EP2532292B1 - Suction nozzle and vacuum cleaner - Google Patents

Description

Background of the invention

The invention relates to a suction nozzle for a vacuum cleaner, with a suction nozzle housing which forms a flow channel for the flow connection of a suction mouth with a suction fan, the cross section of the flow duct narrowing in a funnel shape starting from the suction mouth in a front view. The invention also relates to a vacuum cleaner equipped with such a suction nozzle.

State of the art

Vacuum cleaners are used to pick up dirt on floor surfaces, furniture or the like by means of a suction air stream. For this purpose, the suction mouth of a suction nozzle is placed on the surface to be cleaned so that dust or other contaminants are sucked in by the suction air flow. The suction air flow is generated by a suction fan which is in flow connection with a dust separation device, for example a centrifugal separator or dust filter bag. The dirt particles picked up by the suction nozzle are collected in the dust separator, while the cleaned air is released into the environment. The suction mouth of a suction nozzle suitable for floor cleaning usually has a rectangular shape and extends transversely to the sliding direction. It is desirable that a homogeneous negative pressure is applied over the entire width of the suction mouth in order to achieve a uniform suction result. In order to be able to use the power of the suction fan particularly effectively, the lowest possible pressure loss between the suction mouth and the suction fan is also advantageous.

The suction fan and the dust separation device can be attached, for example, to a push tube that is mechanically connected directly to the suction nozzle and usually also forms part of the flow channel between the suction nozzle and the suction fan (stick vacuum cleaner). According to another common design, the suction fan and the dust separation device are arranged in the housing of a separate subframe, which can be moved over the floor surface by means of a chassis and is fluidly connected to the push tube inserted into the suction nozzle through a flexible hose line (kansiter vacuum cleaner).

A suction nozzle of the type mentioned is from the patent CH 271904 known. The suction nozzle consists of a suction nozzle housing that forms a flow channel for the suction air flow of the vacuum cleaner. At one end, the suction mouth of the suction nozzle, which is guided over the floor surface during the cleaning process, opens into the flow channel of the suction nozzle housing. At its other end, this flow channel opens into a connection piece into which the vacuum cleaner's push tube, which is connected to the suction fan, is inserted. The cross-section of the part of the flow channel on the suction mouth side is funnel-shaped in a front view and forms the transition between the suction mouth extending in the transverse direction and the circular connection piece. In a side view, the longitudinal axis of the funnel-shaped cross section of the flow channel runs straight in the vertical direction before the following, nozzle-side circular cross section bends from the tip of the funnel at an angle of approximately 45 °. This generally customary embodiment can be disadvantageous in terms of flow technology with regard to the distribution of the flow velocity and pressure loss. In addition, after the push tube has been inserted, the suction nozzle can be a hindrance to handling when driving under furniture.

In the European patent application EP 0 404 278 A2 A nozzle tool for a wet cleaning device is disclosed, the cross section of which also narrows in a funnel-shaped manner in a front view. The longitudinal axis of this cross section is straight on the suction mouth side, but inclined at an angle of approximately 20 ° with respect to the vertical, with the subsequent connection piece again bending from the tip of the funnel. This design can also be unfavorable in terms of flow.

The US patent U.S. 1,519,868 A discloses a suction nozzle in which the cross section of the flow channel narrows in a section in a funnel shape. The longitudinal extension of this section of the flow channel extends in an arcuate manner in a side view, the arc of the flow channel formed thereby extending over an angle of approximately 90 °.

A similar suction nozzle is from the international publication WO 2009/128 763 A1 known, there being a further arc which is curved in the opposite direction and which extends over a smaller angular range. A suction nozzle with such a flow channel course is also from the US patent application US 2009/0 320 234 A1 known, where in addition the flow channel either narrows in cross section in the middle or divides into two partial flow channels which later converge again.

From the US patent U.S. 1,951,316 A a suction nozzle with a flow channel is known, the cross section of which also narrows in a funnel shape starting from the suction mouth, the suction nozzle being specially designed so that all paths on which air moves from the suction mouth to the suction nozzle have the same length. In one embodiment, the air in the middle of the flow channel follows an undulating path, while the air at the edges of the flow channel is initially directed a short distance upwards and then directly horizontally to the connection piece.

The problem underlying the invention

The invention is based on the object of providing an improved suction nozzle and an improved vacuum cleaner. In particular, generic suction nozzles and vacuum cleaners are to be developed in such a way that the dust pick-up is improved, the pressure loss is kept low and good suction behavior is also achieved in the lateral end regions of the suction mouth. In addition, the overall height of the nozzle should be dimensioned so that driving under furniture or the like is hindered as little as possible.

Solution according to the invention

The reference signs in all claims do not have a restrictive effect, but are only intended to improve their readability.

The object on which the invention is based is achieved with a suction nozzle having the features of claim 1. The flow channel can then open into the connecting piece for the push tube, which is usually articulated to the remaining part of the suction nozzle.

The object is also achieved by a vacuum cleaner equipped with such a suction nozzle. the vacuum cleaner is preferably a style vacuum cleaner.

In the context of the present invention, the longitudinal extension is the extension of the flow channel in the direction of flow. The cross-section of the flow channel is its cross-sectional area perpendicular to the longitudinal extent of the channel. Terms like frontal, side, above, below, etc. are always to be understood in relation to the intended position of use of the suction nozzle in the context of the present invention.

It is an achievable advantage of the invention that the overall height of such a suction nozzle can be made so small that it is easy to drive under even low furniture, for example beds. The inventors have found that, despite the curvature, a uniform pressure distribution can be achieved over the width of the suction mouth. It can also be achieved that the pressure loss in the flow channel of the suction nozzle on the suction mouth side is relatively low, so that the power of the suction fan is used particularly efficiently.

Preferred embodiment of the invention

Advantageous training or further developments which can be used individually or in combination with one another are the subject matter of the dependent claims.

According to a first preferred embodiment of the invention, the curvature of the cross section of the flow channel runs along a circular or elliptical arc. Such a contour is particularly easy to manufacture in terms of production technology and, due to its compact shape, requires relatively little material expenditure.

It is also advantageous if the arc extends over an angle of 45 ° or more, particularly preferably of 70 ° or more. The arc preferably extends over an angle of 135 ° or less, particularly preferably 120 ° or less. A particularly preferred arc extends over an angle of approximately 90 °. This embodiment of the invention has the particular advantage that a connecting piece can be connected to the suction nozzle housing in such an articulated manner with little effort that it can also be aligned horizontally without difficulty. As a result, a push tube pushed into the connection piece for moving under furniture can advantageously be conveniently displaced into a horizontal position.

In a side view, the cross section of the flow channel has areas with different directions of curvature. The longitudinal extent of the cross-section of the flow channel in a side view from the suction mouth is initially curved in a first arc section around a transverse axis located below the flow channel and then in a second arc section about a transverse axis located above the flow channel. Even if the flow channel is somewhat elongated in this embodiment, the pressure loss in such a bionic pipe bend is surprisingly lower than in a channel that is curved in only one direction. A transverse axis is an axis which, when the vacuum cleaner is used normally, runs perpendicular to the longitudinal extension of the flow channel and parallel to the floor to be cleaned.

This design is particularly effective when the second curved section extends over an angle of 5 ° or more, particularly preferably 7 ° or more. It preferably extends over 30 ° or less, particularly preferably over 20 ° or less. The first arch section extends advantageously for the subsequent compensation of the first of all, the flow channel pointing away from the connecting piece over an angle of 95 ° or more and particularly preferably 110 ° or less.

For moving under furniture, it has proven to be particularly advantageous that the vertical diameter of the curved longitudinal extension is less than 12.5 cm, preferably less than 10 cm and in particular around 7.5 cm in a side view. The suction nozzle is particularly compact as a result, without the function being impaired when the flow channel is designed according to the invention.

Furthermore, it is advantageous for the handling of the vacuum cleaner if the suction nozzle is equipped with a chassis in the form of a wheel arrangement which does not protrude above the suction nozzle housing and thus does not hinder the passage of furniture. The sliding base of the suction nozzle is relieved by the undercarriage, especially in the case of a stick vacuum cleaner, whereby a reduction in the displacement forces can be achieved when cleaning flexible floor coverings.

In this case, it is particularly advantageous that the axis of rotation of the wheel arrangement is arranged below the flow channel of the suction nozzle. With this design, the wheels can be rotatably attached to a continuous axle without affecting the flow in the suction channel. It is also preferred that the outer axial surfaces of the wheels are provided with elastic protective caps so that lateral contact of the wheels does not damage sensitive surfaces on furniture. The center of the thin-walled protective caps is particularly advantageously designed to bulge outwards so that it can deflect inwards when it comes into contact with pieces of furniture.

The preferred wheel diameter is greater than 20 mm, preferably greater than 40 mm, particularly preferably greater than 50 mm. The preferred wheel diameter is smaller than 90 mm, preferably smaller than 80 mm, particularly preferably smaller than 70 mm, for example approx. 60 mm. This advantageously achieves the fact that the wheels sink into a flexible surface as little as possible, on the other hand the wheels are not so large that they prevent furniture from being driven underneath. The running surfaces of adjacent wheels spaced apart in the direction of displacement are preferably less than 40 mm apart, particularly preferably less than 20 mm, particularly preferably less than 10 mm. They are preferably more than 1 mm apart, preferably more than 3 mm, for example 5 mm. On the one hand, this allows a compact design, on the other hand, it prevents larger dirt particles from becoming wedged between the wheels and blocking the wheels as a result.

Furthermore, for the equalization of the pressure distribution over the width of the suction mouth, it is advantageous if the cross-section of the flow channel, which narrows in the form of a funnel in a front view, is curved. A particularly favorable pressure distribution is achieved when the tangent to the cross section of the flow channel in a frontal view on the suction mouth side as in the transition to the suction nozzle runs parallel to the plane of symmetry of the suction nozzle. The plane of symmetry of the suction nozzle is usually spanned by the vertical and the longitudinal extension of the flow channel.

Furthermore, it is favorable in terms of flow if the free flow cross-section in the suction nozzle expands continuously from the suction mouth to the entry into a connection piece for the thrust tube. This design has the effect of a diffuser and reduces the pressure-reducing vortex formation in the flow channel.

With the invention, the overall height of the suction nozzle can advantageously be made so small that it is easy to drive under even low furniture, for example beds. At the same time, the pressure loss in the flow channel of the suction nozzle on the suction mouth side can be kept low and a uniform pressure distribution can be achieved over the width of the suction mouth.

Brief description of the figures

The invention is explained in more detail below with reference to schematic drawings of two exemplary embodiments with further details.

Fig. 1:

die Darstellung eines erfindungsgemäß ausgestatteten Kansiterstaubsaugers;

Fig. 2:

eine frontale Ansicht einer ersten Saugdüse, die abgesehen von dem Winkelbereich des ersten Bogenabschnitts erfindungsgemäß ausgebildet ist;

Fig. 3:

die Saugdüse nach Fig. 2 in einer seitlichen, perspektivischen Ansicht;

Fig. 4:

die Saugdüse nach Fig. 2 und 3 in einer Ansicht von unten;

Fig. 5:

die gleiche Saugdüse in einem Längsschnitt;

und schließlich

Fig. 6:

einen Längsschnitt durch eine andere, erfindungsgemäß ausgebildete Saugdüse.

Show it:

Fig. 1:

the representation of a kansit vacuum cleaner equipped according to the invention;

Fig. 2:

a front view of a first suction nozzle, which is formed according to the invention apart from the angular range of the first arcuate section;

Fig. 3:

the suction nozzle Fig. 2 in a lateral, perspective view;

Fig. 4:

the suction nozzle Fig. 2 and 3 in a view from below;

Fig. 5:

the same suction nozzle in a longitudinal section;

and finally

Fig. 6:

a longitudinal section through another suction nozzle designed according to the invention.

Detailed description of the invention on the basis of two exemplary embodiments

The in Fig. 1 illustrated vacuum cleaner 1 is designed as a kansit vacuum cleaner. In principle, however, the invention can also be used with advantage in other designs, for example a stick vacuum cleaner. All direction and location information relates to a suction nozzle which rests on a horizontal surface and is moved in the forward direction, that is, in the horizontal direction against the longitudinal extension of a suction tube connected to the suction nozzle.

The vacuum cleaner 1 after Fig. 1 consists of a separate subframe 2, which is equipped with a chassis 3 and can therefore be moved comfortably over the floor surface to be cleaned. The housing 4 of the subframe 2 accommodates in particular a suction fan 5 and a dust separation device 6 in the form of a dust filter bag 7. Further, not shown components of the subframe are For example, a windable power cable for electrical connection to a power supply system, control devices for switching on and for power setting, electronic control devices and a storage compartment for accessories such as suction brushes or the like.

Upstream of the dust separation device 6 there is a connection 8 for attaching a flexible suction hose 9, which in turn is flow-connected to a telescopic push tube 10. The thrust tube 10 is pushed into a connection piece 11 of the suction nozzle 12 in a sealed manner. Upstream of the connecting piece 11 articulated to the rest of the suction nozzle 12, the suction nozzle 12 also has a suction nozzle housing 13 and a sliding base 14 with a suction mouth 15 to be guided over the floor surface to be cleaned. The suction nozzle 12 also has a wheel arrangement 16 for supporting the thrust tube 10.

During the cleaning process, the sliding sole 14 lies tightly against the floor surface, with an air flow being sucked in by the negative pressure applied to the suction mouth 15 and carrying the dust on the floor surface with it. The air flow carrying dirt is passed through the thrust tube 10 and the suction hose 9 into the dust separating device 6, where the dust is separated out in the dust filter bag 7. The now cleaned air flow passes through the suction fan 5 and is then discharged into the environment through an opening 17 in the housing 4 of the unit carrier 2.

the Figures 2 to 5 show a first suction nozzle 12 for use on the vacuum cleaner according to FIG Fig. 1 . How out Fig. 4 As can be seen, the suction nozzle 12 has a sliding sole 14 with a rectangular suction mouth 15 which extends essentially transversely to the direction of displacement of the suction nozzle and has a width B which is many times greater than its length L. In order that sufficient dust absorption also takes place in the edge regions of the suction mouth 15, it is desirable that a vacuum that is as uniform as possible is applied over the width B of the suction mouth 15.

As in Fig. 2 recognizable, the flow channel in the suction nozzle housing 13 tapers from the suction mouth 15 in the direction of the connecting piece 11 in a funnel shape. From the shape of the funnel-shaped area shown in the frontal, uncut view of the Suction nozzle housing 13 can be closed directly on the shape of the flow channel located therein, since this has a substantially uniform wall thickness. The funnel-shaped design of the flow channel is slightly curved, the tangent to the arc 18 on the suction mouth side initially running approximately parallel to the plane of symmetry of the suction nozzle 12. This is spanned by the vertical to the bottom surface and the longitudinal extent of the flow channel and protrudes in the illustration Fig. 2 centrally and vertically out of the suction nozzle 12. The bend 18 is adjoined downstream by an area 19 in which the funnel tapers essentially linearly before another bend 20, which is curved in opposite directions, joins in the transition area to the connecting piece 11. This design achieves a gentle flow transition from the suction mouth 15 to the connection piece 11 at the edge.

Fig. 3 and 5 show the course of the flow channel in a side view. The longitudinal extension 21 of the funnel-shaped narrowing cross-section of the flow channel runs in a side view in the exemplary embodiment in an arc-shaped curve starting from the suction mouth 15 and approximately follows the course of a circular arc over an angle of approximately 90 °. This means that the suction air flow is gently deflected in this direction as well, which reduces the pressure loss in the pipe bend. At the same time, the free flow cross-section in the pipe bend widens slightly, which further reduces the pressure-consuming vortex formation in the suction air flow.

The diameter of the wheel arrangement 16 rotatably mounted on the suction nozzle housing 13 is dimensioned such that it only protrudes insignificantly above the suction nozzle housing 13. The wheel arrangement 16 thus does not hinder the driving under furniture, whereby it should be noted that the articulated connection piece 11 together with the inserted push tube 10 can be pivoted downward during this process. The axis of rotation 26 of the wheel arrangement 16 runs below the flow channel of the suction nozzle housing 13, so that the wheel arrangement 16 can in principle be equipped with a continuous axis. In the exemplary embodiment, however, the wheels are inserted separately into associated receptacles in the suction nozzle housing 13 via stub axles 27.

The in Fig. 6 A further reduction in the pressure loss is surprisingly achieved in that the cross section of the flow channel has areas of different curvature directions in a lateral view, shown in the pipe bend shown in the longitudinal section between the suction mouth 15 and the connecting piece 11. It is provided that the longitudinal extension of the cross-section of the flow channel in a side view from the suction mouth 15, starting first from the connecting piece 11, in a first curved section 22 around a first transverse axis 23 located below the flow channel and then pointing towards the connecting piece 11 in a second curved section 24 around a Transverse axis 25 located above the flow channel extends in a curved manner.

Surprisingly, the pressure loss drops due to this meandering course of the flow channel compared to an arcuate pipe bend, without this design being associated with significant disadvantages with regard to its overall height.

Due to the arcuate curvature, the overall height of the suction nozzle 12 can be made so small that it is easy to drive under even low furniture, for example beds. The pressure loss in the flow channel of the suction nozzle 12 on the suction mouth side can be kept low so that the power of the suction fan 5 is used particularly efficiently. A uniform pressure distribution over the width of the suction mouth 15 can also be achieved.

The features disclosed in the above description, the claims and the drawings can be important both individually and in any combination for the implementation of the invention in its various configurations.

Reference number

1

vacuum cleaner

2

Subframe

3

landing gear

4th

casing

5

Suction fan

6th

Dust separator

7th

Dust filter bag

8th

connection

9

Suction hose

10

Thrust tube

11th

Connection piece

12th

Suction nozzle

13th

Suction nozzle housing

14th

Sliding sole

15th

Suction mouth

16

Wheel arrangement

17th

opening

18th

arc

19th

Area

20th

arc

21

Longitudinal extension

22nd

(first) arch section

23

(first) transverse axis

24

(second) arch section

25th

(second) transverse axis

26th

Axis of rotation (of the wheel arrangement)

27

Stub axle

B.

Width (of the suction mouth)

L.

Length (of the suction mouth)

Claims (8)

1. Suction nozzle (12) for a vacuum cleaner, with a suction nozzle housing (13), which embodies a flow channel to connect the flow of a suction mouth (15) to a suction fan (5), wherein the cross section of the flow channel narrows starting from the suction mouth (15) in the shape of a funnel in a frontal view, wherein the longitudinal extent (21) of the cross section of the flow channel which narrows in the shape of a funnel has regions of differing direction of curvature in the suction nozzle housing (13) in a lateral view, in such a way that the longitudinal extent (21) first runs in a curved manner starting from the suction mouth (15) in a first curved section (22) about a first transverse axis (23) situated beneath the flow channel and subsequently in a second curved section (24) about a second transverse axis (25) situated above the flow channel, wherein the first curved section (22) extends over an angle of 95° or more; characterised by a wheel arrangement (16) which does not projects upwardly over the suction nozzle housing (13), wherein the rotational axis (26) of the wheel arrangement (16) is arranged beneath the flow channel of the suction nozzle (12).
2. Suction nozzle according to claim 1, characterised in that the second curved section (24) extends over an angle of 5° to 20°.
3. Suction nozzle according to one of the preceding claims, characterised in that the vertical diameter of the curved longitudinal extent (21) is less than 12.5 cm, preferably less than 10 cm and in particular is around 7.5 cm in a lateral view.
4. Suction nozzle according to one of the preceding claims, characterised in that the wheel arrangement (16) is fitted with a continuous axle.
5. Suction nozzle according to one of the preceding claims, characterised in that the cross section of the flow channel which narrows in the shape of a funnel in a frontal view runs in a curved manner.
6. Suction nozzle according to claim 5, characterised in that the tangent to the cross section of the flow channel in a frontal view runs parallel to the symmetry plane of the suction nozzle (12) on the suction mouth side as in the transition to the suction connecting piece (11).
7. Suction nozzle according to one of the preceding claims, characterised in that the free flow cross section in the suction nozzle (12) narrows continuously from the suction mouth (15) out to the point at which it enters a connecting piece (11) for the push tube (10).
8. Vacuum cleaner (1) with a suction nozzle according to one of the preceding claims.

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