U.S. patent number RE42,873 [Application Number 12/777,358] was granted by the patent office on 2011-11-01 for hand-holdable vacuum cleaners.
This patent grant is currently assigned to Black & Decker Inc.. Invention is credited to Eric Coburn, David Rowntree, Andrew Walker.
United States Patent |
RE42,873 |
Walker , et al. |
November 1, 2011 |
**Please see images for:
( Certificate of Correction ) ** |
Hand-holdable vacuum cleaners
Abstract
There is provided a hand-holdable vacuum cleaner, comprising: an
electric motor; an electrical on-off switch for operating said
motor; a fan connected to an output shaft of said motor; an airflow
pathway comprising an inlet for dirty air, an outlet for clean air,
and a collection chamber located in fluid communication between
said inlet and said outlet; means for separating out debris
entrained with dirty air entering via said inlet and depositing the
debris in said collection chamber; and means for adjusting an angle
of said inlet relative to a main axis of said vacuum cleaner;
wherein the vacuum cleaner further comprises a rigid, elongate nose
having said inlet at one end thereof, said nose being pivotable
relative to said main axis through an angle of at least 135
degrees. The elongate nose can be pivoted from a first, folded
position in which it is angled alongside the main axis of the
vacuum cleaner, substantially parallel thereto, allowing the vacuum
cleaner to be stored in a very compact overall space, to a second,
extended position in which it is angled by only a small amount or
not at all from the main axis of the vacuum cleaner to provide an
extension thereof. Secondly, since the nose is rigid and elongate
and has the dirty air inlet located at one end thereof, it may be
introduced into narrow spaces without any need to be supported by a
hand of a user, unlike a flexible hose extension known from prior
art hand-holdable vacuum cleaners.
Inventors: |
Walker; Andrew (Newton Hall,
GB), Coburn; Eric (Coxhoe, GB), Rowntree;
David (Newton Hall, GB) |
Assignee: |
Black & Decker Inc.
(Newark, DE)
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Family
ID: |
35502521 |
Appl.
No.: |
12/777,358 |
Filed: |
May 11, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
11495742 |
Jul 28, 2006 |
7370387 |
May 13, 2008 |
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Foreign Application Priority Data
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Aug 11, 2005 [EP] |
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05255024 |
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Current U.S.
Class: |
15/344;
15/354 |
Current CPC
Class: |
A47L
9/2873 (20130101); A47L 9/125 (20130101); A47L
9/2857 (20130101); A47L 9/2842 (20130101); A47L
9/20 (20130101); A47L 9/02 (20130101); A47L
9/244 (20130101); A47L 5/24 (20130101); A47L
9/0009 (20130101); A47L 9/1683 (20130101); A47L
9/106 (20130101); A47L 9/1666 (20130101) |
Current International
Class: |
A47L
5/24 (20060101); A47L 5/34 (20060101) |
Field of
Search: |
;15/344,350,354 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1752076 |
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Feb 2007 |
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EP |
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371531 |
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Apr 1932 |
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GB |
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2001112681 |
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Apr 2001 |
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JP |
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Primary Examiner: Thomas; David B
Attorney, Agent or Firm: Harness, Dickey & Pierce,
P.L.C.
Claims
The invention claimed is:
1. A hand-holdable vacuum cleaner comprising: an electric motor
(12); .[.an electrical on-off switch (42) for operating said
motor;.]. a fan (14) connected to an output shaft (16) of said
motor; an airflow pathway comprising an inlet for dirty air (32),
an outlet for clean air, and a collection chamber (20) located in
fluid communication between said inlet and said outlet; means for
separating out debris entrained with dirty air entering via said
inlet and depositing the debris in said collection chamber; and
means for adjusting an angle of said inlet relative to a main axis
(X-X') of said vacuum cleaner; characterized by: a rigid, elongate
nose (30) having said inlet at one end thereof, said nose being
pivotable relative to said main axis (X-X') through an angle of at
least 135 degrees.
2. A vacuum cleaner according to claim 1, wherein the nose (30) is
pivotable relative to the main axis (X-X') of the vacuum cleaner
through an angle of more than 180 degrees.
3. A vacuum cleaner according to claim 1, wherein: the nose (30) or
a part (22) of the vacuum cleaner rigidly connected thereto
comprises first engagement means; a part (24,26) of the vacuum
cleaner rigidly connected to a main body (10) thereof housing the
motor and the fan comprises second engagement means adapted to
engage with said first engagement means; and the vacuum cleaner
further comprises a resiliently biassed button (34) operable to
disengage the first engagement means from the second engagement
means.
4. A vacuum cleaner according to claim 3, wherein the nose (30)
further comprises a rigid telescopic extension tube (38).
5. A vacuum cleaner according to claim 1, wherein: the separating
means comprises a filter (50) located within the collection chamber
(20); the collection chamber (20) has a substantially cylindrical
shape about a central axis (Y-Y') oriented at right angles to the
main axis (X-X') of the vacuum cleaner; the filter (50) is arranged
in an axially symmetric fashion concentric with the central axis
(Y-Y') of the collection chamber (20); the pivotable nose (30) is
arranged to pivot about the central axis (Y-Y') of the collection
chamber; a dirty air outlet (36) from the nose (30) is arranged to
enter the collection chamber (20) on a cylindrical side wall (28)
thereof; and a clean air outlet (21) from the collection chamber
(20) is located within said filter (50).
6. A vacuum cleaner according to claim 5, wherein the filter (50)
has a conical or frusto-conical shape.
7. A vacuum cleaner according to claim 5, wherein the collection
chamber (20) comprises a hinged door (60) on an end face (26)
thereof opposite to said clean air outlet (21).
8. A vacuum cleaner according to claim 7, wherein the door (60) is
held by a main body (10) of the vacuum cleaner which houses the
motor (12) and the fan (14).
9. A vacuum cleaner according to claim 8, wherein: the filter (50)
located within the collection chamber (20) is rotatable relative to
the door (60) when the nose (30) is pivoted; an interior face (68)
of the door (60) is provided with a series of radial tangs (70); an
end face (52) of the filter (50) adjacent to the interior face (68)
of the door (60) has a corresponding set of radial tangs (72); and
the combined height of the tangs (70, 72) on the interior face of
the door and on the end face of the filter is greater than the
separation between the interior face (8) of the door and the end
face (52) of the filter.
10. A vacuum cleaner according to claim 7, wherein: the filter (50)
is held immovable relative to the main body (10) of the vacuum
cleaner during operation thereof; the door (60) is rotatable
relative to the filter (50) when the nose (30) is pivoted; an
interior face (68) of the door is provided with a series of radial
tangs (70); an end face (52) of the filter adjacent to the interior
face of the door has a corresponding set of radial tangs (72); and
the combined height of the tangs (70, 72) on the interior face of
the door and on the end face of the filter is greater than the
separation between the interior face (68) of the door and the end
face (52) of the filter.
11. A vacuum cleaner according to claim 5, wherein: the collection
chamber (20) comprises a door on the cylindrical side wall (28)
thereof; the filter (50) and an end face (26) of the collection
chamber opposite to the clean air outlet (21) are rotatable
relative to each other when the nose (30) is pivoted; an interior
surface of the end face (26) of the collection chamber is provided
with a series of radial tangs (70); an end face (52) of the filter
adjacent to the interior surface of the end face (26) of the
collection chamber has a corresponding set of radial tangs (72);
and the combined height of the tangs (70, 72) on the interior
surface of the end face of the collection chamber and on the end
face of the filter is greater than the separation between the
interior surface of the end face (26) of the collection chamber and
the end face (52) of the filter.
12. A vacuum cleaner according to claim 5, wherein the filter (50)
is removable and replaceable.
13. A vacuum cleaner according to claim 5, wherein the filter (50)
comprise a plurality of filter elements (51, 53).
14. A vacuum cleaner according to claim 5, wherein the motor (12)
and the fan (14) are oriented in the main body (10) of the vacuum
cleaner with the output shaft (16) of the motor and the fan's axis
of rotation (Z-Z') parallel to the central axis (Y-Y') of the
collection chamber (20) and at right angles to the main axis (X-X')
of the vacuum cleaner.
15. A vacuum cleaner according to claim 14, wherein the fan (14) is
configured as an impeller and the main body (10) of the vacuum
cleaner comprises one or more exhaust vents (18) on the rear (19)
thereof, in a location opposite to the dirty air inlet (32) of the
pivotable nose (30) when the nose is in a fully extended position
at 180 degrees to the main axis (X-X') of the vacuum cleaner.
16. A vacuum cleaner according to claim 1, wherein the vacuum
cleaner is adapted to stand on a rear end (19) of the main body
(10) of the vacuum cleaner.
17. A vacuum cleaner according to claim 16, wherein the vacuum
cleaner is a rechargeable model, and the rear end (19) of the main
body (10) of the vacuum cleaner comprises means for connecting the
vacuum cleaner to a recharging unit (90).
18. A vacuum cleaner according to claim 1, wherein the nose
comprises a one-way valve in the form of a hinged flap composed of
a resilient material.
19. A recharging unit (90) adapted to recharge a vacuum cleaner
according to claim 17.
Description
.Iadd.CROSS REFERENCE TO RELATED APPLICATION.Iaddend.
.Iadd.This application is a Reissue of U.S. Pat. No. 7,370,387 B2,
issued May 13, 2008 that claims the benefit and priority of
European Patent priority document EP 05255024.1, filed Aug. 11,
2006..Iaddend.
FIELD OF THE INVENTION
The present invention relates to hand-holdable vacuum cleaners.
Such vacuum cleaners are well known for collecting dust and dirt,
although wet-and-dry variants which can collect spilled liquids as
well are also known. Typically, they are intended for use in a
domestic environment, although they also find uses in other
environments, such as worksites. Generally, hand-holdable vacuum
cleaners are electrically powered and comprise an electric motor,
an electrical on-off switch for a user to operate said motor, a fan
connected to an output shaft of said 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 and the on-off
switch is set to the "on" position, 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. An example of
such a hand-holdable vacuum cleaner in which the separation means
comprises a filter is disclosed in European patent application no.
EP 1 523 916 in the name of the present applicant.
BACKGROUND OF THE INVENTION
More specifically, the present invention relates to hand-holdable
vacuum cleaners comprising a component part which can be adjusted
to allow the dirty air inlet of the vacuum cleaner to be pointed in
different directions, whilst a user of the vacuum cleaner is able
to hold the vacuum cleaner in the same orientation. This has the
advantages that the vacuum cleaner may be used to access awkward
spaces and can be held more comfortably by orienting a main axis of
the vacuum cleaner to suit the user and adjusting the position of
the dirty air inlet to be in proximity to a surface to be cleaned,
rather than orienting the main axis of the vacuum cleaner to best
suit the surface to be cleaned and requiring the user to hold the
vacuum cleaner in whichever orientation this demands. A
hand-holdable vacuum cleaner of this type, which has a pivotable
nose comprising the dirty air inlet, is disclosed in U.S. Pat. No.
4,573,237.
Hand-holdable vacuum cleaners provided with a flexible hose
attachment which give the same advantages as these are also known.
An example of a hand-holdable vacuum cleaner with such a flexible
hose attachment is described in German utility model no. DE 203 14
544 U. However, these vacuum cleaners have other disadvantages over
vacuum cleaners of the type disclosed in U.S. Pat. No. 4,573,237,
which are as follows. Firstly, the hose attachment must either be
stored on the vacuum cleaner itself, as in DE 203 14 544 U, which
takes up valuable room, or if it is removable, it must be stored
elsewhere, in which case it may become lost or may not be readily
to hand when required. Secondly, the flexible hose attachment must
be supported in use by a hand of a user.
However, whereas vacuum cleaners of the type disclosed in U.S. Pat.
No. 4,573,237 are advantageous for these reasons over hand-holdable
vacuum cleaners provided with a flexible hose attachment, there is
still room for considerable improvement over the type of vacuum
cleaner disclosed in U.S. Pat. No. 4,573,237. Specifically, in
spite of the disadvantages of flexible hose attachments just
stated, a flexible hose attachment can access a wider range of
angles than a vacuum cleaner of the type disclosed in U.S. Pat. No.
4,573,237 and can also access narrower spaces in comparison
thereto.
BRIEF SUMMARY OF THE INVENTION
Accordingly, the present invention has as its object the provision
of an improved hand-holdable vacuum cleaner comprising means for
adjusting an angle of the dirty air inlet thereof relative to a
main axis of the vacuum cleaner, which has improved reach in
comparison to a vacuum cleaner of the type disclosed in U.S. Pat.
No. 4,573,237, but which need not comprise a flexible hose
attachment to achieve the same.
The present invention aims to achieve this object by providing a
hand-holdable vacuum cleaner comprising an electric motor; an
electrical on-off switch for operating said motor; a fan connected
to an output shaft of said motor; an airflow pathway comprising an
inlet for dirty air, an outlet for clean air, and a collection
chamber located in fluid communication between said inlet and said
outlet; means for separating out debris entrained with dirty air
entering via said inlet and depositing the debris in said
collection chamber; and means for adjusting an angle of said inlet
relative to a main axis of said vacuum cleaner; further comprising
a rigid, elongate nose having said inlet at one end thereof, said
nose being pivotable relative to said main axis through an angle of
at least 135 degrees.
A hand-holdable vacuum cleaner with these features has several
advantages, as follows. Firstly, the elongate nose may be pivoted
from a first, folded position in which it is angled alongside the
main axis of the vacuum cleaner, allowing the vacuum cleaner to be
stored in a very compact overall space, to a second, extended
position in which it is angled by only a small amount or not at all
to the main axis of the vacuum cleaner to provide an extension
thereof. Secondly, since the nose is rigid and elongate and has the
dirty air inlet located at one end thereof, it may be introduced
into narrow spaces without any need to be supported by a hand of a
user. This is advantageous over a flexible hose attachment of the
prior art, which must be supported by a hand of a user and
consequently cannot be introduced into spaces which are too narrow
or awkward to provide access to a human hand. Thirdly, since the
nose can pivot through an angle relative to the main axis of the
vacuum cleaner of at least 135 degrees, this allows the vacuum
cleaner to be held comfortably by a user in a single orientation,
but have the dirty air inlet thereof directed in a very wide
variety of different directions.
Preferably, the nose is pivotable relative to the main axis of the
vacuum cleaner through an angle of more than 180 degrees. This
allows the nose not only to be bent at an acute or obtuse angle
relative to the main axis of the vacuum cleaner, but also at a
reflex angle, allowing the vacuum cleaner to be held by a user in
the same orientation as for acute and obtuse angles, but for the
dirty air inlet to be directed upwardly towards the user, which
allows the vacuum cleaner to be comfortably used for cleaning under
furniture, for example.
It is also desirable that the pivotable nose can be releasably
engaged in one or more fixed positions throughout its full range of
angles of pivot, for example in the folded-back position of 0
degrees, in the straight-line position of 180 degrees and in a
number of other positions such as 45, 90, 135, 225 and 270 degrees.
This can be achieved by providing the pivotable nose or a part of
the vacuum cleaner rigidly connected thereto with first engagement
means and a part of the vacuum cleaner rigidly connected to a main
body thereof housing the motor and the fan with second engagement
means adapted to engage with the first engagement means, and also
by providing the vacuum cleaner with a resiliently
.[..quadrature.iased.]. .Iadd.biased .Iaddend.button which a user
can depress to disengage the first engagement means from the second
engagement means, thereby releasing the pivotable nose from
engagement in one of the aforementioned positions.
In a preferred embodiment which gives the vacuum cleaner even
greater access to restricted spaces, the nose can further comprise
a rigid telescopic extension tube. Such an extension tube on the
nose of a hand-holdable vacuum cleaner is known, for example, from
U.S. Pat. No. 4,610,048 and international patent publication no.
WO2004/069021. However, the combination of such an extension tube
with a nose which can pivot through an angle relative to the main
axis of the vacuum cleaner of at least 135 degrees is not known
from the prior art and gives the vacuum cleaner greatly increased
versatility in its ability to access awkward spaces.
The separating means of the vacuum cleaner may comprise one or more
filters and/or a cyclonic separation device. In a preferred
embodiment, the separating means comprises a filter located within
the collection chamber, and the collection chamber has a
substantially cylindrical shape about a central axis oriented at
right angles to the main axis of the vacuum cleaner, with the
filter arranged in an axially symmetric fashion concentric with the
central axis of the collection chamber. In this embodiment, the
pivotable nose is also arranged to pivot about the central axis of
the collection chamber and a dirty air outlet from the nose is
arranged to enter the collection chamber on a cylindrical side wall
thereof. Finally, the clean air outlet from the collection chamber
is located within said filter. Thus during operation of the vacuum
cleaner of this embodiment, dirty air enters the collection chamber
from the dirty air outlet of the nose at a tangent to the
cylindrical side wall of the collection chamber regardless of the
angle of the pivotable nose relative to the main axis of the vacuum
cleaner, and swirls around the centrally located filter which
separates out dust and dirt entrained with the dirty air and
deposits these in the collection chamber, before the clean air
exits the collection chamber from the clean air outlet located
within the filter. This arrangement has several advantages, as
follows. Firstly, before it enters the collection chamber, the
dirty air travels in a straight line regardless of the angle of the
pivotable nose, which has the effect of maximising the velocity of
the dirty air and minimising turbulence, therefore improving the
vacuum cleaner's ability to pick up dirt. Secondly, the dirty air
always enters the collection chamber tangentially and since the
collection chamber has a substantially cylindrical shape, this
enables the collection chamber to act as a cyclonic separator,
flinging the entrained dirt outwards centrifugally as it swirls
around the centrally located filter. This cyclonic separation aids
the operation of the filter and may be optimised still further by
the filter being provided with a conical or frusto-conical shape,
which helps to separate out different sizes of dirt particle at
different locations along the central axis of the filter.
In a further preferred embodiment of the embodiment of the vacuum
cleaner just described, the collection chamber comprises a hinged
door on an end face thereof opposite to said clean air outlet. This
allows the collection chamber to be emptied of accumulated dust and
dirt by a user merely opening the hinged door and tipping the
contents of the collection chamber out. This has the advantage that
the user does not have to touch either the dust and dirt or any
components of the vacuum cleaner which come into contact with dust
and dirt in order to empty the vacuum cleaner.
Preferably the door is held by a main body of the vacuum cleaner
which houses the motor and the fan. Thus the door maintains the
same orientation relative to the main body of the vacuum cleaner
regardless of the angle of the pivotable nose. This is more
convenient and less confusing for a user.
If the door is held by the main body of the vacuum cleaner in this
fashion, it is also preferable for the filter located within the
collection chamber to be rotatable relative to the door when the
nose is pivoted and for an interior face of the door to be provided
with a series of radial tangs and for an end face of the filter
adjacent to the interior face of the door to have a corresponding
set of radial tangs. If the combined height of the tangs on the
interior face of the door and on the end face of the filter is
greater than the separation between the interior face of the door
and the end face of the filter, the two facing sets of tangs will
overlap each other, such that when the pivotable nose is rotated
relative to main axis of the vacuum cleaner, the tangs of the
filter will engage with the tangs on the door and agitate the
filter, thereby dislodging dust and dirt adhering to the filter and
causing it to be deposited in the collection chamber. This filter
cleaning mechanism has the advantage that it allows the filter to
be cleaned by a user merely pivoting the nose of the vacuum cleaner
relative to the main body thereof and without the need to touch the
dirty filter at all.
Alternatively, the same filter cleaning effect may be achieved by
the filter being held immovable relative to the main body of the
vacuum cleaner during operation and the door being rotatable
relative to the filter when the nose is pivoted, provided that sets
of opposing tangs are provided on the interior face of the door and
on the end face of the filter in a similar fashion.
Alternatively, the collection chamber may comprise a door on the
cylindrical side wall thereof instead of on an end face thereof
opposite to the clean air outlet. This is less preferred because
the collection chamber is less easy to empty and the door opening
mechanism may interfere with rotation of the pivotable nose.
However, in this case, the same filter cleaning effect may be
achieved by providing a series of radial tangs on the end face of
the collection chamber opposite to the clean air outlet instead of
on the door.
All of the above alternative arrangements for filter cleaning are
unified by the common inventive concept of opposing and overlapping
sets of radial tangs provided on the filter and on another part of
the vacuum cleaner which are caused to rotate relative to each
other when the nose of the vacuum cleaner is pivoted in order to
agitate the filter. However, in yet another alternative arrangement
of a filter cleaning mechanism, regardless of whether a door is
located on the end face of the collection chamber opposite to the
clean air outlet or on the cylindrical side wall thereof, instead
of the set of radial tangs on the filter and the set of tangs on
another part of the vacuum cleaner being caused to rotate relative
to each other when the nose is pivoted, one of the sets of tangs
may instead be coupled to a filter cleaning wheel which a user can
rotate in order to cause the set of tangs coupled thereto to rotate
relative to the other set of tangs, in the manner already disclosed
in EP 1 523 916 in the name of the present applicant.
Notwithstanding the foregoing, the filter may still be removable
and replaceable when the vacuum cleaner is not in use, so that a
worn, damaged or permanently clogged filter may be substituted by a
new one.
The filter may also comprise a plurality of filter elements, such
as a course filter for filtering larger particles of dirt and a
fine filter contained therein for filtering finer particles of dust
from the airflow pathway. The filter elements may themselves be
independently removable and replaceable.
In embodiments in which the collection chamber has a substantially
cylindrical shape about a central axis oriented at right angles to
the main axis of the vacuum cleaner, it is also preferable for the
motor and the fan to be oriented in the main body of the vacuum
cleaner with the output shaft of the motor and the fan's axis of
rotation parallel to the central axis of the collection chamber and
at right angles to the main axis of the vacuum cleaner. This is in
contrast to the conventional orientation of the motor and the fan
in a hand-holdable vacuum cleaner, which is usually along or
parallel to the main axis of the vacuum cleaner (as in, for
example, EP 1 523 916). This new arrangement has several advantages
over the conventional layout, as follows. Firstly, it is beneficial
for the overall compactness of the vacuum cleaner, considering that
the collection chamber is already oriented at right angles to the
main axis of the vacuum cleaner. Secondly, it means that the fan
can be located on the same side of the vacuum cleaner as the clean
air outlet from the collection chamber and in close proximity
thereto, thereby shortening the airflow pathway between these two
components, which improves the overall speed and efficiency of the
vacuum cleaner in operation. Thirdly, if the fan is configured as
an impeller which draws air in axially thereto and expels air out
radially therefrom, the main body of the vacuum cleaner can also be
provided with one or more exhaust vents on the rear of the main
body, i.e. in a location opposite to the dirty air inlet of the
pivotable nose when the nose is in its fully extended or 180-degree
position. In this way, air expelled by the fan will travel in a
straight-line path from the fan to the exhaust vents without having
to be directed around any corners, but is nonetheless also directed
away from a surface to be cleaned in completely the opposite
direction to the dirty air inlet to the nose, which avoids
disturbing dust and dirt on the surface to be cleaned with the
exhausted air. The same desirable objective of not disturbing dust
and dirt on a surface to be cleaned with clean air from the exhaust
vents on a hand-holdable vacuum cleaner of a conventional layout
can only be achieved if the exhaust vents are also located on the
rear of the main body of the vacuum cleaner. However in this case,
air expelled by the impeller has to be directed around one or more
corners within the body in order to reach the exhaust vents, since
the orientation of the fan's axis of rotation parallel to the main
axis of the vacuum cleaner means that the fan expels air at right
angles to the main axis, sideways to the main body. This both
increases the length of the airflow pathway between the fan and the
exhaust vents in the conventional arrangement and also increases
the turbulence of the exhausted air. Accordingly, the proposed new
arrangement has improved speed and efficiency of airflow in
comparison thereto, as well as reduced noise, which is generated by
turbulent air.
In another preferred embodiment, the vacuum cleaner may be adapted
to stand on the rear end of the main body of the vacuum cleaner.
This allows the vacuum cleaner to be stood in a very small surface
area, and if the nose is pivoted to its folded-back position at 0
degrees to the main axis of the vacuum cleaner, this can be
achieved without the vacuum cleaner having an excessive height.
Moreover, if the vacuum cleaner is a rechargeable model, the rear
end of the main body of the vacuum cleaner can also be provided
with means for connecting the vacuum cleaner to a recharging unit,
such as a jack plug, which allows the vacuum cleaner to be stood on
its rear end on a recharging unit also occupying a small surface
area.
Finally, the nose of the vacuum cleaner may be provided with an
one-way valve in the form of a flap composed of a resilient
material, such as rubber, which allows dirty air to enter the nose
via the dirty air inlet when the vacuum cleaner is in operation,
but which prevents dust and dirt from leaving the nose via the
dirty air inlet under the influence of gravity if the nose is
directed downwards when the vacuum cleaner is not in operation.
Such a one-way valve in the form of a rubber flap is known from
conventional hand-holdable vacuum cleaners, but is particularly
desirable in embodiments of the present vacuum cleaner, considering
that it is likely to be stored with the pivotable nose directed
downwards when the vacuum cleaner is not in operation.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention will be
better understood from the following detailed description, which is
given by way of example and in association with the accompanying
drawings, in which:
FIGS. 1A, 1B, 1C and 1D are schematic perspective views of a
hand-holdable vacuum cleaner according to a first embodiment of the
invention, respectively showing the pivotable nose thereof in 90,
180, 210 and 0 degree positions relative to the main axis of the
vacuum cleaner;
FIGS. 2A, 2B and 2C are schematic side views of a hand-holdable
vacuum cleaner according to a second embodiment of the invention,
respectively showing the pivotable nose thereof in 210, 135 and 160
degree positions relative to the main axis of the vacuum
cleaner;
FIG. 3 is a longitudinal cross-section through the nose of a
hand-holdable vacuum cleaner according to a third embodiment of the
invention, showing a telescopic extension tube thereof;
FIG. 4 is a schematic perspective view of the collection chamber of
a hand-holdable vacuum cleaner according to a fourth embodiment of
the invention, having a hinged door and shown with the door in an
open condition;
FIG. 5 is a schematic perspective view of an exterior face of the
door shown in FIG. 4;
FIG. 6 is a longitudinal cross-section through the collection
chamber of a hand-holdable vacuum cleaner according to a fifth
embodiment of the invention;
FIG. 7 is a schematic plan view of the main body and collection
chamber of a hand-holdable vacuum cleaner according to a sixth
embodiment of the invention; and
FIG. 8 is a schematic perspective view of a hand-holdable vacuum
cleaner according to a seventh embodiment of the invention, shown
with the pivotable nose thereof in the 0 degree position relative
to the main axis of the vacuum cleaner and standing on a recharging
unit.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring firstly to FIGS. 1A, 1B, 1C and 1D of the accompanying
drawings, these show a hand-holdable vacuum cleaner according to a
first embodiment of the invention, comprising a main body 10, a
collection chamber 20 for dust and dirt, a rigid, elongate nose 30
and a handle 40. The nose 30 has an inlet 32 for dirty air located
at one end thereof. Mounted on handle 40 is an electrical on-off
switch 42 for operating an electric motor housed within main body
10. In this embodiment, switch 42 has three settings, namely a
first position for switching the motor off, a second position for
low-speed operation of the motor and a third position for
high-speed operation of the motor.
In all of FIGS. 1A, 1B, 1C and 1D, broken line X-X' represents a
main axis of the vacuum cleaner and broken line Y-Y' represents a
central axis of the collection chamber 20, which in this embodiment
has a substantially cylindrical shape. Central axis Y-Y' of the
collection chamber 20 is oriented at right angles to the main axis
X-X' of the vacuum cleaner. As can be seen from these four figures,
the elongate nose 30 is pivotable about axis Y-Y' through a range
of angles from 0 degrees (as shown in FIG. 1D) through acute angles
up to 90 degrees (as shown in FIG. 1A) through obtuse angles
between 90 and 180 degrees (the latter of which is shown in FIG.
1B) and up to a reflex angle of 210 degrees (as shown in FIG. 1C).
Thus in this embodiment, nose 30 is pivotable through a range of
angles relative to the main axis X-X' of more than 180 degrees.
With the nose pivoted to the reflex angle shown in FIG. 1C, this
allows the vacuum cleaner to be comfortably used for cleaning under
furniture. On the other hand, with the nose folded back to the 0
degree position shown in FIG. 1D, the vacuum cleaner can also be
stored in a very compact space. The underside of main body 10 is
also provided with a corresponding groove 11 for receiving nozzle
30 in this folded-back position. This improves the overall
compactness of the vacuum cleaner for storage still further. With
the nose positioned at an in-between angle, as shown in FIG. 1A,
the vacuum cleaner can be used for cleaning in gaps between
objects, but can still be held in a comfortable orientation by a
user.
In this embodiment, the nose 30 is rigidly connected to a central
portion 22 of the collection chamber 20. End faces 24, 26 of the
collection chamber on the other hand are rigidly connected to the
main body 10 of the vacuum cleaner, so that as nose 30 pivots about
axis Y-Y', central portion 22 of the collection chamber 20 rotates
relative to the end faces 24, 26. The outer surface of central
portion 22 is provided with two sets of teeth on each end thereof
adjacent end faces 24 and 26, and the inner surfaces of end faces
24, 26 are each provided with second sets of teeth which are
adapted to engage with respective ones of the two sets of teeth
provided on central portion 22. Accordingly, nose 30 cannot pivot
relative to main body 10 because the interengaging sets of teeth
prevent movement of central portion 22 relative to end faces 24,
26. However, mounted on handle 40, in addition to electrical on-off
switch 42, is a further button 34, which is resiliently biassed and
which when depressed by a user, will disengage the sets of teeth
mounted on end faces 24, 26 from the two sets of teeth provided on
central portion 22, thereby allowing nose 30 to pivot freely
relative to main body 10. Nose 30 can therefore be locked in
position at whatever angle the user desires from across the full
range of angles available for the nose to pivot through, until such
time as the user wishes to unlock the nose and adjust it to a new
angle by depressing button 34.
FIGS. 2A, 2B and 2C show a hand-holdable vacuum cleaner according
to a second embodiment of the invention, in which the collection
chamber 20 has a substantially cylindrical shape and a filter 50 is
located within the collection chamber, arranged in an axially
symmetric fashion concentric with the central axis Y-Y' of the
collection chamber. Since FIGS. 2A, 2B and 2C are side elevational
views, they all show axis Y-Y' of the collection chamber and the
filter 50 end-on. In this embodiment, nose 30 is also arranged to
pivot about the central axis Y-Y' and a dirty air outlet 36 from
nose 30 enters the collection chamber 20 on a cylindrical side wall
28 thereof. Thus as FIGS. 2A, 2B and 2C show, regardless of the
angle of nose 30 relative to main body 10, dirty air always enters
the collection chamber 20 from dirty air outlet 36 at a tangent to
cylindrical side wall 28, and swirls around centrally located
filter 50 in the manner indicated by the arrows in FIGS. 2A, 2B and
2C. This separates out dust and dirt entrained with the dirty air
and deposits them in the collection chamber 20, before clean air
exits the collection chamber from within the filter via a clean air
outlet located on the opposite side from the end face of filter 50
visible in FIGS. 2A, 2B and 2C.
FIG. 3 shows a third embodiment of the invention, in which nose 30
comprises a rigid telescopic extension tube 38, which dirty air
enters in the direction indicated by arrow A in FIG. 3 during
operation of the vacuum cleaner. In this embodiment, nose 30 also
comprises an inner tube 31 and an outer tube 33. Telescopic
extension tube 38 can therefore slide within a space 35 provided
between inner and outer tubes 31, 33 in the directions indicated by
double-headed arrow J-K in FIG. 3, but is prevented from being
removed from space 35 completely by end stops 37 which abut against
corresponding lips 39 provided on inner tube 31. In this way, the
overall length of nose 30 may be adjusted by a user by sliding
extension tube 38 to a location where dirty air inlet 32 is
positioned as required. Extension tube 38 has a larger transverse
cross-sectional area than inner tube 31. This decreasing
cross-sectional area in the direction of the airflow during
operation of the vacuum cleaner ensures that use of extension tube
38 does not cause a corresponding drop in air pressure. It is also
beneficial for avoiding dirt becoming trapped at the interface
between extension tube 38 and inner tube 31, in comparison to the
converse arrangement, in which the cross sectional area of inner
tube 31 would be larger than the cross-sectional area of extension
tube 38. On the other hand, outer tube 33 is provided in addition
to inner tube 31 largely for aesthetic reasons: firstly in order to
create an outward impression of decreasing cross-sectional area
towards dirty air inlet 32 (which looks more natural to the human
eye), and secondly to cover any scratches on the outer surface of
inner tube 31 which may be created by repeated sliding of extension
tube 38 over the outer surface of inner tube 31.
FIG. 4 shows the collection chamber 20 of a hand-holdable vacuum
cleaner according to a fourth embodiment of the invention. In this
embodiment, the collection chamber has a substantially cylindrical
shape and comprises end faces 24, 26 and a cylindrical side wall
28. Arranged in an axially symmetric fashion concentric with the
central axis of the collection chamber is a filter 50. Filter 50
has a frusto-conical shape and comprises an end face 52 and a
conical side wall 54. End face 52 is impervious to air, but conical
side wall 54 is provided with a plurality of fine pores 56 through
which air can pass. A clean air outlet from collection chamber 20
is located within filter 50, allowing air to exit the collection
chamber through end face 24. Thus during operation of the vacuum
cleaner, dirty air enters the collection chamber at a tangent to
cylindrical side wall 28 and swirls around filter 50. The entrained
dirt is flung outwardly as it swirls around filter 50 under the
action of centrifugal force, strikes side wall 28 and is deposited
in collection chamber 20. Side wall 28 is transparent, allowing a
user to see how much dirt has accumulated within the collection
chamber and therefore when it needs emptying. The frusto-conical
shape of filter 50 helps to separate out different sizes of dirt
particle from the dirty air at different locations along the
central axis of the filter, which in turn helps to prevent the
filter pores 56 from becoming blocked. Clean air is then able to
pass through pores 56 and thence to the clean air outlet from
collection chamber 20 located within filter 50.
A user can gain access to collection chamber 20 to empty the
accumulated dust and dirt therefrom by means of a door 60 mounted
on end face 26 opposite to said clean air outlet. Door 60, which is
shown in an open condition in FIG. 4, opens by means of a hinge 62
which connects it to collection chamber 20. However in an
alternative embodiment, hinge 62 may instead connect door 60 to a
main body 10 of the vacuum cleaner, in which case door 60 will
maintain the same orientation relative to main body 10 regardless
of the orientation of collection chamber 20 relative thereto. Door
60 can also be securely closed by means of a latch 64 mounted
thereon. This latch interengages with a catch 66 provided in a
suitable location on end face 26 of collection chamber 20. The
locations of latch 64 and catch 66 may however be interchanged as
between the door 60 and the collection chamber 20.
In this embodiment, an interior face 68 of door 60 is provided with
a series of radial tangs 70. These tangs 70 cooperate with a
corresponding set of radial tangs 72 provided on the end face 52 of
filter 50. The combined height of tangs 70 and 72 is greater than
the separation between the interior face 68 of the door 60 and the
end face 52 of the filter 50, so that the two facing sets of tangs
70,72 will overlap each other when door 60 is in a closed
condition. Tangs 70 are coupled to a filter cleaning wheel 74 which
is movable within door 60, such that it can be rotated relative
thereto. As can be seen in FIG. 5, which shows an exterior face 69
of the door 60 of FIG. 4, filter cleaning wheel 74 projects
outwardly of door 60 and is provided with a knurled outer surface.
A user can therefore grip this knurled surface and rotate filter
cleaning wheel 74 relative to door 60 in either of the directions
indicated in FIG. 5 by double-headed arrow P-Q. This has the effect
of rotating tangs 70 relative to door 60 and also relative to the
set of tangs 72 on end face 52 of filter 50, which is held
immovable in collection chamber 20 and is therefore unable to
rotate relative thereto. As the tangs 70 are rotated, they engage
with tangs 72 and agitate filter 50, thereby dislodging dust and
dirt adhering to the filter and causing it to be deposited in
collection chamber 20.
In an alternative embodiment not shown in FIGS. 4 and 5, tangs 70
may instead be rigidly mounted to door 60 and unable to rotate
relative thereto, but the door itself may be rotatable relative to
the immovable filter 50 when a nose of the vacuum cleaner is
pivoted in the manner described previously in relation to FIGS. 1A,
1B, 1C and 1D. This dispenses with the need for filter cleaning
wheel 74 and means that in this alternative embodiment, tangs 70
will engage with tangs 72 and agitate filter 50 whenever the nose
of the vacuum cleaner is pivoted. In another alternative embodiment
also not shown in FIGS. 4 and 5, filter 50 may instead be free to
rotate within collection chamber 20 whenever the nose of the vacuum
cleaner is pivoted and door 60 may instead be held immovable
relative to the main body of the vacuum cleaner. This other
alternative embodiment, which also dispenses with the need for
filter cleaning wheel 74, also means that tangs 70 will engage with
tangs 72 and agitate filter 50 whenever the nose of the vacuum
cleaner is pivoted. In both of these alternative embodiments,
therefore, filter 50 is cleaned automatically during normal use of
the vacuum cleaner by pivoting of the nose thereof, without a user
having to pay particular attention to performing a filter cleaning
operation.
In a still further alternative embodiment also not shown in the
figures, the door may instead be provided on the cylindrical side
wall 28 of collection chamber 20, and may, for example, be a
sliding, rather than a hinged door, thereby allowing a user to gain
access to collection chamber 20 to empty dust and dirt therefrom.
In this further alternative embodiment, only one of end face 26 and
filter 50 is caused to rotate when a nose of the vacuum cleaner is
pivoted, but the other of the end face 26 and filter 50 is held
immovable, so that filter 50 and end face 26 are rotated relative
to each other when the nose is pivoted. This alternative embodiment
therefore also dispenses with the need for filter cleaning wheel
74, and means that the tangs 70 will engage with tangs 72 and
agitate filter 50 whenever the nose of the vacuum cleaner is
pivoted.
Referring now to FIG. 6, there is shown yet another alternative
embodiment in which filter cleaning is effected by means of a
filter cleaning wheel 74 which a user can rotate about central axis
Y-Y' of collection chamber 20. In this embodiment, filter 50
comprises a course filter element 51 and a fine filter element 53.
Course filter element 51 is typically made of a stiff plastics
material and is provided with a plurality of fine pores in the
manner already represented in FIG. 4 by reference numeral 56. Fine
filter element 53 on the other hand is made of a soft fabric
material and is folded into pleats 55 in the manner shown in FIG. 6
in order to increase its surface area to volume ratio. Thus dirty
air entering collection chamber 20 passes firstly through pores 56
in course filter 51 before encountering pleats 55 of fine filter
element 53 and exiting collection chamber 20 via a clean air outlet
21 formed in its end face 24.
As can also be seen from FIG. 6, course filter element 51 comprises
a circumferential flange 57 which is retained by a lip 25 formed on
end face 24 of collection chamber 20. Course filter element 51 is
therefore free to rotate about central axis Y-Y'. Fine filter
element 53 on the other hand comprises an annular frame 58 which is
attachable to end face 24, such that fine filter element 53 is held
immovable in collection chamber 20. Course filter element 51
further comprises a number of wings 59 formed on the inner surface
thereof which overlap with the pleats 55 of fine filter element 53.
Thus if a user rotates filter cleaning wheel 74 about axis Y-Y',
tangs 70 provided on the interior face 68 of door 60 which are
coupled to filter cleaning wheel 74 are caused to rotate in the
same direction, and push against tangs 72 provided on the end face
52 of course filter element 51. This in turn causes course filter
element 51 to rotate about central axis Y-Y' by flange 57 sliding
under lip 25, and the wings 59 of the course filter element to ride
over successive pleats 55 of fine filter element 53. This agitates
fine filter element 53, thereby dislodging fine dust adhering to
fine filter element 53, which falls through the pores 56 formed in
course filter element 53 and is deposited in collection chamber 20.
This has the effect of cleaning fine filter element 53 of fine
dust. Course filter element 51 may also be cleaned of larger dirt
particles because the stiff plastics material of which it is made
is also resilient. This allows a user to flex course filter element
51 until flange 57 disengages from under lip 25, and to remove the
course filter element from collection chamber 20 through door 60.
Course filter element 51 may then be cleaned (for example, by
washing) and replaced. When course filter element 51 is removed
from collection chamber 20, this also gives a user direct access to
fine filter element 53, which may be detached from end face 24 and
also removed through door 60. Finally, FIG. 6 also shows how door
60 is maintained in an airtight seal when in the closed condition
by the provision of an annular sealing element 65 permanently
attached to the interior face 68 of door 60. Sealing element 65 is
made of a resilient elastomeric material, such as rubber, which
deforms elastically when compressed between door 60 and collection
chamber 20.
FIG. 7 shows the main body 10 and collection chamber 20 of a
hand-holdable vacuum cleaner according to another embodiment of the
invention, in which main body 10 houses both a motor 12 and a fan
14 mounted on an output shaft 16 of the motor 10. In this
embodiment, motor 12 and fan 14 are oriented in the main body 10
with the output shaft 16 and the axis of rotation of the fan 14
aligned on an axis Z-Z', which is parallel to the central axis Y-Y'
of collection chamber 20 and at right angles to a main axis X-X' of
the vacuum cleaner. Clean air outlet 21 of collection chamber 20 is
also linked to main body 10 via a duct 80, which transports clean
air during operation of the vacuum cleaner in the direction
indicated by the arrows in FIG. 7 and onto the face of fan 14. Fan
14 is configured as an impeller, such that when the fan rotates,
air is drawn in axially thereto and expelled radially therefrom.
Main body 10 further comprises an exhaust vent 18 formed on a rear
end 19 thereof. Thus when the pivotable nose of the vacuum cleaner
(which is not shown in FIG. 7) is in a fully extended position, at
180 degrees to the main axis X-X' of the vacuum cleaner and at a
location to the right of FIG. 7, exhaust vent 18 is located
opposite to the dirty air inlet to the nose. Air expelled by the
fan 14 during operation of the vacuum cleaner therefore travels in
a straight-line path out of exhaust vent 18 in completely the
opposite direction to the dirty air inlet to the nose and away from
a surface to be cleaned. The space in main body 10 between motor 12
and fan 14 on the one hand and collection chamber 20 on the other
is occupied in this embodiment by a bank of rechargeable electric
cells (not shown in FIG. 7) to power the motor 12 of the vacuum
cleaner, which is a rechargeable model in this embodiment. In an
alternative embodiment to that shown in FIG. 7, motor 12 may
instead be mains powered, in which case the main body 10 houses an
electrical transformer instead of a bank of rechargeable electric
cells. In either case, however, main body 10 is adapted to fit the
contents thereof as compactly as possibly, thereby minimizing the
length of duct 80 and the overall length of main body 10. In
particular, motor 12 and fan 14 may be located next to collection
chamber 20 and a bank of rechargeable electric cells or an
electrical transformer, as appropriate, being located either above
or below the motor 12 and fan 14, in order to make the length of
duct 80 as short as possible, whilst also allowing exhaust vent 18
to be provided on a rear end 19 of main body 10.
Finally, FIG. 8 shows an embodiment of the invention in which the
vacuum cleaner is rechargeable and has been stood on the rear end
19 of the main body 10 thereof. FIG. 8 also shows this vacuum
cleaner in a condition in which its nose 30 has been pivoted to its
folded-back position at 0 degrees to the main axis of the vacuum
cleaner, in order to give the vacuum cleaner a very compact overall
profile. Moreover, rear end 19 of main body 10 comprises means,
such as a jack plug (not visible in FIG. 8), for connecting the
vacuum cleaner to a recharging unit 90, which allows the vacuum
cleaner to be stood on recharging unit 90 on its rear end 19 for
recharging.
* * * * *