U.S. patent application number 13/649536 was filed with the patent office on 2013-04-18 for vacuum cleaner.
This patent application is currently assigned to BLACK & DECKER INC.. The applicant listed for this patent is BLACK & DECKER INC.. Invention is credited to Kevin SMITH.
Application Number | 20130091656 13/649536 |
Document ID | / |
Family ID | 45002578 |
Filed Date | 2013-04-18 |
United States Patent
Application |
20130091656 |
Kind Code |
A1 |
SMITH; Kevin |
April 18, 2013 |
VACUUM CLEANER
Abstract
A vacuum cleaner comprising: a motor coupled to a fan for
generating air flow; a dirt separation means located in a path of
the air flow generated by the fan; a cleaner head located in the
path of the air flow upstream of the dirt separation means; at
least one support wheel for supporting the vacuum cleaner upon a
floor; and an elongate body with a handle at a longitudinal end,
wherein the motor, the fan, the cleaner head, the dirt separation
means and the at least one support wheel are arranged about an
opposite longitudinal end of the elongate body to the handle,
wherein the elongate body is telescopically extendible to alter the
length of the vacuum cleaner between a compact position and an
extended position and wherein the extended position is at least
double the length of the compact position.
Inventors: |
SMITH; Kevin; (Durham,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BLACK & DECKER INC.; |
Newark |
DE |
US |
|
|
Assignee: |
BLACK & DECKER INC.
Newark
DE
|
Family ID: |
45002578 |
Appl. No.: |
13/649536 |
Filed: |
October 11, 2012 |
Current U.S.
Class: |
15/344 |
Current CPC
Class: |
A47L 9/0063 20130101;
A47L 5/28 20130101; A47L 9/009 20130101; A47L 9/325 20130101 |
Class at
Publication: |
15/344 |
International
Class: |
A47L 5/24 20060101
A47L005/24 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 12, 2011 |
EP |
EP11184784.4 |
Claims
1. A vacuum cleaner comprising: a motor coupled to a fan for
generating air flow; a dirt separation means located in a path of
the air flow generated by the fan; a cleaner head located in the
path of the air flow upstream of the dirt separation means; at
least one support wheel for supporting the vacuum cleaner upon a
floor; and an elongate body with a handle at a longitudinal end,
wherein the motor, the fan, the cleaner head, the dirt separation
means and the at least one support wheel are arranged about an
opposite longitudinal end of the elongate body to the handle,
wherein the elongate body is telescopically extendible to alter the
length of the vacuum cleaner between a compact position and an
extended position and wherein the extended position is at least
double the length of the compact position.
2. A vacuum cleaner as claimed in claim 1, wherein the elongate
body is lockable in the compact position and in the extended
position.
3. A vacuum cleaner as claimed in claim 2, wherein the elongate
body is lockable in at least one intermediate position between the
compact position and in the extended position.
4. A vacuum cleaner as claimed in claim 1, wherein the dirt
separation means comprises: a hollow substantially cylindrical dirt
container with a longitudinal central axis arranged transverse to
the elongate body; and an air inlet port to the dirt container,
wherein the air inlet port is in communication with the cleaner
head and wherein the at least one support wheel rotates about the
dirt container.
5. A vacuum cleaner as claimed in claim 4, wherein the at least one
support wheel has a bearing to support rotation of the at least one
support wheel about the dirt container.
6. A vacuum cleaner as claimed in claim 4, wherein the at least one
support wheel rotates about the central axis of the dirt
container.
7. A vacuum cleaner as claimed in claim 4, wherein the cleaner head
is supported by a dirty air duct between the air inlet port and the
cleaner head and wherein the dirt container is rotatingly connected
to the elongate body to pivot about the central axis.
8. A vacuum cleaner as claimed in claim 7, wherein the at least one
support wheel comprises one support wheel and wherein the cleaner
head is pivotable in relation the dirt container about a
longitudinal axis of the dirty air duct.
9. A vacuum cleaner as claimed in claim 8, wherein the diameter of
the support wheel is substantially the same as the longitudinal
length of the dirt container and wherein the support wheel is
arranged at substantially the midpoint of the longitudinal length
of the dirt container.
10. A vacuum cleaner as claimed in claim 7, wherein the dirt
container is rotatingly connected to the elongate body near or at a
longitudinal end of the dirt container.
11. A vacuum cleaner as claimed in claim 7, wherein the elongate
body comprises a bracket adapted to couple the dirt container to
said longitudinal end of the elongate body.
12. A vacuum cleaner as claimed in claim 4, wherein the motor is
located within the dirt container.
13. A vacuum cleaner as claimed in claim 4, wherein the dirt
separation means comprises a cyclonic separation apparatus
comprising: a first cyclonic separating unit comprising the dirt
container the air inlet port arranged tangentially through a side
of the dirt container and an air outlet; and a second cyclonic
separating unit comprising at least one cyclone with an air inlet
port an air outlet port and a discharge nozzle; wherein the second
cyclonic separating unit receives air flow downstream from the
first cyclonic separating unit and wherein the second cyclonic
separating unit is located within the dirt container.
14. A vacuum cleaner as claimed in claim 13, wherein the at least
one cyclone of the second cyclonic separating unit comprises a
generally circular array of cyclones arranged about the central
axis and wherein the motor is nested within the circular array of
cyclones.
15. A vacuum cleaner as claimed in claim 1, wherein the motor is
battery-powered.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to EP Patent Application
No. EP 11 184 784.4 filed Oct. 12, 2011, the contents thereof to be
incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a vacuum cleaner.
BACKGROUND OF THE INVENTION
[0003] Vacuum cleaners are well known for collecting dust and dirt,
although wet-and-dry variants which can also collect liquids are
known as well. Typically, vacuum cleaners are intended for use in a
domestic environment, although they also find uses in other
environments, such as worksites or in the garden. Generally, they
are electrically powered and therefore comprise an electric motor
and a fan connected to an output shaft of the motor, an inlet for
dirty air, an outlet for clean air and a collection chamber for
dust, dirt and possibly also liquids. Electrical power or the motor
may be provided by a source of mains electricity, in which case the
vacuum cleaner will further comprise an electrical power cable, by
a removable and replaceable battery pack, or by one or more
in-built rechargeable cells, in which case the vacuum cleaner will
further comprise some means, such as a jack plug or electrical
contacts, for connecting the vacuum cleaner to a recharging unit.
When the vacuum cleaner is provided with electrical power from one
of these sources, the electric motor drives the fan to draw dirty
air along an air flow pathway in through the dirty air inlet, via
the collection chamber to the clean air outlet. The fan is often a
centrifugal fan, although it can be an impeller or a propeller.
[0004] Interposed at some point along the air flow pathway, there
is also provided some means for separating out dust and dirt (and
possibly also liquids) entrained with the dirty air and depositing
these in the collection chamber. This dirt separation means may
comprise a bag filter, one or more filters and/or a cyclonic
separation apparatus.
[0005] In the event that the dirt separation means comprises a bag
filter, dirty air, which has entered the vacuum cleaner via the
dirty air inlet, passes through the bag filter. This filters out,
and collects within the bag filter, dust and dirt entrained with
the dirty air. The filtered material remains in the bag filter
which lines the collection chamber. The clean air then passes to
the other side of bag filter and through a grille in the collection
chamber under the influence of the fan. The fan draws air in and
expels it out, from where the air then passes to the clean air
outlet of the vacuum cleaner.
[0006] There is always a small risk of dust and dirt passing
through the bag filter and it is undesirable that it be allowed to
pass through the fan and cause damage. To reduce this potential
problem, there is often a fine filter located across the grille of
the collection chamber to remove any fine dust and dirt particles
remaining in the air flow after passage through the bag filter.
This is commonly known as a pre-fan filter.
[0007] Occasionally, and in addition to any pre-fan filter, there
is a high efficiency filter located downstream of the fan before
the air flow leaves the vacuum cleaner. This is to remove any
remaining extremely fine particulate matter which will not harm the
fan or motor, but which may be harmful to the household
environment. The term "filtering efficiency" is intended to relate
to the relative size of particulate matter removed by a filter. For
example, a high efficiency filter is able to remove smaller
particulate matter from air flow than a low efficiency filter. A
HEPA filter is a high efficiency filter which should be able to
remove extremely fine particulate matter having a diameter of 0.3
micrometers (.mu.m) and lower.
[0008] The purpose of the bag filter is to filter dust and dirt
entrained in dirty air flow and to collect the filtered material
within the bag filter. This progressively clogs the bag filter. The
volumetric flow rate of air through the vacuum cleaner is
progressively reduced and its ability to pick up dust and dirt
diminishes correspondingly. Hence, the bag filter needs replacement
before it becomes too full and before vacuum cleaner performance
becomes unacceptable. The volume of the collection chamber must be
sufficiently large to merit the cost of regular bag filter
replacement.
[0009] An upright vacuum cleaner commonly has an upright main body
with a dirt separating means, a motor and fan unit, a handle at the
top and a pair of support wheels at the bottom. A cleaner head with
a dirty air inlet facing the floor is pivotally mounted to the main
body. A cylinder vacuum cleaner commonly has a cylindrical main
body with a separating dirt means, a motor and fan unit and
maneuverable support wheels underneath. A flexible hose with a
cleaner head communicates with the main body. Bag filters are
commonly used in upright and cylinder vacuum cleaners as separation
means because their main body has sufficient internal space for the
large collection chamber required to accommodate the bag
filter.
[0010] In the event that the dirt separation means comprises a
filter, dirty air, which has entered the vacuum cleaner via the
dirty air inlet, passes through the filter. This filters out dust
and dirt entrained with the dirty air and the filtered material
remains in the collection chamber on the upstream side of the
filter. Sometimes the filter is supplemented by a sponge to absorb
any liquids entrained in the dirty air flow. The clean air then
passes to the other side of filter under the influence of the fan,
and from the fan the air then passes to the clean air outlet of the
vacuum cleaner.
[0011] Filtered material accumulates around, and progressively
clogs, the filter. The volumetric flow rate of air through the
vacuum cleaner is progressively reduced and its ability to pick up
dust and dirt diminishes correspondingly. Hence, the collection
chamber needs regular emptying and the filter needs frequent
cleaning to mitigate against this effect. Sometimes, the vacuum
cleaner has a filter cleaning mechanism. Alternatively, the filter
needs to be removable for cleaning with a brush, or in a dish
washer, for example.
[0012] Hand-holdable vacuum cleaners, as their name would suggest,
are compact and lightweight and are intended to perform light, or
quick, cleaning duties around a household. Typically, hand-holdable
vacuum cleaners are battery-powered to be easily portable.
[0013] An example of a hand-holdable vacuum cleaner having the
conventional motor, fan and filter arrangement is described in
European patent publication no. EP 1 752 076 A, also in the name of
the present applicant. This vacuum cleaner has dirty air inlet at
one end of a dirty air duct leading to a collection chamber with a
filter. The collection chamber is generally cylindrical and is
arranged transverse the body of the vacuum cleaner. The dirty air
duct is rotatable, with the collection chamber, in relation to the
body. The dirty air duct may be adjusted to access awkward spaces
while the vacuum cleaner is held comfortably by a user.
[0014] In the event that the dirt separation means comprises
cyclonic separation apparatus, dirty air, which has entered the
vacuum cleaner via the dirty air inlet, passes through the cyclonic
separation apparatus having one or more cyclones. A cyclone is a
hollow cylindrical chamber, conical chamber, frustro-conical
chamber or combination of two or more such types of chamber. The
cyclone may have a vortex finder part way, or all way, along its
internal length. The vortex finder is commonly a hollow cylinder
and it has a smaller external diameter than the internal diameter
of the cyclone.
[0015] Dirty air enters via a tangentially arranged air inlet port
and swirls around the cyclone in an outer vortex. Centrifugal
forces move the dust and dirt outwards to strike the side of the
cyclone unit and separate it from the air flow. The dust and dirt
is deposited at the bottom of the cyclone and into a collection
chamber below. An inner vortex of cleaned air then rises back up
the cyclone. The role of a vortex finder is to gather and direct
the cleaned air through an air outlet port at the top of the
cyclone. As an alternative to a vortex finder, the cyclone may have
an inner cylindrical air permeable wall providing the cleaned air
with a path from the cyclone. From the cyclone the cleaned air
passes, under the influence of the fan, to the clean air outlet of
the vacuum cleaner.
[0016] As with a bag filter, a vacuum cleaner with a cyclonic
separation apparatus may have a pre-fan filter to protect the fan
and motor, especially if the air flow is used to cool the motor.
Nevertheless, volumetric flow rate of air through the vacuum
cleaner remains virtually constant as separated material
accumulates in the collection chamber. Thus, an attraction of
cyclonic separation apparatus in a vacuum cleaner is a consistent
ability to pick up dust and dirt. Another attraction is that the
cost of regular bag filter replacement is avoided.
[0017] An example of an upright vacuum cleaner having a motor, fan
and cyclonic separation apparatus is described in European patent
publication no. EP 0 042 723 A. This cyclonic separation apparatus
is divided into a first cyclonic separating unit with a cyclone
formed by an annular chamber and a second cyclonic separating unit
with a generally frustro-conical cyclone. The first cyclonic
separating unit is ducted in series with the second cyclonic
separating unit. Air flows sequentially through the first, and then
the second, cyclonic separating units. The frustro-conical cyclone
has a smaller diameter than the annular chamber within which the
frustro-conical cyclone is partially nested. Separated material
from both cyclonic separating units collects in the cylindrical
collection chamber formed at the bottom of the annular chamber.
[0018] The term "separation efficiency" is used in the same way as
filtering efficiency and it relates to the relative ability of a
cyclonic separation apparatus to remove small particulate matter.
For example, a high efficiency cyclonic unit can remove smaller
particulate matter from air flow than a low efficiency cyclonic
separating unit. Factors that influence separation efficiency can
include the size and inclination of the dirty air inlet of a
cyclone, size of the clean air outlet of a cyclone, the angle of
taper of any frustro-conical portion of a cyclone, and the diameter
and the length of a cyclone. Small diameter cyclones commonly have
a higher separation efficiency than large diameter cyclones,
although other factors listed above can have an equally important
influence.
[0019] The first cyclonic separating unit of EP 0 042 723 A has a
lower separating efficiency than the second cyclonic separating
unit. The first cyclonic separating unit separates larger dust and
dirt from the air flow. This leaves the second cyclonic separating
unit to function in its optimum conditions with comparatively clean
air flow and separate out smaller dust and dirt.
[0020] A hand-holdable vacuum cleaner having a motor, fan and
cyclonic separation apparatus is described in United Kingdom patent
publication no. GB 2 440 110 A. This cyclonic separation apparatus
is smaller than that of EP 0 042 723 A in order to be used in a
hand-holdable vacuum. It is divided into a first cyclonic
separating unit and a second cyclonic separating unit located
downstream of the first cyclonic separating unit. The separating
efficiency of the first cyclonic separating unit is lower than that
of the second cyclonic separating unit.
BRIEF SUMMARY OF THE INVENTION
[0021] It is an object of the present invention to provide an
improved vacuum cleaner which is more easily stored when not in use
and is more easily deployed from storage when use is required.
[0022] Accordingly, in a first aspect, the present invention
provides a vacuum cleaner comprising: a motor coupled to a fan for
generating air flow; a dirt separation means located in a path of
the air flow generated by the fan; a cleaner head located in the
path of the air flow upstream of the dirt separation means; at
least one support wheel for supporting the vacuum cleaner upon a
floor; and an elongate body with a handle at a longitudinal end,
wherein the motor, the fan, the cleaner head, the dirt separation
means and the at least one support wheel are arranged about an
opposite longitudinal end of the elongate body to the handle,
wherein the elongate body is telescopically extendible to alter the
length of the vacuum cleaner between a compact position and an
extended position and wherein the extended position is at least
double the length of the compact position. The elongate body spans
the length of the vacuum cleaner between the handle and the other
components clustered about the other longitudinal end. As such,
vacuum cleaner resembles a stick-vac and is used in the same way as
an upright vacuum cleaner. And yet, when the elongate body is
retracted, the overall length of the vacuum cleaner is at least
halved so that the vacuum cleaner adopts the dimensions of a
hand-holdable vacuum cleaner. When in the compact position it can
be used as a hand-holdable vacuum cleaner with the cleaner head
deployed upon raised surfaces rather than the floor. The compact
position also provides a vacuum cleaner which is easily stored
about a household. The vacuum cleaner can be stored in a relatively
confined space, like, for example, a household cupboard. The
telescopic nature of the elongate body provides a neat shortening
means. The elongate body is shortened, or extended, with ease and
convenience.
[0023] Preferably, the elongate body is lockable in the compact
position and in the extended position. As such, the vacuum
cleaner's length is stable when the elongate body is in the
extended position. Also, the vacuum cleaner can be stored above
floor height by suspending it by the handle from a hook in a
cupboard or elsewhere about the household. The elongate body
remains in the retracted position with the vacuum cleaner suspended
where it was originally intended to be stored.
[0024] Preferably, the elongate body is lockable in at least one
intermediate position between the compact position and in the
extended position. This provides versatility in the length of the
vacuum cleaner. The vacuum cleaner may be used comfortably upon
various different level surfaces and to suit the needs of different
users.
[0025] Preferably, the dirt separation means comprises: a hollow
substantially cylindrical dirt container with a longitudinal
central axis arranged transverse to the elongate body; and an air
inlet port to the dirt container, wherein the air inlet port is in
communication with the cleaner head and wherein the at least one
support wheel rotates about the dirt container. This lowers the
centre of gravity of the vacuum cleaner making it easier to handle
and more stable. Also, it shortens the air flow path between the
cleaner head and the air inlet which may reduce energy losses. The
vacuum cleaner is more compact because the dirt separation means
consumes space within the support wheel. This combination of two
major components may provide additional freedom in vacuum cleaner
design so that previously unused positions may become possible. The
dirt separating means may comprise a filter, a bag filter or a
cyclonic separation apparatus.
[0026] Preferably, the at least one support wheel has a bearing to
support rotation of the at least one support wheel about the dirt
container. The dirt container may remain still while the support
wheel rotates freely upon the bearing.
[0027] Preferably, the at least one support wheel rotates about the
central axis of the dirt container. Coaxial arrangement of support
wheel and dirt container may eliminate unused space between the
support wheel dirt container.
[0028] Preferably, the cleaner head is supported by a dirty air
duct between the air inlet port and the cleaner head and wherein
the dirt container is rotatingly connected to the elongate body to
pivot about the central axis. This arrangement provides close
communication between the dirt container and the cleaner head.
Rotation of the dirt container provides a pivot about which the
handle can rock back and forth while the cleaner head remains
facing the floor.
[0029] Preferably, the at least one support wheel is one support
wheel and wherein the cleaner head is pivotable in relation the
dirt container about a longitudinal axis of the dirty air duct.
This arrangement provides a pivot about which the handle can rock
from side to side about the support wheel while the cleaner head
remains facing the floor.
[0030] Preferably, the diameter of the support wheel is
substantially the same as the longitudinal length of the dirt
container and wherein the support wheel is arranged at
substantially the midpoint of the longitudinal length of the dirt
container. The handle can rock from side to side by approximately
45 degrees each way. This provides a vacuum cleaner which is
maneuverable in tight spaces.
[0031] Preferably, the dirt container is rotatingly connected to
the elongate body near or at a longitudinal end of the dirt
container. This arrangement clears space for location of the or
each support wheel and improves visibility of the dirt
container.
[0032] Preferably, the elongate body comprises a bracket adapted to
couple the dirt container to said longitudinal end of the elongate
body. The bracket is formed to fit around the side of the dirt
container and connect itself to a transverse longitudinal end of
the dirt container.
[0033] Preferably, the motor is located within the dirt container.
This provides a vacuum cleaner which is more compact because it
need not accommodate the motor elsewhere.
[0034] The dirt separation means may comprise a filter, a bag
filter or a cyclonic separation apparatus. Preferably, the dirt
separation means comprises a cyclonic separation apparatus
comprising: a first cyclonic separating unit comprising the dirt
container, the air inlet port arranged tangentially through a side
of the dirt container and an air outlet; and a second cyclonic
separating unit comprising at least one cyclone with an air inlet
port, an air outlet port and a discharge nozzle, wherein the second
cyclonic separating unit receives air flow downstream from the
first cyclonic separating unit and wherein the second cyclonic
separating unit is located within the dirt container. This
arrangement combines improved two-stage cyclonic separation with a
more compact design of cyclonic separation apparatus.
Advantageously, it can be used in a transverse position because of
its diminished axial length. The shorter overall internal flow
paths reduce energy loss.
[0035] Preferably, the at least one cyclone of the second cyclonic
separating unit comprises a generally circular array of cyclones
arranged about the central axis and wherein the motor is nested
within the circular array of cyclones. This arrangement makes more
economic use of space within the cyclonic separation apparatus by
locating the motor within space that may otherwise be unused.
[0036] Preferably, the motor is battery-powered. This provides a
readily portable vacuum cleaner which can be used without need for
connection to a mains electrical power supply.
[0037] Preferably, the cyclones are arranged at equi-angular
intervals about the central axis. Preferably, the longitudinal axis
of each cyclone is in line with the central axis. Preferably, the
longitudinal axis of each cyclone is parallel with the central
axis. Preferably, the cyclonic separation apparatus comprises an
intermediate wall defining a chamber arranged within the dirt
container and around the air inlet port of the or each cyclone,
wherein the intermediate wall comprises an air permeable wall
arranged as the air flow outlet from the dirt container to the
chamber. The intermediate wall shields the air inlet ports from the
dirty air flow vortex within the dirt container. This helps to
avoid re-entrainment of dirt in the partially cleaned air destined
for the cyclones. The air permeable wall acts as an additional dirt
filter. Preferably, the air permeable wall has a hollow cylindrical
cross-sectional profile normal to the central axis. This provides
even air flow into the chamber. Preferably, the intermediate wall
comprises a bulkhead arranged to exclude the discharge nozzle of
the or each cyclone from the chamber. The bulkhead helps to avoid
re-entry of separated dirt into the chamber. Preferably, the
cyclonic separation apparatus comprises a funnel arranged about the
discharge nozzle of the or each cyclone, wherein the funnel
comprises a conical wall tapered towards a longitudinal end of the
dirt container to convey material separated by the first cyclonic
separating unit to a part of the dirt container isolated by the
funnel from air flow in the second cyclonic separating unit. This
helps to deposit small particles in a relatively smaller area of
the dirt container than the larger dirt particles which take more
space. This may prolong the time between emptying the dirt
container by balancing the filling rate of the dirt container.
Preferably, the dirt container comprises a substantially
cylindrical exterior wall and a door detachably connected the
exterior wall at said longitudinal end of the dirt container and
wherein the air inlet port is arranged tangentially through the
exterior wall. The door facilitates emptying of the dirt container.
Preferably, the funnel is connected to the intermediate wall and a
longitudinal end wall of the funnel is in a complementary mating
arrangement with the door. This helps to ensure that the components
within the dirt container are properly aligned. Preferably, the
second cyclonic separating unit is located near or at an opposite
longitudinal end of the dirt container to the door. This improves
dirt collection capacity of the dirt container. Preferably, the or
each cyclone comprises: a hollow cylindrical and/or frustro-conical
body with a longitudinal axis; the discharge nozzle arranged at a
longitudinal end of the cyclone body; the air inlet port through a
side of the body, wherein the air inlet port is arranged
tangentially to the cyclone body; and the air outlet port through
an opposite longitudinal end of the cyclone body. Preferably, the
or each cyclone body is divided into a cylindrical portion and a
frustro-conical portion depending from the cylindrical portion,
wherein the cylindrical portion has the air inlet port and wherein
the frustro-conical portion terminates at the discharge nozzle. The
vortex of air flowing towards the discharge nozzle accelerates as
the body's diameter decreases to separate ever smaller dust
particles and increase separation efficiency. Preferably, the first
cyclonic separating unit comprises a vortex finder assembly
comprising a planar base surrounding a vortex finder for the air
outlet port of the or each cyclone, wherein the base abuts the
cylindrical portion of the or each cyclone. Preferably, the planar
base is arranged as a boundary of the chamber. Preferably, the dirt
container is transparent so that a user can see when it needs to be
emptied. Preferably, the vacuum cleaner comprises an annular
pre-fan filter located in the path of the air flow downstream of
the first cyclonic separating unit and upstream of the fan and
wherein a portion of the motor is nested within the annular pre-fan
filter. This saves space within the cyclonic separation apparatus.
Preferably, the vacuum cleaner comprises an outlet duct for ducting
the path of air flow between the first cyclonic separation
apparatus and the fan if the motor is not located inside the
cyclonic separation apparatus. Preferably, the outlet duct has a
transparent and/or detachable duct wall so that any blockages can
be seen by the user and to provide access to a pre-fan filter in
the event it needs renewal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Further features and advantages of the present invention
will be better understood by reference to the following
description, which is given by way of example and in association
with the accompanying drawings, in which:
[0039] FIG. 1 shows perspective view of a first embodiment of a
hand-held vacuum cleaner with a motor, fan and cyclonic separation
apparatus arrangement;
[0040] FIG. 2 shows a longitudinal cross-section of the motor, fan
and cyclonic separation apparatus arrangement of FIG. 1;
[0041] FIG. 3 shows a perspective view of the longitudinal
cross-section of FIG. 2;
[0042] FIG. 4 shows an exploded perspective view of the motor, fan
and cyclonic separation apparatus arrangement of FIG. 1;
[0043] FIG. 5 shows an exploded perspective view of internal
components of the cyclonic separation apparatus of FIG. 1;
[0044] FIG. 6 shows a partially exploded perspective view of the
motor, fan and cyclonic separation apparatus arrangement of FIG.
1;
[0045] FIG. 7 shows a perspective view of an end cap of the
cyclonic separation apparatus arrangement of FIG. 1;
[0046] FIG. 8 shows a perspective view of a vortex finder assembly
of the cyclonic separation apparatus of FIG. 1;
[0047] FIGS. 9A to 9H show the longitudinal cross-section of FIG. 2
including the air flow pathways through the motor, fan, cyclonic
separation apparatus and a motor cooling passage, in use;
[0048] FIG. 10 shows a perspective view of a second embodiment of a
hand-held vacuum cleaner with a motor, fan and cyclonic separation
apparatus arrangement;
[0049] FIG. 11 shows the perspective view of FIG. 10 with a portion
of the body removed;
[0050] FIG. 12 shows a longitudinal cross-section of the cyclonic
separation apparatus of FIG. 10;
[0051] FIG. 13 shows a perspective view of the cross-section of
FIG. 12;
[0052] FIG. 14 shows a longitudinal cross-section of the motor, fan
and cyclonic separation apparatus arrangement of FIG. 10;
[0053] FIG. 15 shows an exploded perspective view of the motor, fan
and cyclonic separation apparatus arrangement of FIG. 10;
[0054] FIG. 16 shows an exploded perspective view of internal
components of the cyclonic separation apparatus of FIG. 10;
[0055] FIG. 17A to 17F shows the longitudinal cross-section of FIG.
12 including the air flow through the cyclonic separation apparatus
arrangement, in use;
[0056] FIGS. 18 to 22 show diagrammatical representations of
various constructions of the cyclonic separation apparatus of FIG.
10;
[0057] FIG. 23 shows a perspective view of a third embodiment of a
hand-held vacuum cleaner with a motor, fan and cyclonic separation
apparatus arrangement;
[0058] FIG. 24 shows a perspective view of the vacuum cleaner of
FIG. 23 without a dirt container wall;
[0059] FIG. 25 shows a perspective view of a vortex finder;
[0060] FIG. 26 shows a perspective view of the vacuum cleaner of
FIG. 23 with a transparent dirt container wall;
[0061] FIG. 27 shows a diagrammatical cross-section XXVI-XXVI of
the vacuum cleaner of FIG. 23 including air flow pathways;
[0062] FIG. 28 shows a diagrammatical cross-section XXVII-XXVII of
the vacuum cleaner of FIG. 23 including air flow pathways;
[0063] FIG. 29 shows side elevation view of a battery-powered
vacuum cleaner with an extendible dirty air duct and the motor, fan
and cyclonic separation apparatus arrangement of FIGS. 2 to 9;
[0064] FIG. 30 shows a perspective view of the vacuum cleaner of
FIG. 29;
[0065] FIG. 31 shows a cross-sectional view, of a portion of the
vacuum cleaner of FIG. 29 showing a battery pack;
[0066] FIG. 32 shows a perspective view of the vacuum cleaner of
FIG. 29 with the dirty air duct extended;
[0067] FIG. 33 shows a side elevation view of a battery-powered
vacuum cleaner with a flexible hose and the motor, fan and cyclonic
separation apparatus arrangement of FIGS. 2 to 9;
[0068] FIG. 34 shows a perspective view of the vacuum cleaner of
FIG. 33;
[0069] FIG. 35 shows a perspective view of a battery-powered vacuum
cleaner with a telescopic body and a cleaner head with the motor,
fan and cyclonic separation apparatus arrangement of FIGS. 2 to
9;
[0070] FIG. 36 shows a close-up perspective view of the vacuum
cleaner of FIG. 35;
[0071] FIG. 37 shows a side elevation view of the vacuum cleaner of
FIG. 35 with the telescopic body retracted;
[0072] FIG. 38 shows a perspective view of a removable battery pack
and the cyclonic separation apparatus of FIGS. 2 to 9;
[0073] FIG. 39 shows a transverse cross-section XXXVIII-XXXVIII of
the battery pack of FIG. 38 with cylindrical rechargeable
cells;
[0074] FIG. 40 shows a transverse cross-section XXXVIII-XXXVIII of
the battery pack of FIG. 38 with flat plate rechargeable cells;
[0075] FIG. 41 shows a transverse cross-section of an annular
battery pack with cylindrical rechargeable cells;
[0076] FIGS. 42 and 43 show a transverse cross-section of an
annular battery pack with flat plate rechargeable cells; and
[0077] FIG. 44 shows a table of test data relating to the
temperature of the motor of FIG. 2 in different operational
conditions.
DETAILED DESCRIPTION OF THE INVENTION
[0078] Referring to FIG. 1, there is shown first embodiment of a
hand-held vacuum cleaner 2 comprising a main body 4, a handle 6
connected to the main body, a cyclonic separation apparatus 8
mounted transverse across the main body, and a dirty air duct 10
with a dirty air inlet 12 at one end. The vacuum cleaner comprises
a motor coupled to a fan for generating air flow through the vacuum
cleaner and rechargeable cells (not shown) to energise the motor
when electrically coupled by an on/off switch 14.
[0079] Referring to FIGS. 2 to 8, there is shown an arrangement
comprising the motor 16, the fan 18 and the cyclonic separation
apparatus 8. The motor has a drive shaft 20 with a central axis 21.
The fan is a centrifugal fan 18 with an axial input 22 facing the
motor and a tangential output 24. The fan has a diameter of 68 mm.
The fan is mounted upon the drive shaft at the top of the motor. In
use, the motor drives the fan to generate air flow through the
cyclonic separation apparatus, as will be described in more detail
below. A small portion of the drive shaft 20 protrudes from the
bottom of the motor 16. A second fan, comprising a paddle wheel 26,
is mounted upon the drive shaft 20 at the bottom of the motor. The
motor and the paddle wheel are clad in a cylindrical outer body of
the motor, which is often referred to as a "motor can". In use, the
motor turns the paddle wheel to circulate and augment air flow
inside the motor can and about the bottom of the motor.
[0080] The motor 16 and the fan 18 are housed in a motor fan
housing 27 comprising a generally cylindrical body portion 28
enclosing the motor and a generally circular head portion 29
enclosing the fan. The head portion 29 has a larger diameter than
the body portion 28. The motor fan housing 27 comprises a
perforated end cap 30 mounted upon the head portion on the opposite
side to the body portion. The end cap 30 protects the fan. The end
cap has a circular array of perforations 36 near where air flow is
expelled from the fan. The head portion acts as a baffle to direct
air flow from the fan and out the perforations. The body portion
has an array of bottom slots 32 around the bottom of the motor and
an array of top slots 34 about where the drive shaft 20 protrudes
from the top of the motor.
[0081] The cyclonic separation apparatus 8 comprises a pre-fan
filter 40, a vortex finder assembly 50, a generally cylindrical
inner wall 60, a cyclone seal 70, a cyclone assembly 80, a
cylindrical perforated intermediate wall 90, a circular bulkhead
100, a tapered funnel 110, a transparent generally cylindrical dirt
container 120, and a circular bowl door 130 all arranged about the
central axis 21 of the motor drive shaft 20.
[0082] The pre-fan filter 40 is an annular shape surrounding the
top air flow slots 34 of the body portion 28 of the motor fan
housing 27. The pre-fan filter is enclosed in an annular shell 42
except where the pre-fan filter communicates with the vortex finder
assembly 50 and with the top air flow slots 34 of the body portion
28. This permits air flow from the cyclonic separating apparatus,
through the pre-fan filter and on to the fan.
[0083] The vortex finder assembly 50 comprises planar ring 52
moulded with twelve hollow cylindrical vortex finders 54 protruding
from one side of the planar ring. Holes 56 through the vortex
finders penetrate the opposite side of the planar ring whereupon
the pre-fan filter 40 is seated. The pre-fan filter 40 helps to
muffle high frequency sounds caused by Helmholtz resonance as air
flows through the vortex finder holes 56. The vortex finders are
arranged in a circular array about the central axis 21 of the motor
drive shaft 20. Each vortex finder has its own longitudinal central
axis 57 arranged parallel to the central axis 21. The vortex
finders may have longitudinal internal ribs (not shown) along the
vortex finder holes to further reduce high frequency noise caused
by Helmholtz resonance. The longitudinal ribs also tend to
straighten air flow in the vortex finder to help reduce energy
losses as the air flows into the pre-fan filter 40.
[0084] The inner wall 60 is a generally cylindrical shape in two
portions of different diameter. The inner wall comprises an annular
flange 62 at an open end of the inner wall, a hollow cylindrical
cup 64 at an opposite closed end of the inner wall, a hollow
cylindrical wall 66 and an annular shoulder 68. The flange extends
radially outwardly from the open end of the cylindrical wall. The
cylindrical wall is located between the flange and the cylindrical
cup. The cylindrical wall has a larger diameter than the
cylindrical cup. The annular shoulder joins the cylindrical wall to
the cylindrical cup. The shoulder is perforated with a circular
array of twelve holes 69 spaced at equi-angular intervals about the
central axis 21. The annular flange 62 is connected to an annular
roof wall 121 of the dirt container 120.
[0085] The vortex finder assembly 50 is seated in the cylindrical
wall 66 with the planar ring 52 facing the shoulder 68 and the
vortex finders 54 protruding through the shoulder's holes 68. The
pre-fan filer 40 is nested within the cylindrical wall 66. The
bottom of the motor fan housing's body portion 28 is nested within
the cylindrical cup 64.
[0086] The cyclone seal 70 is perforated with a circular array of
twelve holes 72 spaced at equi-angular intervals about the central
axis 21. The shoulder 68 of the inner wall 60 is seated upon the
cyclone seal. The vortex finders 54 protrude through the seal holes
72.
[0087] The cyclone assembly 80 comprises a cylindrical collar 82
and a circular array of twelve cyclones 84 surrounded by the
collar. The cyclones are spaced at equi-angular intervals about the
central axis 21. Each cyclone has a hollow cylindrical top part 85
and a hollow frustro-conical bottom part 86 depending from the
cylindrical top part and terminating with a discharge nozzle 87 at
the bottom of the cyclone.
[0088] The shoulder 68 of the inner wall 60 is arranged upon the
cyclone assembly 80 with the cyclone seal 70 interposed
therebetween. The collar 82 has the same outer diameter as, and
abuts with, the cylindrical wall 66 of the inner wall 60. The
vortex finders 54 protrude through the holes 72 in the cyclone seal
and into the cylindrical top part 85 of a respective cyclone 84.
The only passage through the top of the cyclone 84 is via its
vortex finder 54 which acts as an air flow outlet port to the
pre-fan filter 40. Each vortex finder is concentric with its
respective cyclone. The plane of each nozzle 87 is inclined with
respect to the central axis 57. This helps to prevent dust and dirt
particles from re-entry after discharge from the nozzle.
[0089] The cylindrical top part 85 of each cyclone 84 has an air
inlet port 88 arranged tangentially through the side of the cyclone
and proximal the vortex finder 54. The twelve air inlet ports are
in communication with a distribution chamber 170 below the collar
82 around the cyclones 84, as is described in more detail
below.
[0090] The intermediate wall 90 is arranged upon the cyclone
assembly 80. The intermediate wall 90 has the same outer diameter
as, and abuts with, the cylindrical collar 82.
[0091] The bulkhead 100 is arranged upon, and has approximately the
same outer diameter as, the intermediate wall 90. The bulkhead 100
is perforated by a circular array of twelve holes 102 spaced at
equi-angular intervals about the central axis 21. The discharge
nozzles 87 of the cyclones 84 protrude through respective bulkhead
holes 102. The bulkhead 100 has a circumferential lip 104 inclined
radially outwardly from the central axis 21 towards the bowl door
130. The lip 104 protrudes a small way from the intermediate wall
90.
[0092] The tapered funnel 110 comprises a hollow circumferential
skirt 112, a frustro-conical cone 114 depending from the skirt, and
a hollow cylindrical nose 116 depending from the cone. The skirt is
arranged upon, and has approximately the same outer diameter as,
the bulkhead. The cone tapers radially inwardly from the bulkhead
100 towards the bowl door 130. A perforated portion 118 of the
skirt protrudes axially rearward from the cone towards the bowl
door 130.
[0093] The generally cylindrical dirt container 120 comprises the
annular roof wall 121 and a hollow cylindrical exterior wall 122
with a frustro-conical dirt collection bowl 124 depending from the
exterior wall. The dirt container has a dirty air inlet port 126
arranged tangentially through the exterior wall 122. The dirt
container 120 has a circumferential lip 128 inclined radially
inwardly towards the central axis 21 and towards the bowl door 130.
The lip 128 protrudes a small way in from the transition between
the exterior wall and the dirt collection bowl. The motor fan
housing's head portion 29 is nested within the centre of the
annular roof wall 121. The annular roof wall is detachably
connected to an outer circumferential edge 138 of the exterior wall
122. The annular roof wall 121 may be connected to the exterior
wall 122 and the inner wall 60 by snap-fit, bayonet fit,
interlocking detents, interference fit or by a hinge. A resilient
seal or seals made of polyethylene, rubber or a similar elastomeric
material is provided around the annular roof wall to ensure
airtight connection with the exterior wall.
[0094] The bowl door 130 is detachably connected to an outer
circumferential edge 132 of the dirt collection bowl 124. The bowl
door abuts the cylindrical nose 116 thereby dividing the dirt
collection bowl into two separate chambers: a generally circular
chamber 134 inside the tapered funnel 110 and a generally annular
chamber 162 outside the tapered funnel. The bowl door 130 may be
connected to the dirt collection bowl 124 by snap-fit, bayonet fit,
interlocking detents, interference fit or by a hinge. A resilient
seal made of polyethylene, rubber or a similar elastomeric material
is provided around bowl door 130 to ensure airtight connection with
the dirt collection bowl.
[0095] The annular flange 62 of the inner wall 60 is in
complementary mating relationship with a circular ring 123
protruding from inside the annular roof wall 121. The nose 116 is
in complementary mating relationship with a circular ring 140
protruding from inside the bowl door 130. This ensures that
components of the cyclonic separation apparatus 8 remain concentric
with the central axis 21 when the bowl door is closed.
[0096] Between the annular roof wall 121 and the bowl door 130, the
various components of the cyclonic separation apparatus 8 (i.e.
pre-fan filter 40, vortex finder assembly 50, inner wall 60,
cyclone seal 70, cyclone assembly 80, intermediate wall 90,
bulkhead 100, tapered funnel 110) are arranged upon each other by
detachable connection, typically a snap-fit, bayonet fit,
interlocking detents, or interference fit. The permits disassembly
and reassembly, without tools, of the cyclonic separation apparatus
8 in order to clean, or replace, its individual components.
Resilient seals made of polyethylene, rubber or a similar
elastomeric material, or other suitable seal material, are provided
around connections of the annular flange 62 and pre-fan filter
shell 42 with the annular roof wall 121. The seals are to ensure
airtight connection. The internal diameter of the dirt container
120 and the bowl door 130 is large enough to permit removal of the
components of the cyclonic separation apparatus 8 (i.e. pre-fan
filter 40, vortex finder assembly 50, inner wall 60, cyclone seal
70, cyclone assembly 80, intermediate wall 90, bulkhead 100,
tapered funnel 110) through either end of the dirt container.
[0097] In use, dirty air flows, under the influence of the fan 18,
in the dirty air inlet 12, up the dirty air duct 10 and into the
cyclonic separation apparatus 8 where dust and dirt entrained in
the air flow is separated therefrom. The dust and dirt is collected
within the cyclonic separation apparatus. The air flows out the
cyclonic separation apparatus 8, through the pre-fan filter 40,
into the motor fan housing 27 via the top slots 34, though the fan
18 and out the perforations 36 in the end cap 30.
[0098] Referring to FIG. 9A, the cyclonic separation apparatus 8 is
divided into a first cyclonic separating unit 160, a second
cyclonic separating unit 150 and a distribution chamber 170. The
first cyclonic separating unit is located in the air flow pathway
upstream of the distribution chamber. The distribution chamber is
located in the air flow pathway upstream of the second cyclonic
separating unit.
[0099] The first cyclonic separating unit 160 comprises the
cylindrical dirt container 120. The second cyclonic separating unit
150 comprises the circular array of twelve cyclones 84. The dirt
container is concentric with the central axis 21 of the motor drive
shaft 20. The distribution chamber 170 is bounded by the hollow
cylindrical cup 64 of the inner wall, cyclone assembly 80,
intermediate wall 90 and bulkhead 100. The second cyclone unit 150
received air flow from the first cyclone unit 160 via the
distribution chamber 170.
[0100] The exterior wall 122 of the dirt container 120 has a
diameter of approximately 130 mm. The cyclones 84 have a much
smaller diameter than the dirt container. Helical air flow in the
cyclones experiences greater centrifugal forces than in the annular
chamber. Thus, the cyclones of the second cyclonic separating unit
150, when combined, have higher separation efficiency than the dirt
container of the first cyclonic separating unit 160.
[0101] The air flow pathway though the cyclonic separation
apparatus 8 is described in more detail with reference to FIGS. 9B
to 9E.
[0102] Referring to FIG. 9B, dirty air (triple-headed arrows) flows
into the first cyclonic separating unit 160 via the dirty air inlet
port 126. The tangential arrangement of the dirty air inlet port
126 causes the dirty air to flow in a helical path around the
cylindrical dirt container 120. This creates an outer vortex in the
dirt container. Centrifugal forces move the comparatively large
dust and dirt particles outwards to strike the side of the dirt
container and separate them from the air flow. The dust separated
and dirt (D) swirls towards the dirt collection bowl 124 where it
is deposited.
[0103] Referring to FIG. 9C, partially-cleaned air (double-headed
arrows) flows back on itself to follow an inner helical path
closely about the tapered funnel 110 and towards the cylindrical
intermediate wall 90. The partially-cleaned air flows through the
perforated portion 118 of the tapered funnel's skirt 112 largely
unimpeded. The circumferential lip 104 of the bulkhead 100 and the
lip 128 of the dirt container 120 converge at a width restriction X
in the first cyclonic separating unit 160. The width restriction
reduces a radial width between the dirt container and the
intermediate wall by at least 15 percent The width restriction
tapers towards the bowl door 130 so that air, and entrained dirt,
can flow more easily towards the bowl door than in the opposite
direction. Thus, the circumferential lips 104, 128 and perforated
portion 118 of the tapered funnel's skirt 112 catch separated dirt
in the bowl 124 before it can be re-entrained in the
partially-cleaned air flow. The partially-cleaned air flows through
perforations in the intermediate wall, which filters any remaining
large dirt particles, and into the distribution chamber 170.
[0104] As can be seen in FIG. 5, the air inlet ports 88 of the
twelve cyclones are moulded into the collar 82 of the cyclone
assembly 80. The distribution chamber 170 is in communication with
the air inlet ports 88 of the twelve cyclones 84. Referring to FIG.
9D, the partially-cleaned air flow (double-headed arrows) divides
itself, in the distribution chamber, evenly between the twelve air
inlet ports 88 from where it flows into the twelve cyclones 84 of
the second cyclonic separating unit 150. The air inlet ports 88
direct the partially-cleaned air flow in a helical path around the
vortex finders 54. This creates an outer vortex inside each cyclone
84. Centrifugal forces move the dust and dirt outwards to strike
the side of the cyclone and separate it from the air flow. The
separated dust and dirt swirls towards the discharge nozzle 87. The
internal diameter of the frustro-conical part 86 of cyclone
diminishes as the air flow approaches the nozzle. This accelerates
the outer helical air flow thereby increasing centrifugal forces
and separating ever smaller dust and dirt particles. The dust and
dirt particles exit the nozzle to be deposited inside the part of
the bowl 124 bounded by the tapered funnel 110.
[0105] Referring to FIG. 9E, cleaned air (single-headed arrows)
flows back on itself to follow a narrow inner helical path through
the middle of the cyclone 84. The cleaned air flows out the
internal hole 56 of the vortex finder 54, under the influence of
the fan, into the pre-fan filter 40. The pre-fan filter 40 is to
remove any fine dust and dirt particles remaining in the air flow
after the cyclonic separation apparatus 8.
[0106] The pre-fan filter is in communication with the motor fan
housing 27. Cleaned air flows, via the top slots 34 in the motor
fan housing, to the axial input 22 of the fan 18, out the
tangential output 24 of the fan and through the perforations 36 of
the end cap 30 where it is exhausted from the vacuum cleaner 2.
Dust and dirt separated by the first and second cyclonic separating
units and deposited in the dirt collection bowl 124 which can be
emptied by opening the bowl door 130.
[0107] Returning to FIG. 7, there are shown three of a total of
four motor cooling inlet ports 31 in the annular roof wall 121 of
the dirt container 120. One other motor cooling inlet port is
obscured by the end cap 30 in FIG. 7.
[0108] Returning to FIGS. 8, there are shown four vortex finder
seals 58. Each vortex finder seal forms a webbed collar around
three consecutive vortex finders 54. Four equiangular spaced small
gaps 59 exist between the four vortex finder seals. The vortex
finder seals 58 seal the connection between the vortex finder
assembly 50 and the inner wall 60 except where the gaps 59 are
located.
[0109] Referring to FIG. 9F, there is shown the pathway of clean
motor cooling air (single-headed arrow) flow through the motor 16
and fan 18. The four motor cooling inlet ports are in communication
with a first motor cooling passage 61a between the shell 42 of the
pre-fan filter 40 and the cylindrical wall 66 of the inner wall
60.
[0110] Referring to FIG. 9G, there is shown a longitudinal
cross-section of a vortex finder 54 in the region of Detail X of
FIG. 9F. Here, the vortex finder seal 58 blocks communication
between the first motor cooling passage 61a and a second motor
cooling passage 61b between the motor fan housing 27 and the
cylindrical cup 64 of the inner wall 60.
[0111] Referring to FIG. 9H, there is shown a longitudinal
cross-section between two vortex finders 54 and two vortex finder
seals 58 in the region of Detail X of FIG. 9F. Here, the gap 59
between the vortex finder seals 58 permits communication between
the first and second motor cooling passages 61a, 61b.
[0112] Returning to FIG. 9F, in use, clean motor cooling air flows
under the influence of the fan though the four motor cooling inlet
ports 31 and along the first motor cooling passage 61a, through the
gaps 59 and along the second motor cooling passage 61b from where
it enters the motor fan housing 27 via the bottom air flow slots
32. The motor comprises motor vents 17a in the bottom, and motor
vents 17b in the top, of the motor can to ventilate the interior of
the motor. The paddle wheel 26 circulates and augments motor
cooling air about the bottom of the motor. Motor cooling air is
drawn, under the influence of the fan, into the bottom motor vents
17a, through the interior of the motor, and passes out of the top
motor vents 17b. The motor is cooled by the motor cooling air flow.
The motor cooling air flow pathway joins the cleaned air flow
pathway from the cyclonic separation apparatus 8 around the axial
input 22 of the fan 18. The motor cooling air flow is expelled from
the tangential output 24 of the fan and out the perforations 36 of
the end cap 30.
[0113] The motor cooling inlet ports 31 are spaced at equiangular
intervals about the central axis 21. The motor cooling inlet ports
are axially aligned with the gaps 59 between the vortex spaces
seals 58 and with the bottom air flow slots 32 in the motor fan
housing 27. This axial alignment is to help minimise any resistance
encountered by the motor cooling air flow along the motor cooling
passages 61a, 61b. The bottom motor vents 17a are also aligned with
the bottom air flow slots 32 in the motor fan housing 27 to help
minimise any resistance encountered by the motor cooling air
flow.
[0114] The clean motor cooling air flow pathway is separate from
the air flow pathway through the cyclonic separation apparatus 8 up
to the axial input of the fan 18. This has particular benefits in
vacuum cleaning. Typically, motor speed increases as the fan
encounters resistance to volumetric air flow and the pressure
across the fan increases accordingly. An example of how this may
occur is when the vacuum cleaner is operational and the dirty air
inlet contacts carpet, hard floor, curtains or other surface to
restrict air flow. Should the air flow path through the cyclonic
separation apparatus 8 become blocked, or impeded, for whatever
reason, the motor cooling air flow path would not necessarily be
blocked, or impeded. Instead, the increased pressure across the fan
18 would increase suction through the motor cooling air flow
pathway. This has the benefit of increased motor cooling when the
motor is working hardest and cooling is needed most.
[0115] Referring to FIG. 44, there is shown a table of test data
relating to the temperature of the motor 16. Two thermocouples were
attached to the motor can while the motor was driving the fan 18 to
generate air flow. The cyclonic separation apparatus 8 was
subjected to three separate tests involving different operational
conditions: (a) free air flow (dirty air inlet 12 fully open); (b)
maximum power output (air watts) of cyclonic separation apparatus;
and (c) sealed suction (dirty air inlet 12 closed). As the skilled
person will appreciate, air watt is a measurement of vacuum power
calculated from volumetric flow rate (volume/time) multiplied by
suction (force/area) multiplied by a correction factor depending on
humidity and atmospheric pressure. The ambient temperature was
measured and compared to the motor temperature after ten minutes
run time. The same three tests were carried out with four motor
cooling inlet ports 31 and then repeated with one of the four motor
cooling inlet ports 31 closed. The test data clearly reveal the
benefits of the motor cooling air flow pathway and the importance
of having four motor cooling inlet ports 31.
[0116] Referring to FIGS. 10 and 11, there is shown a second
embodiment of a hand-held vacuum cleaner 202 comprising a main body
204 with a main axis 205, a handle 206, a cyclonic separation
apparatus 208 mounted transverse to the main axis of the main body,
and a dirty air duct 210 with a dirty air inlet 212 at one end. The
vacuum cleaner comprises a motor 216 coupled to a fan for
generating air flow through the vacuum cleaner and rechargeable
cells 217 to energise the motor when electrically coupled by an
on/off switch 214.
[0117] Referring to FIGS. 12 to 16, there is shown an arrangement
comprising the motor 216, the rechargeable cells 217, the fan 218,
a pre-fan filter 240, a cyclonic separation apparatus outlet duct
260 and the cyclonic separation apparatus 208.
[0118] The motor has a drive shaft 220 with a longitudinal central
axis 221. The fan is a centrifugal fan 218 with an axial input 222
facing away from the motor and a tangential output 224. The fan has
a diameter of 68 mm. The fan is mounted upon the drive shaft at the
top of the motor. The cells 217 are arranged in a circular array
about the motor 216 with the longitudinal axis of the cells
parallel to the central axis 221, as is shown most clearly in FIGS.
11 and 14. In use, the motor drives the fan to generate air flow
through the cyclonic separation apparatus, as will be described in
more detail below.
[0119] The main body 204 comprises a central housing 226, a motor
housing 228, a frame 230 and an end cap 232. The fan 218 is housed
in the central housing 226. The central housing is connected to the
handle 206. The motor 216 and the cells 217 are housed in the motor
housing 228. The motor housing is generally elongate to suit the
profile of the cells. The end cap 230 is connected to an opposite
end of the motor housing to the fan. The end cap has a circular
array of perforations 236.
[0120] The frame 230 connects the central housing 226 to the
cyclonic separation apparatus 208. One end of the frame supports a
pre-fan filter 240 arranged in front of the axial input 222 of the
fan 218. The other end of the frame supports the cyclonic
separation apparatus.
[0121] The outlet duct 260 is defined by a generally oval-shaped
duct wall 262 arranged upon the frame 230 to form the outlet duct
between the duct wall and frame. The outlet duct 260 provides an
air flow path between the cyclonic separation apparatus 208 and the
pre-fan filter 240. The duct wall is detachable from the frame. The
duct wall is transparent to permit visual inspection of the pre-fan
filter. The duct wall is removed from the frame if the pre-fan
filter needs cleaning or replacement.
[0122] The cyclonic separation apparatus 208 comprises, a vortex
finder assembly 250, a vortex finder seal 270, a cyclone assembly
280, a cylindrical perforated intermediate wall 290, a circular
bulkhead 300, a tapered funnel 310, a transparent generally
cylindrical dirt container 320 with a longitudinal central axis
321, and a circular dirt collection bowl 330 all arranged about the
central axis 321 of the dirt container 320.
[0123] The vortex finder assembly 250 comprises a planar generally
circular base 252 with six hollow cylindrical vortex finders 254.
Each vortex finder has a central through-hole 256 and its own
longitudinal central axis 257. The vortex finders are arranged in a
circular array about the central axis 321 of the dirt container
320. Each vortex finder is parallel to the central axis 321. The
vortex finders protrude from one side of the base. A small portion
of each vortex finder also protrudes from the opposite side of the
base. The vortex finders may have longitudinal internal ribs (not
shown) along the through-holes to help dampen high frequency sounds
caused by Helmholtz resonance as air flows through the vortex
finder though-holes 256.
[0124] The cyclone assembly 280 comprises a generally cylindrical
collar 282 and a circular array of six cyclones 284 surrounded by
the collar. The cyclones are spaced at equi-angular intervals about
the central axis 321 of the dirt container 320. Each cyclone has a
hollow cylindrical top part 285 and a hollow frustro-conical bottom
part 286 depending from the cylindrical top part and terminating
with a discharge nozzle 287 at the bottom of the cyclone.
[0125] The vortex finder assembly 250 is arranged upon the collar
282 of the cyclone assembly 280. The vortex finders 254 protrude
into the cylindrical top part 285 of a respective cyclone 284. The
only passage through of the top of the cyclone 284 is via its
vortex finder 254 which acts as an air flow port to the outlet duct
260. Each vortex finder is concentric with its respective cyclone.
The plane of each nozzle 287 is inclined with respect to the
central axis 257. This helps to prevent dust and dirt particles
from re-entry after discharge from the nozzle.
[0126] The cylindrical top part 285 of each cyclone 284 has an air
inlet port 288 arranged tangentially through a side of the cyclone
and proximal the vortex finder 254. The six air inlet ports are in
communication with a distribution chamber 370 located below the
collar 282 around the cyclones 284 as described in more detail
below.
[0127] The intermediate wall 290 is arranged upon the cyclone
assembly 280. The intermediate wall 290 has approximately the same
outer diameter as, and abuts with, the cylindrical collar 282.
[0128] The bulkhead 300 is arranged upon, and has approximately the
same outer diameter as, the intermediate wall 290. The bulkhead 300
is perforated by a circular array of six holes 302 spaced at
equi-angular intervals about the central axis 321. The discharge
nozzles 287 of the cyclones 284 protrude through respective
bulkhead holes 302. The bulkhead 300 has a circumferential lip 304
inclined radially outwardly from the central axis 321 towards the
collection bowl 330. The lip 304 protrudes a small way from the
intermediate wall 290.
[0129] The tapered funnel 310 comprises a hollow circumferential
skirt 312, a frustro-conical cone 314 depending from the skirt, and
a hollow cylindrical nose 316 depending from the cone. The skirt is
arranged upon, and has approximately the same outer diameter as,
the bulkhead 300. The cone tapers radially inwardly from the
bulkhead towards the collection bowl 330. A perforated portion 318
of the skirt protrudes axially rearward from the cone towards the
collection bowl 330.
[0130] The generally cylindrical dirt container 320 comprises a
hollow cylindrical exterior wall 322 with a circular shoulder 324
extending radially inwardly from the top of the exterior wall. The
dirty container has a dirty air inlet port 326 arranged
tangentially through the exterior wall 322. The dirty air inlet
port communicates with the dirty air duct 210. The exterior wall
322 is rotatingly connected to the frame 230 to enable the cyclonic
separation apparatus 208 to rotate about its central axis 321 in
relation to the main body 204. The dirty air duct 210 is rotatable
with the cyclonic separation apparatus 208, as is shown in FIG. 11
where the dirty air duct is in a folded position.
[0131] The planar base 252 of the vortex finder assembly 250 nests
within the aperture in the circular shoulder 324 of the dirt
container 320. The collar 282 of the cyclone assembly 280 abuts the
circular shoulder 324. The cyclones 284 are located within the dirt
container 320.
[0132] The dirt collection bowl 330 is detachably connected to an
outer circumferential edge 332 of the dirt container 320. The dirt
collection bowl abuts the nose 316 thereby dividing the dirt
container and dirt collection bowl into two separate chambers: a
circular chamber 334 inside the tapered funnel 310 and a generally
annular chamber 362 outside the tapered funnel. The dirt collection
bowl 330 may be connected to the dirt container's outer
circumferential edge by snap-fit, bayonet fit, interlocking
detents, interference fit or by a hinge. A resilient seal 336 made
of polyethylene, rubber or a similar elastomeric material is
provided around the dirt collection bowl 330 to ensure airtight
connection with the dirt container.
[0133] The dirt container 320 has an annular lip 328 inclined
radially inwardly to the central axis 321 towards the collection
bowl 330. The lip 328 protrudes a small way in from the exterior
wall. The lip 328 is proximal to the bowl 330.
[0134] The nose 316 of the tapered funnel 310 is in complementary
mating relationship with a circular ring 340 protruding from inside
the dirt collection bowl 330. This ensures that components of the
cyclonic separation apparatus 208 remain concentric with the
central axis 321 of the dirt container 320.
[0135] In use, dirty air flows, under the influence of the fan 218,
in the dirty air inlet 212, up the dirty air duct 210 and into the
cyclonic separation apparatus 208 where dust and dirt entrained in
the air flow is separated therefrom. The dust and dirt is collected
within the cyclonic separation apparatus. The air flows out the
cyclonic separation apparatus 208, via the through-holes 256 of the
vortex finders, along the outlet duct 260, through the pre-fan
filter 240, through the fan 218 and over the motor 216 and
batteries cells 217 via the motor housing 228 and out the
perforations 236 in the end cap 230.
[0136] Referring to FIG. 17A, the cyclonic separation apparatus 208
is divided into a first cyclonic separating unit 360, a second
cyclonic separating unit 350 and the distribution chamber 370. The
first cyclonic separating unit is located in the air flow pathway
upstream of the distribution chamber. The distribution chamber is
located in the air flow pathway upstream of the second cyclonic
separating unit.
[0137] The first cyclonic separating unit 360 comprises the
cylindrical dirt container 310. The second cyclonic separating unit
350 comprises the circular array of six cyclones 284. The dirt
container is concentric with the central axis 321 of the dirt
container. The distribution chamber 370 is bounded by the collar
282, cyclone assembly 280, intermediate wall 290 and bulkhead 300.
The second cyclonic separating unit 350 receives air flow from the
first cyclonic separating unit 360 via the distribution chamber
370.
[0138] The exterior wall 322 of the dirt container 320 has a
diameter of approximately 120 mm. The cyclones 284 have a smaller
diameter than the annular chamber 362. Helical air flow in the
cyclones experiences greater centrifugal forces than in the dirt
container. Thus, the cyclones of the second cyclonic separating
unit 350, when combined, have higher separation efficiency than the
dirt container of the first cyclonic separating unit 360.
[0139] The air flow pathway though the cyclonic separation
apparatus 208 is described in more detail with reference to FIGS.
17B to 17F.
[0140] Referring to FIG. 17B, dirty air (triple-headed arrows)
flows from the dirty air duct 210 and into the dirt container 320
via the dirty air inlet port 326. The tangential arrangement of the
dirty air inlet port 326 causes the dirty air to flow in a helical
path around the dirt container. This creates an outer vortex in the
dirt container. Centrifugal forces move the comparatively large
dust and dirt (D) particles outwards to strike the side of the dust
container 320 and separate them from the air flow. The separated
dust and dirt swirls towards the dirt collection bowl 330 where it
is deposited.
[0141] Referring to FIG. 17C, partially-cleaned air (double-headed
arrows) flows back on itself to follow an inner helical path
closely about the tapered funnel 310 and towards the cylindrical
intermediate wall 290. The partially-cleaned air flows through the
perforated portion 318 of the tapered funnel's skirt 312 largely
unimpeded. The circumferential lip 304 of the bulkhead 300 and the
lip 328 of the dirt container 320 converge at a width restriction Y
in the first cyclonic separating unit 360. The width restriction
reduces a radial width between the dirt container and the
intermediate wall by at least 15 percent. The width restriction
tapers towards the bowl 330 so that air, and entrained dirt, can
flow more easily towards the bowl door than in the opposite
direction. Thus, the circumferential lips 304, 328 and perforated
portion 318 of the tapered funnel's skirt 312 catch separated dirt
in the bowl 324 before it can be re-entrained in the
partially-cleaned air flow. The partially-cleaned air flows through
perforations in the intermediate wall, which filters any remaining
large dirt particles, and into the distribution chamber 370.
[0142] As can be seen in FIG. 16, the air inlet ports 288 of the
six cyclones are moulded into the collar 282 of the cyclone
assembly 280. The distribution chamber 370 is in communication with
the air inlet ports 288 of the six cyclones 284. Referring to FIG.
17D, the partially-cleaned air flow (double-headed arrows) divides
itself, in the distribution chamber, evenly between the six air
inlet ports 288 from where it flows into the six cyclones 284 of
the second cyclonic separating unit 350. The air inlet ports 288
direct the partially-cleaned air flow in a helical path around the
vortex finders 254. This creates an outer vortex inside each
cyclone 284. Centrifugal forces move the dust and dirt outwards to
strike the side of the cyclone and separate it from the air flow.
The separated dust and dirt swirls towards the discharge nozzle
287. The internal diameter of the frustro-conical body 286 of
cyclone diminishes as the air flow approaches the nozzle. This
accelerates the helical air flow thereby increasing centrifugal
forces and separating ever smaller dust and dirt particles. The
dust and dirt particles exit the nozzle to be deposited inside the
part of the bowl 330 bounded by the tapered funnel 310.
[0143] Referring to FIG. 17E, cleaned air (single-headed arrows)
flows back on itself to follow a narrow inner helical path through
the middle of the cyclone 284. The cleaned air flows out the
internal through-hole 256 of the vortex finder 254, under the
influence of the fan.
[0144] Returning to FIG. 17F, the cleaned air flows from the vortex
finders 254 into the outlet duct 260 and to the pre-fan filter 240.
The pre-fan filter 240 is to remove any fine dust and dirt
particles remaining in the air flow after the cyclonic separation
apparatus 208 and before the fan 218. The clean air flows into the
axial input 222 of the fan 218 and is expelled from the tangential
output 224 of the fan. Pathways in the central housing 226 direct
the clean air flow from the fan over the motor 216 and cells 217,
to cool the motor and cells, before the air flows out the
perforations 236 in the end cap 232.
[0145] Dust and dirt separated by the first and second cyclonic
separating units and deposited in the dirt collection bowl 330
which can be opened for emptying.
[0146] Referring to FIG. 18, there is shown a diagrammatical view
of the various components of the cyclonic separation apparatus 208
(vortex finder assembly 250, vortex finder seal 270, cyclone
assembly 280, intermediate wall 290, bulkhead 300, tapered funnel
310) located within confines of the outlet duct 260, frame 230,
dirt container 320 and dirt collection bowl 330.
[0147] The vortex finder seal 270 seals the connections between the
vortex finder assembly 250 and the dirt container 320 in an
airtight manner. An outlet duct seal 266 seals the connection
between the frame 230 and the outlet duct wall 262 in an airtight
manner. The vortex finder seal 270 and the outlet duct seal 266 are
made of polyethylene, rubber or a similar elastomeric material.
[0148] Certain components of the cyclonic separation apparatus 208
are detachably connected, typically by a snap-fit, bayonet fit,
interference fit or by interlocking detents. This permits
disassembly and reassembly, without tools, of the cyclonic
separation apparatus in order to clean, or replace, its individual
components, as is described with reference to FIGS. 19 to 22.
[0149] Referring to FIG. 19, there is shown a method of
disassembling a first construction of the cyclonic separation
apparatus 208 whereby the outlet duct wall 262 is detachable from
the frame 230. The dirt container 320 is detachable from the frame.
The vortex finder assembly is detachable from the frame with, or
without, the dirt container. The cyclone assembly 280, intermediate
wall 290, bulkhead 300, and tapered funnel 310 are also detachable,
in unison, from the vortex finder assembly. The dirt collection
bowl 330 has a large enough diameter to enable, when the dirt
collection bowl is opened, removal of the cyclone assembly 280,
intermediate wall 290, bulkhead 300, and tapered funnel 310 out the
dirt container 320.
[0150] Referring to FIG. 20, there is shown a method of
disassembling an alternative construction of the cyclonic
separation apparatus 208 whereby the outlet duct wall 262 is
detachable from the frame 230. The dirt container 320 is detachable
from the frame. The vortex finder assembly 250, cyclone assembly
280, intermediate wall 290, bulkhead 300, and tapered funnel 310
are detachable, in unison, from the frame with, or without, the
dirt container. The dirt collection bowl 330 is can be opened for
emptying.
[0151] Referring to FIG. 21, there is shown a method of
disassembling a second alternative construction of the cyclonic
separation apparatus 208 whereby the outlet duct wall 262 is
detachable from the frame 230. The dirt container 320, vortex
finder assembly 250, cyclone assembly 280, intermediate wall 290,
bulkhead 300, and tapered funnel 310 are detachable, in unison,
from the frame. The dirt collection bowl 330 can be opened for
emptying.
[0152] Referring to FIG. 22, there is shown a method of
disassembling a third alternative construction of the cyclonic
separation apparatus 208 whereby the outlet duct 260 (i.e. duct
wall 262 and frame 230) is detachable from the frame. The dirt
container 320 remains with the frame. The vortex finder assembly
250, cyclone assembly 280, intermediate wall 290, bulkhead 300, and
tapered funnel 310 are removable, in unison, from the frame when
the dirt bowl 330 is opened.
[0153] Referring to FIG. 23, there is shown a third embodiment of
hand-held vacuum cleaner 402 comprising a main body 404 with a
handle 406, a cyclonic separation apparatus 408 mounted to the main
body, and a dirty air duct 410 with a dirty air inlet 412 at one
end. The vacuum cleaner comprises a motor coupled to a fan for
generating air flow through the vacuum cleaner and rechargeable
cells to energise the motor when electrically coupled by an on/off
switch 414.
[0154] Referring to FIGS. 24 to 27, there is shown in more detail
the motor 416, the rechargeable cells 417, the fan 418, a pre-fan
filter 440, a cyclonic separation apparatus outlet duct 460 and the
cyclonic separation apparatus 408.
[0155] The motor has a drive shaft 420. The fan 418 is mounted upon
the drive shaft at the top of the motor. The fan has a diameter of
approximately 68 mm. The cells 417 are arranged about the motor
416. In use, the motor drives the fan to generate air flow through
the cyclonic separation apparatus, as will be described in more
detail below.
[0156] The main body 404 comprises a central housing 426 and a
frame 430. The motor 416, fan 418 and cells 417 are housed in the
central housing 426. The central housing is connected to the handle
406. The central housing has an array of perforations 436 near the
bottom of the motor. The perforations 436 are for air flow expelled
from the central housing.
[0157] The frame 430 connects the central housing 426 to the
cyclonic separation apparatus 408. One end of the frame supports a
pre-fan filter 440 arranged in front of the fan's input. The other
end of the frame supports the cyclonic separation apparatus. The
cyclonic separation apparatus is rotatingly connected to the
frame.
[0158] Outlet duct 460 comprises a duct wall 462 arranged upon the
frame to form a passage between the duct wall and frame
approximately 10 mm deep. The outlet duct 460 provides an air flow
path between the cyclonic separation apparatus 408 and the pre-fan
filter 440. The duct wall is detachable from the frame. The duct
wall is transparent to permit visual inspection of the pre-fan
filter. A resilient seal made of polyethylene, rubber or similar
elastomeric material is provided around the duct wall to ensure air
tight connection with the frame. The duct wall is removed from the
frame if the pre-fan filter needs cleaning or replacement.
[0159] The cyclonic separation apparatus 408 comprises a vortex
finder assembly 450, a cyclone assembly 480, and an elongate
generally oval-shaped dirt container 520 with a transparent door
530.
[0160] The vortex finder assembly 450 has a hollow cylindrical
vortex finder 452 with a tapered deflector fin 454. The vortex
finder has a central through-hole 456 with a longitudinal central
axis 457. The deflector fin protrudes radially from the outer
surface of the vortex finder. In the present embodiment the tapered
deflector fin is triangular although it could have another tapered
profile. The triangular profile of the deflector fin 454 is a right
angled triangle.
[0161] The cyclone assembly 480 comprises a cyclone 484 and a dirty
air inlet port 488. The cyclone has a hollow cylindrical body 485
with the dirty air inlet port and a hollow frustro-conical bottom
body 486 extending from the cylindrical body and terminating with a
discharge nozzle 487 at the narrower end. The air inlet port is
arranged tangentially through a side of the cylindrical body. The
vortex finder 454 is arranged inside the cyclone 484. The vortex
finder is concentric with the cyclone. The deflector fin 454 is
arranged transverse to the path of air flow from the air inlet
port. The radially extending short side of the deflector fin abuts
the frame 430. An apex 4541 of the deflector fin is proximal to the
air inlet port. The hypotenuse side of the deflector fin tapers
radially inwardly from the apex to the end of the vortex finder
proximal to the discharge nozzle 487. There is a small gap of Z
approximately 5 mm between the apex and the cylindrical body 485 of
the cyclone 484.
[0162] The dirt container 520 is connected to the central housing
426 at one end and the discharge nozzle 487 of the cyclone 484 at
the other end. The dirt container comprises a perimeter wall 522
following the outer perimeter of the elongate generally oval-shaped
dirt container and base wall 524 with a cylindrical pocket 526
protruding from the base wall into the confines of the dirt
container. The cyclone 484 is in communication with the dirt
container where the nozzle 487 protrudes through the base wall 524.
The bottom of the motor 416 is seated inside the pocket 526 on the
opposite side to the dirt container thereby reducing the overall
width of the vacuum cleaner by about 20 to 25 mm.
[0163] The cyclone 484 has a curved fin 490 protruding axially from
the discharge nozzle 487 into the dirt container 520. The curved
fin circumscribes an arc of about half the circumference of the
nozzle facing the pocket 526. The ends of the curved fin taper
towards the nozzle. The dirt container has a flat fin 492
protruding from the base wall 524. The flat fin extends
tangentially from the top of the pocket 526 to about the middle of
the dirt container. The flat fin is generally parallel to an
adjacent initial flat portion 522a of the perimeter wall 522
uppermost on the dirt container in normal use.
[0164] The door 530 is detachably connected to the perimeter wall
522 of the container 520. The door 530 may be connected to the dirt
container by snap-fit, interlocking detents, a hinge 528 or by
interference fit with the dirt container's exterior wall. In the
example shown, the door is held firmly closed by a spring-loaded
latch 529. A resilient seal (not shown) made of polyethylene,
rubber or a similar elastomeric material is provided around the
door 530 to ensure connection to the dirt container 320 in an
airtight manner. Dust and dirt separated by the cyclonic separation
apparatus and deposited in the dirt container 520 can be emptied by
opening the door 530. The door is transparent to enable visual
inspection of when the dirt container 520 is full and is in need of
emptying.
[0165] In use, dirty air flows, under the influence of the fan 418,
in the dirty air inlet 412, up the dirty air inlet duct 410 and
into the cyclonic separation apparatus 408 where dust and dirt
entrained in the air flow is separated therefrom. The dust and dirt
is collected within the cyclonic separation apparatus. Air flows
out the cyclonic separation apparatus 408, via the through-hole 456
of the vortex finder, along the outlet duct 460, through the
pre-fan filter 440, through the fan 418 and over the motor 416 and
cells 417 via the central housing 426 and out the perforations 436
in the central housing.
[0166] Referring to FIGS. 24, 27 and 28, air flow though the
cyclonic separation apparatus 408 is described in more detail.
Dirty air (triple headed arrows) from the dirty air duct 410 enters
the cylindrical body 485 of the cyclone 484 via the air inlet port
488. The tangential arrangement of the air inlet port 488 and
presence of the triangular deflector fin 454 protruding from the
vortex finder 452 direct the dirty air to flow in a helical path
around the cyclone and towards the frustro-conical body 486 and
then the discharge nozzle. This creates an outer vortex in the
cyclone. Centrifugal forces move the comparatively large dust and
dirt particles outwards to strike the side of the cyclone and
separate them from the air flow. The separated dust and dirt swirls
towards the discharge nozzle 487 and into the dirt container
520.
[0167] The partially-cleaned air flow (double-headed arrows) is
directed by the curved fin 490 and a proximal curved portion 522d
of the perimeter wall 522 to leave the cyclone 484 in an
anti-clockwise upward direction, as viewed in FIG. 24. This helps
maintains air flow speed. The flat fin 492 and the pocket 526 help
to direct the partially cleaned air flow to follow an elongate
circuit about the perimeter wall 522 of dirt container 520, similar
in shape to a two-pulley belt drive wherein the discharge nozzle
487 simulates a pulley at one end and the pocket 526 simulates a
pulley at the opposite end. For example, the elongate circuit of
air flow begins outbound away from the discharge nozzle in
proximity to the initial flat portion 522b of the perimeter wall
522 and is redirected inside a distal curved portion 522c of the
perimeter wall 522 to turn around the pocket 526 and continue
inbound towards the discharge nozzle adjacent to a further flat
portion 522d of the perimeter wall lower most on the dirt container
in normal use. An axis of elongation of the elongate circuit runs
approximately through the centres of the discharge nozzle and the
pocket. The flat fin and the pocket prevent the bulk of the dust
and dirt particles (D) from dropping out of the circulating air
flow before being deposited upon the further flat portion 522d of
the perimeter wall at the bottom of the dirt container. The
perimeter wall 522 has a generally lozenge shape in cross-section
parallel to the base wall 524. The initial flat portion 522a and
the further flat portion 522c of the perimeter wall taper inwardly
and away from the distal curved portion 522b of the perimeter wall.
This encourages deposit of dust and dirt around the pocket end of
the dirt container where there is more space than at the opposite
discharge nozzle end of the dirt container. Also, the curved fin
490 acts as an obstacle to laminar air flow inbound to the
discharge nozzle. The air flow is forced to deviate around the
curved fin. This disruption of laminar air flow provokes deposit of
any remaining entrained dirt and dust (D) in the dirt container. As
such, the shape of the perimeter wall 522, the flat fin 492, the
pocket 526 and the curved fin 490 combine to help to separate any
remaining dust and dirt from air flow path destined for the pre-fan
filter 440. This increases sustained performance of the vacuum
cleaner 502.
[0168] Having deviated past the curved fin 490, clean air flow
(single-headed arrows) turns back on itself and, under the
influence of the fan, flows in a narrow inner helical path into the
vortex finder's through-hole 456 from where it leaves the cyclonic
separation apparatus 408 and enters the outlet duct 460.
[0169] Referring to FIGS. 29 to 38, there is shown a variety of
battery-powered vacuum cleaners with the motor 16, fan 18 and
cyclonic separation apparatus 8 arrangement of the first
embodiment. The arrangement is, in all examples, arranged with the
central axis 21 of the drive shaft 20 orientated transverse a main
axis of the main body of the vacuum cleaner. In particular, there
is shown a hand-holdable vacuum cleaner 602 with pivotable dirty
air duct 610; a hand-holdable vacuum cleaner 702 connected to a
cleaning nozzle 712 by a flexible hose 710 to resemble a small
cylinder vacuum cleaner; and a vacuum cleaner 802 with an elongate
body 806, a support wheel 807 and a cleaner head 812 to resemble an
upright vacuum cleaner, also commonly referred to as a
"stick-vac".
[0170] Referring to FIGS. 29 to 32, the hand-holdable vacuum
cleaner 602 comprises a main body 604 with a main axis 605 and a
handle 606. The motor 16, fan 18 and cyclonic separation apparatus
8 of the first embodiment are rotatingly connected to the main body
604 at the annular roof wall 121 of the dirt container 120. The
central axis 21 of the cyclonic separation apparatus is orientated
at a right angle (i.e. transverse) to the main axis of the main
body. The vacuum cleaner 602 comprises a battery pack 900 of
rechargeable cells 917 to energise the motor 16 when electrically
coupled by an on/off switch. The dirty air duct 610 is connected to
the air inlet port 126.
[0171] Referring in particular to FIG. 31, the battery pack 900 has
a curvilinear cross-sectional profile with a curvilinear inner wall
902 shaped to fit around the cylindrical dirt container 120. The
battery pack 900 has a pair of electrical contacts 904 on a
curvilinear outer wall 906 so that the cells may be recharged in
situ. The battery pack is detachably connected to the dust
container 120. The battery pack may be detached from the duct
container to enable replacement, or external recharging of the
cells, if necessary. The cells have a generally cylindrical shape.
Longitudinal axes of cells are arranged parallel to the central
axis 21 of the motor 16.
[0172] The dirty air duct 610 and the battery pack 900 are
rotatable, with the cyclonic separation apparatus 8, about the
central axis 21 through an arc subtending 210 degrees from a folded
position. This allows the vacuum cleaner 602 to be pointed in
different directions, whilst a user is able to hold the vacuum
cleaner in the same orientation. The vacuum cleaner may be used to
access awkward spaces and can be held more comfortably by
orientating the main axis 605 of the main body 604 to suit the user
and adjusting the position of the dirty air inlet 612 to point at a
surface to be cleaned, rather than orientating the main axis to
best suit the surface to be cleaned and requiring the user to hold
the vacuum cleaner in whichever orientation this demands.
[0173] FIGS. 29 and 30 show the vacuum cleaner 602 in the folded
position where the dirty air duct is folded at zero degrees under
the handle 606 for compact storage. The battery pack 900 is rotated
to the diametrically opposite side of the dirt container 120. The
vacuum cleaner may be cradled by a battery charger 916 in the
upright position shown in FIG. 29. This allows the vacuum cleaner
to be stood in a small surface area and without excessive height
because the dirty air duct is folded under the handle. Arranged
like this, the vacuum cleaner is easier to grab. The vacuum
cleaner's centre of gravity is lowered by the battery pack thus
making the upright position more stable. Moreover, the cells 917
are electrically coupled by the electrical contacts 904 to the
battery charger 916 for recharging in the upright position.
[0174] FIG. 32 shows the vacuum cleaner 602 in an extended
position. The dirty air duct 610 is rotated through 180 degrees
from the folded position and is ready for use. The dirty air duct
610 has been telescopically extended to double its length. The
battery pack 900 occupies a gap 616 between the handle 606 and the
dirt container 120. The battery pack is relatively heavy and its
location in the gap 616 moves the vacuum cleaner's centre of
gravity closer to the handle. This improves the ergonomics of the
vacuum cleaner.
[0175] Referring to FIGS. 33 and 34, the hand-holdable vacuum
cleaner 702 comprises a body 704 with a handle 706. The motor 16,
fan 18 and cyclonic separation apparatus 8 is connected to the body
704 at the annular roof wall 121 of the dirt container 120. The
vacuum cleaner 702 comprises a pack 910 of rechargeable cells. The
cells are to energise the motor 16 when electrically coupled by an
on/off switch. The air inlet port 126 is connected to one end of
the flexible hose 710. The cleaning nozzle 712 is connected to the
other end of the flexible hose.
[0176] The battery pack 910 has a curvilinear inner wall 902 which
is shaped to cradle the cylindrical dust container 120. The battery
pack is detachably connected to the dust container 120. The cells
may be recharged in situ. The battery pack may be detached from the
dirt container to enable replacement, or external recharging of the
cells, if necessary. The battery pack has a pair of feet 912
arranged to support the vacuum cleaner 702 in a stable manner when
placed upon a flat surface. The cells have a generally cylindrical
shape. Longitudinal axes of the cells are arranged parallel to the
central axis 21 of the motor 16.
[0177] FIGS. 32 and 34 show a compact configuration of the vacuum
cleaner 702. The flexible hose 710 is wrapped around the dirt
container 120 and under the battery pack 910 via rebates 914 in the
battery pack feet 912. The cleaning nozzle 712 is cradled by the
handle 706. The handle is moulded in plastics material with natural
resilience. The cleaning nozzle is gripped by the handle. The
cleaning nozzle can be readily detached from the handle for use in
vacuum cleaning.
[0178] Referring to FIGS. 35 and 37, the vacuum cleaner 802
comprises the elongate body 804. The elongate body is telescopic.
The elongate body has a handle 806 at one end and a bracket 805 at
the other end. The motor 16, fan 18 and cyclonic separation
apparatus 8 of the first embodiment are rotatingly connected to the
bracket 805 at the annular roof wall 121 of the dirt container 120.
The bracket arches around one side of the dirt container so that
the latter may be connected transverse to the elongate body. The
support wheel 807 surrounds the dirt container 120. The support
wheel is supported for rotation about the dirt container by a
bearing 809. The air inlet port 126 is connected to one end of the
dirty air duct 810. The cleaner head 812 is connected to the other
end of the dirty air duct 810. The cleaner head is pivotable in
relation to the dirt container about a longitudinal axis 8100 of
the dirty air duct. The dirty air duct is arranged tangentially to
the dirt container.
[0179] The vacuum cleaner comprises a battery pack 900 of
rechargeable cells 917 to energise the motor 16 when electrically
coupled by an on/off switch. Referring to FIG. 37, the battery pack
900 has a curvilinear inner wall 902 which is shaped to embrace the
support wheel 807 and part of the cylindrical dirt container 120.
The battery pack is detachably connected to the bracket 805. The
cells 917 may be recharged in situ. The battery pack may be
detached from the bracket to enable replacement, or external
recharging of the cells, if necessary. The cells have a generally
cylindrical shape. Longitudinal axes of the cells are arranged
parallel to the central axis 21 of the motor 16.
[0180] Returning to FIG. 35, there is shown the vacuum cleaner 802,
prepared for use, with the support wheel 807 and the cleaning head
812 upon a floor and the elongate body 804 fully extended. The
support wheel 807 is arranged about the midpoint of the axial
length of the dirt container. The diameter of support wheel 807 is
approximately the same as the axial length of the dirt container
120 so that the elongate body can be rocked from side to side by
about 45 degrees each way and the vacuum cleaner 802 can be steered
with ease.
[0181] Returning to FIG. 37, there is shown the vacuum cleaner with
the elongate body 804 fully retracted to approximately a quarter of
the elongate body's extended length. The vacuum cleaner's overall
length when the elongate body is extended is at least double the
vacuum cleaner's overall length when the elongate body is
retracted. The vacuum cleaner 802 is prepared for storage in a
kitchen cupboard when the elongate body is retracted. The elongate
body may be locked in its retracted and extended positions. The
skilled person will appreciate that any suitable locking system
will suffice, like, for example, a spring-loaded detent
interlockable with holes along the elongate body corresponding to
the retracted position, the extended position and any intermediate
position therebetween.
[0182] Referring to FIG. 38, there is shown in perspective the
shape of the battery pack 900 and, in particular, the curvilinear
inner wall 902 which is to embrace, or connect to, the outside of
the dirt container 120 of the cyclonic separation apparatus 8.
[0183] Referring to FIGS. 39 and 40, there is shown the battery
pack 900 along cross-section XXXVIII-XXXVIII. Commercially
available rechargeable cells may be cylindrical in shape. FIG. 39
shows five cylindrical cells 917 stacked in a curved array to
conform to the internal cavity of the curvilinear cross-section
profile of the battery pack. Also commercially available are plate
rechargeable cells 927 composed of flexible anode and cathode
plates, or sheets, interposed by a polymer electrolyte material and
separator material. The anode sheets are electrically connected to
the positive cell terminal and the cathode sheets are electrically
connected to the negative cell terminal, and those sheets can be
connected in series or in parallel to form a battery pack. These
plate cells are flexible and they can be stacked upon each other.
FIG. 40 shows three plate cells 927 stacked upon each other and
curved to conform to the internal cavity of the curvilinear
cross-section profile of the battery pack.
[0184] Referring to FIGS. 41 to 43 there is shown an annular
battery pack 920 in cross-section which is adapted to surround the
dirt container 120 of the cyclonic separation apparatus 8 with a
hollow cylindrical inner surface 922. The annular battery pack has
a cylindrical inner wall 922 and a cylindrical outer wall 926.
[0185] FIG. 41 shows 12 cylindrical cells 917 arranged in a
circular array to conform to the internal cavity of the annular
cross-sectional profile of the annular battery pack 920.
[0186] FIG. 42 shows three plate cells 927 stacked upon each other
and curved into a hollow cylindrical shape to conform to the
internal cavity of the annual cross-section of the annular battery
pack 920.
[0187] FIG. 43 shows five plate cells 927 wound into a hollow
cylindrical shape to conform to the internal cavity of the annular
cross-section of the annular battery pack 920.
[0188] The curved plate cells 927 improve use of the internal
cavity of the battery packs 920 by eliminating the gaps which
naturally exist between the cylindrical cells 917. This results in
a more compact design of battery pack with reduced packaging and a
higher energy density.
[0189] The curvilinear or cylindrical inner walls 902,922 of the
curvilinear battery pack 900,910 and the annular battery pack 920
embrace, or attach themselves to, the dirt container 120. This
facilitates new design choices for accommodating cells in a compact
manner.
[0190] The skilled addressee will appreciate that the rechargeable
cells can be any type of energy accumulator, including rechargeable
Lithium Ion, Nickel Metal Hydride or Nickel Cadmium rechargeable
cells, for driving the electric motor 16, 216, 416.
[0191] The skilled addressee will appreciate that the specific
overall shapes and sizes of the arrangements comprising the motor
16, 216, 416 the fan 18, 218, 418 and the cyclonic separation
apparatus 8, 208, 408 can be varied according to the type of vacuum
cleaner in which either of the arrangements is to be used. For
example, the overall length or width of each arrangement, and, in
particular, the cyclonic separation apparatus, can be increased or
decreased with respect to its diameter, and vice versa.
[0192] In particular, the hand-holdable vacuum cleaner 702 of FIGS.
33 and 34 can be modified to comprise the motor 216, fan 218 and
cyclonic separation apparatus 208 of the embodiment by modifying
the form of the battery pack 910 to suit the underside of the dirt
container 320. The flexible hose 710 would need extension to be
wrapped around the dirt container 320 and the central housing 226
and motor housing 228.
[0193] Further, the hand-holdable vacuum cleaner 802 of FIGS. 35 to
38 can be modified to comprise the motor 216, fan 218 and cyclonic
separation apparatus 208 of the second embodiment by substituting
the central housing 226 and motor housing 228 for the main bracket
805. This could be done by attaching the elongate body 804 directly
to the central housing 226 in place of the handle 206 and the
bracket 805. The cyclonic separation apparatus outlet duct 260
would need extension to create enough clearance for the support
wheel 807 and bearing 809 to surround the dirt container 320.
[0194] The motor 16, 216, 416 discussed above is a typically a
brushed d.c. motor with its drive shaft 20,220,420 directly coupled
to the centrifugal fan 18, 218, 418. The motor's drive shaft has a
rotational speed within a range of 25,000 and 40,000 revolutions
per minute (rpm). A centrifugal fan with a rotational speed within
this range has an outer diameter approximately double the outer
diameter of the motor can in order to have sufficient tip speed to
generate the required volumetric flow rate through the cyclonic
separation apparatus. The skilled person will appreciate that the
motor 16,216,416 can be a d.c. motor, an a.c. motor, or an
asynchronous multi-phase motor controlled by an electronic circuit.
A permanent magnet brushless motor, a switched reluctance motor, a
flux switching motor, or other brushless motor type, may have a
high rotational speed within a range of 80,000 to 120,000 rpm. If
such a high speed motor were used then the fan diameter could be at
least halved and yet still generate the required volumetric flow
through the cyclonic separation apparatus because the fan's tip
speed would be so much higher. This would make the fan's outer
diameter the same as the motor can's outer diameter and could
possibly make it less than the motor can's outer diameter if the
motor operates at around the upper end of the high rotational speed
range. A smaller diameter fan operating within this range of high
rotational speeds would typically be an impeller although it may be
an axial fan or a centrifugal fan. The outer profile of the smaller
fan coupled to the drive shaft of the high rotational speed motor
would have a generally cylindrical outer profile. This provides
additional flexibility in the layout of the cyclonic separation
apparatus.
[0195] In a modification of the first or second embodiment of a
cyclonic separation apparatus 8,208 which is not shown in the
drawings, the cyclones 84,284 can be rearranged to accommodate a
high rotational speed permanent magnet brushless motor, a switched
reluctance motor or a flux switching motor coupled to a fan which
is coaxial with the motor and has an outer diameter substantially
the same as or less than the outer diameter of the motor. The
generally cylindrical outer profile of high speed motor and fan can
be sunk into the cyclonic separation apparatus amongst the cyclones
and clustered into a generally circular array. Air flow can be
directed to the axial input of the fan and expelled from the
tangential output of the fan by a baffle. The high speed motor and
fan may be located on the periphery of the circular array in which
case air flow from the fan may be expelled from one side of the
circular array and directed out of the cyclonic separating
apparatus. The high speed motor and fan may be nested near, or at,
the middle of the circular array in which case air flow from the
fan may be expelled from one end of the circular array and directed
out of the cyclonic separating apparatus. If the high speed motor
and fan were nested in a circular array of cyclones inclined with
respect to a central axis, like, for example, a modified version of
the cyclones disclosed by GB 2 440 110 A, then air flow from the
fan may be expelled from one end of the circular array of cyclones
or through gaps between the cyclones.
* * * * *