
16;
Figure 18A is an open view of the air purifier shown in Figure 16 looking at
the
fan and scroll relationship with the rear panel and top grill removed;
Figure 18B is a perspective view of the motor mount assembly of the air
purifier shown in both Figures 16 and 22;
Figure 18C is a partially exploded perspective view of the motor mount
1 S assembly shown in Figure 18B illustrating the relationship of the boss
caps to the
assembly;
Figure 18D is a front elevational view of the motor mount assembly shown in
Figure 18B;
Figure 18F is a perspective view of the fan blade of the air purifiers shown
in
both Figures 16 and 22;
Figure 19 is a front perspective view of a fourth member of a family of air
purifiers in accordance with the present invention;
Figure 20 is an exploded perspective view of the air purifier shown in Figure
19;
Figure 21 is a cross-sectional view taken along line 21-21 as shown in Figure
19;
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Figure 21 A is an open view of the air purifier shown in Figure 19 looking at
the
fan and scroll relationship with the rear panel and top grill removed;
Figure 22 is a front perspective view of a fifth member of a family of air
purifiers in accordance with the present invention;
Figure 23 is an exploded perspective view of the air purifier shown in Figure
22;
Figure 24 is a cross-sectional view taken along line 24-24 as shown in Figure
22;
Figure 24A is an open view of the air purifier shown in Figure 22 looking at
the
fan and scroll relationship with the rear panel and top grill removed;
Figure 25 is an exploded view of a filter assembly for the family of air
purifiers
shown in Figures 10 through 24;
Figure 26 is a partially exploded view showing the relation of the filter
assembly to the housing;
Figure 27 is a perspective view showing the filter assembly mounted to the
housing inside the door;
Figure 28 is a cross-sectional view taken along line 28-28 as shown in Figure
27;
Figure 29 is a partial elevational view showing the connection of the filter
assembly to the housing as shown in Figure 27;
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Figure 30 is similar to Figure 26 but illustrates an alternative configuration
of
the housing; and
Figure 31 is a view similar to Figure 29 of the housing shown in Figure 30.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Initially referring to Figures 1 through 4, an air purifying device 10 in
accordance with the present invention is depicted. The device includes a
housing 12, a
fan 14, a filter assembly 16, first and second hangers 18, 20, and first and
second
elongate hanger 22, 24 supports as shown in Figure 4.
Referring now to Figure 3, the housing 12 includes an air inlet 26 and an air
outlet 28. Preferably both the air inlet 26 and an air outlet 28 are
configured as a grill
with a plurality of slot-like openings or the like formed in the exterior
walls of the
housing 12. The housing 12 preferably includes a filter assembly cover 30 that
is
removable and has the air inlet 26 formed therein as shown in Figure 2. As
shown in
Figures 3 and 4, the housing 12 preferably includes an inner grate 32 having a
plurality
of slot-like openings positioned between the filter assembly 16 and the fan
14. The
particular shapes of the openings is not deemed critical so long as they
permit
satisfactory throughput of air. The lower portion of the housing 12 below the
filter
assembly 16 preferably includes a plurality of stiffening ribs 34 to
strengthen the
housing 12 between the air inlet 26 and the inner grate 32. The housing 12 is
preferably configured to accommodate a control knob 36 for adjusting the fan
speed to
control the flow of air. The housing 12 is preferably made from a light weight
durable
material such as a rigid plastic.
The fan 14 includes an electric motor 38, which is preferably operable on
alternating current, and a fan blade 40 that is coupled to the electric motor
38 by a
drive shaft 42. The fan 14 is positioned within the housing 12 so that air is
drawn
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through the air inlet 26 and is expelled through the air outlet 28 as shown in
Figure 3.
Preferably the fan 14 is a forward curved centrifugal blower which draws air
in axially
to the center of the fan blade 40 and then expels the air out radially into a
scroll 44.
The scroll 44 is preferably attached to the air outlet 28 of the housing 12 to
accommodate the resulting airflow.
Referring again to Figure 3, the filter assembly 16 is positioned within the
housing 12 between the air inlet 26 and the fan 14. The filter assembly 16
includes a
frame 46 and a filter element 48 mounted to the frame 46 as shown in Figures 3
and 5.
Preferably the filter element 48 is a high efficiency particulate air (HEPA)
filter. The
frame 46 has an exterior surface 50 including top 52 and first and second side
surfaces
54, 56. The frame 46 preferably includes a top wall 58, a bottom wall 60, and
first and
second opposing side walls 62, 64 connecting the top and bottom walls 58, 60
with the
filter element 48 being positioned within the walls as shown in Figure 5. The
frame 46
is generally rectangular, but could include other shapes and sizes. The frame
46
includes an outlet end 66 and an inlet end 68. Preferably a support 70 is
coupled to the
outlet end 66 of the frame 46. The support 70 includes a plurality of strap-
like
elements 72 which extend across the frame 46 to maintain the filter element 48
against
the air pressure created by the fan 14 as air is drawn through the filter
assembly 16. A
seal 74 is preferably mounted to the outlet end 66 of the frame 46. As shown
in
Figures 3 and 4, preferably the housing 12 is formed with a cavity 76 defined
by a
perimeter 78 that is adapted to bear against the seal 74 when the filter
assembly 16 and
filter assembly cover 30 are installed. A substantially air-tight seal is
formed by the
engagement of the frame seal 74 and housing 12. Operation of the blower tends
to
draw the frame 46 towards the housing 12, thereby enhancing the seal.
Referring now to Figures 4 and 5, the first and second hangers 18, 20 are
coupled to the frame 46 of the filter assembly 16. Each of the hangers 18, 20
preferably includes a channel 80. Preferably the hangers 18, 20 are coupled to
an
exterior surface 50 of the frame 46 as shown in Figures 5 and 7. In a
preferred
embodiment of the invention, the hangers 18, 20 are coupled to the top surface
52 of
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the frame 46 as shown in Figures 4 and 5. In an alternative embodiment of the
invention, the first and second hangers 18, 20 are respectively coupled to the
first and
second side surfaces 54, 56 of the frame 46 as shown in Figure 7 (second
hanger not
shown). Preferably each hanger 18, 20 includes at least one pair of converging
walls
82 bounding the channel 80 as shown in Figure 3. In an alternative embodiment,
each
of the hangers 18, 20 preferably includes two pairs of converging walls. The
converging walls 82 serve to ensure that the filter assembly is installed
correctly. In
another embodiment of the invention, the channels 80 are plugged at their end
adjacent
to the inlet end 68 of the frame 46 to prevent the filter assembly 16 from
being
installed backwards. Although the cross section of the channels 80 as shown in
Figures 4 and 5 is generally rectangular, the cross section can also be
circular, ovular,
triangular or polygonal provided that the first and second elongate hanger
supports 22,
24 as described below are configured accordingly. In addition, although it is
preferable
to practice the present invention using first and second hangers 18, 20, the
present
invention can be practiced with only one hanger.
Referring now to Figures 4 and 7, the first and second elongate hanger
supports
22, 24 are mounted to the housing 12. The first and second elongate hanger
supports
22, 24 are respectively configured to be removably extended within the first
and
second hangers 18, 20. While the filter assembly 16 should be easily installed
or
removed, a relatively snug fit between the hangers 18, 20 and hanger supports
22, 24 is
preferred. Such a fit will provide for frictional retention of the filter
assembly 16.
Detents may optionally be provided on the hangers 18, 20 and/or hanger
supports 22,
24 for retention purposes. The hanger supports 22, 24 provide support for the
filter
assembly 16 so that it can be hung between the air inlet 26 and the fan 14.
The hanger
supports 22, 24 preferably, but not necessarily, provide the sole means of
supporting
the filter assembly 16. As noted above with respect to the first and second
hangers 18,
20, the present invention can be practiced with only one hanger support.
Referring now to Figure 6, an alternative embodiment of the invention is
shown where the first and second hangers 18, 20 are coupled to the housing 12
and the
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first and second elongate hanger supports 22, 24 are coupled the frame 40 of
the filter
assembly 16. The alternative embodiment is similar to the embodiment that is
shown
in Figures 4 and 5 as the hanger supports 22, 24 are coupled to the top
surface 52 of
the frame 46. The alternative embodiment can be similarly configured to that
as
shown in Figure 7, where the hanger supports 22, 24 are coupled to the side
surfaces
54, 56 of the frame 46 and the hangers 18, 20 are coupled to the housing 12.
In another alternative embodiment of the invention (not shown) that includes
first and second hangers 18, 20 and first and second elongate hanger supports
22, 24,
one of the hangers is coupled to the frame 46 of the filter assembly 16 while
the other
is coupled to the housing 12. The hanger supports 22, 24 are similarly coupled
to
cooperate with the hangers 18, 20 for supporting the filter assembly 16. This
configuration is beneficial in that the arrangement 18, 20 of the hangers and
hanger
supports 22, 24 ensures that the filter assembly 16 is not installed
backwards.
In operation, the control knob 36 on the housing 12 is turned by the user to
select a desired fan speed. Rotation of the fan blade 40 causes air to be
drawn into the
air inlet 26 through the filter assembly 16. The filtered air then moves
through the
inner grate 32 and enters the fan 14. The fan 14 expels the air into the
scroll 44 which
then exits through the air outlet 28. Since the filter assembly 16 restricts
the airflow,
considerable suction is created across the outlet end 66 of the filter
assembly 16
causing the filter assembly 16 to be drawn towards the perimeter 78 of the
cavity 76.
This enhances the engagement of the seal 74 and the perimeter 78 of the
housing
cavity 76 to ensure that unfiltered air does not bypass the filter assembly 16
prior to
entering the fan 14.
The filter assembly 16 of the air purifier 10 is easily replaced. The filter
assembly cover 30 is first removed and then the spent filter assembly 16 is
taken off
the elongate hanger supports 22, 24. The new filter assembly 16 is installed
by
aligning the hangers thereof with the hanger supports and sliding the new
filter
assembly onto the hanger supports 22, 24. The hangers 18, 20 and hanger
supports 22,
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24 are advantageous because a user is assured that the correct replacement
filter
assembly 16 is being used when it is properly mounted to the air purifier 10.
The
converging walls 82 of the hangers 18, 20 are beneficial to the user in that
they prevent
the user from installing the filter assembly 16 backwards.
The present invention can also be used in a family of air purifiers 110 that
use a
modular filter assembly 116. Referring now to Figures 10 through 24, a family
of air
purifiers 110 that use a modular filter assembly 116 in accordance with the
present
invention are shown. As discussed above with respect to the embodiment shown
in
Figures 1 through 5, the air purifying devices 110 generally include a housing
112, a
fan 114, at least one filter assembly 116, at least one set of first and
second hangers
118, 120, and at least one set of first and second elongate hanger supports
122, 124.
The housings 112 also include air inlets 126 and air outlets 128 as described
above.
All of the purifiers 110 shown in Figures 10, 13, 16, 19, and 22 are
configured
to use the same filter assembly 116 that is detailed in Figures 25 through 31.
As
illustrated in the exploded views (see Figures 11, 14, 17, 20, and 23), the
air purifying
devices 110 use either 2, 3 or 4 filter assemblies 116. Although not shown,
one skilled
in the art would understand that an air purifier can be configured to use only
1 filter
assembly 116 as evidenced by the embodiments shown in Figures 1 through 9. The
exploded views also illustrate that the filter assemblies 116 can be either
vertically
hung (as shown in Figures 17 and 23), cantilevered--horizontally arranged--(as
shown
in Figures 11 and 20), or a combination of both vertically hanging and
cantilevering
(as shown in Figure 14).
Referring now to Figures 25 and 28, the filter assembly 116 includes a frame
146 and a first filter element 148 mounted within the frame 146 and preferably
a
second filter element 152 mounted on the intake side 168 of the filter
assembly 116.
Preferably the first filter element 148 is a HEPA filter for removing
particulate matter
and the second filter element 148 is a carbon filter 152 for removing odors.
The
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second filter element 152 is preferably removably attached to the filter
assembly 116
by a plurality of filter tabs 154.
The frame 146 of the filter assembly 116 has an exterior surface 150 and
preferably includes a top wall 158, a bottom wall 160, and first and second
opposing
side walls 162, 164 connecting the top and bottom walls 158, 160 with the
first filter
element 148 being positioned within the walls. The frame 146 is generally
rectangular,
but could include other shape and sizes. Preferably the frame 146 includes
straps 166
that extend between the first and second opposing side walls 162, 164. The
frame 146
is preferably configured to receive a rubber gasket 174 to ensure a good seal
against
the housing. Preferably the frame 146 includes a lip 170 that extends around
the
perimeter of the frame 146 formed with a recess for receiving the gasket 174.
The filter assembly 146 also includes at least one hanger for facilitating the
connection to an elongate hanger support. As shown in Figure 26, preferably
the filter
assembly includes first and second hangers 118, 120. Each hanger 118, 120
preferably
includes a pair of legs 119 attached to the top wall 158 at the lip 170 to
form an open
"C" shaped section. This arrangement defines a gap 121 between the legs 119.
When
the filter assembly 146 is mounted to the housing 112 as shown in Figures 29
and 31
each leg 119 engages a portion of the respective elongate hanger support 122,
124.
Referring now to Figure 26, the elongate hanger supports 122, 124 are attached
at one end to the housing 112 as a cantilever. To complement the configuration
of the
hangers 118, 120, preferably the elongate hanger supports 122, 124 include at
least one
rib 130 extending between the gap, and most preferably a pair of ribs 130 that
are
arranged to contact the legs of the hanger 118, 120 when the filter assembly
116 is
installed thereon as shown in Figure 29. The ribs 130 help stiffen the
elongate member
122, 124 against bending and reduce the rotation of the filter assembly 116
when the
filter assembly 116 is cantilevered--horizontally arranged--as shown in
Figures 11 and
20. In an alternative embodiment, the housing 112 includes a wall element 132
that is
attached to the ribs 130 and runs substantially perpendicular thereto as shown
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Figures 30 and 31. Figures 8 and 9 illustrate another embodiment of the
present
invention that includes the housing 12 and filter assembly 16 of the
embodiment
shown in Figures 1 through 5 while utilizing the hangers 118, 120 and hanger
supports
122, 124 as detailed in Figures 29 and 31.
Referring again to Figures 10 through 24, the air purifiers 110 preferably
include a door 134 for gaining access to the filter assemblies 116. Referring
now to
Figure 27, the filter assembly 116 is shown positioned within the housing 12
with
respect to the door 134. Preferably the door 134 includes door tabs 136 that
are
configured to make contact with the filter tabs 154 that secure the second
filter element
152 to the filter assembly 116. The contact helps ensure that a good seal is
maintained
between the gasket 174 and housing 112. The door tabs 136 can be arranged to
make
contact with the filter tabs 154 in a variety of ways as shown in Figures 27
and Figure
15. Preferably the door tabs 136 are arranged to span the filter assembly 116
in a
horizontal manner. That is, where the filter assembly 116 is hung vertically
as shown
in Figure 27 preferably at least one pair of door tabs 136 makes contact with
the filter
tabs 154 on opposite side walls 162, 164. Where the filter assembly 116 is
cantilevered as represented by the top filter assembly 116 in Figure 15
preferably at
least one pair of door tabs 136 makes contact with the filter tabs 154 on the
top and
bottom walls 158, 160.
The family of air purifiers 110 formed in accordance with the present
invention
solves a huge problem with retailers that market air purifiers. The family of
air
purifiers 110 includes a variety of members designed to have different Clean
Air
Delivery Rates ("CADR") to suit consumers particular performance requirements.
The
filter assembly disclosed herein can be used in all the members' housings.
This allows
retailers to stock a single filter assembly 116 to suit the demands of all
consumers.
This benefits the retailer because the filter assemblies will turn over more
frequently
and the retailer does not have to allocate as much shelf space as is needed to
stock a
variety of different size units.
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In addition, the filter assembly 116 also provides advantages in reducing
shelf
space by having the hangers formed as an open "C" shaped section that defines
the gap
121. The hanger 118, 120 could have been designed as illustrated by the
embodiment
shown in Figures 1 through 5 without a gap 121, but it was found that the gap
allows
for the packaging size for the replacement filter assemblies 116 to be reduced
if the
ribs 130 of the elongate members 122, 124 are allowed to extend between the
legs 119
of each hanger 118, 120.
The family of air purifiers illustrated in Figures 10, 13, 16, 19, and 22
offer
improved performance characteristics over comparable commercially available
units
that use HEPA filters when considering Clean Air Delivery Rate, the size of
the unit,
and the noise generated by the unit. The improved performance is attributed to
the
overall design as well as the design of the individual component parts. The
dimensional relationship has been found to be important to the improved
performance
and is illustrated in the drawings. The drawings are to scale with the
dimensions
shown therein in millimeters. The design improvements of the following
component
parts have enhanced each air purifiers performance characteristics:
1. Housing 112 design having a cavity 176 that extends around the
perimeter thereof;
2 Motor mount assembly 178; and
3. Fan 114.
These major components are generally illustrated in Figures that include a
similar
letter as part of their identification. For example, Figures 12A, 15A, 18A,
21A, and
24A all illustrate the same view for each purifier. Accordingly for the
remainder of
this disclosure reference to a similarly noted group of Figures will be
hereinafter
referred to as the "A drawings," "B drawings" etc.
Referring now to the Figures 12, 15, 18, 21, 24, and the "A drawings," the
scroll 144 and fan 114 relationship for each purifier within the housing 112
is shown.
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The housing 112 in each purifier has an exterior surface 180 that is formed
with the air
inlet 126 and air outlet 128. In each purifier, the scroll 144 is located
within the
housing 112 and has walls 182 formed with an intake opening 184 and an exhaust
port
186. The exterior surface 180 and the walls 182 define the cavity 176. The
cavity 176
S has a first portion 188 and a second portion 190. The first portion 188 is
in
communication between the exhaust port 186 and the air outlet 128. The scroll
144
preferably includes an exhaust duct portion 192 having a first end 194 and a
second
end 196 with the walls 182 defining a cross section of the exhaust duct
portion 192.
The first end 194 is in fluid communication with the intake opening 184 and
the
second end 196 terminates at the exhaust port 186. Preferably the cross
section
increases between the first end 194 and the second end 196. Preferably the
walls 182
of the scroll 144 are configured to form a reducer 198 at the intake opening
184 having
a cross section. Preferably the cross section of the reducer 198 is circular
and
decreases from the intake opening I 84 towards the fan blade 200. When an air
purifier
is activated non-filtered air is drawn through the filter assemblies 116
creating a
negative pressure zone between the outlet end 169 of the filter assemblies 116
and the
central portion of the fan 114 while a positive pressure develops outside of
the fan 114
within the scroll 144. In addition, a positive pressure of filtered clean air
is developed
in the second portion 190 of the cavity 176 that surrounds the negative
pressure zone.
With respect to the exterior surface 180 of the housing 112, this helps ensure
that air
exiting the purifier will be filtered clean air and that air entering the
purifier will enter
through the air inlet 126 and pass through one of the filter assemblies 116.
Referring now to the Figures 12, 15, 18, 21, and 24, the fan 114 preferably
includes a motor mount assembly 178 connected to either the housing 112 or the
scroll
144, and a fan blade 200 coupled to the motor mount assembly 178. Preferably
the fan
blade 200 is positioned within the scroll 144 adjacent to the reducer 198. The
motor
mount assembly 178 and fan blade 200 for the first member ( Figure 10) and the
fourth
member (Figure 19) of the family of air purifiers are the same and are shown
in
Figures 12B through 12F. In addition, the motor mount assembly 178 and fan
blade
200 for the third member ( Figure 16) and the fifth member (Figure 22) of the
family
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of air purifiers are the same and are shown in Figures 18B through 18F.
Referring now to the "B", "C", "D", and "E" drawings the motor mount
assembly 178 for the air purifiers are shown. The motor mount assembly 178
includes
a motor 202 and motor mount frame 204 attached to the motor 202. Preferably
the
assembly 178 also includes a motor mount ring 206 that has a center and
facilitates the
connection between the motor 202 and motor mount frame 204. The motor 202 is
generally an electric motor that is powered by A.C. current. The motor 202
preferably
has a shaft 210 for coupling to the fan blade 200. The motor mount frame 204
preferably includes a plurality of U-shaped brackets 208 made from wire. Each
of the
brackets 208 preferably has a pronged end 212 that is attached to the motor
mount ring
206 and extends radially from the center, and a curved end 214 for connecting
to either
the housing 112 or the scroll 144. Preferably a wire ring 216 is connected to
at least
two of the plurality of brackets 208 adjacent to the curved end 214 for
stiffenning the
motor mount frame 204. Preferably a grommet 218 made from rubber is located at
the
curved end 214 of each bracket. Preferably the mounting assembly 178 also
includes
boss caps 220 to fit over the star shaped bosses 222 of the housing 112 or
scroll 144 as
shown in Figure 13. The mounting assembly 178 is generally secured with screws
through washers to sandwich the grommet 218 between the boss cap 220. The
motor
mount assembly 178 is advantageous because it is designed to reduce air
turbulence
and vibration providing for quieter operation without loss of CADR.
Referring now to the "F" drawings, the details of the fan blade 200 for each
air
purifier are shown. The fan blade 200 includes a plurality of fins 224
sandwiched
between a circular plate 226 and a circular ring 228. The circular plate 226
is
preferably formed with an opening in the center for cooperating with the shaft
210 of
the motor 202. Preferably the fan blade 200 is made from plastic such as ABS.
The
configuration of the fan blade 200 is also significant in enhancing each air
purifiers
performance characteristics.
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Although illustrative embodiments of the present invention have been
described herein with reference to the accompanying drawings, it is to be
understood
that the invention is not limited to those precise embodiments, and that
various other
changes and modifications may be effected by one skilled in the art without
departing
from the scope or spirit of the invention.
