Note: Descriptions are shown in the official language in which they were submitted.
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MOTOR, FAN AND FILTER ARRANGEMENT FOR A VACUUM CLEANER
The present invention concerns a motor, fan and filter arrangement for a
vacuum cleaner and vacuum cleaners comprising such a motor, fan and filter
arrangement. 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. 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 for 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, 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 airflow pathway in through the dirty air inlet, via the collection
chamber to
the clean air outlet.
Interposed at some point along the airflow 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
separation
means may comprise one or more filters and/or a cyclonic separation device.
Conventionally, in the event that the separation means comprises a filter, the
motor,
fan and filter have an arrangement as represented schematically in Fig. 1. As
may
be seen from Fig. 1, dirty air which has entered the vacuum cleaner via the
dirty air
inlet passes from region P to region Q through filter 30. This separates out
dust and
dirt (and possibly also liquids) entrained with the dirty air and the filtered
material
therefore remains in region P. If, as is usually the case, filter 30 is
located within the
collection chamber itself, the filtered material remaining in region P also
accumulates
there. The clean air then passes from region Q on the other side of filter 30
to a third
region R through a grille 42 formed in a wall 40 on which filter 30 is
mounted.
Although it may be provided with an additional filter, grille 42 does not
generally have
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a filtering effect. Its primary purpose is instead to prevent users from
gaining access
to fan 20 mounted on motor output shaft 12 of motor 10, which draws air
through the
vacuum cleaner when motor 10 is supplied with electricity through electrical
terminals
14, 16. As shown in Fig. 1, fan 20 is an impeller, which draws air in axially
towards
its face and expels air out tangentially, from where the air then passes to
the clean
air outlet of the vacuum cleaner. An example of a hand-holdable vacuum cleaner
having the conventional motor, fan and filter arrangement of Fig. 1 is
described in
European patent publication no. EP 1 523 916 A, also in the name of the
present
applicant.
The conventional arrangement of motor, fan and filter described above
therefore creates three separate regions, P, Q and R, of which the second
region,
region Q, is effectively "dead" space. In other words, whereas region P can be
used
to provide the collection chamber for filtered material as described, and
region R
houses the motor 10 and fan 20, region Q only consumes space without
fulfilling any
purpose. On the one hand, filter 30 should have as large a surface area as
possible
in order to increase its filtering effect, which tends to increase the size of
region Q.
This is the reason why just a flat filter located across the face of fan 20 in
the location
of grille 42 is generally avoided. Whereas this would dispense with region Q
altogether, such a small filter would also dramatically reduce the efficiency
of the
vacuum cleaner by creating a bottleneck in the airflow pathway. Moreover, in
order
to improve the effectiveness of filter 30 still further, the filter is often
also provided
with a cylindrical or frusto-conical shape. Such a shape encourages dirty air
in
region P to swirl around filter 30 before passing therethrough, which has the
effect of
throwing dust and dirt particles outwardly, away from filter 30, under the
action of
centrifugal force in a cyclonic separation. On the other hand, however, if it
is
necessary to provide filter 30 with a large surface area or such a shape, the
alternative solution of inserting fan 20 and possibly also part or all of
motor 10 into
region Q, in order to save space and reduce the size of region 0, cannot be
contemplated either, since this would impede the outflow of air expelled
tangentially
from fan 20 towards the clean air outlet of the vacuum cleaner and instead
cause the
air expelled by the fan to impinge on the inner surface of filter 30, thereby
countering
the inflow of clean air through filter 30 and dramatically diminishing the
efficiency of
the filtering operation once again.
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The conventional arrangement of motor, fan and filter shown in Fig. 1 is
therefore inefficient in its use of space, but no obvious solution how to
overcome this
problem presents itself. Such an inefficient use of space is particularly
undesirable in a
compact or hand-holdable vacuum cleaner, where the efficient use of space is
of great
importance and any wasted space will necessarily add to the overall weight of
the
vacuum cleaner, without giving any counteracting benefit.
It is therefore an object of an aspect of the present invention to provide a
motor, fan and filter arrangement for a vacuum cleaner which makes much better
use
of space than the conventional arrangement shown in Fig. 1. It is also an
object of an
aspect of present invention to provide a motor, fan and filter arrangement
particularly
suitable for use in a compact or hand-holdable vacuum cleaner. A further
object of an
aspect of the invention is to provide a vacuum cleaner comprising such a
motor, fan
and filter arrangement.
Accordingly, in a first aspect, the present invention provides a motor, fan
and
filter arrangement for a vacuum cleaner, comprising: a motor; a fan connected
to an
output shaft of the motor and having an axial air intake; and a filter;
wherein the fan is
arranged with its axial intake facing the motor; and the motor is housed
within the filter.
Such an arrangement allows the motor to be positioned within the filter in a
reversed
direction in comparison to the conventional arrangement, so that clear air
from the filter
is drawn over the motor before encountering the fan. The fan may thus still be
located
outside the filter by protruding therefrom on the output shaft of the motor,
so that air
expelled by the fan remains unimpeded by the filter and may still pass easily
to the
clean air outlet of the vacuum cleaner. Moreover, since the clean air from the
filter is
drawn over the motor before it encounters the fan, a beneficial side-effect of
cooling
the motor with air from the filter is also provided, unlike in the
conventional
arrangement of Fig. 1, where if the motor were to be cooled with air expelled
by the
fan, the outflow of air from the fan would have to be re-routed in order to
pass over the
motor. This would require the flow of air to change direction, thereby
introducing
aerodynamic resistance into the airflow and reducing the overall efficiency of
the
vacuum cleaner. In contrast, the motor, fan and filter arrangement of the
invention
does not require the air expelled by the fan to be re-routed, and since the
motor is
contained within the filter, it makes efficient use of space and is therefore
particularly
suitable for use in a compact or hand-holdable vacuum cleaner.
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The motor, fan and filter arrangement of the invention also has the
significant
advantage that whereas the fan in the conventional arrangement of Fig. 1 is an
impeller which expels air out tangentially, the fan in the motor, fan and
filter
arrangement of the invention can be either an impeller or a propeller, the
latter of
which expels air out axially from the opposite side to the face towards which
air is
drawn in axially by the fan. This is because in the conventional arrangement,
the
rear face of the fan is obstructed by the motor, so the outflow of air from
the fan must
be directed tangentially, whereas in the motor, fan and filter arrangement of
the
invention, the rear face of the fan is unobstructed, so that air from the fan
can be
expelled either tangentially, as in an impeller, or axially, as in a
propeller. This gives
far greater versatility in overall design of the airflow within a vacuum
cleaner
comprising such a motor, fan and filter arrangement to direct the air expelled
by the
fan as desired.
The motor, fan and filter arrangement of the invention may further comprise an
air-permeable housing interposed between the motor and the filter. Thus, if
the filter
is removable, for example in order to clean or replace it, the housing
prevents a user
from gaining access to the motor and fan, but air is still able to pass
through the
housing from the filter to the fan.
Alternatively the motor housing may be
impermeable to air, in which case the arrangement may further comprise a
grille
located between the motor and the fan, through which grille the output shaft
of the
motor passes. Thus, the impermeable housing completely prevents a user from
gaining access to the electrical components of the motor, but air may still
pass
through the grille from the filter to the fan. This alternative is safer for a
user than an
air-permeable motor housing, but has the countervailing disadvantage that the
motor
is not cooled by air from the filter.
Preferably, the output shaft of the motor extends from within the filter and
an
end of the output shaft is mounted on a bearing located on an opposite side of
the
-fan-from-the motor.-In-this way, th_e_axial_intake_to_ the_fan is not blocked
by either the
motor or the bearing, which improves the aerodynamic efficiency of the airflow
into
the fan, and the extended motor output shaft is supported by the bearing,
which
prevents the extended shaft from vibrating under any potential imbalance in
the fan
as it rotates.
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In a second aspect, the present invention also provides a vacuum cleaner
comprising: a motor; a fan connected to an output shaft of said motor and
having an
axial intake; and a filter, wherein the fan is arranged with said axial intake
facing said
motor and the motor is housed within said filter and wherein the vacuum
cleaner is a
5 hand-
holdable vacuum cleaner comprising a main body portion, a handle and a dust
collection chamber oriented orthogonally to the longitudinal axis of said main
body
portion, wherein, in use of the vacuum cleaner, said dust collection chamber
is held
substantially horizontally and wherein said main body portion is pivotable
relative to
said handle about an axis of said dust collection chamber.
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:
Fig. 1 is a cross-sectional view of a conventional motor, fan and filter
arrangement for a vacuum cleaner;
Fig. 2A is an isometric view of a motor and fan suitable for use in a motor,
fan
and filter arrangement according to an embodiment of the invention;
Fig. 2B is a plan view of the motor and fan shown in Fig. 2A;
Fig. 2C is an end elevational view of the motor and fan of Fig. 2A looking in
the
direction of the arrow labelled "Y" in Fig. 2B;
Fig. 2D is a cross-sectional view of the motor and fan of Fig. 2A along the
line
A-A' represented in Fig. 2B;
Fig. 3 is an isometric view of a first embodiment of a vacuum cleaner
comprising a motor, fan and filter arrangement according to the invention;
Fig. 4 is close-up isometric view of a central portion of the vacuum cleaner
shown in Fig. 3;
Fig. 5 is an exploded view of the central portion of the vacuum cleaner shown
in Fig. 4;
Fig. 6 is a cross-sectional view through the central portion of the vacuum
cleaner shown in Fig. 4;
Fig. 7 is a perspective view of a second embodiment of a vacuum cleaner
comprising a motor, fan and filter arrangement according to the invention;
Fig. 8 is a perspective view from below of the hand-holdable vacuum of Fig. 7;
Fig. 9 is a perspective view of the underside of the hand-holdable vacuum
cleaner of Fig. 7;
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Fig. 10 is an exploded view of the major components of the hand-holdable
vacuum cleaner of Fig. 7;
Fig. 11 is a perspective view of a third embodiment of a vacuum cleaner
comprising a motor, fan and filter arrangement according to the invention;
Figs. 12A, 12B and 12C are perspective views of the hand-holdable vacuum
cleaner of Fig. 11, respectively showing the pivotable nose thereof in 180,
360 and
135 degree positions relative to the main axis of the vacuum cleaner;
Fig. 13 is an exploded view of the major components of the hand-holdable
vacuum cleaner of Fig. 11.
Firstly referring to Figs. 2A to 2D, these show a motor and fan suitable for
use
in a motor, fan and filter arrangement according to an embodiment of the
invention.
Motor 10 has an output shaft 12 on which is mounted fan 20. Electrical power
is
supplied to motor 10 through electrical contacts 14, 16, so that during
operation of
the motor, air passes over motor 10 in the direction of the arrows indicated
in Fig. 2A
axially into the intake or "eye" 24 of fan 20, which is an impeller and which
therefore
expels the air out tangentially. An end of output shaft 12 remote from motor
10 is
mounted on a bearing 22 which supports output shaft 12, preventing it from
vibrating
under any potential imbalance in fan 20 as it rotates. As may best be seen in
the
plan view of Fig. 2B, motor output shaft 12 has a length sufficiently great to
allow the
free flow of air around motor 10 into intake 24 unimpeded, and as may further
be
seen in the end-on view of Fig. 2C, axial intake 24 of fan 20 has a diameter
greater
than motor 10, so that a circumferential portion of intake 24 presents itself
completely
unobstructed by motor 10. Fig. 2B also indicates by means of the arrow
labelled "X"
the usual length of a motor output shaft found in a conventional motor and fan
arrangement suitable for use in a vacuum cleaner. In
such a conventional
arrangement, bearing 22 is generally not required because the shorter length
of the
motor output shaft makes the shaft stiffer and therefore less susceptible to
vibration
caused by any potential imbalance in the fan as it rotates. A conventional
motor may
however be adapted_for us.e in a matocian_and filter arrangement according to
the
invention by the addition of an extension piece to the shorter motor output
shaft
thereof and/or a coupling to another shaft which carries the fan. The arrow
labelled
"X" in Fig. 2B also indicates the approximate location of where a grille (not
shown)
may be located between motor 10 and fan 20, through which grille output shaft
12 of
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the motor may pass, thereby screening fan 20 off from access by a user. This
grille
may be used to supply additional support for the motor output shaft.
Turning next to Fig. 3, there is shown a first embodiment of a vacuum cleaner
comprising a motor, fan and filter arrangement according to the invention.
This is a
compact stick-shaped vacuum cleaner (or "stick-vac") previously described in
more
detail in European Patent No. EP 1955631, from which the present application
claims
priority. Vacuum cleaner 100 comprises an upper body portion 50, a lower body
portion 60, a floorhead 70, a handle 80 and a dust-filtering portion 90. Upper
body
portion 50 is pivotable relative to lower body portion 60 about an axis of
dust filtering
portion 90. Floorhead 70 comprises a dirty air inlet and a pair of floor-
running wheels
71, 72, whereas handle 80 comprises an electrical on/off switch 81. Dust
filtering
portion 90 comprises a tangential entry duct 91, a dust collection chamber, a
clean air
outlet, and a motor, fan and filter arrangement according to the invention,
which is
described in greater detail below in relation to Figs. 4 to 6. During
operation of
vacuum cleaner 100, a user activates the motor contained in dust filtering
portion 90
by operating electrical on/off switch 81, which is connected to the motor via
electrical
wires running inside upper body portion 50. This causes dirty air to pass from
the dirty
air inlet of floorhead 70 up a duct located within lower body portion 60 to
tangential
entry duct 91, whence it enters the dust collection chamber of dust filtering
portion 90.
The dust collection chamber may best be seen in Fig. 4, where it is labelled
by
reference numeral 92. Dirty air entering dust collection chamber 92 via
tangential
entry duct 91 swirls around a cylindrical coarse filter 93 in a clockwise
fashion as
indicated by the arrows in Fig. 4. Coarse filter 93 surrounds and contains a
smaller
cylindrical fine filter 30, so that between them, coarse filter 93 and fine
filter 30 act to
filter out successively smaller particles of dust and dirt entrained with the
dirty air,
which therefore start to collect in dust collection chamber 92. An end face of
dust
collection chamber 92 comprises a door 94 mounted on a hinge 99 and closed via
a
series of latches 95, which are designed to engage with a corresponding lip on
a rim of
dust filtering portion 90. When door 94 is closed, a series of first component
parts 96
of a filter cleaning mechanism provided on an end face of fine filter 30
engage with a
corresponding series of second component parts 97 of the filter cleaning
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mechanism provided on the inside face of door 94. The engagement of these
first
and second component parts 96, 97 allows a user to operate the filter cleaning
mechanism when the door is closed via a wheel (not visible in Fig. 4, but
labelled 940
in Fig. 6) located on the outside face .of door 94. A resilient seal 98 made
of
polyethylene, rubber or a similar elastomeric material provided around the
circumference of door 94 ensures that the door closes in an airtight fashion.
Turning now to Fig. 5, there is shown an exploded view of the central portion
of
the vacuum cleaner of Fig. 3 indicating how fine filter 30 is contained within
coarse
filter 93. Within fine filter 30, there may also be seen a housing 18 of motor
10.
Housing 18 is made air-permeable by the presence of a plurality of first vents
180
formed in an end face thereof. Thus, clean air passing through fine filter 30
may
enter housing 18 via vents 180. Fig. 6 shows a cross-section through the
central
portion of this vacuum cleaner in greater detail. As may be seen in Fig. 6,
motor
output shaft 12 in this embodiment is constructed from an extension piece
added to
the shorter motor output shaft of a conventional motor. This drawing also
shows how
a plurality of second vents 181 formed in the opposite end face of housing 18
from
the plurality of first vents 180 allows clean air to exit housing 18 and pass
around
motor output shaft 12 towards fan 20, which finally directs the clean air back
to
atmosphere via clean air outlet vents 900a, 900b. Thus, the entire filtering
process
from the entry of dirty air via tangential entry duct 91 to the exit of clean
air via clean
air outlets 900a, 900b, including motor 10, motor housing 18, fan 20, fine
filter 30,
coarse filter 93, filter cleaning mechanism 96, 97, 940 and dust collection
chamber
92, is all contained within the particularly compact, substantially
cylindrical body of
dust filtering portion 90 of the vacuum cleaner.
Fig. 7 shows a second embodiment of a vacuum cleaner comprising a motor,
fan and filter arrangement according to the invention, which is a hand-
holdable
vacuum cleaner 200. As shown in Fig. 7, vacuum cleaner 200 comprises a main
-body-portion-260,-a handle 280, and-a dust collection chamber 292 containing
a filter
assembly 230, both of which are oriented orthogonally to the longitudinal axis
of main
body portion 260, such that in use of the vacuum cleaner, dust collection
chamber
292 and filter assembly 230 are held substantially vertically, and dust
collects in the
bottom of dust collection chamber 292. The view from below of Fig. 8 of hand-
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holdable vacuum cleaner 200 shows how dust collection chamber 292 is emptied.
Dust collection chamber 292 comprises a door 294 hinged on an end face
thereof,
which opens in the direction of the arrow shown in Fig. 8. Dust collection
chamber
292 is transparent to allow a user to view dust swirling around filter
assembly 230
during operation of the vacuum cleaner and also to see when dust collection
chamber 292 is full and therefore needs emptying. The view from below of Fig.
8
also shows a dirty air inlet 270 of the vacuum cleaner 200.
Fig. 9 shows filter assembly 230 removed from within dust collection chamber
292 to reveal an air permeable motor housing 218 contained therein. Motor
housing
218, which in turn contains a motor not visible in Fig. 9, has a plurality of
first vents
218a formed in an end face thereof to allow clean air which has passed through
filter
assembly 230 to enter the motor housing. The exploded view of Fig. 10 shows
the
major internal components of hand-holdable vacuum cleaner 200. As shown in
Fig.
10, main body portion 260 and handle 280 are composed from two half-clamshells
261, 262. This reveals how dirty air inlet 270 is placed in fluid
communication with
dust collection chamber 292 via a duct 273 integrally moulded into lower half-
clamshell 262. Duct 273 is shaped so as to provide a tangential inlet to dust
collection chamber 292. Space within lower half-clamshell 262 either side of
duct
273 is used to house a plurality of rechargeable cells 264, which are
electrically
connected via wires 266 to a jack plug charger socket 268. This allows the
bank of
cells 264 to be recharged by means of a conventional removable jack plug
charger
265 (which does not form part of the vacuum cleaner 200). Cells 264 are also
electrically connected via wires 282 with an electrical on/off switch 281
mounted in
handle 280. Electrical on/off switch 281 has a cover 284 to insulate it from a
user.
Cells 264 and on/off switch 281 are also in electrical connection via wires
216 with
motor 10, such that when a user operates on/off switch 281, motor 10 is
activated by
cells 264, causing fan 20 mounted on motor output shaft 12 to begin to rotate
and
dirty air to start to be drawn up duct 273. Motor output shaft 12 is supported
on a
-30 bearing 22 .to prevent_itico.m_vibrating. Motor 1.0itself is _contained
within a housing
218. This has a separate end cap 220 for ease of manufacture. Housing 218, 220
is
in turn contained within filter assembly 230 inside dust collection chamber
292. The
filter assembly 230 has a frusto-conical shape to act in concert with dust
collection
chamber 292 as a cyclonic separator.
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Fig. 10 also shows door 294 of dust collection chamber 292, which door is
mounted on a hinge 299 and sealed by a resilient seal 298 made of
polyethylene,
rubber or a similar elastomeric material, in order to ensure that the door 294
closes in
an airtight fashion. Thus, during operation of vacuum cleaner 200, dirty air
entering
5 dust collection chamber 292 via duct 273 from dirty air inlet 270 swirls
around filter
assembly 230 and the clean air which passes therethrough is drawn through air-
permeable motor housing 218 by fan 20, which directs the air through a
plurality of
holes 291 formed in an end face of the dust collection chamber opposite door
294
before it is expelled from a plurality of clean air outlet vents 290 formed in
half-
10 clamshell 261. In order to allow a user to empty dust collection chamber
292, half-
clamshell 261 is also provided with a hole 263 revealing a spring-loaded
release
button 244 which acts against the force of a spring 246 to depress a push rod
248.
This in turn pushes door 294 open about hinge 299. In order to allow a user to
close
door 294 again once the dust collection chamber has been emptied, door 294 is
provided with a latch 250 that engages with a lip formed on the rim of dust
collection
chamber 292.
Finally turning to Fig. 11, there is shown a third embodiment of a vacuum
cleaner comprising a motor, fan and filter arrangement according to the
invention,
which is a hand-holdable vacuum cleaner 300. As shown in Fig. 11, vacuum
cleaner
300 comprises a main body portion 360, a handle 380, and a dust collection
chamber
392 designed to contain a filter assembly 330 therein, which is shown removed
therefrom in Fig. 11. When mounted in dust collection chamber 392, both filter
assembly 330 and dust collection chamber 392 are oriented orthogonally to the
longitudinal axis of main body portion 360, such that in use of the vacuum
cleaner,
dust collection chamber 392 and filter assembly 330 are held substantially
horizontally, and dust collects in the lower side of dust collection chamber
392. Dust
collection chamber 392 is transparent to allow a user to view dust swirling
around
filter assembly 330 during operation of the vacuum cleaner and also to see
when
_d.ust.colle_ction chamber 392 is fu.11..and therefore_needs..e.mpfying
Fig. 11 also shows how dust collection chamber 392 can be emptied by means
of a door 394 hinged on an end face thereof. Fig. 11 also reveals an air
permeable
motor housing 318 contained inside filter assembly 330. Motor housing 318,
which in
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11
turn contains a motor not visible in Fig. 11, has a plurality of vents 318a
formed in an
end face thereof to allow clean air which has passed through filter assembly
330 to
enter the motor housing.
Vacuum cleaner 300 is able to pivot about the central axis of dust collection
chamber 392 in a manner similar to that described in European patent
publication no.
1 752 076 A, also in the name of the present applicant. Thus, as shown in
Figs. 12A
to 120, vacuum cleaner 300 may be folded as indicated by the arrows in Figs.
12B
and 12C from the 180 degree position shown in Fig. 12A into the 360 degree
position
shown in Fig. 12B, for example for storage or shipping, or into the 135 degree
position shown in Fig. 13C, for example to permit access to awkward corners.
Fig.
12 C also reveals a dirty air inlet 370 of vacuum cleaner 300.
The exploded view of Fig. 13 shows the major internal components of hand-
holdable vacuum cleaner 300. As shown in Fig. 13, main body portion 360 is
formed
from upper and lower components 361 and 362, respectively, and handle 380 is
composed from two half-clamshells 385, 386. Dirty air inlet 370 is placed in
fluid
communication with dust collection chamber 392 via a duct 373 contained within
main body portion 360 and which enters dust collection chamber 392
tangentially.
Space within lower body component 362 beneath duct 373 is occupied by a
plurality
of rechargeable cells 364, which are electrically connected via wires 366 to a
jack
plug charger socket 368. This allows the bank of cells 364 to be recharged by
means of a conventional removable jack plug charger 365 (which does not form
part
of the vacuum cleaner 300). Cells 364 are also electrically connected via
wires 382
with an electrical on/off switch 381 mounted in handle 380. Electrical on/off
switch
381 has a cover 384 to insulate it from a user. Cells 364 and on/off switch
381 are
also in electrical connection via wires 316 with motor 10, such that when a
user
operates on/off switch 381, motor 10 is activated by cells 364, causing fan 20
mounted on motor output shaft 12 to begin to rotate and dirty air to start to
be drawn
_30
_up_duci 373. Be_causemacuurn_cleaner 300__can_pivot in the manner described
above
in relation to Figs. 12A to 12C, wires 382 connected to on/off switch 381
terminate in
a pair of electrical contacts 388, which remain in sliding contact with a
corresponding
pair of conducting tracks 389 mounted on dust collection chamber 392. Thus, an
electrical circuit can always be established between cells 364, on/off switch
381 and
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motor 10, regardless of the angle of orientation of main body 360 relative to
handle
380.
As can also be seen in Fig. 13, a bearing 22 located at the end of motor
output
shaft 12 remote from motor 10 supports motor output shaft 12 to prevent it
from
vibrating. Motor 10 itself is contained within housing 318. This has a
separate end
cap 320 for ease of manufacture, in which can be seen the vents 380 to allow
clean
air which has passed through filter assembly 330 to enter the motor housing.
Housing 318, 320 is in turn contained within filter assembly 330 inside dust
collection
chamber 392. The filter assembly 330 has a frusto-conical shape to act in
concert
with dust collection chamber 392 as a cyclonic separator.
Fig. 13 also shows door 394 of dust collection chamber 392, which door has a
spring-loaded latch 344 that can be depressed against the force of a spring
346 to
open door 394. Latch 344 engages with a lip formed on the rim of dust
collection
chamber 392 to allow the door to be closed again. The door is sealed by a
resilient
seal 398 made of polyethylene, rubber or a similar elastomeric material, in
order to
ensure that the door 394 closes in an airtight fashion. Thus, during operation
of
vacuum cleaner 300, dirty air entering dust collection chamber 392 via duct
373 from
dirty air inlet 370 swirls around filter assembly 330 and the clean air which
passes
therethrough is drawn through air-permeable motor housing 318 by fan 20, which
directs the air through a plurality of holes 391 formed in an end face of the
dust
collection chamber opposite door 394 before it is expelled from a plurality of
clean air
outlet vents 390 formed in half-clamshell 385. To allow a user to adjust the
angle of
main body 360 relative to handle 380, half-clamshell 386 is finally also
provided with
a ratchet wheel 350 having a plurality of teeth formed on the inner
circumference
thereof. These act to lock main body 360 in one of a plurality of orientations
relative
to handle 380. Ratchet wheel 350 is also provided with a spring-loaded release
button 352 which can be depressed against the force of a spring 354 to allow a
user
-to-disengage the- teeth and therefore-rotate main body 360 from one
orientation into
another. Releasing button 352 again relocks main body in the new orientation
relative to handle 380.
