U.S. patent application number 11/515363 was filed with the patent office on 2007-02-22 for vacuum-cleaner nozzle.
This patent application is currently assigned to Alfred Kaercher GmbH & Co. KG. Invention is credited to Erich Moritsch, Hendrik Rust, Timo Spengler, Christian Stewen.
Application Number | 20070039128 11/515363 |
Document ID | / |
Family ID | 34877577 |
Filed Date | 2007-02-22 |
United States Patent
Application |
20070039128 |
Kind Code |
A1 |
Rust; Hendrik ; et
al. |
February 22, 2007 |
Vacuum-cleaner nozzle
Abstract
The invention relates to a vacuum-cleaner nozzle for vacuuming
an underlying surface, having a suction channel which opens out
into a suction mouth. In order to form the vacuum-cleaner nozzle
such that it has a relatively pronounced suction action for a
sustained period of time, it is proposed according to the invention
that the vacuum-cleaner nozzle comprises a lifting mechanism which
interacts with the underlying surface and by means of which it is
possible to change the distance of the suction mouth from the
underlying surface on a periodic basis.
Inventors: |
Rust; Hendrik;
(Remshalden-Hebsack, DE) ; Spengler; Timo; (Weil
der Stadt, DE) ; Stewen; Christian; (Marbach a.N.,
DE) ; Moritsch; Erich; (Plochingen, DE) |
Correspondence
Address: |
Lipsitz & McAllister, LLC
755 MAIN STREET
MONROE
CT
06468
US
|
Assignee: |
Alfred Kaercher GmbH & Co.
KG
Winnenden
DE
|
Family ID: |
34877577 |
Appl. No.: |
11/515363 |
Filed: |
August 31, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP05/01496 |
Feb 15, 2005 |
|
|
|
11515363 |
Aug 31, 2006 |
|
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Current U.S.
Class: |
15/354 |
Current CPC
Class: |
A47L 9/009 20130101;
A47L 9/0072 20130101; A47L 9/02 20130101; A47L 9/0494 20130101 |
Class at
Publication: |
015/354 |
International
Class: |
A47L 5/34 20060101
A47L005/34 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 3, 2004 |
DE |
10 2004 011 745 |
Claims
1. Vacuum-cleaner nozzle for vacuuming an underlying surface, the
vacuum-cleaner nozzle having a suction channel which opens out into
a suction mouth, and a lifting mechanism which interacts with the
underlying surface, it being possible, by means of the lifting
mechanism, to change the distance of the suction mouth from the
underlying surface on a periodic basis.
2. Vacuum-cleaner nozzle according to claim 1, wherein the suction
mouth is bounded at least partially in the circumferential
direction by a surround which can be raised from the underlying
surface, and lowered onto the same, by means of the lifting
mechanism.
3. Vacuum-cleaner nozzle according to claim 1, wherein the suction
mouth is mounted fixedly on a base plate which can be raised from
the underlying surface, and lowered on to the same, by means of the
lifting mechanism.
4. Vacuum-cleaner nozzle according to claim 1, the vacuum-cleaner
nozzle having a supporting wheel, which can be rotated about an
axis of rotation and can be positioned on the underlying surface,
and the vacuum-cleaner nozzle being pivotable back and forth about
a pivot axis which is oriented parallel to, or coaxially in
relation to, the axis of rotation.
5. Vacuum-cleaner nozzle according to claim 1, wherein the width of
the suction mouth in the operating direction of the vacuum-cleaner
nozzle corresponds at least to the distance covered by the
vacuum-cleaner nozzle at a speed of 0.5 m/s along the underlying
surface within a raising/lowering cycle of the lifting
mechanism.
6. Vacuum-cleaner nozzle according to claim 1, wherein the lifting
mechanism can be switched on and off.
7. Vacuum-cleaner nozzle according to claim 1, it being possible to
change the extent of the periodic variation in distance.
8. Vacuum-cleaner nozzle according to claim 1, wherein the lifting
mechanism has at least one rotatable rolling element which acts on
the underlying surface and is coupled to the suction mouth, it
being possible for the suction mouth to be raised from the
underlying surface, and lowered onto the same, by means of the
rolling element.
9. Vacuum-cleaner nozzle according to claim 8, wherein the rolling
element is exchangeable.
10. Vacuum-cleaner nozzle according to claim 8, wherein the rolling
element is mounted eccentrically.
11. Vacuum-cleaner nozzle according to claim 8, wherein the rolling
element is of non-round configuration.
12. Vacuum-cleaner nozzle according to claim 11, wherein the
rolling element has a contour in the form of a polygon.
13. Vacuum-cleaner nozzle according to claim 11, wherein the
rolling element has a star-shaped contour.
14. Vacuum-cleaner nozzle according to claim 8, wherein the contour
of the rolling element is non-symmetrical.
15. Vacuum-cleaner nozzle according to claim 14, wherein the
contour of the rolling element is star-shaped and has a plurality
of points with in each case two flanks running toward one another,
the two flanks being inclined differently in relation to the radial
direction of the rolling element.
16. Vacuum-cleaner nozzle according to claim 8, wherein the at
least one rolling element has a friction-enhancing covering.
17. Vacuum-cleaner nozzle according to claim 8, wherein the at
least one rolling element is configured as a wheel or roller.
18. Vacuum-cleaner nozzle according to claim 8, wherein the rolling
element is disposed between a supporting wheel and the suction
mouth, as seen in the operating direction of the vacuum-cleaner
nozzle.
19. Vacuum-cleaner nozzle according to claim 8, wherein the at
least one rolling element is mounted such that it can be adjusted
obliquely or perpendicularly in relation to the underlying
surface.
20. Vacuum-cleaner nozzle according to claim 1, wherein the lifting
mechanism comprises a turbine wheel which can be subjected to the
action of a suction flow, is mounted such that it can be rotated
about an axis of rotation and the center of gravity of which is
disposed at a distance from the axis of rotation, and a supporting
element acting on the underlying surface at a distance from the
axis of rotation, as seen in the operating direction.
21. Vacuum-cleaner nozzle according to claim 20, wherein the
turbine wheel is disposed within the suction channel and does not
completely fill the suction-channel cross-section.
22. Vacuum-cleaner nozzle according to claim 20, wherein the
turbine wheel is disposed in an end portion of the suction channel
which opens out into the suction mouth.
23. Vacuum-cleaner nozzle according to claim 17, wherein the
turbine wheel has turbine blades of different mass.
24. Vacuum-cleaner nozzle according to claim 1, wherein the suction
mouth is bounded at least partially in the circumferential
direction by a surround which forms that region of the
vacuum-cleaner nozzle which projects furthest in the direction of
the underlying surface.
25. Vacuum-cleaner nozzle according to claim 1, the vacuum-cleaner
nozzle having at least one thread-lifting means mounted on a base
plate, a surround which bounds the suction mouth at least partially
in the circumferential direction having no interruption in its
region which is adjacent to the thread-lifting means.
26. Vacuum-cleaner nozzle according to claim 1, wherein a surround
which bounds the suction mouth at least partially in the
circumferential direction has at least one front crosspiece, which
runs transversely to the operating direction, and a rear
crosspiece, which runs transversely to the operating direction.
Description
[0001] This application is a continuation of international
application number PCT/EP2005/001496 filed on Feb. 15, 2005.
[0002] The present disclosure relates to the subject matter
disclosed in international application number PCT/EP2005/001496 of
Feb. 15, 2005 and German application number 10 2004 011 745.4 of
Mar. 3, 2004, which are incorporated herein by reference in their
entirety and for all purposes.
BACKGROUND OF THE INVENTION
[0003] The invention relates to a vacuum-cleaner nozzle for
vacuuming an underlying surface, having a suction channel which
opens out into a suction mouth.
[0004] Such vacuum-cleaner nozzles are usually connected to the
free end of a suction hose or suction tube which is in flow
connection with a suction subassembly for vacuuming the underlying
surface. The suction subassembly produces a suction flow which,
starting from the suction mouth, is channeled through the suction
channel. In order to enhance the cleaning action, the suction flow
can be intensified by the volume flow being increased. This
requires the use of a more powerful suction subassembly, in which
case there is a risk of the vacuum-cleaner nozzle sucking fast to
the underlying surface for a sustained period of time. Utility
Model DE 93 12 261 U1 has therefore proposed to interrupt the
suction stream on a periodic basis by means of a flap valve
disposed in the suction channel. When the valve is closed, the
action of the suction subassembly causes an increase in the
negative pressure between the suction subassembly and the valve. If
the valve is opened, the increased negative pressure gives rise to
an increased suction flow, so that an enhanced suction action can
be achieved within this period of time without a more powerful
suction subassembly having to be used and without there being any
risk of the vacuum-cleaner nozzle sucking fast to the underlying
surface for a sustained period of time.
[0005] The disadvantage with such a configuration of a
vacuum-cleaner nozzle, however, is that particles of dirt can
settle in the region of the flap valve, and these may result in
leakage and damage to the valve. This reduces the service life of
the vacuum-cleaner nozzle and also the suction action thereof.
[0006] It is an object of the present invention to develop a
vacuum-cleaner nozzle of the type mentioned in the introduction
such that its suction action can be enhanced for a sustained period
of time.
SUMMARY OF THE INVENTION
[0007] This object is achieved according to the invention, in the
case of a vacuum-cleaner nozzle of the generic type, in that the
vacuum-cleaner nozzle has a lifting mechanism which interacts with
the underlying surface, it being possible, by means of the lifting
mechanism, to change the distance of the suction mouth from the
underlying surface on a periodic basis.
[0008] The invention incorporates the idea that periodically
changing the distance between the suction mouth and the underlying
surface can achieve a periodic variation in the suction flow
without there being any risk of leakage or damage to a valve
element. By means of the lifting mechanism, which interacts with
the underlying surface, the position of the suction mouth can be
moved back and forth between two end positions on a periodic basis.
In a first end position, the suction mouth assumes a position in
which it is as close as possible to the underlying surface and, in
a second end position, the suction mouth assumes a position in
which it is spaced apart from the underlying surface to the maximum
extent. In the first end position, the suction flow, in the region
of the suction mouth, experiences a considerable loss in pressure
on account of the small distance between the suction mouth and the
underlying surface. With the operation of the suction subassembly
remaining the same, this results in an increased negative pressure
being established in the region between the suction subassembly and
the suction mouth. If the suction mouth is then transferred into
its second end position by means of the lifting mechanism, the
distance between the suction mouth and the underlying surface
increases, and this results in a considerable reduction in the loss
in pressure of the suction flow in the region of the suction mouth,
so that a pulsating suction flow forms overall, this resulting in a
considerable increase in the suction action without valve elements
which close the suction channel having to be used for this
purpose.
[0009] It may be provided, for example, that the suction mouth is
bounded at least partially in the circumferential direction by a
surround, for example by one or more crosspieces, it being possible
for the surround to be raised from the underlying surface, and
lowered onto the same, at least in certain regions by means of the
lifting mechanism. Depending on the position assumed by the
surround in relation to the underlying surface, it is possible to
achieve a specified loss in pressure for the suction flow, and a
periodic variation in distance, in turn, results in a pulsating
suction flow being formed.
[0010] It is advantageous if the suction mouth is mounted fixedly
on a base plate of the vacuum-cleaner nozzle, it being possible for
the base plate to be raised from the underlying surface, and
lowered onto the same, by means of the lifting mechanism.
[0011] In the case of a particularly preferred embodiment of the
invention, the vacuum-cleaner nozzle has a supporting wheel, which
can be rotated about an axis of rotation and can be positioned on
the underlying surface, and the vacuum-cleaner nozzle can be
pivoted back and forth about a pivot axis which is oriented
parallel to, or coaxially in relation to, the axis of rotation. In
the case of such a configuration, on account of the lifting
mechanism interacting with the underlying surface, the
vacuum-cleaner nozzle executes a periodic pivoting movement, the
supporting wheel supporting the vacuum-cleaner nozzle on the
underlying surface and the axis of rotation of the supporting wheel
defining a pivot axis of the vacuum-cleaner nozzle. The pivoting
movement of the vacuum-cleaner nozzle results in a periodic
variation in distance of the suction mouth and is brought about by
the lifting mechanism.
[0012] In order to ensure that, despite the periodic variation in
distance of the suction mouth, the underlying surface is cleaned
uniformly, it is advantageous if the width of the suction mouth in
the operating direction of the vacuum-cleaner nozzle corresponds at
least to the distance covered by the vacuum-cleaner nozzle at a
speed of 0.5 m/s along the underlying surface within a
raising/lowering cycle of the lifting mechanism. The speed of 0.5
m/s corresponds to a standard speed at which the vacuum-cleaner
nozzle is usually moved along the underlying surface by the user.
If the width of the suction mouth in the operating direction of the
vacuum-cleaner nozzle is greater than or equal to the distance
which is covered at the abovementioned standard speed within a
raising/lowering cycle of the lifting mechanism, then it is ensured
that each region of the underlying surface is also covered by an
enhanced suction flow and there are no regions of the underlying
surface which are subjected just to a minimal suction flow.
[0013] It is of particular advantage if the width of the suction
mouth corresponds at least to 1.5 times the distance which is
covered by the vacuum-cleaner nozzle at a speed of 0.5 m/s along
the underlying surface within a raising/lowering cycle of the
lifting mechanism. It may thus be provided, for example, that the
lifting mechanism changes the distance of the suction mouth from
the underlying surface on a periodic basis at a frequency of
approximately 25 Hz and the width of the suction mouth is at least
20 mm.
[0014] In the case of a preferred embodiment, the lifting mechanism
can be switched on and off. This makes it possible for the lifting
mechanism to be switched on, and accordingly for the distance of
the suction mouth from the underlying surface to be varied, only
when an enhanced suction action is desirable for cleaning the
underlying surface, for example in the case of a carpet. If the
vacuum-cleaner nozzle is used for a merely lightly soiled
underlying surface or for a hard surface, the cleaning of which
does not require any enhanced suction action, then the lifting
mechanism can be switched off.
[0015] It may be provided that the lifting mechanism can be
optionally switched on and off by the user. This makes it possible
for the user to switch the lifting mechanism on or off manually
depending on the degree of soiling of the underlying surface.
[0016] In many cases, the vacuum-cleaner nozzle has a
bristle-covered rim which can be moved back and forth between two
different positions by means of an actuating device, so that, for
cleaning a hard surface, the bristle-covered rim can be extended
out of a housing of the vacuum-cleaner nozzle and, for cleaning a
carpet, it can be retracted into the housing. It is advantageous
here if the lifting mechanism is coupled to the actuating device of
the bristle-covered rim. This makes it possible to switch on the
lifting mechanism by means of the actuating device for cleaning a
carpet, whereas it is switched off for cleaning a hard surface.
[0017] The suction action is more pronounced the greater the
difference between the minimum and maximum distances of the suction
mouth from the underlying surface. In the case of a large
difference between the minimum and maximum distances, that is to
say in the case of a large displacement of the suction mouth, a
suction flow which pulsates to a pronounced extent and results in
an enhanced suction action is established. If, in contrast, the
difference between the minimum distance and the maximum distance of
the suction mouth from the underlying surface is reduced, then the
pulsation of the suction flow is reduced. It is thus advantageous
if it is possible to change the extent of the periodic variation in
distance, i.e. of the displacement of the suction mouth. This makes
it possible to adapt the suction action of the vacuum-cleaner
nozzle to the degree of soiling of the underlying surface.
[0018] No more specific details have been given up until now
regarding the configuration of the lifting mechanism. It is
advantageous if the lifting mechanism has at least one rotatable
rolling element which acts on the underlying surface and is coupled
to the suction mouth, for example is connected fixedly to the
suction mouth, it being possible for the suction mouth to be raised
from the underlying surface, and lowered onto the same, by means of
the rolling element. If the vacuum-cleaner nozzle is moved along
the underlying surface, then the rolling element, which acts on the
underlying surface, is made to rotate and, since the rolling
element is coupled to the suction mouth, rolling movement of the
rolling element can cause the suction mouth to move back and forth
in the direction of the underlying surface and in the direction
away from the underlying surface. The distance of the suction mouth
from the underlying surface can thus be changed on a periodic basis
by means of the rolling element in a constructionally simple
manner.
[0019] It is advantageous if the rolling element is mounted in an
exchangeable manner on a housing of the vacuum-cleaner nozzle, for
example such that it can be connected in a releasable manner, in
particular latched, thereto. This makes it possible, depending on
the nature of the underlying surface, to use different rolling
elements which differ, for example, in the extent of the back and
forth movement of the suction mouth brought about by them or also
in the frequency of this movement.
[0020] The rolling element is preferably mounted eccentrically
because it is thus possible for the rolling movement of the rolling
element to be translated into a back and forth movement of the
suction mouth in a constructionally simple manner.
[0021] It may also be provided that the rolling element is of
non-round configuration, for example in the form of a rolling cam
which is supported on the underlying surface and raises the
vacuum-cleaner nozzle, and then lowers it again, at least in the
region of the suction mouth.
[0022] It is advantageous if the rolling element has a contour in
the form of a polygon, in particular of a pentagon.
[0023] As an alternative, it may be provided that the rolling
element has a star-shaped contour. The rolling element may, for
example, be in the form of a star wheel, preferably of a star wheel
with five arms or points.
[0024] It may be provided that the rolling element is configured as
a wheel or as a roller or brush. It is advantageous here if the
width of the rolling element corresponds approximately to the width
of a classic thread-lifting means.
[0025] As an alternative, it is possible to use a rolling element,
the width of which corresponds substantially to the width of the
vacuum-cleaner nozzle.
[0026] It may also be provided that use is made of a plurality of
rolling elements which are connected fixedly to one another and are
distributed over the width of the vacuum-cleaner nozzle. The
vacuum-cleaner nozzle can thus be prevented from tilting laterally
in a constructionally simple manner.
[0027] The rolling element exhibits slip in relation to the
underlying surface as it rolls. It is advantageous if the contour
of the rolling element is non-symmetrical because it is thus
possible to ensure, in a constructionally simple manner, that the
rolling element has different slippage behavior depending on
whether the vacuum-cleaner nozzle is moved in the forward or in the
rearward direction. This, in turn, ensures that the suction mouth,
which is driven to perform a back and forth movement by the rolling
element, covers all regions of the underlying surface, even when it
is at a small distance from the underlying surface, so that a
uniform cleaning action along the underlying surface is
achieved.
[0028] In the case of a preferred embodiment of the vacuum-cleaner
nozzle according to the invention, the contour of the rolling
element is star-shaped and has a plurality of arms or points with
in each case two flanks running toward one another, the two flanks
being inclined differently in relation to the radial direction of
the rolling element. The different flank inclination in the case of
a star-shaped contour ensures different slippage of the rolling
element during forward and rearward movement of the vacuum-cleaner
nozzle. The different slippage, in turn, means that, during forward
and rearward movement of the vacuum-cleaner nozzle, different
positions of the rolling element are established in relation to a
specific region of the underlying surface, and thus different
positions of the suction mouth are also established in relation to
the underlying surface. This ensures that each point of the
underlying surface is also cleaned with an increased suction
flow.
[0029] The rolling element preferably has a friction-enhancing
covering. It may thus be provided, for example, that the rolling
element is coated with a rubber or latex covering or with a felt.
The friction-enhancing covering ensures that movement of the
vacuum-cleaner nozzle along the underlying surface results in a
rotary movement of the rolling element and thus in a variation in
distance of the suction mouth.
[0030] It is of particular advantage if, by way of the
friction-enhancing covering, the frictional behavior of the rolling
element as it rolls along the underlying surface in the operating
direction of the vacuum-cleaner nozzle differs from that as it
rolls counter to the operating direction, because this makes it
possible to ensure different slippage during forward and rearward
movement of the vacuum-cleaner nozzle.
[0031] It may be provided, for example, that the friction-enhancing
covering is structured and subjects the underlying surface to a
frictional force which is dependent on the rolling direction of the
rolling element.
[0032] The vacuum-cleaner nozzle preferably has a supporting wheel
which can be positioned on the underlying surface, the rolling
element being disposed between the supporting wheel and the suction
mouth, as seen in the operating direction of the vacuum-cleaner
nozzle. As an alternative, it may be provided that the rolling
element is positioned upstream of the suction mouth, as seen in the
operating direction.
[0033] It is advantageous if the vacuum-cleaner nozzle has at least
one thread-lifting means, the rolling element being disposed
between the suction mouth and the thread-lifting means. It is of
particular advantage if the rolling element and the suction mouth
are positioned between two thread-lifting means.
[0034] As has already been explained, it has proven to be
advantageous if the width of the suction mouth corresponds to
approximately 20 mm. It has been found that such a configuration of
the suction mouth allows reliable and uniform cleaning of the
underlying surface.
[0035] It is advantageous if it is possible to change the position
of the rolling element in relation to the underlying surface. This
makes it possible for the user to render the rolling element
inoperative by placing the rolling element in a position in which
it does not come into contact with the underlying surface. If, in
contrast, the rolling element is to be made operative, then it is
transferred by the user into a position in which it is much closer
to the underlying surface. It may thus be provided that the rolling
element is mounted such that it can be adjusted obliquely or
perpendicularly in relation to the underlying surface.
[0036] It is of particular advantage if the position of the rolling
element is coupled to the position of an adjustable bristle-covered
rim of the vacuum-cleaner nozzle. The bristle-covered rim is only
used for cleaning a hard surface; for cleaning a carpet, it is
moved to be at a distance from the carpet. Conversely, the rolling
element can be moved closer to the carpet, whereas, for cleaning a
hard surface, it can be moved a distance away from the hard
surface. This results in the rolling element only being used for
cleaning a carpet, that is to say that it is only for cleaning a
carpet that the distance of the suction mouth from the underlying
surface is changed on a periodic basis.
[0037] It may also be provided that the axial position of the
rolling element, that is to say the height of the latter in
relation to the suction mouth, cannot be changed. If use is made,
in such a case, of a bristle-covered rim which can be changed in
position, this results, depending on the position of the
bristle-covered rim, in the rolling element coming into mechanical
contact with the underlying surface and thus being able to become
operative, or else, on account of the bristle-covered rim, the
rolling element is kept at a distance from the underlying surface
and thus remains inoperative.
[0038] It is of particular advantage if the rotary movement of the
rolling element can be detected visually or acoustically by the
user. It is thus possible to provide, for example, a viewing window
through which the user can see the rolling element. It is possible
here for the viewing window to comprise a transparent covering with
colored marking over which the rolling element passes as it
rotates, so that a kind of "stroboscope effect" is established and
the rotation of the rolling element is represented to enhanced
effect. As an alternative, and/or in addition, the rotary movement
of the rolling element can be used to produce a sound.
[0039] As has been explained above, the rotary movement of the
rolling element along the underlying surface results in a back and
forth movement of the suction mouth. In the case of a preferred
embodiment, this movement can be detected by the user by touch.
[0040] However, it may also be provided that the vacuum-cleaner
nozzle has damping elements, so that mechanical vibrations of the
vacuum-cleaner nozzle can only be transmitted to a small extent to
a suction tube or a suction hose which can be connected to the
vacuum-cleaner nozzle.
[0041] Instead of using a rolling element, it is provided, in the
case of an advantageous embodiment of the invention, that the
lifting mechanism comprises a turbine wheel which can be subjected
to the action of a suction flow, is mounted such that it can be
rotated about an axis of rotation and the center of gravity of
which is disposed at a distance from the axis of rotation, and a
supporting element acting on the underlying surface at a distance
from the axis of rotation, as seen in the operating direction. In
the case of such a configuration, the raising and lowering
movements of the suction mouth are brought about by the rotation of
the eccentric turbine wheel, which can be made to rotate by the
suction flow. The turbine wheel has a center of gravity which is
disposed at a distance from its axis of rotation and, when the
turbine wheel rotates, this results in an unbalance, so that the
vacuum-cleaner nozzle is subjected to forces of inertia in the
bearing region of the turbine wheel. Since a supporting element
which can be positioned on the underlying surface, for example a
supporting wheel, is positioned at a distance from the axis of
rotation of the turbine wheel, the unbalance of the turbine wheel
results in a periodic pivoting movement of the vacuum-cleaner
nozzle such that the suction mouth is raised and lowered on a
periodic basis, while the supporting element assumes a constant
position in relation to the underlying surface.
[0042] It is advantageous if the turbine wheel is disposed within
the suction channel and does not completely fill the
suction-channel cross-section, because this ensures that the
suction flow which is channeled through the suction channel is not
adversely affected to any significant extent by the turbine
wheel.
[0043] The turbine wheel is preferably disposed in an end portion
of the suction channel which opens out into the suction mouth. It
is particularly advantageous if the turbine wheel is positioned
above the suction mouth.
[0044] The configuration of the turbine wheel with an unbalance is
achieved, in the case of a preferred embodiment, in that the
turbine wheel has turbine blades of different masses. It may thus
be provided, for example, that the turbine wheel has four turbine
blades oriented at an angle of approximately 90.degree. in relation
to one another, although one turbine blade is of a considerably
greater mass than the other turbine blades.
[0045] In order to it to be possible for the action of the turbine
wheel to be switched on and off optionally, it is provided, in the
case of an advantageous embodiment of the invention, that the
turbine wheel can be arrested. As an alternative, it may be
provided that the turbine wheel can be introduced into the suction
channel and removed therefrom, so that, in accordance with the
position of the turbine wheel, it is possible for a periodic
variation in distance of the suction mouth to be switched on and
off.
[0046] It may be provided that the rotatability of the turbine
wheel is coupled to the position of a bristle-covered rim of the
vacuum-cleaner nozzle. The bristle-covered rim is only used for
cleaning a hard surface and, in this case, the rotatability of the
turbine wheel can be blocked. If, instead, the bristle-covered rim
is deactivated, then the turbine wheel can be activated at the same
time because, in this case, the vacuum-cleaner nozzle is used for
cleaning a carpet, in the case of which it is advantageous if an
enhanced suction action can be achieved.
[0047] It is advantageous if the rotary movement can be detected by
the user visually, acoustically and/or by touch. It may thus be
provided, for example, that the vacuum-cleaner nozzle has a viewing
window through which the user can see the turbine wheel. The
viewing window may carry a transparent covering with a colored
marking over which the turbine blades of the turbine wheel pass. As
an alternative, and/or in addition, the turbine wheel can produce a
sound which makes the user aware that the turbine wheel is
rotating.
[0048] As explained in the introduction, the periodic change in
distance of the suction mouth from the underlying surface results
in an enhanced suction action, on account of which an improved
cleaning action can be achieved. The cleaning action is enhanced
further, in the case of a particularly advantageous embodiment, by
the suction mouth being bounded at least partially in the
circumferential direction by a surround which forms that region of
the vacuum-cleaner nozzle which projects furthest in the direction
of the underlying surface. The surround of the suction mouth thus
forms a projecting region by means of which the underlying surface
can be cleaned mechanically when the suction mouth assumes the
position in which it is minimally spaced apart from the underlying
surface. In this position, the underlying surface is treated
mechanically by the suction-mouth surround. For cleaning a carpet,
the surround penetrates into the pile of the carpet, so that this
is mechanically scrubbed. The cleaning action can thus be enhanced
to a considerable extent, but without this being associated with
the disadvantage of the user having to apply increasing pushing
force in order to move the vacuum-cleaner nozzle; rather, the
periodic change in distance of the suction mouth, and thus also of
the surround, which bounds the suction mouth at least partially in
the circumferential direction, ensures that, despite the mechanical
treatment of the underlying surface, the pushing forces which are
necessary in order to move the vacuum-cleaner nozzle can be kept to
a low level.
[0049] According to a preferred embodiment, the suction-mouth
surround forms the bearing surface for the vacuum-cleaner nozzle on
the underlying surface. In comparison with known vacuum-cleaner
nozzles, the vacuum-cleaner nozzle according to the invention thus
has a small bearing surface. This results in it being possible for
the vacuum-cleaner nozzle to penetrate to a more pronounced extent
into a carpet. The increased pushing forces which occur here are
reduced by the action of the lifting mechanism, which interacts
with the underlying surface and causes the suction mouth to be
raised and lowered cyclically. Despite an improved cleaning
performance, it is thus the case that the pushing forces are not
increased in relation to conventional vacuum-cleaner nozzles.
[0050] It is advantageous if the surround of the suction mouth
forms a crosspiece. It may be provided here that, in relation to
the operating direction of the vacuum-cleaner nozzle, use is made
of a front crosspiece and a rear crosspiece which extend over the
entire width of the vacuum-cleaner nozzle substantially at a
constant distance from one another.
[0051] It is advantageous if the vacuum-cleaner nozzle has at least
one thread-lifting means mounted on a base plate, the surround
projecting beyond the thread-lifting means in the direction of the
underlying surface and having no interruption in its region which
is adjacent to the thread-lifting means. It has been found that it
is thus possible to enhance the cleaning action of the
vacuum-cleaner nozzle.
[0052] The following description of preferred embodiments of the
invention serves for a more detailed explanation in conjunction
with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] FIG. 1 shows a basic illustration of a first embodiment of a
vacuum-cleaner nozzle according to the invention at a minimum
distance from an underlying surface;
[0054] FIG. 2 shows a basic illustration of the vacuum-cleaner
nozzle according to FIG. 1 at a maximum distance from the
underlying surface;
[0055] FIG. 3 shows a bottom view of the vacuum-cleaner nozzle
according to FIGS. 1 and 2;
[0056] FIG. 4 shows a basic illustration of a second embodiment of
a vacuum-cleaner nozzle according to the invention at a minimum
distance from the underlying surface; and
[0057] FIG. 5 shows a basic illustration of the vacuum-cleaner
nozzle according to FIG. 4 at a maximum distance from the
underlying surface.
DETAILED DESCRIPTION OF THE INVENTION
[0058] In FIGS. 1 to 3, there is illustrated, schematically, a
first embodiment of a vacuum-cleaner nozzle according to the
invention which is designated as a whole by the reference numeral
10 and can be displaced along an underlying surface, in the
embodiment illustrated along a carpet 12. The vacuum-cleaner nozzle
10 comprises a housing 14 with a suction channel 16 which passes
through the housing 14 and opens out into a suction mouth 18, which
is disposed on a base plate 20 of the housing 14 and is directed
toward the carpet 12.
[0059] The suction mouth 18 is bounded in a circumferential
direction by a surround which, in relation to an operating
direction 22 of the vacuum-cleaner nozzle 10, has a front
transverse crosspiece 24 and a rear transverse crosspiece 25, which
extend virtually over the entire width of the vacuum-cleaner nozzle
10, at a constant spacing from one another, and are connected
integrally to one another at the ends via longitudinal crosspieces
26, 27.
[0060] At its end which is directed away from the base plate 20,
the suction channel 16 forms a connector 29 for connection to a
suction tube, which is known per se and is therefore not
illustrated in the drawing, or a suction hose of a vacuum cleaner.
The latter has a suction subassembly (not illustrated), with the
aid of which a suction flow which leads through the suction channel
18 can be achieved.
[0061] Disposed on the underside of the base plate 20 upstream and
downstream of the surround of the suction mouth 18, as seen in the
operating direction 22, are two thread-lifting means 31, 32 which
cause threads to be picked up from the underlying surface which is
to be vacuumed, and which may be configured, for example, in the
form of a plastic strip which is covered with a bristly velours in
the direction of the carpet 12.
[0062] In its rearward region, in relation to the operating
direction 22, the vacuum-cleaner nozzle 10 has a supporting wheel
34 which is mounted on the housing 14 such that it can be rotated
about an axis of rotation 35 which is oriented at right angles to
the operating direction 22. For support on the carpet 12, the
vacuum-cleaner nozzle 10 also has two supporting rollers 37, 38
which are mounted in a rotatable manner on the housing 14 and are
disposed approximately level with the free ends of the transverse
crosspieces 24, 25, downstream of the rear transverse crosspiece 25
as seen in the operating direction 22.
[0063] As is clear from FIGS. 1 and 2, the transverse crosspieces
24, 25 project beyond the thread-lifting means 31, 32 and the
circumference of the supporting wheel 34 in the direction of the
carpet 12. Those peripheral regions of the transverse crosspieces
24 and 25 which are directed toward the carpet 12 form that region
of the vacuum-cleaner nozzle 10 which projects furthest in the
direction of the carpet 12, that is to say the transverse
crosspieces 24, 25 form the bearing surface for the vacuum-cleaner
nozzle 10 on the carpet 12 and penetrate into the pile 40 of the
carpet 12, so that the latter is treated mechanically by the
transverse crosspieces 24 and 25.
[0064] In order to clean the carpet 12, the vacuum-cleaner nozzle
10 is displaced back and forth in the operating direction 22 and
the carpet 12 is vacuumed. At the same time, the vacuum-cleaner
nozzle 10 is pivoted back and forth on a periodic basis about the
axis of rotation 35 of the support wheel 34, so that the distance
which the suction mouth 18 assumes from the carpet 12 is increased
and decreased on a periodic basis, as is illustrated in FIGS. 1 and
2. In order to produce the periodic movement of the vacuum-cleaner
nozzle 10, use is made of a lifting mechanism which, in the
exemplary embodiment illustrated in FIGS. 1 to 3, is formed as a
non-round rolling element which is mounted in a rotatable manner on
the housing 14 and is in the form of a star wheel 42 which acts on
the carpet 12 and is made to rotate as the vacuum-cleaner nozzle 10
is displaced. The star wheel 42 has the contour of a five-pointed
star which is of non-symmetrical configuration such that the five
points 45, 46, 47, 48 and 49 of the star have in each case two side
flanks 43, 44 which run toward one another and are inclined
differently in relation to the radial direction of the star wheel
42. The points 45, 46, 47, 48 and 49 of the star wheel 42 are
rounded at the ends, so that they each form a minimum bearing
surface for the star wheel 42 on the carpet 12, which ensures that
the star wheel 42 only penetrates to a slight extent into the pile
40 of the carpet 12.
[0065] On account of the non-round configuration of the star wheel
42, the rolling movement of the latter along the carpet 12 results
in periodic raising and lowering of the front region of the
vacuum-cleaner nozzle 10, as seen in the operating direction 22,
that is to say of the suction mouth 18 in particular. If the latter
assumes a position in which it is close to the carpet 12, as
illustrated in FIG. 1, then an increased flow resistance forms in
the region of the surround, this resulting in a strengthened
negative pressure within the suction channel 16. As the star wheel
42 rolls further, the vacuum-cleaner nozzle 10 is raised in the
region of the suction mouth 18, as is illustrated in FIG. 2. This
results in a reduced flow resistance in the region of the surround,
so that ambient air can be taken into suction channel 16. The
continuous periodic raising and lowering movement of the suction
mouth 18 thus results in a pulsating suction flow within the
suction channel 16, and this allows the suction action of the
vacuum-cleaner nozzle 10 to be enhanced to a considerable
extent.
[0066] The axial position of the star wheel 42 can be changed by
means of an adjusting member which is known per se and is therefore
not illustrated in the drawing, for example a connecting rod or a
pivot lever, so that the star wheel 42 can be moved to a distance
away from the carpet 12, so that it becomes inoperative.
Conversely, the star wheel 42 can also be moved closer to the
carpet 12 by means of the adjusting member, this resulting in an
increased displacement, that is to say an increased movement
amplitude of the suction mouth 18 as it moves back and forth.
[0067] The star wheel 42 may be covered by a friction-enhancing
covering, in particular by a bristly velours as is used for the
thread-lifting means 31, 32.
[0068] The periodic raising and lowering of the suction mouth 18
and of the front and rear transverse crosspieces 24, 25 also
ensures that, although mechanical treatment of the pile 40 of the
carpet 12 can take place, there is no need for the user of the
vacuum-cleaner nozzle 10 to apply any increased pushing force in
order to displace the vacuum-cleaner nozzle 10 along the carpet
12.
[0069] FIGS. 4 and 5 illustrate a second embodiment of a
vacuum-cleaner nozzle according to the invention, which is
designated as a whole by the reference numeral 55. This is a
similar configuration to the vacuum-cleaner nozzle 10 which has
been explained above with reference to FIGS. 1 to 3. For identical
components, use is thus made of the same reference numerals as were
used in FIGS. 1 to 3. To avoid repetition, reference is made in
this respect to the explanations which have been given above.
[0070] The vacuum-cleaner nozzle 55 differs from the vacuum-cleaner
nozzle 10 in that the lifting mechanism used, rather than being a
rolling element in the form of a star wheel, is formed by a turbine
wheel 57 which is disposed within the suction channel 16 and has
four turbine blades 58, 59, 60 and 61 which are oriented in a
mirror-symmetrical manner in relation to one another and at an
angle of 90.degree. in relation to one another in each case, the
turbine blade 58 having a considerably greater mass than the
turbine blades 59, 60 and 61. This results in the center of gravity
of the turbine wheel 57, which is mounted such that it can be
rotated freely about an axis of rotation 63, being disposed at a
distance from the axis of rotation 63. The turbine wheel 57 thus
forms an unbalance, and a rotation of the turbine wheel 57 as is
brought about by the suction flow drawn through the suction channel
16 results in the front region of the housing 14, as seen in the
operating direction 22, being raised and lowered on a periodic
basis, while the rearward region of the housing is supported on the
floor 12 by means of the supporting wheel 34. The periodic raising
and lowering of the front region of the housing 14, and thus of the
suction mouth 18 in particular, results, as has been explained
above, in a pulsating suction flow since the flow resistance in the
region of the surround changes on a periodic basis. An enhanced
suction action can thus be achieved in a constructionally simple
manner by using the unbalanced turbine wheel 57 in combination with
the supporting wheel 34 supported on the carpet 12. At the same
time, using the turbine wheel 57 makes it possible to form the
front and rear transverse crosspieces 24, 25 such that they project
beyond the thread-lifting means 31, 32 and the supporting wheel 34
in the direction of the carpet 12 and treat the pile 40 of the
carpet 12 mechanically without this nevertheless requiring an
increased pushing force in order to displace the vacuum-cleaner
nozzle 10.
* * * * *