U.S. patent application number 12/675636 was filed with the patent office on 2011-06-23 for cyclonic surface cleaning apparatus with sequential filtration members.
This patent application is currently assigned to G.B.D. CORP.. Invention is credited to Wayne Ernest Conrad.
Application Number | 20110146024 12/675636 |
Document ID | / |
Family ID | 40385176 |
Filed Date | 2011-06-23 |
United States Patent
Application |
20110146024 |
Kind Code |
A1 |
Conrad; Wayne Ernest |
June 23, 2011 |
CYCLONIC SURFACE CLEANING APPARATUS WITH SEQUENTIAL FILTRATION
MEMBERS
Abstract
A cyclonic surface cleaning apparatus incorporates a series of
sequential physical filtration members to progressively remove
smaller particulate matter whereby the physical filtration members
collectively have a longer in use time prior to being clogged,
thereby permitting a longer operating time prior to the cleaning or
replacement of the physical filtration members.
Inventors: |
Conrad; Wayne Ernest;
(Hampton, CA) |
Assignee: |
G.B.D. CORP.
Nassau
BS
|
Family ID: |
40385176 |
Appl. No.: |
12/675636 |
Filed: |
August 27, 2008 |
PCT Filed: |
August 27, 2008 |
PCT NO: |
PCT/CA08/01519 |
371 Date: |
February 26, 2010 |
Current U.S.
Class: |
15/347 |
Current CPC
Class: |
A47L 7/0038 20130101;
A47L 9/20 20130101; Y10T 428/19 20150115; A47L 9/1666 20130101;
A47L 9/1625 20130101; A47L 9/1641 20130101; A47L 9/122 20130101;
Y10T 428/17 20150115; A47L 7/0028 20130101; A47L 9/1683 20130101;
Y10T 156/1158 20150115; A47L 9/1658 20130101; A47L 9/1608 20130101;
A47L 9/165 20130101; A47L 5/24 20130101; Y10T 428/24488
20150115 |
Class at
Publication: |
15/347 |
International
Class: |
A47L 9/16 20060101
A47L009/16 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 29, 2007 |
CA |
2,599,303 |
Claims
1. A surface cleaning apparatus comprising: (a) a dirty air inlet,
a clean air outlet downstream, a fluid flow passage extending from
the dirty air inlet to the clean air outlet, (b) a suction motor
provided in the fluid flow passage; (c) a filtration apparatus
downstream from the dirty air inlet and comprising a cyclone having
a cyclone outlet, (d) a foam filter downstream from the cyclone
outlet; (e) a felt filter downstream from the foam filter; and, (f)
a HEPA filter downstream from the felt filter.
2. The surface cleaning apparatus of claim 1 further comprising a
screen downstream from the cyclone outlet and upstream from the
foam filter.
3. The surface cleaning apparatus of claim 2 wherein the screen
comprises an open wire mesh.
4. The surface cleaning apparatus of claim 1 wherein the cyclone
outlet comprises a vortex finder and the vortex finder has an
upstream end in the cyclone and the upstream end is
unobstructed.
5. The surface cleaning apparatus of claim 1 wherein the cyclone
outlet has a shroud.
6. The surface cleaning apparatus of claim 5 wherein the shroud
comprises an apertured end of the cyclone outlet.
7. The surface cleaning apparatus of claim 1 wherein the suction
motor is downstream from the HEPA filter.
8. The surface cleaning apparatus of claim 1 wherein the suction
motor is upstream from the HEPA filter.
9. The surface cleaning apparatus of claim 2 wherein the screen is
mounted in a housing having an outer wall that is transparent.
10. The surface cleaning apparatus of claim 9 wherein the outer
wall is openable.
11. The surface cleaning apparatus of claim 1 wherein the foam
filter, the felt filter and the HEPA filter are removably mounted
in the surface cleaning apparatus.
12. The surface cleaning apparatus of claim 11 wherein the foam
filter, the felt filter and the HEPA filter are removable as a
unit.
13. The surface cleaning apparatus of claim 1 wherein each layer of
physical filtration media is selected to remove a particular size
range of particles that is larger then that of the next downstream
layer of filtration material.
14. The surface cleaning apparatus of claim 1 wherein the cyclone
has a separation efficiency for IEC dirt of 98% of particles that
are from 3 to 5 microns and at least 96.5% of particles that are
from 1-2 microns.
15. The surface cleaning apparatus of claim 14 wherein the foam has
separation efficiency of 70-85% of particles that are 1-2 microns
and 30-50% of particles that are 0.3-0.9 microns.
16. The surface cleaning apparatus of claim 14 wherein the felt has
a separation efficiency of 70-85% of particles that are 0.5-0.9
microns and 30-50% of particles that are 0.3 microns.
17. The surface cleaning apparatus of claim 15 wherein the felt has
a separation efficiency of 70-85% of particles that are 0.5-0.9
microns and 30-50% of particles that are 0.3 microns.
Description
FIELD
[0001] This application relates to surface cleaning apparatus, such
as vacuum cleaners.
BACKGROUND
[0002] Various types of vacuum cleaners are known in the art.
Currently, many of the vacuum cleaners, which are sold for
residential applications, utilize at least one cyclone as part of
the air filtration mechanism. More recently, to obtain higher
levels of filtration, cyclonic vacuum cleaners have been designed
which utilize two cyclonic stages. An example is shown in Conrad
(U.S. Pat. No. 6,782,585). As shown therein, a vacuum cleaner has a
first cyclonic cleaning stage comprising a single first stage
cyclone and a second cyclonic cleaning stage that is downstream
from the first cyclonic cleaning stage and comprises a plurality of
cyclones in parallel.
[0003] The plurality of second stage cyclones typically remove
particulate matter finer than the particulate matter that is
removed in the first cyclonic cleaning stage. Accordingly, the
coarsest particulate matter that is entrained in an air stream is
removed in the first cyclonic cleaning stage and finer particulate
matter is removed in the downstream cyclonic cleaning stage.
However, the air exiting the second cyclonic cleaning stage may
still contain sufficient particulate matter to damage a suction
motor positioned downstream from the second cyclonic cleaning
stage. Accordingly, as disclosed in Conrad, a screen or filter may
be positioned downstream from the second cyclonic cleaning stage
and upstream from the suction motor. Further, a HEPA filter may be
positioned downstream from the suction motor.
SUMMARY
[0004] In accordance with this invention, a surface cleaning
apparatus uses a plurality of filtration members having varying
filtration ability. In accordance with this embodiment, a surface
cleaning apparatus utilizes a foam filter positioned downstream
from a cyclone, a felt filter positioned downstream from the foam
filter and a HEPA filter positioned downstream from the felt
filter. Preferably, a screen is provided for the air outlet of a
cyclone chamber. The suction motor of the surface cleaning
apparatus is preferably provided downstream from the HEPA filter,
but may be upstream of the HEPA filter.
[0005] An advantage of this design is that filtration materials
having finer pore sizes are positioned downstream from a series of
coarse filtration elements thereby extending the lifetime of the
finer filter elements.
[0006] In accordance with this invention, there is provided a
surface cleaning apparatus comprising: [0007] (a) a dirty air
inlet, a clean air outlet downstream, a fluid flow passage
extending from the dirty air inlet to the clean air outlet; [0008]
(b) a suction motor provided in the fluid flow passage; [0009] (c)
a filtration apparatus downstream from the dirty air inlet and
comprising a cyclone having a cyclone outlet; [0010] (d) a foam
filter downstream from the cyclone outlet; [0011] (e) a felt filter
downstream from the foam filter; and, [0012] (f) a HEPA filter
downstream from the felt filter.
[0013] In one embodiment, the surface cleaning apparatus further
comprises a screen downstream from the cyclone outlet and upstream
from the foam filter. Preferably, the screen comprises an open wire
mesh.
[0014] The screen may have a surface area that is 2 times,
preferably at least about 5 times, more preferably at least about
10 times and, most preferably at least about 20 times, e.g. 20-50
times, the cross sectional area of the cyclone air outlet. It will
be appreciated that the screen may be flat or may be curved, e.g.,
bowl shaped. The use of such a large screen enhances the time
during which the vacuum surface cleaning apparatus may be used
without having to clean or replace the screen. Further, by
positioning the screen exterior to the cyclone chamber, a large
screen may be provided without reducing the size of the cyclone
chamber
[0015] In any embodiment, the cyclone outlet may comprise a vortex
finder, the vortex finder may have an upstream end in the cyclone
and the upstream end may be unobstructed.
[0016] In any embodiment, the cyclone outlet may have a shroud.
Preferably, the shroud comprises an apertured end of the cyclone
outlet.
[0017] In any embodiment, the suction motor may be positioned
downstream from the HEPA filter. Alternately, the suction motor may
be positioned upstream from the HEPA filter.
[0018] In any embodiment, the screen may be mounted in a housing
having an outer wall that is transparent. Preferably, the outer
wall is openable, e.g. a pivotally mounted door. Alternately, it
may be removably mounted, such as by a screw thread or a bayonet
mount, a snap fit or the like. Alternately, it may be slidably
mounted or rotationally mounted.
[0019] In any embodiment, the foam filter, the felt filter and the
HEPA filter may be individually or selectively removably mounted in
the surface cleaning apparatus and, preferably removable as a
unit.
[0020] In any embodiment, each layer of physical filtration media
may be selected to remove a particular size range of particles that
is larger than that of the next downstream, layer of filtration
material.
[0021] In any embodiment, the cyclone may have a separation
efficiency for IEC dirt of 98% of particles that are from 3 to 5
microns and at least 96.5% of particles that are from 1-2
microns.
[0022] In any embodiment, the foam may have a separation efficiency
of 70-85% of particles that are 1-2 microns and 30-50% of particles
that are 0.3-0.9 microns.
[0023] In any embodiment, the felt may have a separation efficiency
of 70-85% of particles that are 0.5-0.9 microns and 30-50% of
particles that are 0.3 microns.
[0024] It will be appreciated by those skilled in the art that any
of the embodiments may be used individually or in a single surface
cleaning apparatus, as exemplified in a preferred embodiment
described herein, or in any particular sub-combination.
Accordingly, any two or more embodiments may be used in a single
surface cleaning apparatus. In addition, any of the optional
features described herein may be used in combination with any
alternate embodiment or sub-combination or combination of alternate
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and other advantages of the instant invention will be
more fully and completely understood in conjunction with the
following description of the preferred embodiments of the invention
in which:
[0026] FIG. 1 is a side elevational view of a preferred embodiment
of a vacuum cleaner in accordance with this design wherein the
outer casing surrounding the cyclone and forming an outer wall of a
dirt collection chamber is optionally transparent;
[0027] FIG. 2 is a perspective view from the front and the right
side of the vacuum cleaner of FIG. 1;
[0028] FIG. 3 is a cross-section along the line 3-3 in FIG. 2;
[0029] FIG. 4 is a schematic drawing of the vacuum cleaner of FIG.
1 showing the airflow passage therethrough;
[0030] FIG. 5 is a perspective view from the bottom of the vacuum
cleaner of FIG. 1 wherein the bottom of the first and second
housings is open;
[0031] FIG. 6 is a perspective view of the bottom of the vacuum
cleaner of FIG. 1 wherein the first and second housings are closed
but an access door is open; and,
[0032] FIG. 7 is a longitudinal section through an alternate
embodiment of a vacuum cleaner in accordance with this
invention.
DETAILED DESCRIPTION
[0033] As shown in FIGS. 1-6, a surface cleaning apparatus
comprises a vacuum cleaner 10 having a filtration apparatus having
at least one cyclone. The filtration apparatus may be of any design
or configuration. As exemplified, surface cleaning apparatus 10 has
a first housing 12 and a second housing 14. First housing 12
comprises at least one cyclone 16 and a dirt collection chamber 18
and second housing 14 houses the filtration members and the suction
motor. Dirty air entrained in dirty air inlet 38 travels through
the filtration apparatus, through suction motor 26 and exits the
surface cleaning apparatus via clean air outlet 60. As shown in
FIG. 7, a surface cleaning apparatus 10 has a first cyclonic
cleaning stage comprising a single cyclone 150 having a dirt
collection chamber 152 and a second cyclonic cleaning stage
comprising a plurality of second stage cyclones 154 in
parallel.
[0034] It will be appreciated that, surface cleaning apparatus may
be a vacuum cleaner, a carpet extractor, a bare floor cleaner or
the like. As exemplified, the surface cleaning apparatus is hand
held. However the surface cleaning apparatus may be configured as
an upright vacuum cleaner, a stick vacuum cleaner, a canister
vacuum cleaner, a back pack or shoulder strap vacuum cleaner or
other configuration known in the art. The surface cleaning
apparatus may have a single cyclonic cleaning stage, which may be
of any construction known in the art, or a plurality of cyclonic
cleaning stages, each of which may be of any construction known in
the art, e.g. they may comprise a single cyclone or a plurality of
cyclones in parallel.
[0035] In accordance with this invention, a series of filtration
members are positioned in series downstream from the cyclone
chamber of cyclone 16, or alternately downstream from the outlet of
the last cyclonic cleaning stage. The filtration members comprise a
foam filter 20, a felt filter 22 downstream from foam filter 20 and
a HEPA filter 24 downstream from felt filter 22. Preferably, all of
these filters are positioned upstream from suction motor 26.
Alternately, one or more of these filters may be positioned
downstream from suction motor 26. In particular HEPA filter 24 may
be downstream from suction motor 26 (see for example FIG. 7).
Accordingly, a plurality of filtration members, each of which have
a finer filtration capacity (e.g. smaller pores) than the previous
filter, are provided in series in the downstream direction.
[0036] For example, the foam filter may be an open cell foam made
from materials currently used to manufacture foam filters for
vacuum cleaners and may be selected to have pore sizes from 0.25-5
microns and may have a mean pore size of 2 microns. Accordingly,
the foam will filter particles larger than 5 microns and some of
the particles that are between 0.25-5 microns. The felt filter may
be woven or non-woven and may be made from plastic, preferably
rayon, nylon, polypropylene or a combination thereof. The felt may
be selected to have pore sizes from 0.1-2.5 microns and may have a
mean pore size of 1 micron. Accordingly, the felt will filter
particles larger than 2.5 microns and some of the particles that
are between 0.1-2.5 microns. HEPA filtration is typically defined
as removal of 99.97% of particles larger than 0.3 microns.
[0037] In a preferred embodiment, cyclone 16, or the cyclonic
cleaning stages combined (e.g. cyclone 16 in FIG. 1 or cyclones 150
and 152 in FIG. 7), may achieve a separation efficiency for IEC
dirt as specified as IEC 60312, which is representative of
household dirt, of 98% of particles that are from 3 to 5 microns
and at least 96.5% of particles that are from 1-2 microns. By
removing a high percentage of particles in this size range, the
foam will not prematurely clog. Similarly, the foam preferably has
a separation efficiency of 70-85% of particles that are 1-2 microns
and 30-50% of particles that are 0.3-0.9 microns. By removing a
high percentage of particles in this size range, the felt will not
prematurely clog. Similarly, the felt preferably has separation
efficiency of 70-85% of particles that are 0.5-0.9 microns and
30-50% of particles that are 0.3 microns. By removing a high
percentage of particles in this size range, the HEPA will not
prematurely clog.
[0038] It will be appreciated that each of the foam and the felt
may have varying pore sizes as long as each filters a significant
amount of particles that would prematurely clog the next sequential
filter media. Accordingly, the filtration specification of each
layer of filtration media is selected to be complimentary to the
next sequential layer of filtration media and may essentially
remove particles that are larger than those that are within the
size range targeted for the next sequential filtration media. In
other words, each layer of filtration material is selected to
remove a particular size range of particles. Accordingly, each
upstream layer is selected to remove a particular size range of
particles that is larger then that of the next downstream layer of
filtration material.
[0039] In a preferred embodiment, foam filter 20, felt filter 22
and HEPA filter 24 are removably mounted as a unit (e.g., they may
be mounted in a filter housing or directly secured to each other).
For example, when second housing 14 is opened, e.g., by opening
bottom 66, foam filter 20, felt filter 22 and HEPA filter 24 may be
removed together. Alternately, they may be separately removable. In
either embodiment, it is preferred that they are separable when
removed so that individual filters may be cleaned and/or replaced.
Alternately, the foam filter 20, felt filter 22 and HEPA filter 24
may be an assembly that is replaceable as a unit, e.g., a new
filter housing containing all three filters may be inserted.
[0040] It will be appreciated that each of the foam filter 20, felt
filter 22 and HEPA filter 24 may comprise a single filter or a
plurality of filters. For example, foam filter 20 may comprise a
series of layers of foam.
[0041] Preferably, a screen 78 is provided upstream from foam
filter 20 and preferably downstream from the cyclone chamber of
cyclone 16, or alternately downstream from the outlet of the last
cyclonic cleaning stage. For example, it may be adjacent outlet 52
of outlet or vortex finder 36, e.g., connected thereto, or
positioned in the air flow path, e.g., filtration chamber 80, such
that air flow is caused to pass therethrough. It will be
appreciated that screen 78 may be provided immediately upstream of
foam filter 20, e.g., it may be provided below foam filter 20 in
second housing 14.
[0042] Optionally, a shroud (e.g. a perforated or apertured plastic
cover) may be provided surrounding or overlying inlet 50 of outlet
36.
[0043] In the exemplified embodiment, cyclone 16 has a dirt outlet
28 and an optional impingement surface 30 spaced from dirt outlet
28 in dirt collection chamber 18. As shown in FIG. 3, impingement
surface 30 is preferably spaced a distance D from outlet 28 wherein
distance D is from 8 to 30 millimeters and, preferably from 12 to
25 millimeters. It will be appreciated that impingement member 30
may be mounted to lid 32 of dirt collection chamber 18.
Alternately, impingement member 30 may be mounted to a sidewall of
dirt collection chamber 18 and/or cyclone 16.
[0044] As exemplified in FIG. 3, cyclone 16 is an inverted cyclone.
Accordingly, cyclone 16 has a lower air inlet 34 and a lower air
outlet 36. Air inlet 34 is positioned downstream from dirty air
inlet 38 of surface cleaning nozzle 40. Surface cleaning nozzle 40
may be any surface cleaning nozzle known in the art. Air inlet 34
of cyclone 16 may be in airflow communication with surface cleaning
nozzle 40 in any manner known in the art. The exact structure of
surface cleaning nozzle 40 and the communication passage between
surface cleaning nozzle 40 and air inlet 34 will vary depending on
if the surface cleaning apparatus is an upright vacuum cleaner,
canister vacuum cleaner or, as exemplified, a portable hand held
vacuum cleaner.
[0045] In operation, air will enter cyclone 16 through inlet 34 and
travel upwardly, as exemplified in FIG. 4. The air will then travel
downwardly to exit cyclone 16 via outlet 36. As shown in FIG. 4 by
the hatched arrows, dirt will exit upwardly through outlet 28 and
deposit on dirt collection chamber floor 42. In addition, some of
the heavier particulate matter may not be entrained in the air
stream and may be deposited on cyclone floor 44.
[0046] In an alternate embodiment, it will be appreciated that
cyclone 16 need not be inverted. Cyclone 16 may be any cyclone with
a dirt outlet provided wherein, preferably, impingement member or
members are positioned spaced from the dirt outlet. The cyclone may
accordingly be an upright cyclone or a cyclone having a single
direction of travel of the air.
[0047] As exemplified, cyclone 16 is a frustoconical cyclone having
cylindrical portion 46 and frustoconical portion 48. Alternately,
or in addition to the orientation of cyclone 16, it will be
appreciated that cyclone 16 may be cylindrical, entirely
frustoconical or any other shape known in the art.
[0048] As exemplified in FIG. 3, cyclone outlet 36 of cyclone 16
comprises a vortex finder that extends inwardly into the cyclone
chamber defined by cyclone 16. Outlet 36 preferably comprises a
generally cylindrical passage, i.e. vortex finder, having an inlet
50 and an outlet 52. It will be appreciated that, in an alternate
embodiment any outlet known in the art for cyclones may be
utilized.
[0049] In some embodiments, inlet 50 may be covered by a screen,
shroud or filter as in known in the art. However, it is preferred
that vortex finder 36 is unobstructed, i.e., no screen, shroud or
filter is provided on inlet 50. Accordingly, as exemplified in FIG.
3, vortex finder 36 is not surrounded by a screen, shroud or filter
and no physical separation member is positioned in the cyclone
chamber of cyclone 16. Accordingly, no filtration or screen member
interior of cyclone 16 requires cleaning. Elongate material such as
hair or fibre can become adhered to a shroud, requiring the shroud
to be manually cleaned. If the shroud is inside the cyclone
chamber, then the chamber should be openable sufficiently to permit
a user to insert their hand to clean the shroud, or to remove the
shroud for cleaning. Accordingly, it will be appreciated that
bottom 44 need not be openable to permit a screen or a shroud or
filter associated with inlet end 50 of outlet 36 to be cleaned.
Preferably, a screen is positioned downstream from cyclone 16 and
upstream from the pre-motor filters. For example, a screen 78 is
preferably provided.
[0050] As exemplified in FIGS. 1-6, vacuum cleaner 10 comprises a
hand held vacuum cleaner. Accordingly, vacuum cleaner 10 may be
provided with handle 54, which is affixed to lid 32 and lid 58 of
second housing 14. Handle 54 may alternately be affixed to any
other portion or portions of vacuum cleaner 10 as is known in the
art. Optionally, as exemplified, on/off switch 56 may be provided
on handle 54. On/off switch 56 may alternately be provided on any
other portion of vacuum cleaner 10.
[0051] As exemplified in FIG. 3, suction motor 26 is positioned in
second housing 14, preferably with a suction fan provided below the
electric motor. Clean air outlet 60 is provided downstream from
suction motor 26. An optional post-motor filter may be provided
downstream from suction motor 26, such as in post-motor filter
housing 62, which may be accessible via post motor filter housing
door 64, which could be pivotably mounted to second housing 14.
[0052] As exemplified, dirt collection chamber 18 surrounds cyclone
16. Accordingly, cyclone 16 may be positioned in dirt collection
chamber 18 and, preferably, generally centrally therein.
Accordingly, vacuum cleaner 10 is preferably configured such that
the dirt collected on floor 44 of cyclone 16 is emptied at the same
time as dirt collected on floor 42 of dirt collection chamber 18.
Accordingly, floor 42 and floor 44 are both movable and connected
to each other whereby both floor 42 and 44 are concurrently movable
such that dirt collection chamber 18 and cyclone 16 are
concurrently emptied.
[0053] As exemplified in FIG. 5, floors 42 and 44 may comprise a
pivoting bottom 66 of first housing 12 and, alternately, of the
filtration apparatus (e.g. housings 12 and 14 of this embodiment).
Accordingly, as seen in FIG. 5, when floors 42 and 44 are opened,
both cyclone 16 and dirt collection chamber 18 may be emptied by
holding vacuum cleaner 10 in the upright position (as shown in FIG.
1). Accordingly, the dirt will fall out of collection chamber 16
and cyclone 16 and will fall downwardly off of floors 42 and
44.
[0054] As shown in FIG. 5, housings 12 and 14 have a pivoting
bottom 66, which is secured to each of housings 12 and 14 by a
pivot 68. In the closed position exemplified in FIGS. 1 and 4,
pivoting bottom 66 is secured in position by latch 70. Latch 70 has
a button 72 which, when pressed, causes arm 74 to move outwardly
thereby disengaging a flange provided on the bottom end of arm 74
from flange 76 provided on pivoting bottom 66. A gasket or other
sealing member may be provided at the interface of housings 12 and
14 and pivoting bottom 66 to provide an air tight or fluid tight
seal. It will be appreciated that bottom 66 may be moveable in any
other direction by any other means known in the art and may
optionally be removable from housings 12, 14. Further, bottom 66
may be moveably secured in position by any other means known in the
art and need not be connected to surface cleaning apparatus 10 for
relative motion thereto.
[0055] As exemplified in FIG. 5, outlet 36 is provided as part of
floor 42, and is preferably integrally molded therewith. In an
alternate embodiment, it will be appreciated that outlet 36 need
not be removable from cyclone 16 with floor 42.
[0056] In an alternate embodiment, it will be appreciated that only
floors 42 and 44 may be pivotably mounted to housing 12. In such an
embodiment, foam filter 20 may remain sealed when cyclone 16 and
dirt collection chamber 18 are emptied. In such a case, the housing
that contains foam filter 20 may be separately opened. In an
alternate embodiment, a side-by-side design as exemplified in FIG.
1 need not be utilized. In such a case, floor 42 and floor 44 may
comprise the entire floor of the filtration assembly.
[0057] If bottom 66 opens both housings 12 and 14, then it will be
appreciated that dirt positioned on the upstream surface of filter
20 will be emptied when bottom 66 is opened.
[0058] Preferably a screen is provided adjacent outlet 36 and,
preferably, in sealing engagement with outlet 52. Screen 78 may be
mounted in a housing (filtration chamber 80), having an outer wall
all or a portion of which is preferably transparent and positioned
downstream from vortex finder 36. Referring to FIG. 3, screen 78 is
positioned spaced from and in sealing engagement with rear surface
84 of floor 44 and overlies outlet 52. Accordingly, air that exits
outlet 36 travels through screen 78. The air then travels through
filtration chamber 80 and travels laterally to outlet 86, which is
in air flow communication with headspace 88 below filter 20.
[0059] Preferably, screen 78 may be an open mesh screen, e.g., a
wire mesh screen or, alternately, a plastic mesh screen.
[0060] An access door 82 may be provided to permit access to screen
78 such that screen 78 may be cleaned. Access door 82 may be any
door that is movably mounted in overlying relationship to
filtration chamber 80. As exemplified in FIG. 6, access door 82
comprises the lower half of filtration chamber 80 and is pivotally
mounted by pivot 90 to pivoting bottom 66, and is secured in
position by a latch 120. Latch 120, for example, may have a button
122 which, when pressed, causes arm 124 to move outwardly thereby
disengaging a flange on the bottom end of arm 124 from flange 92
provided on the front end of access door 82. A sealing gasket or
other sealing member known in the art may be utilized to provide an
air tight or fluid tight seal for filtration chamber 80. Any other
securing member known in the art may be used. Further door 82 may
be removable and need not be connected to surface cleaning
apparatus 10 for relative motion thereto.
[0061] Preferably, screen 78 is mounted and, more preferably,
movably mounted and, most preferably, removably mounted to access
door 82. As shown in FIG. 6, screen 78 is pivotally mounted to the
inner surface of access door 82. Accordingly, when a user desires
to clean screen 78, it may be pivoted in the direction shown by
arrow A in FIG. 6 to an open or cleaning position. It will be
noticed that access door 82 may be opened independently of pivoting
bottom 66. In an alternate embodiment, it will be appreciated that
a pivoting bottom 66 need not be provided.
[0062] Preferably, at least a portion of and, more preferably, all
of access door 82, which as exemplified is the outer wall of
filtration chamber 80, is transparent. Accordingly, a user may lift
the vacuum cleaner, invert the vacuum cleaner or tilt the vacuum
cleaner on its side to view screen 78 and determine whether screen
78 requires cleaning or, alternately, replacement.
[0063] The use in a vacuum cleaner of a foam filter, a felt filter
and a HEPA filter in series, preferably with a screen upstream of
the foam filter, may be used alone or in combination with one or
more of the spacing of an impingement surface, an access door to
permit cleaning or replacement of the screen, the screen being
positioned downstream of a cyclone outlet and mounted in a housing
which is transparent, a configuration to allow a cyclone chamber
and a surrounding dirt collection chamber to be emptied
concurrently, a bottom door that opens to expose the foam filter
and permit the filters to be removed such that one or more of them
may be cleaned or replaced, or any particular combination or
sub-combination thereof.
[0064] It will also be appreciated that any of the aforementioned
embodiments may be used singly or in any particular combination or
sub-combination of the remaining features listed above.
[0065] Although the invention has been described in conjunction
with specific embodiments thereof, if is evident that many
alternatives, modifications and variations will be apparent to
those skilled in the art. Accordingly, it is intended to embrace
all such alternatives, modifications and variations that fall
within the spirit and broad scope of the appended claims. In
addition, citation or identification of any reference in this
application shall not be construed as an admission that such
reference is available as prior art to the present invention.
* * * * *