U.S. patent application number 10/828250 was filed with the patent office on 2004-10-07 for vacuum cleaner having two cyclonic cleaning stages.
This patent application is currently assigned to Fantom Technologies Inc.. Invention is credited to Conrad, Helmut Gerhard, Conrad, Wayne Ernest.
Application Number | 20040194250 10/828250 |
Document ID | / |
Family ID | 26921524 |
Filed Date | 2004-10-07 |
United States Patent
Application |
20040194250 |
Kind Code |
A1 |
Conrad, Wayne Ernest ; et
al. |
October 7, 2004 |
Vacuum cleaner having two cyclonic cleaning stages
Abstract
A vacuum cleaner has a first and second cyclonic cleaning stages
in series. The second cyclonic cleaning stage has a plurality of
second stage cyclones. A conduit connects the first cyclonic
cleaning stage outlet and the second stage cyclone inlets.
Inventors: |
Conrad, Wayne Ernest;
(Hampton, CA) ; Conrad, Helmut Gerhard; (Hampton,
CA) |
Correspondence
Address: |
BERESKIN AND PARR
SCOTIA PLAZA
40 KING STREET WEST-SUITE 4000 BOX 401
TORONTO
ON
M5H 3Y2
CA
|
Assignee: |
Fantom Technologies Inc.
Welland
CA
|
Family ID: |
26921524 |
Appl. No.: |
10/828250 |
Filed: |
April 21, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10828250 |
Apr 21, 2004 |
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09679353 |
Oct 5, 2000 |
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09679353 |
Oct 5, 2000 |
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09239860 |
Jan 29, 1999 |
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6334234 |
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09239860 |
Jan 29, 1999 |
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09227534 |
Jan 8, 1999 |
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6141826 |
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Current U.S.
Class: |
15/353 |
Current CPC
Class: |
B04C 2009/002 20130101;
A47L 9/165 20130101; A47L 9/1625 20130101; B04C 2009/004 20130101;
A47L 9/009 20130101; B04C 5/28 20130101; A47L 9/0009 20130101; B04C
9/00 20130101; A47L 5/28 20130101; A47L 9/1691 20130101; A47L 5/225
20130101; B04C 5/26 20130101; A47L 5/32 20130101; A47L 9/1641
20130101; Y10S 55/03 20130101; B04C 5/02 20130101; B04C 5/103
20130101; B01D 45/16 20130101 |
Class at
Publication: |
015/353 |
International
Class: |
A47L 009/16 |
Claims
We claim:
1. A vacuum cleaner comprising: a) a dirty air inlet and a source
of suction to draw air containing particulate matter into the dirty
air inlet and produce an air stream in the vacuum cleaner; b) a
first cyclonic cleaning stage comprising a cyclone having a first
cyclonic cleaning stage inlet and a first cyclonic cleaning stage
outlet; c) a second cyclonic cleaning stage positioned in series
with the first cyclonic cleaning stage, the second cyclonic
cleaning stage comprising a plurality of second stage cyclones,
each of the second stage cyclones having a second stage cyclone
inlet and a second stage cyclone outlet; and, d) a passage
connecting the first cyclonic cleaning stage outlet and the second
stage cyclone inlets, and the passage is configured to inhibit
settling out of particulate matter from the air stream.
2. The vacuum cleaner as claimed in claim 1 wherein the second
stage cyclones at least partially surround the passage.
3. The vacuum cleaner as claimed in 1 wherein the passage is at
least partially defined by the second stage cyclones.
4. The vacuum cleaner as claimed in claim 1 wherein the passage has
a cross sectional area which is approximately the same as the cross
sectional area of the first cyclonic cleaning stage outlet.
5. The vacuum cleaner as claimed in claim 1 wherein the passage is
substantially free of horizontal spaces that are transverse to the
direction of fluid flow through the passage.
6. The vacuum cleaner as claimed in claim 1 wherein the passage is
substantially free of any dead air spaces.
7. The vacuum cleaner as claimed in claim 1 wherein the passage is
substantially free of regions that are adapted to separate
particulate matter from the air stream.
8. The vacuum cleaner as claimed in claim 1 wherein the passage is
defined by a single conduit.
9. A vacuum cleaner comprising: a) a dirty air inlet and a source
of suction to draw air containing particulate matter into the dirty
air inlet and produce an air stream in the vacuum cleaner; b) a
first cyclonic cleaning stage comprising a cyclone having a first
cyclonic cleaning stage inlet and a first cyclonic cleaning stage
outlet; c) a second cyclonic cleaning stage positioned in series
with the first cyclonic cleaning stage, the second cyclonic
cleaning stage comprising a plurality of second stage cyclones,
each of the second stage cyclones having a second stage cyclone
inlet and a second stage cyclone outlet; and, d) a passage
extending from the first cyclonic cleaning stage outlet to the
second stage cyclone inlets, and the passage is substantially free
of any dead air spaces.
10. The vacuum cleaner as claimed in claim 9 wherein the second
stage cyclones at least partially surround the passage.
11. The vacuum cleaner as claimed in claim 9 wherein the passage is
at least partially defined by the second stage cyclones.
12. The vacuum cleaner as claimed in claim 9 wherein the passage
has a cross sectional area which is approximately the same as the
cross sectional area of the first cyclonic cleaning stage
outlet.
13. The vacuum cleaner as claimed in claim 9 wherein the passage is
substantially free of horizontal spaces that are transverse to the
direction of fluid flow through the passage.
14. The vacuum cleaner as claimed in claim 9 wherein the passage is
substantially free of regions that are adapted to separate
particulate matter from the air stream.
15. The vacuum cleaner as claimed in claim 9 wherein the passage is
defined by a single conduit.
16. A vacuum cleaner comprising: a) a dirty air inlet and a source
of suction to draw air containing particulate matter into the dirty
air inlet and produce an air stream in the vacuum cleaner; b) a
first cyclonic cleaning stage comprising a cyclone having a first
cyclonic cleaning stage inlet and a first cyclonic cleaning stage
outlet; c) a second cyclonic cleaning stage positioned in series
with the first cyclonic cleaning stage, the second cyclonic
cleaning stage comprising a plurality of second stage cyclones,
each of the second stage cyclones having a second stage cyclone
inlet and a second stage cyclone outlet; and, d) a conduit
extending from the first cyclonic cleaning stage outlet to the
second stage cyclone inlets.
17. The vacuum cleaner as claimed in claim 16 wherein the second
stage cyclones at least partially surround the passage.
18. The vacuum cleaner as claimed in claim 16 wherein the passage
is at least partially defined by the second stage cyclones.
19. The vacuum cleaner as claimed in claim 16 wherein the passage
does not increase in cross sectional area in a downstream
direction.
20. The vacuum cleaner as claimed in claim 16 wherein the passage
has a cross sectional area which is approximately the same as the
cross sectional area of the first cyclonic cleaning stage
outlet.
21. The vacuum cleaner as claimed in claim 16 wherein the passage
is substantially free of horizontal spaces that are transverse to
the direction of fluid flow through the passage.
22. The vacuum cleaner as claimed in claim 16 wherein the passage
is substantially free of regions that are adapted to separate
particulate matter from the air stream.
23. The vacuum cleaner as claimed in claim 16 wherein the passage
is substantially free of any dead air spaces.
Description
[0001] This application is a continuation of application Ser. No.
09/679,353 filed on Oct. 5, 2000 which is a division of application
Ser. No. 09/239,860 filed on Jan. 29, 1999 now issued as U.S. Pat.
No. 6,334,234, which is a continuation-in-part of application Ser.
No. 09/227,534 filed on Jan. 8, 1999 now issued as U.S. Pat. No.
6,141,826.
FIELD OF THE INVENTION
[0002] The present invention relates generally to vacuum cleaners
having at least two cyclonic separation stages.
BACKGROUND OF THE INVENTION
[0003] Various types of vacuum cleaners are traditionally produced.
These include built in vacuum cleaners, canister vacuum cleaners
and upright vacuum cleaners. Upright vacuum cleaners have a ground
engaging portion and an upwardly extending portion. The ground
engaging portion typically has wheels for movement of the cleaning
head across a floor and a suction inlet for the intake of dirty air
into the vacuum cleaner. The upwardly extending portion comprises
the filter means for removing dirt which is entrained in the air.
The upwardly extending portion generally has a handle for guiding
the vacuum cleaner across the floor.
[0004] Traditionally in upright vacuum cleaners, the motor to draw
the dirty air through the vacuum cleaner is positioned in the
ground engaging head and the upward extending portion is pivotally
mounted to the upper portion of the ground engaging member at a
position adjacent the motor.
[0005] More recently, cyclonic technology has been introduced
commercially into canister and upright vacuum cleaners. See for
example U.S. Pat. Nos. 4,373,228; 4,571,772; 4,573,236; 4,593,429;
4,643,748; 4,826,515; 4,853,008; 4,853,011; 5,062,870; 5,078,761;
5,090,976; 5,145,499; 5,160,356; 5,255,411; 5,358,290; 5,558,697;
and RE 32,257. These patents disclose a novel approach to vacuum
cleaner design in which sequential cyclones are utilized as the
filtration medium for a vacuum cleaner. Pursuant to the teaching of
these patents, the first sequential cyclone is designed to be of a
lower efficiency to remove only the larger particles which are
entrained in an air stream. The smaller particles remain entrained
in the air stream and are transported to the second sequential
cyclone which is frusto-conical in shape. The second sequential
cyclone is designed to remove the smaller particles which are
entrained in the air stream. If larger particles are carried over
into the second cyclone separator, then they will typically not be
removed by the cyclone separator but exit the frusto-conical
cyclone with the air stream.
[0006] The advantages of cyclonic separation have been combined
with an upright vacuum cleaner to provide a household cyclonic
vacuum cleaner, as shown in U.S. Pat. No. 4,593,429 to Dyson. As
shown in FIG. 1, this vacuum cleaner 10 essentially comprises a
large, outer cylindrical cyclone 12, with an inner cyclone 14
nested therein, which is mounted on a ground engaging member or
floor-cleaning head and provided with a push handle for convenient
movement of the unit. A motor, located in the floor cleaning head,
draws air through the cleaning head and into an intake conduit 16,
which delivers air to the dirty air inlet 18 of the outer cyclone
container 12. From the outer cyclone the air flows into inner,
nested dust separating cyclone 14, and from there, continues on
through the vacuum motor to a clean air exhaust port.
[0007] The air intake conduit 16 connects the floor cleaning head
and the dirty air inlet in air flow communication. Air intake
conduit 16 extends upwardly along the outside of outer cyclone
container 12 generally parallel to the longitudinal axis of the
cyclones 12, 14. At a position adjacent air inlet 18 to outer
cyclone 12, air intake conduit 16 bends 90.degree. and travels
inwardly to provide a tangential air flow inlet to air inlet 18 of
outer cyclone container 12.
[0008] In use, air intake conduit 16 may become blockage. If the
blockage occurs at a midpoint of the conduit, it may be difficult
to clear the blockage. While a clean out port may be provided, the
port may not be located near where the blockage occurs. Further,
the addition of a port increases the cost and complexity of the
manufacture of the product.
[0009] A bend in a conduit for a fluid causes a turbulent pressure
loss in the conduit as the fluid travels through the bend in the
conduit and the greater the sharpness of the bend, the greater the
pressure loss. The pressure loss in the air flow decreases the
amount of suction which can be generated at the cleaning head of
the vacuum cleaner for any given motor in the vacuum cleaner and
therefore the efficiency of the vacuum cleaner.
[0010] One disadvantage of cyclonic vacuum cleaners is the amount
of power which is required to create an air flow sufficient to
convey the dirty air through the cyclones at sufficient speeds to
maintain the air flowing cyclonically through the cyclones.
SUMMARY OF THE INVENTION
[0011] In accordance with the instant invention, there is provided
an upright vacuum cleaner comprising:
[0012] (a) a cleaning head for cleaning a surface;
[0013] (b) an upper body portion mounted on the cleaning head, the
upper portion having a longitudinally extending axis and
comprising:
[0014] (i) at least one cyclone having an air entry port; and,
[0015] (ii) a motor positioned above the at least one cyclone and
in air flow communication with the at least one cyclone.
[0016] In accordance with the instant invention, there is also
provided an upright vacuum cleaner comprising:
[0017] (a) a cleaning head for cleaning a surface having a forward
portion and two spaced apart rear portions extending rearwardly
from the forward portion;
[0018] (b) an upper body portion mounted on the cleaning head, the
upper portion having a longitudinally extending axis and at least
one cyclone having an air entry port, the upper body portion
mounted on the cleaning head at a position forward of the spaced
apart rear portions, the spaced apart rear portions defining on
open space therebetween sized for receiving the upper body portion
therebetween when the upper body portion is in the lowered storage
position.
[0019] In one embodiment, the cleaning head has a forward portion
including an opening in air flow communication with the at least
one cyclone and two spaced apart rear portions extending rearwardly
from the forward portion, the spaced apart rear portions defining
on open space therebetween, the upper body portion mounted on the
cleaning head at a position forward of the spaced apart rear
portions.
[0020] In another embodiment, the upper portion is positionable in
a lowered in use position wherein the longitudinally extending axis
is at an angle of 40.degree. to the vertical and, when the upper
body portion is in the lowered in use position, the centre of
gravity of the upper body portion is positioned above the open
space. The upper body portion may further comprise a handle, the
weight of the handle in the lowered in use position being 2 lbs. or
less.
[0021] The spaced apart rear members may have floor contacting
members such as glides or wheels adjacent the ends thereof. The
floor contacting members may be positioned rearwardly of the centre
of gravity when the upper body portion is in the lowered in use
position.
[0022] In another embodiment, the upper body portion is pivotally
connected to the cleaning head whereby the upper body portion is
moveable between an in use position in which the upper body portion
extends upwardly and rearwardly from the cleaning head and a
lowered storage position in which the upper body portion extends
generally rearwardly from the cleaning head. The cleaning head may
have a forward portion and two spaced apart rear portions extending
rearwardly from the forward portion, the upper body portion mounted
on the cleaning head at a position forward of the spaced apart rear
portions, the spaced apart rear portions defining on open space
therebetween sized for receiving the upper body portion
therebetween when the upper body portion is in the lowered storage
position.
[0023] In another embodiment, the vacuum cleaner further comprises
a mounting member engageable with a support member mounted on a
wall whereby the vacuum cleaner may be hung flush against the wall
when the upper body portion is in the lowered storage position.
[0024] In another embodiment, the vacuum cleaner further comprises
a second cleaning member positioned downstream from the at least
one cyclone.
[0025] In another embodiment, the vacuum cleaner further comprises
an air outlet to the at least one cyclone for passage therethrough
of air, the air passing generally upwardly from the air outlet to
the motor.
[0026] In another embodiment, the second cleaning member is an
electrostatic cleaning member.
[0027] In another embodiment, the second cleaning member is
positioned between the at least one cyclone and the motor.
[0028] In another embodiment, the second cleaning member comprises
at least one second cyclone.
[0029] In another embodiment, the second cleaning member comprises
a plurality of second cyclones.
[0030] In another embodiment, the second cleaning member is
positioned between the at least one cyclone and the motor, the
vacuum cleaner further comprising an air outlet to the at least one
cyclone and an air outlet to each of the at least one second
cyclones, the air passing generally upwardly from the air outlet to
the at least one cyclone to the at least one second cyclones and
generally upwardly from the air outlet to the at least one second
cyclones to the motor.
[0031] In another embodiment, the second cleaning member is
positioned downstream of the motor, the vacuum cleaner further
comprising an air outlet to the at least one cyclone, the air
passing generally upwardly from the air outlet to the at least one
cyclone to the motor and generally upwardly from motor to the at
least one second cyclones.
[0032] In another embodiment, the vacuum cleaner further comprises
an air inlet to the at least one cyclone and an air supply conduit
communicating with the cleaning head and with the air entry port, a
portion of the air supply conduit extending longitudinally through
the cyclone. The air supply conduit may connect to the air entry
port other than through a 90.degree. elbow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] For a better understanding of the present invention, and to
show more clearly how it may be carried into effect, reference will
now be made by way of example to the accompanying drawing which
show a preferred embodiment of the present invention, in which:
[0034] FIG. 1 is a cross-sectional side elevation of an upright
cyclonic vacuum cleaner with an air intake conduit according to the
prior art;
[0035] FIG. 2 is a perspective view of an upright cyclonic vacuum
cleaner according to the present invention;
[0036] FIG. 3 is a cross-section along line 3-3 in FIG. 2 of the
upright cyclonic vacuum cleaner of FIG. 2;
[0037] FIG. 4 is a side view of the vacuum cleaner of FIG. 2 in an
in use position;
[0038] FIG. 5 is a cross-section along line 5-5 in FIG. 3;
[0039] FIG. 6 is a cross-section along line 5-5 in FIG. 3 of an
alternate preferred embodiment;
[0040] FIG. 7 is a cross-section along the line 7-7 in FIG. 8 of a
further alternate preferred embodiment of the instant
invention;
[0041] FIG. 8 is a cross-section along line 8-8 in FIG. 7;
[0042] FIG. 9 is a cross-section along the line 9-9 in FIG. 10 of a
further alternate preferred embodiment of the instant
invention;
[0043] FIG. 10 is a cross-section along line 10-10 in FIG. 9;
[0044] FIG. 11 is a cross-section along the line 11-11 in FIG. 12
of a further alternate preferred embodiment of the instant
invention;
[0045] FIG. 12 is a cross-section along line 12-12 in FIG. 11;
[0046] FIG. 13 is a cross-section along the line 13-13 in FIG. 3;
and, FIG. 14 is a side elevational view of the cleaning head of the
vacuum cleaner of FIG. 2 when the vacuum cleaner is in the lowered
in use position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0047] An upright cyclonic vacuum 20 according to the present
invention is shown in the FIGS. 2 and 3. A floor cleaning head 22
is provided at the lower end of vacuum cleaner 20. Head 22
comprises a forward portion 21 and two rear portions 23 extending
rearwardly from the forward portion 21. Rear portions 23 are spaced
apart and define a space 25 there between. Head 22 has a dirty air
inlet 27 which is positioned in forward portion 21 and, preferably,
adjacent the front end of forward portion 21 (see FIG. 3).
Preferably, head 22 also comprises a transversely extending,
floor-contacting rotating brush member 26 which is mounted for
rotation in head 22. A handle 42 and rear wheels 44 may be provided
on head 22 to facilitate movement of the unit for cleaning of a
floor, and the like. Head 22 may also incorporate a forward set of
wheels (not shown) as is known in the art.
[0048] In order to be able to convert the vacuum cleaner for above
the floor cleaning, handle 42 may be hollow and be connected to a
flexible hose 43 for connecting handle in air flow communication
with the dirt filtration stages in upper body portion 29.
[0049] Upper body portion 29 incorporates the filtration means for
removing entrained dirt from the dirty air which is introduced into
the vacuum cleaner, via, for example, dirty air inlet 27 and motor
24 which draws the air through vacuum cleaner 20. Upper body
portion 29 comprises at least one cyclonic separation stage.
Preferably, the vacuum cleaner includes at least two dirt
separation stages. The first of the dirt separation stages
preferably comprises a cyclonic dirt separation stage. The second
stage may be a second cyclonic dirt separation stage or an
electrostatic cleaner (e.g. an electrostatic precipitator). It will
be appreciated that additional dirt separation stages may be
incorporated into the vacuum cleaner. For example, a screen or
filter may be positioned between first and second cyclonic
separations stages. Further, or alternately, a filter or a screen
may be positioned upstream of motor 24. Further, a HEPA.TM. filter
may be positioned in the air flow path through the vacuum cleaner,
such as after motor 24.
[0050] According to the preferred embodiment of the vacuum cleaner
shown in FIGS. 2 and 3, upper body portion 29 comprises cyclonic
unit 28 positioned in the lower portion of upper body portion 29.
Cyclonic unit 28 may comprise any type of dirt separation cyclone
known in the art, e.g. cylindrical or frusto-conical, and may
comprise a single cyclone or multiple cyclones (either in series
and/or in parallel). Preferably, cyclonic unit 28 comprises a
single cyclone. Referring to FIG. 3, cyclone unit 28 comprises
cyclone container 30 having an air inlet 32, typically at an upper
end 34 thereof, adapted for providing an air flow tangentially to
an inner dirt rotation surface 36 of container 30. Container 30
also has a dirt collection surface or bottom 38 and a clean air
outlet 40. Upper end 34 of container 30 is sealed, such as by an
upper panel 35.
[0051] If the vacuum cleaner is used in the upright vacuum cleaner
mode, the air flow path through cleaner 20 commences with an air
supply conduit 46 having an upstream portion 48 in flow
communication with dirty air intake 27 and a downstream portion 50.
Upstream portion 48 is provided in head 22 and has a first end 52
positioned adjacent brush member 26 for receiving the dirt laden
air and a distal second end 54. Downstream portion 50 is positioned
in air flow communication with second end 54. Preferably upstream
and downstream portions 48, 50 are substantially sealed together to
prevent air and dirt leaking therefrom.
[0052] In one embodiment, upstream and downstream portions 48, 50
may comprise a single member (whether integrally formed or
connected together). In such a case, portions 48, 50 are preferably
flexible so as to allow cyclone container 30 to be emptied.
Preferably, they are separate elements which are in air flow
communication when container 30 is mounted in vacuum cleaner 20.
Thus, if a blockage develops in conduit 46, by removing container
30 from vacuum cleaner 20, portions 48 and 50 may be individually
accessed at end 54 to clean out the blockage.
[0053] As shown in FIGS. 3, 7 and 11 downstream portion 50 may
extend upwardly through container 30. Alternately, as shown in
FIGS. 9 and 11, downstream portion 50 may extend upwardly at a
position adjacent the outer surface of container 30. Whether
downstream portion 50 is provided internally (FIG. 11) or
externally (FIG. 9) to container 30, by manufacturing the vacuum
cleaner so that downstream portion 50 is removable with container
30 from the vacuum cleaner, access is provided to both the upstream
and downstream portions of downstream portion 50 as well as end 54
of upstream portion 48. Accordingly, multiple access ports are
effectively provided as part of the construction of the vacuum
cleaner. It will be appreciated that downstream portion 50 may be
manufactured as part of container 30 (such as by moulding it
integrally therewith). Alternately, it may be separately
manufactured (such as by extrusion) and subsequently affixed to
container 30 by any means known in the art.
[0054] Downstream portion 50 may enter container 30 at any point
(e.g. via a side wall) but preferably enters through bottom 38.
Further downstream portion 50 preferably extends generally upwardly
through the central portion of container 30 which comprises the
area occupied by the vertical return path of the air as it travels
from bottom 38 to outlet 40. As shown in FIG. 3, downstream portion
50 preferably extends coaxially with the longitudinal axis A of
container 30, however, it may be positioned off centre either
internal of container 30 (see for example FIG. 11) or external of
container 30 (see for example FIG. 9).
[0055] Downstream portion 50 is preferably positioned at any
location within container 30 where it does not unduly interfere
with the cyclonic flow of air within container 30. For this reason,
if downstream portion 50 is positioned within container 30, it
preferably is centrally located in container 30. In particular, in
a cyclone, the air travels generally in an annular band adjacent
surface 36 of container 30. The air travels generally downwardly
until it reaches a position towards bottom 38 of container 30 at
which point the air travels upwardly through the central portion of
cyclone container 30. In a most preferred embodiment of this
invention, downstream portion 50 is positioned within this central
portion of container 30 which contains this upflow of air.
[0056] As shown in FIG. 11, downstream portion 50 may be positioned
adjacent sidewall 36. In such cases, downstream portion 50 is
preferably constructed so as to minimize its interference with the
flow of air around surface 36. For example, downstream portion 50
may be constructed with rounded surfaces so as to direct the flow
of air around downstream portion 50. Further, downstream portion 50
need not be circular in shape but may be elliptical or of other
constructions wherein it has a radial extent (i.e. around inner
surface 36) which is substantially greater than its width in a
direction transverse thereto (i.e. radially inwardly). Thus,
downstream portion 50 would extend only slightly into container 30
and would not substantially interfere with the cyclonic flow of air
in container 30.
[0057] Exit portion 56 is positioned at the upper end of downstream
portion 50. Inlet 32 is positioned at the distal end of exit
portion 56 from downstream portion 56. Exit portion 56 may extend
along any desired path from downstream portion 50 to inlet 32.
Preferably, exit portion 56 is wholly positioned within container
30 (e.g. it does not exit container 30 through upper end 34).
[0058] Exit portion 56 may extend at a right angle to downstream
portion 50 as shown in FIG. 3. Further, it may extend in a straight
line to inlet 32 as shown in FIG. 4. It will be appreciated that
inlet 32 may be any inlet known in the cyclonic art to introduce
air tangentially into a cyclone and it may be positioned at any
point along the longitudinal length of container 30 as is known in
the cyclonic art.
[0059] In one preferred embodiment, exit portion 56 includes a
curved portion. More preferably, as shown in FIG. 6, exit portion
56 is curved so as to impart circular momentum to the dirty air as
it travels therethrough. Depending upon the degree of curvature,
exit portion 56 may assist in tangentially introducing the dirty
air into container 30 or it may be the sole source of tangential
entry into container 30 (e.g. inlet 32 may merely be an opening in
exit portion 56 which does not impart any tangential rotation to
the dirty air). By constructing the supply conduit in this manner,
a 90.degree. elbow is not required to redirect the dirty air to
enter container 30 tangentially. In a typical application,
replacing a 90.degree. elbow with a gradual curved path to redirect
the dirty air results in a about a 5 to 10% reduction in the loss
of suction as the air travels through the vacuum cleaner. Thus, a
smaller motor may be incorporated into the vacuum cleaner to obtain
the same pressure at inlet 32 or the suction at end 52 may be
increased if the same motor is used.
[0060] Referring to FIG. 7, it will be appreciated that the dirty
air travelling in downstream portion 50 travels outwardly to inlet
32. In an alternate preferred embodiment, exit portion 56 curves
gently from the upper end of downstream portion 50 so as to travel
outwardly towards inlet 32. More preferably, the change in
direction of the dirty air from vertical to horizontal and from
horizontal to tangential occurs so as to reduce the pressure drop
during its travel from downstream portion 50 to container 30.
[0061] Centrally located in upper end 34 of container 30 is a clean
air outlet 40 for permitting withdrawal of air from container 30.
From clean air outlet 40, the air flow may proceed to vacuum fan
motor 24 or to a second stage of filtration, such as a second
cyclone or other filtration means (e.g. an electrostatic
precipitator, a mesh screen or a filter). Subsequently, it may be
in air flow communication with vacuum fan motor 24.
[0062] In operation, the vacuum fan motor 24 is activated to induce
an air flow through cleaner 20. The air flow causes a partial
vacuum to form at end 52. Air, and entrained dirt, is drawn into
upstream portion 48, with the aid of brush member 26. The dirty air
flow moves upwardly in downstream portion 50 to dirty air inlet 32
via exit portion 56 and is introduced tangentially to container 30.
The airflow is then accelerated around dirt rotation surface 36,
and proceeds generally downwardly along and around dirt rotation
surface 36 until it reaches a position towards bottom 38 of
container 30, at which point the air flow travels upwardly through
the central portion of cyclone container 30. Container 30 may
incorporate a wall which is a cylindrical sleeve extending
downwardly from outlet 40 to assist in preventing the treated air
travelling upwardly to outlet 40 from mixing with the dirty air
which is introduced into container 30 via inlet 32.
[0063] As can be seen by a comparison of intake conduits 16 and 46,
of cleaner 10 and cleaner 20 respectively, the reduction of bends
in the air conduit of the present invention beneficially results in
a significant reduction in the turbulent pressure loss in the
intake conduit, thereby markedly improving the efficiency of the
cyclonic separation device as a whole.
[0064] The presence of downstream portion 50 extending through the
centre of container 30 interferes minimally with the cyclonic
action of the air flow within container 30. Thus the presence of
downstream portion 50 does not significantly effect the efficiency
of the cyclone.
[0065] If upper body portion 29 comprises only a single dirt
filtration stage, then outlet 40 may be an air communication with
motor 24. Alternately, if upper body portion 29 comprises a second
or more filtration stage, then outlet 40 may be an air
communication with the second filtration stage (as is shown in FIG.
3). It will be appreciated that motor 24 may be positioned at any
stage in the air flow path through upper body portion 29 provided a
sufficient amount of dirt has been removed from the air so as not
to damage or unduly damage motor 24.
[0066] As shown in FIG. 2, vacuum cleaner 20 includes second
filtration stage 60. The second filtration stage may comprise one
or more cyclones. If the second stage comprises a plurality of
cyclones, they may be either in series or parallel but are
preferably in parallel. In the preferred embodiment of FIGS. 3 and
13, second filtration stage 60 comprises three second cyclones 62.
Second cyclones 62 may be the same or different and may of any
particular configuration known in the art. Second filtration stage
60 also comprises a conduit 64 in fluid flow communication with
outlet 40 from the first stage cyclone 28. Conduit 64 is in air
flow communication with inlets 66 to second stage cyclones 62. The
partially cleaned air is introduced tangentially into second stage
cyclones 62 and travels downwardly therethrough with the separated
dirt exiting second cyclones 62 via dirt outlets 68. The further
cleaned air travels upwardly through the central portion of second
cyclones 62 to air outlets 70.
[0067] The air may travel directly to motor 24 or may pass through
a screen or filter 72 which is positioned between second filtration
stage 60 and motor 24. The cleaned air travelling by motor 24 cools
the motor. The cooled air may then exit the vacuum cleaner or may
pass through a further filtration stage.
[0068] In FIGS. 2 and 3, the air passes upwardly from motor 24 to a
third filtration stage which comprises, e.g., a HEPA.TM. filter or
an electrostatic precipitator. The further cleaned air exits vacuum
cleaner 20 after passage through third filtration stage 74.
[0069] In an alternate embodiment, if the vacuum cleaner is
convertible for off the floor cleaning (i.e. in a canister mode),
then handle 42 may be in air flow communication with the upstream
portion of conduit 48 by a flexible hose 43 and conduit 76.
Suitable valving means known in the art may be incorporated to
selectively connect in air flow communication dirty air inlet 27
and handle 42 with conduit 50.
[0070] By this design, it will be appreciated that from second end
54, the dirty air travels upwardly through the filtration stages
and exits the vacuum cleaner at the top. In particular, the air
travels upwardly to air inlet 32 to cyclonic unit 28. The air then
travels upwardly to the air inlets 66 to the second cyclone 62. The
air then travels upwardly from air outlet 70 to the motor and, if
desired, further upwardly to the third filtration stage 74 prior to
exiting the vacuum cleaner. Regardless of the sequence of the
filtration stages, or their numbers, the air continues to travel
generally upwardly from one stage to the next without substantial
bends or 90.degree. elbows being required to direct the air
flow.
[0071] In conventional designs as shown in FIG. 1, the air must
reverse course and flow downwardly into head 22 so as to cool the
motor. By positioning the motor in upper body portion 29 in the air
flow path, a substantially more direct air flow path may be created
(by the elimination of several elbows required to bring the cleaned
air down to head 22) thus substantially reducing the pressure drop.
For example, the pressure drop through the vacuum cleaner such as
is shown in FIG. 3 may be about 35 inches of water at 45 cfm. By
substantially reducing the pressure drop through the vacuum
cleaner, the size of motor 24 may be consequentially reduced
without reducing the air flow or suction through the vacuum
cleaner.
[0072] Upper body portion 29 is preferably pivotally mounted to
head 22 such as by a ball joint 78. Accordingly, the upper body
portion may be positionable in an upright storage position as shown
in FIG. 3 wherein upper body portion 29 extends generally
vertically upwardly from head 22. Upper body portion 29 may be
lockingly positioned in this place by a locking means as is known
in the art. Upper body portion 29 is preferably so positioned at a
position forward of rear portions 23 and more preferably on front
portion 21. Head 22 is preferably configured given the vertical
position of motor 24 in upper body portion 29 such that when upper
body portion 29 is at an angle of 40.degree. to the vertical as
shown in FIG. 14, then the centre of gravity of upper body portion
29 is positioned in front of wheels 44 and, more preferably, above
space 25.
[0073] In a particularly preferred embodiment, upper body portion
29 is positionable in a lowered storage position wherein upper body
portion 20 extends generally rearwardly from front portion 21 of
head 22. Preferably, space 25 has a sufficient width so as to allow
upper body portion 20 to fit therewithin so that longitudinal axis
B of head 22 is generally parallel to longitudinal axis A of upper
body portion 29. More preferably, longitudinal axis A and B define
a continuous axis when upper body portion 29 is a lowered stored
position.
[0074] In a particular preferred embodiment, space 25 has a
sufficient width to accommodate therein the lower portion of upper
body portion 29. Thus rear portions extend on either side of upper
body portion 29 when upper body portion 29 is in the lowered
storage position. However, if the portion of conduit 48 extending
from joint 78 to bottom 38 is sufficiently long, upper body portion
20 may be positionable in the lowered storage position such that
bottom 38 is spaced from rearward ends 80 of rear portions 23. With
this profile, vacuum cleaner 20 may be easily placed under many
beds and like pieces of furniture for storage or cleaning. Further,
it may be hung for storage such as from a hook mounted in a wall or
from a ceiling by means of hanger 82 using any hanger means known
in the art.
[0075] Despite having motor 24 positioned on upwardly extending
portion 29, only a small amount of force may be required to hold
vacuum cleaner 20 in an in use position as shown in FIG. 4. For
example, when upper body portion 29 is inclined such that axis A is
at an angle a (see FIG. 14) of 40.degree. to the vertical, the
weight exerted by handle 42 in the hand of a user may be less than
three pounds and, preferably, is less than two pounds. Accordingly,
the vacuum cleaner provides ease of use despite the position of the
motor towards the upper body portion 29.
[0076] Therefore, the configuration of the air path through the
vacuum cleaner according to the present invention advantageously
permits a substantial reduction in the pressure loss without
interfering with the overall performance of the cyclone separation
device. Thus, the present invention permits a smaller motor to be
used to provide a similar draw at the intake end 52 compared to
current designs.
[0077] While the above description constitutes the preferred
embodiments, it will be appreciated that the present invention is
susceptible to modification and change without departing from the
fair meaning of the proper scope of the accompanying claims.
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