Note: Descriptions are shown in the official language in which they were submitted.
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VACUUM CLEANERS AND HOSES
This invention relates to vacuum cleaners of the kind including a suction unit
and a
flexible hose assembly.
Cylinder vacuum cleaners are used with a hose. Upright vacuum cleaners may
also be
used with a hose where it is necessary to clean less accessible locations.
Hoses are also used
in central vacuum cleaner installations, where a suction unit and ducting is
built into a
building. A long hose is useful in some situations but causes problems with
storage and
manipulation. The length of a hose is usually a compromise between a long
length for ease of
use and a short length to facilitate storage. One form of hose that can be
long yet is easy to
store is the extensible or stretch hose, which has a naturally short length b-
ut can be pulled to
extend it to a longer length. The hose has a helical reinforcement with a
natural contracted
length but which can be extended resiliently. Although these hoses can be used
satisfactorily,
they have a disadvantage because the force needed to extend the hose and to
maintain its
extension makes it more difficult to manipulate the cleaning head.
Furthermore, the force
may pull over or move the vacuum cleaner or any furniture around which the
hose is lead.
One solution to this is the retractable hose, which has a naturally extended
length and which
can be retracted by suction. This is achieved by selecting the resilience of
the helical
reinforcement of the hose so that the suction created by the vacuum cleancr
when the far end
of the hose is obstructed is sufficient to pull the hose to a retracted
length. The hose is then
held in its retracted state so that it does not extend when the vacuum
clear3er is turned off.
This form of retractable hose is described in WO 03/024294. Although this form
of hose has
many advantages, there may be situations where it is desirable to have a hose
that can be
extended to even longer lengths but without an increased storage length, or
where the
construction of the hose does not allow for it to be retracted by suction, or
where a non-
retractable form of hose is preferred.
It is an object of the present invention to provide an alternative vacuum
cleaner and
hose.
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According to one aspect of the present invention there is provided a vacuum
cleaner
of the above-specified kind, characterised in that the hose assembly includes
at least two
flexible sections one of which has a smaller external diameter than the other
and is slidable
within the other, and that the two sections are arranged to seal with one
another at least when
the two sections are extended relative to one another.
The flexible sections are preferably corrugated. The smaller diameter section
may be
stretchable from a natural short length to a longer length by applying an
axial force.
Alternatively, the smaller diameter section may be retractable from a natural
extended length
to a shorter length, such as by suction applied by the suction unit when the
end of the hose
assembly is occluded. The shorter length of the smaller diameter section may
be substantially
equal to the length of the larger diameter section. The two sections of the
hose assembly may
be provided with cooperating couplings that can be engaged with one another to
retain the
two sections in a compact configuration one within the other for storage. The
larger diameter
section of the hose assembly may be stretchable from a natural short length to
a longer length
by applying an axial force.
According to another aspect of the present invention there is provided a hose
assembly for a vacuum cleaner, characterised in that the hose assembly
includes inner and
outer corrugated, flexible sections, that the inner section has a first end
slidably retained
within the outer section, that the hose assembly has a short configuration
where the major
part of the length of the inner section extends within the outer section and
the first end of the
inner section is located adjacent the first end of the outer section, and that
the hose assembly
has a longer configuration where the inner section is extended beyond a second
end of the
outer section and the first end of the inner section is located adjacent the
second end of the
outer section and in which a seal is provided between the two sections.
The imier section is preferably extensible from a~ shorter length
substantially equal to
the length of the outer section to a longer length greater than that of the
outer section.
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A vacuum cleaner including a hose assembly and its method of use, according to
the
present invention, will now be described, by way of example, with reference to
the
accompanying drawing, in which:
Figure 1 is a simplified perspective view of the cleaner and hose assembly in
an
extended state; and
Figure 2 is a simplified enlarged cross-sectional view of a part of the hose
assembly in an extended state.
With reference first to Figure 1 there is shown a vacuum cleaner including a
suction
unit 1, a hose assembly 2 and a cleaning wand 3 with a cleaning head 4 at one
end.
The unit 1 is conventional, being a portable cylinder cleaner with a pump,
dust
collection bag, controls and filters of the usual kind (not shown). The unit ~
has a suction
inlet 10 towards one end to which the hose assembly 2 is connected.
With reference now also to Figure 2, the hose assembly 2 has a first, outer
section 20
with a coupling 21 at one end connected with the suction inlet 10. The main
part of the first
section 20 is provided by a corrugated, flexible tubular wall 22 of a plastics
material, which is
reinforced by a helical wire 23. The invention is also applicable to other
forms of hose, such
as tho se made entirely of plastics. The end of the first section 20 remote
from the vacuum
cleaner housing 1 is terminated by a sealing coupling 24. The first section 20
of the hose
assembly 2 is typically about 1.8m long and is relatively inextensible
axially. The first hose
section 20 may alternatively be of a stretch construction, that is, one that
has a natural short,
retracted length but can be pulled by applying an axial force to a longer
length against the
axial resilience of the hose.
The hose assembly 2 also has a second, inner, smaller diameter section 25,
which is
flexible and corrugated, being provided by a sleeve 26 of a highly flexible
plastics material
supported on the outside of a helical reinforcement member in the form of a
spring metal wire
27, as described in W003024294. The helical reinforcement wire 27 has a
natural extended
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state but can be compressed axially against its resilience by an applied
external force. The
sleeve 26 is sufficiently flexible that the second section 25 itself naturally
takes up the
extended length of the reinforcement wire helix 27. The sleeve 26 has shallow
hills extending
outwardly between turns of the reinforcement wire 27, thereby allowing the
sleeve to fold
outwardly when the hose is retracted. The second section 25 is terminated at
one end by a
rigid circular end fitting 28 located within the first, larger diameter
section 20 and freely
slidable along it. The dimensions of the end fitting 28 and the coupling 24 on
the first section
are such as to prevent withdrawal of the end fitting. The end fitting 28 and
the coupling 24
have engaging sealing surfaces 29 and 30 that extend laterally and abut and
seal with one
another when the end fitting is pulled against the coupling. The natural,
extended length of
the second section 25 is about 3.6m and it can be retracted to a length of
about the same as
that of the first section, that is, about 1.8m. This gives a total maximum
length of about 5.4m.
In general, if both sections of the hose are non-retractable or non-
compressible the minimum
overall length of the hose will be about 50% of its maximum length. Where one
of the hose
sections is retractable, as described above, the same maximum length can be
achieved but the
minimum length can be only about 25% of the maximum.
The opposite end of the second section 25 is terminated by a handle 32, such
as of the
kind described in GB2403403. The rear end of the handle 32 is formed with a
coupling 33
adapted to mate with the coupling 24 at the end of the first section 20. The
handle 32 has a
trigger 34 that can be operated by the user to close a valve (not shown)
within the handle and
thereby prevent or restrict flow of air through the handle and hence along the
hose assembly
2. The cleaning wand 3 is connected to the forward end of the handle 32.
.,
Before use, the second section 25 is retracted and withdrawn within the first,
outer
section 20, as shown by the broken lines in Figure 2, and is held in this
retracted state by
engagement of the couplings 33 and 24, thereby providing a relatively compact
configuration
for storage. The hose assembly 2 can be used in this compact configuration for
cleaning
where a longer length is not needed. A stretch construction of the first
section 20 facilitates
use in this compact configuration. Normally, however, the user would release
the two
couplings 33 and 24 so that the resilience of the second section 25 extends it
to its natural
extended length. The user then pulls the second section 25 slightly to pull it
out of the first
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section 20 to its maximum extent, in a telescopic fashion. Until the end
fitting 28 is pulled
into sealing engagement with the coupling 24, air will be able to flow between
the outside of
the second section 25 and the coupling on the first section 20, so the suction
effect at the
cleaning head will be reduced. Once the end fitting 28 is engaged with the
coupling 24, a seal
is formed between the surfaces 29 and 30 preventing leakage of air into the
hose assembly 2
except at the cleaning head 4. The total length of the extended hose assembly
2 is, therefore,
equal to the combination of the length of the first section 20 and the
extended length of the
second section 25, that is, about 5.4m. It will be appreciated that, if the
first, outer section 20
has a stretch construction, the overall effective length of the entire hose
assembly can be
further extended by applying a light pulling force to the remote end of the
assembly.
When the user has finished cleaning and wishes to store the cleaner, he closes
the
trigger 34 on the handle 32 to restrict air flow along the hose assembly 2.
This creates a
suction pressure within the hose assembly 2 thereby retracting the second
section 25 in
length. The suction also has the effect of withdrawing the second section 25
back into the
first section 20, telescopically, like a piston. Once the end fitting 28 is
displaced from the
coupling 24, some air will flow into the first section 20 at the coupling but
it is still easy for
the user fully to retract the second section 25 into the first with the
combination of the suction
and some manual guiding and pushing. When the second section 25 has been
withdrawn fully
into the first section 20 and has been retracted in length, the coupling 33 on
the handle 32 is
engaged with the coupling 24 on the first section. The vacuum cleaner can now
be tunied off
allowing pressure within the hose assembly 2 to rise to atmosphere. The
tendency of the
second section 25 to extend is restrained by engagement of the couplings 33
and 24.
-,
By providing for the second section 25 to slide within the first section 20
the overall
effective length of the hose assembly 2 can be further extended over the
arrangement
described in W003024294 without any increase in the stowed length of the hose
assembly.
Or, the same extended length can be achieved with a hose assembly having
reduced stowed
length.
The invention could also be used with conventional hoses that cannot be
extended or
retracted in length. In the simplest case, the user would simply pull the
smaller diameter hose
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out of the larger diameter hose to its full extent when cleaning and would
push the two hoses
telescopically together when the vacuum cleaner is to be stored. This enables
the effective
usable length of the hose to be up to twice that of the stowed length. In a
modification of this
arrangement employing conventional hose sections, the remote end of the hose
assembly
could have a valve similar to that described above that the user can close so
that suction is
created within the hose assembly. The suction helps produce a telescopic
piston effect to
withdraw the smaller diameter hose into the larger diameter hose.
It will be appreciated that the hose assembly could have various different
configurations. For example, the hose assembly could include three or more
hose sections of
different diameters nested one within the other, so that the effective,
usable, extended length
of the hose is three or more times the stowed length. The larger diameter
section could be
secured at the remote end of the hose assembly and the smaller diameter
section secured with
the vacuum cleaner housing. The hose need not have a wire-reinforced
construction but
could, for example, be a low cost hose made entirely of plastics material.
The seal between the different sections of the hose need not be provided by
abutting
lateral surfaces but could instead be provided by one or more sliding seals,
such as provided
on the outer section facing inwardly to make a wiping seal with the outside of
the inner
section, or on the inner section facing outwardly to make a wiping seal with
the inside of the
outer section, or both of these arrangements.
The invention is not confined to portable cylinder cleaners but could be used
with
upright cleaners, central vacuum cleaner installations, fixed garage forecourt
vacuum cleaners
or the like.
