U.S. patent application number 16/969916 was filed with the patent office on 2021-11-25 for retaining plate with centering device.
This patent application is currently assigned to Eurofilters Holding N.V.. The applicant listed for this patent is Eurofilters Holding N.V.. Invention is credited to Ralf SAUER, Jan Schultink.
Application Number | 20210361133 16/969916 |
Document ID | / |
Family ID | 1000005821139 |
Filed Date | 2021-11-25 |
United States Patent
Application |
20210361133 |
Kind Code |
A1 |
SAUER; Ralf ; et
al. |
November 25, 2021 |
RETAINING PLATE WITH CENTERING DEVICE
Abstract
The invention relates to a retainer plate for a vacuum cleaner
filter bag, comprising at least one sealing element, a base plate
in which a passage opening is formed, and a centering device which
extends at least partly around the periphery of the passage
opening, said centering device having at least one first spring
element which, upon deformation in the radial direction, exerts a
restoring force directed counter to the deformation.
Inventors: |
SAUER; Ralf; (Overpelt,
BE) ; Schultink; Jan; (Overpelt, BE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Eurofilters Holding N.V. |
Overpelt |
|
BE |
|
|
Assignee: |
Eurofilters Holding N.V.
Overpelt
BE
|
Family ID: |
1000005821139 |
Appl. No.: |
16/969916 |
Filed: |
February 22, 2019 |
PCT Filed: |
February 22, 2019 |
PCT NO: |
PCT/EP2019/054412 |
371 Date: |
August 13, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A47L 9/1436
20130101 |
International
Class: |
A47L 9/14 20060101
A47L009/14 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2018 |
EP |
18158368.3 |
Claims
1. A retaining plate for a vacuum cleaner filter bag, comprising: a
sealing element; a base plate in which a passage opening is formed;
and a centering device which extends at least partially along the
circumference of the passage opening, wherein the centering device
comprises at least one first spring element which, when deformed in
a radial direction, exerts a restoring force opposing the
deformation.
2. The retaining plate according to claim 1, wherein the at least
one spring element is formed from a deformed region of the
retaining plate.
3. The retaining plate according to claim 2, wherein the deformed
region is wave-shaped.
4. The retaining plate according to claim 3, wherein the deformed
region comprises one or more waves arranged concentrically with
respect to the passage opening.
5. The retaining plate according to claim 1, wherein the centering
device is a diaphragm spring.
6. The retaining plate according to claim 1, wherein the centering
device is formed integrally with the base plate.
7. The retaining plate according to claim 1, wherein the retaining
plate has at least one radial recess in the region of the centering
device.
8. The retaining plate according to claim 1, wherein the centering
device further comprises at least one second spring element;
wherein the at least one second spring element, when deformed in
the radial direction, exerts a restoring force opposing the
deformation; and wherein the arrangement of the at least one first
and second spring elements has no rotational symmetry with respect
to the passage opening.
9. The retaining plate according to claim 1, comprising a
thermoplastic and/or a recycled plastic
10. The retaining plate according to claim 9, wherein the retaining
plate is thermoformed, a deep-drawn part or an injection-molded
part.
11. The retaining cleaner filter bag comprising a retaining plate
according to claim 1.
12. A vacuum cleaner filter bag comprising: at least one sealing
element; and a retaining plate, wherein the retaining plate
comprises: a base plate in which a passage opening is formed; and a
centering device which extends at least partially along the
circumference of the passage opening, wherein the centering device
comprises at least one first spring element which, when deformed in
a radial direction, exerts a restoring force opposing the
deformation.
13. The vacuum cleaner filter bag according to claim 12, wherein
the at least one sealing element is provided in the bag and/or
between the bag and the retaining plate.
14. The vacuum cleaner filter bag according to claim 12, wherein
the at least one sealing element consists of rubber, TPE, or the
material of the vacuum cleaner filter bag.
Description
[0001] The invention concerns a retaining plate for a vacuum
cleaner bag.
[0002] Such retaining plates are known in many different forms, and
have a passage or filling opening through which the connection
nozzle of a vacuum cleaner can be inserted into the vacuum cleaner
bag. Such vacuum cleaner nozzles can have very different diameters.
In order to be able to use one retaining plate for different nozzle
diameters, an elastic seal or sealing ring is often used. Such
seals are usually made of rubber or a thermoplastic elastomer
(TPE). They can be formed integrally with the retaining plate, or
as a separate component on or under the retaining plate, or in the
filter bag. Retaining plates made of cardboard, where pre-cut parts
can be cut out to adapt the diameter of the opening to the vacuum
cleaner nozzle, are also known.
[0003] In particular, a vacuum cleaner bag is known from DE 20 2008
004 025, in which an elastic rubber layer is arranged between a
retaining plate and the vacuum cleaner bag, which is reinforced by
a further stiff material layer. In DE 20 2008 002 010 U1, a dust
collection bag is directly glued to a seal made of a polymeric
material. DE 10 2010 060 353 A1 describes a vacuum cleaner bag
comprising a plane, elastic sealing element which is arranged
inside and/or outside the bag wall. A vacuum cleaner bag is known
from DE 20 2004 008971 U1, in which a flexible sealing ring is
welded to the bag, and the retaining plate is welded to the sealing
ring. DE 10 2007 062 028 B4 describes a dust filter bag in which a
layer of rubber-elastic material forms a protruding sealing ring on
the inside of the filter bag.
[0004] In the following, the term "reference position" refers to
the relative position of a retaining plate to a vacuum cleaner
nozzle that is inserted into the plate, in the case when an
unfilled vacuum cleaner bag is fixed in the housing of a vacuum
cleaner. In the reference position, the vacuum cleaner nozzle is
usually centered in the passage opening, i.e., in the plane in
which the passage opening extends, the distance between the vacuum
cleaner nozzle and the edge of the passage opening is essentially
constant along the entire circumference of the vacuum cleaner
nozzle. In the reference position, the seal seals the vacuum
cleaner nozzle evenly around its circumference. This means that the
sealing properties of the retaining plate are optimal in the
reference position.
[0005] Depending on the arrangement of the retaining plate in the
installation space of a vacuum cleaner, it may occur that the
retaining plate is displaced in a radial direction relative to the
reference position when the vacuum cleaner bag is filled with dust
due to the weight of the suction material. Here, "radial" refers to
directions that lie in the plane in which the passage opening
extends. On the other hand, the vacuum cleaner nozzle itself is
usually not displaced by the weight of the suction material, as, in
operation, it is additionally fixed by the vacuum cleaner housing,
which has a much higher rigidity than the retaining plate.
[0006] Such a radial displacement of the retaining plate leads, in
particular, to the passage opening being displaced from the
reference position relative to the vacuum cleaner nozzle which is
inserted into the retaining plate. This often leads to a
deformation of the seal and thus to a deterioration of the sealing
properties.
[0007] Further, the retaining plate can shift in its holder when
the vacuum cleaner is opened to check the level of the dust bag,
which often involves removing the vacuum cleaner nozzle from the
bag. This, in turn, leads to a radial displacement of the vacuum
cleaner nozzle and the passage opening relative to each other when
the vacuum cleaner is closed, and, as a consequence, to the
negative effects on the sealing properties described above.
[0008] The object of the invention is therefore to provide a
retaining plate which enables reliable sealing.
[0009] This object is achieved by a retaining plate according to
claim 1. Particularly advantageous further embodiments are listed
in the dependent claims.
[0010] The retaining plate comprises a sealing element and a base
plate in which a passage opening is formed. In particular, the
passage opening can be circular. However, other shapes of the
passage opening are also possible, for example it can be oval, in
particular ellipsoidal, or rectangular.
[0011] The retaining plate may be configured to be attached to a
retaining device in a vacuum cleaner housing. Alternatively, the
vacuum cleaner filter bag may be configured to be slid over a
connection nozzle on the side of the vacuum cleaner with the help
of the retaining plate.
[0012] The sealing element is intended to prevent or limit the
escape of dust from the vacuum cleaner filter bag by sealing the
area between the inner edge of the passage opening and the outside
of a connection nozzle of the vacuum cleaner. The sealing element
can be made of rubber and/or TPE and/or the material of the vacuum
cleaner filter bag. However, it can also be made of any other
material that has sufficient elasticity to provide the necessary
sealing effect. The sealing element can be moulded onto the
retaining plate.
[0013] The inventors of the present application have recognized
that a problem with conventional retaining plates is that the
gaskets used therein do not have sufficient resilience to
compensate for the displacements described above. For this reason,
the retaining plate comprises a centering device which extends at
least partially along the edge of the passage opening, and
comprises at least one first spring element. According to the
invention, the spring element, when deformed in a radial direction,
exerts a restoring force opposing the deformation.
[0014] If a deformation of the spring element results from a radial
displacement of the passage opening relative to a vacuum cleaner
nozzle received in the retaining plate, the centering device
ensures, by means of the restoring force, that the retaining plate
is held in the reference position relative to the vacuum cleaner
nozzle and/or is returned to the reference position. In other
words, the deformation of the spring element creates a spring force
which is transferred to the vacuum cleaner nozzle. Since the nozzle
is fixed by the vacuum cleaner housing, as explained above, the
resulting counterforce acting from the vacuum cleaner nozzle on the
retaining plate results in a displacement of the retaining plate
which is opposite to the original radial displacement.
[0015] The spring element may be formed from a deformed region of
the retaining plate, in particular the base plate.
[0016] The deformed area may preferably be deformed in a wave-like
manner, and such deformation may include one or more waves. A wave
is defined as an elevation and/or depression perpendicular to the
main plane of extension of the retaining plate. In addition, a
plane area adjoining an elevation and/or depression can also be
part of the wave. The profile of such an elevation can be V- or
U-shaped, for example. If the deformed area contains several waves,
the individual waves may have the same profile or different
profiles. In the case of several waves, all waves may consist of
elevations or depressions, or elevations and depressions may
alternate. The individual waves may be directly adjacent to each
other or they can be separated from each other by undeformed
regions of the retaining plate.
[0017] The waves may be arranged concentrically in relation to the
passage opening. Here, concentric means that the waves run
essentially parallel to the edge of the opening.
[0018] On the one hand, such a deformation directly causes the
deformed region to assume spring-like properties. Further, the
deformed region can be compressed, thus allowing for the insertion
of vacuum cleaner nozzles with different diameters. Instead of
waves, the deformed region may also include other structures that
give the region spring-like properties.
[0019] The dimensions of the deformed region in the circumferential
direction of the opening may increase in a radially outward
direction. For example, in the case of a circular passage opening,
the spring element may be formed by the wave-like deformation of a
circular ring sector of the retaining plate, i.e. by a segment of
the retaining plate which, starting from the center of the passage
opening, is formed by two different radii and an intermediate
circular ring. Such a design makes it easy to ensure that the
restoring force acts perpendicular to the edge of the passage
opening.
[0020] The retaining plate may be manufactured in several pieces.
The centering element may be glued or welded to the base plate.
[0021] Alternatively, the retaining plate may be formed integrally,
in particular the centering device may be formed integrally with
the base plate. In this embodiment, the centering device may form
at least part of the edge of the passage opening.
[0022] The retaining plate may also include at least a second
spring element. In this case, the arrangement of the spring
elements may in particular be such that it has no rotational
symmetry with respect to the passage opening. In this case, n-fold
rotational symmetry of the arrangement of the spring elements with
respect to the passage opening is to be understood as meaning that
the arrangement of the spring elements can be transformed into
itself by a rotation of 360.degree./n about an axis corresponding
to the central axis of the vacuum cleaner nozzle in the reference
position. It should be noted that a "one-fold" rotational symmetry
is equivalent to no rotational symmetry. By arranging the spring
elements in this way, it is possible to achieve a stronger spring
effect against a main load direction. For example, the main load
direction can be the direction of gravity when the vacuum cleaner
is in operation.
[0023] The spring elements may be of the same size or of different
sizes. In particular, they may have different dimensions in the
circumferential direction of the passage opening. Furthermore, the
spring elements can be spaced apart from each other in the
circumferential direction, or they may only be separated by
cut-outs. In other words, between every two spring elements there
can be an undeformed region of the retaining plate, or a free
space.
[0024] The centering device of the retaining plate may also be
formed as a diaphragm spring. Here, a diaphragm spring describes a
spring which extends essentially in a main expansion plane, wherein
the dimensions in this plane (length, width) are many times greater
than in a direction perpendicular to this plane (thickness). The
diaphragm spring has a restoring force perpendicular to its main
expansion plane. In this way, it is possible to achieve
stabilization of the inserted vacuum cleaner nozzle not only in the
radial but also in the axial direction, i.e. against displacement
along its central axis. For example, the deformation of the
retaining plate due to the weight of the vacuumed material can be
prevented or compensated for even if the central axis of the vacuum
cleaner nozzle is parallel to the direction of gravity during
operation.
[0025] The retaining plate may include a thermoplastic. In
particular, the centering device may be made wholly or partly of a
thermoplastic material. In particular, the spring elements can be
made of a thermoplastic. In this context, a thermoplastic is
understood to be a thermoplastic material that is not a
thermoplastic elastomer. The thermoplastic can be, for example,
polyethylene terephthalate (PET), polycarbonate (PC), rigid
polyvinyl chloride (rigid PVC), polypropylene (PP), polyethylene
(PE) or polyactate (PLA). In one embodiment the thermoplastic can
be a recycled plastic, for example recycled PET (rPET) or recycled
PP (rPP). This can improve the environmental compatibility of the
retaining plate.
[0026] The retaining plate may be manufactured by thermoforming or
deep drawing. Production by injection moulding is also
possible.
[0027] The invention further provides a vacuum cleaner filter bag
according to claim 11, comprising a bag wall and one of the
retaining plates described above.
[0028] The retaining plate may therefore have one or more of the
features described above.
[0029] The bag wall of the vacuum cleaner filter bag may comprise
one or more layers of filter material, in particular one or more
layers of nonwoven fabric. Vacuum cleaner filter bags with such a
bag wall consisting of several layers of filter material are known
from EP 2 011 556 or EP 0 960 645, for example. As material for the
nonwoven layers, a wide variety of plastics can be used, for
example polypropylene and/or polyester. In particular, the layer of
the bag wall to be connected to the retaining plate can be a
nonwoven layer. The bag wall of the vacuum cleaner filter bag may
also contain or consist of recycled plastic. For example, the bag
wall can be designed as described in EP 3 219 376 A1.
[0030] The term nonwoven (German "Vliesstoff") is used according to
the definition in ISO Standard IS09092:1988 or CEM Standard
EN29092. In particular, the terms fibrous web or web and nonwoven
fabric are defined in the field of the manufacture of nonwoven
fabrics and also to be understood in the sense of the present
invention as follows. For the manufacture of a nonwoven, fibers
and/or filaments are used. The loose or loose and still unbound
fibers and/or filaments are referred to as web or fibrous web. Via
a so-called web bonding step, a nonwoven fabric is finally formed
from such a fibrous web, which has sufficient strength to be, e.g.,
wound up into rolls. In other words, a nonwoven fabric is made
self-supporting by bonding. (Details of the use of the definitions
and/or processes described herein can also be found in the standard
work "Nonwovens", W. Albrecht, H. Fuchs, W. Kittelmann, Wiley-VCH,
2000).
[0031] The bag wall may have a passage opening, in particular such
that the passage opening of the bag wall is aligned with the
passage opening of the base plate. Through the passage opening in
the base plate and the passage opening in the bag wall, an inlet
opening can be formed through which the air to be cleaned can flow
into the interior of the vacuum cleaner filter bag.
[0032] The vacuum cleaner filter bag may also include one or more
sealing elements that complement the sealing effect of the
centering device.
[0033] The sealing elements may be arranged in the bag and/or
between the bag and the retaining plate and/or on the retaining
plate.
[0034] The sealing elements may be made of rubber and/or TPE and/or
the material of the vacuum cleaner filter bag. However, they may
also be made of any other material that has sufficient elasticity
to provide the necessary sealing effect.
[0035] The invention further provides a vacuum cleaner bag
according to claim 12, comprising a bag wall, at least one sealing
element, and a retaining plate. The retaining plate comprises a
base plate in which a passage opening is formed, and a centering
device which extends at least partially along the edge of the
passage opening and comprises at least one first spring element.
When being deformed in radial direction, the spring element exerts
a restoring force in the opposite direction to the deformation.
[0036] In contrast to the vacuum cleaner bag according to claim 11,
in this embodiment, the at least one sealing element is not part of
the retaining plate, but a separate component. The at least one
sealing element may be located in the bag and/or between the bag
and the retaining plate.
[0037] The bag wall, the sealing element and the centering device
may each have one or more of the features described above.
[0038] Further features of the invention are explained below using
the exemplary figures, where
[0039] FIGS. 1a-1c schematically show a conventional retaining
plate with vacuum cleaner nozzle in reference position in top view
(a), as well as in reference position (b) and under load in a
radial direction (c) in sectional view
[0040] FIG. 2 schematically shows the structure of an exemplary
vacuum cleaner filter bag;
[0041] FIG. 3 shows a schematic representation of an exemplary
mounting plate in top view;
[0042] FIGS. 4a and 4b show a schematic diagram of an exemplary
retaining plate in reference position (a) and under load in a
radial direction (b) in sectional view; and
[0043] FIGS. 5a-5c show profiles of exemplary centering
devices.
[0044] FIG. 1a schematically shows a conventional retaining plate 1
with a passage opening 2 and a sealing element 3 attached to the
retaining plate 1 in a top view. A vacuum cleaner nozzle 4 is
inserted into the passage opening 2.
[0045] FIG. 1b shows a sectional view of the retaining plate 1 with
vacuum cleaner nozzle 4 in reference position. It can be seen that
the sealing element 3 completely seals the vacuum cleaner nozzle
4.
[0046] FIG. 1c shows the retaining plate 1 with inserted vacuum
cleaner nozzle 4 after a displacement in radial direction, e.g. due
to the weight force of suction material contained in a vacuum
cleaner bag, which is illustrated by the arrow pointing downwards.
The displacement has created a gap 5 between the sealing element 3
and the vacuum cleaner nozzle 4, through which dust can escape from
the vacuum cleaner bag into the interior of the vacuum cleaner.
[0047] FIG. 2 shows the schematic structure of an exemplary vacuum
cleaner filter bag. The filter bag comprises a bag wall 6, a
retaining plate 7 and an inlet opening through which the air to be
filtered flows into the filter bag. The inlet opening is formed
here by a passage opening 8 in the base plate of the retaining
plate 7 and an aligned passage opening in the bag wall 6. The
retaining plate 7 is used to fix the vacuum cleaner filter bag in a
corresponding holder in a vacuum cleaner housing.
[0048] Bag wall 6 comprises at least one nonwoven layer, for
example of a meltblown nonwoven or a spunbond nonwoven.
[0049] The retaining plate 7 comprises a base plate made of a
thermoplastic material. For example, recycled plastic material such
as recycled polypropylene (rPP) or recycled polyethylene
terephthalate (rPET) can be used for the base plate.
[0050] For many plastic recyclates there are relevant international
standards. For PET plastic recyclates, for example, DIN EN
15353:2007 is relevant.
[0051] The term "recycled plastics" used for the purposes of the
present invention is to be understood as synonymous with plastic
recyclates. For the conceptual definition, reference is made to the
standard DIN EN 15347:2007.
[0052] A top view of an exemplary retaining plate, which can be
used in conjunction with a filter bag as shown in FIG. 2, is shown
in FIG. 3. This shows the retaining plate 7 with passage opening 8.
The base plate of the retaining plate 7 is here illustrated to be
schematically rectangular, but it can have any shape, in particular
one which may correspond to the corresponding retaining device in
the vacuum cleaner housing.
[0053] FIG. 3 also shows a centering device 9 as part of the
retaining plate 7, shown here as integrally formed with the base
plate of the retaining plate 7, but it can also be a separate
element connected to the retaining plate 7 by gluing and/or
welding. In FIG. 3, the centering device runs completely around the
circumference of the passage opening 8, but it can also be limited
to part of the circumference.
[0054] The centering device 9 shown in FIG. 3 comprises four spring
elements 10, 11, 12, 13, which are separated from each other by
cut-outs 14. In other words, in the embodiment shown in FIG. 3, the
centering device 9 consists of the four spring elements 10, 11, 12,
13, but the centering device 9 can also comprise a base plate on
which the spring elements are fixed, for example by gluing,
screwing or welding. In this case, the spring elements may be
separate elements spaced from each other, in particular they may be
spaced from each other in the circumferential direction of the
passage opening 8. The distances between the spring elements may be
equal or different. The number of spring elements is not limited to
four, but the centering device 9 always includes at least one
spring element.
[0055] In FIG. 3, the spring elements 10, 11, 12, 13 are formed by
deformed regions of the retaining plate 7. The deformed regions are
formed by alternating elevations and/or depressions, whereby
additional flat regions can be arranged between the elevations
and/or depressions. In particular, the sequence of deformations
repeats itself periodically, with one period forming a wave 15,
e.g. if the deformed regions are formed by alternating elevations
and depressions, one elevation and an adjacent depression each
represent a wave 15.
[0056] In FIG. 3 the spring elements 10, 11, 12, 13 each comprise
four waves 15, but the spring elements can have any number of waves
15.
[0057] In the embodiment shown in FIG. 3, the waves 15 form
concentric ring structures around the passage opening 8.
[0058] FIG. 3 further shows that the arrangement of the spring
elements 10, 11, 12, 13 has no rotational symmetry with respect to
the passage opening 8. In particular, the spring element 10 is
larger than the spring elements 11, 12 and 13, which also means
that the spring force of the spring element 10 is larger than that
of the spring elements 11, 12 and 13. If the retaining plate 7 is
installed in a vacuum cleaner in such a way that the main load
direction of is directed towards the spring element 10, the largest
restoring force is achieved in this direction. In FIG. 3, this is
illustrated with an arrow indicating the direction of gravity. If
gravity acts in the direction of the arrow, spring element 10 is
compressed the most by the displacement of the retaining plate 7.
Since spring element 10 also has the strongest restoring force,
this ensures that the displacement in the main load direction can
be compensated.
[0059] The arrangement of the spring elements can also have n-fold
rotational symmetry with respect to the passage opening 8, where n
is an integer greater than 1. This is advantageous, for example, if
there is no main load direction in the plane of the retaining plate
7 during operation of the vacuum cleaner. In particular, this may
be the case when the axis of the vacuum cleaner nozzle 4 is
substantially parallel to the direction of gravity during
operation.
[0060] FIGS. 4a and 4b show a schematic sectional view through the
exemplary retaining plate 7 with an inserted vacuum cleaner nozzle
4, analogous to FIGS. 1b and 1c. FIG. 4a and FIG. 4b also show a
sealing element 16, which is attached to the inside of the
retaining plate 7. In particular, the illustrated sealing element
16 is attached to a spring element, which can be advantageous in
order to save material. The sealing element 16 can also be attached
to undeformed regions of the retaining plate 7. Furthermore,
sealing element 16 can completely cover the spring elements in
radial direction when viewed in a top view. This is advantageous,
for example, if the spring elements are separated from each other
by cut-outs 14. The sealing element 16 can also be attached to the
outside of the retaining plate 7.
[0061] The sealing element 16 may comprise a thermoplastic
elastomer, e.g., based on polypropylene, or may consist of it. The
sealing element 16 is intended to prevent or limit the escape of
dust from the vacuum cleaner filter bag by sealing the area between
the inner edge of the passage opening 8 and the outside of a
connection nozzle of the vacuum cleaner. However, the sealing lip
shown here is only optional. It is also conceivable that the bag
material of the vacuum cleaner filter bag itself could be used as a
sealing ring, as for example disclosed in DE 102 03 460. It is also
possible to use a sealing diaphragm between retaining plate 7 and
bag wall 6, as disclosed in EP 2 044 874.
[0062] FIG. 4a shows the retaining plate 7 and the vacuum cleaner
nozzle 4 in reference position. It can be seen that the sealing
element 16 completely seals the vacuum cleaner nozzle 4.
[0063] FIG. 4b shows the support plate 7 and the vacuum cleaner
nozzle 4 under the influence of a force, illustrated by the arrow,
which corresponds to the force acting on the support plate 1 in
FIG. 1c. FIG. 4b shows that the spring element 10 is deformed when
compared to FIG. 4a. Due to this deformation, it exerts a restoring
force which is opposite to the acting force. The displacement of
plate 7 and the resulting deformation of sealing element 16 is less
than in the case illustrated in FIG. 1c, even though the acting
force is the same. This means that there is no gap, or a smaller
one, between the sealing element 16 and the vacuum cleaner nozzle
4. In other words, the sealing properties of the sealing element 16
are improved by the force acting in a radial direction.
[0064] In the situation illustrated in FIG. 4b, the forces between
the spring element and the vacuum cleaner nozzle 4 act indirectly
via the sealing element 16, but it is also possible that the vacuum
cleaner nozzle 4 is in direct contact with the spring element and
the forces act directly between these elements.
[0065] FIG. 5 shows possible designs of spring elements 10, 11, 12,
13 in profile. A wave 15, for example, can be formed by alternating
U-shaped elevations and flat regions, as shown in FIG. 5a.
Alternatively, they can be formed by alternating U-shaped
elevations and U-shaped depressions, as shown in FIG. 5b. In this
case, the entire wave has an S-profile. FIG. 5c shows an embodiment
in which V-shaped elevations and depressions alternate. However, it
is also possible to combine U- and V-shaped elevations with each
other and/or flat regions. The elevations and/or depressions need
not be pointed or rounded either, but may be flattened at their
respective ends.
[0066] It is understood that features described in the embodiments
above are not limited to these special combinations and are also
possible in any other combination. Further, it is understood that
the geometries shown in the figures are only exemplary and can also
be designed in any other form.
* * * * *