EP2338399B1 - Floor nozzle for a vacuum cleaner - Google Patents

Description

The invention relates to a floor nozzle for vacuum cleaners with an intermediate piece, a suction head which is tiltably connected about a horizontal tilting axis to a first, front end of the intermediate piece, at least one support element, which is arranged at a second, rear end of the intermediate piece, and a suction tube or Saugschlauchanschluss which is connected about a horizontal hinge axis between an upper and a lower stop position in a predetermined angular range pivotally connected to the second, rear end of the intermediate piece, wherein the angle formed above the horizontal hinge axis between the Saugrohranschluss and the intermediate piece angle before the upper stop position increases to the lower stop position.

Floor nozzles usually have at least one joint between the suction head and the suction pipe connection. This ensures that raising or lowering the suction tube does not lead to tilting of the suction head and an associated reduction in suction power. Such tilting arises in so-called Einelenkdüsen even when the suction pipe is pivoted about an upper or lower attachment point of the joint.

To prevent these disadvantages generic double-jointed nozzles are known, for example from the DE 28 46 847 A1 , In the known Doppelgelenkdüse takes place when cleaning a horizontal floor surface, a force support in the vertical direction on two rear rollers as support elements. As a result, vertical forces introduced at the suction pipe connection via a vacuum cleaner pipe are compensated, wherein the suction head can align itself freely due to the double-jointed connection with the intermediate piece designed as suction channel and always rests flatly on the surface to be cleaned. The double-articulated design causes in the known floor nozzle at the same time that the suction head initially rests only by its weight on the surface to be cleaned. When using the floor nozzle, a negative pressure is generated by the suction air flow at the bottom of the suction head, are absorbed by the dirt particles and the bottom surface is cleaned. Due to the negative pressure, the suction head sucks on the bottom surface, whereby the forces generated by the negative pressure and acting in the vertical direction add up to the weight of the suction head. Although, as described above, the vertical forces introduced via the vacuum cleaner tube are compensated by the rollers provided at the back as a support element, substantial sliding forces can occur due to the suction of the suction head against the bottom surface and the additional weight of the suction head then the handling of the floor nozzle is difficult and requires a certain amount of force.

From the DE 196 24 360 B4 a double-jointed nozzle is known in which a flexible hose section is used to reduce the false air, ie air that does not enter through the suction mouth, but columns and cracks of the floor nozzle and thus does not contribute to the suction, extending from the Saugrohranschluss up to the Suction head extends. The other properties of the floor nozzle are unchanged compared to a double-joint nozzle without a flexible hose section.

From the EP 1 714 599 A1 a nozzle for a canister vacuum cleaner is known, which has a flexible conduit. The line is arranged such that axial forces are kept away from the line by a hinge connection. In contrast, the line has a high torsional stiffness, so that rotational movements of a pipe socket are transmitted to its axis as a steering movement on the suction head.

From the EP 2 092 869 A2 a nozzle for a canister vacuum cleaner is known which has a hinge axis. The hinge axis is arranged such that a Saugrohranschlussstück is pivotally mounted on a chassis with at least one roller. Between the Saugrohranschlussstück and a suction head a flexible conduit is provided for suction air.

Starting from a generic floor nozzle with the features of the preamble of claim 1, the invention has for its object to further facilitate handling by the necessary sliding forces are reduced to move the nozzle.

The object of the invention and solution of the problem is a floor nozzle with the features described above, which is characterized in that between the intermediate piece and the Saugrohranschluss an elastic element is arranged, which generates a torque D between the upper and lower stop position, the connection from intermediate piece and intake manifold connection to smaller angles. The present invention is thus based on the idea of compensating for the force acting on the suction head weight force F _G and in the suction additionally generated by the negative pressure and acting in the same direction as the weight F _G force, at least to some extent, to the friction on the underside of the suction head and thus to reduce the sliding forces required for movement. The floor nozzle is thus designed according to the invention such that the torque D exerts a force F _D , which is opposite to the weight force F _G acting on the suction head, at a fixed suction pipe connection and when the floor nozzle rests on a flat bottom surface via the intermediate piece.

The floor nozzle according to the invention is supported in the support on a bottom surface on the one hand by the at least one support element and on the other hand by the underside of the suction head. While the rear-mounted support member receives the introduced via a vacuum cleaner tube vertical sliding forces, the suction head is based on its own weight on the bottom surface. In addition, the weight of the intermediate piece distributed on the one hand on the back support element and on the other hand on the weight acting on the suction head. In contrast, the additional force acting in the vertical direction by the vacuum on the suction head depends on various design and operating parameters, for example the geometry of the suction head, the nature of the floor surface to be cleaned and the power set on a vacuum cleaner.

According to the invention, a torque is generated between the upper and lower stop position, which generates an upward force on the intermediate piece as a lever and the horizontal tilting axis as a suspension of the suction head, which is opposite to the weight. The stop positions themselves are not to be considered in this consideration, since there takes place via the stop a direct power transmission from the suction pipe connection to the intermediate piece. If no suction tube is connected to the suction pipe connection, the torque generated by the elastic element generally causes the intake pipe connection, which usually has only a comparatively small inherent weight, to be raised to the upper stop position or at least until shortly before the upper stop position.

To generate the torque, the elastic element over the entire angular range or almost the entire angular range by the intake manifold is pivotable relative to the intermediate piece, biased. In the context of the invention may be provided that the elastic element is biased in the upper stop position, so that there is a certain force compensation, or relaxed in the upper stop position, which corresponds to no conventional sliding position with a connected intake manifold. Thus, for example, the elastic element can be designed so that it can be mounted easily and without bias during assembly of the floor nozzle, when the articulated connection between the suction pipe connection and adapter is in the upper stop position, in which case by a deflection from the upper stop position an elastic tension of the element takes place.

As the angle between the intake manifold connection and the intermediate piece increases, so does the torque and thus also the force F _D opposite to the weight force F _G. The elastic properties of the elastic element are taking into account the weight of the suction head on the one hand and the additional force generated by the vacuum in the suction operation on the other hand select. Starting from a per se conventional form and configuration of a Doppelgelenkdüse is provided according to a preferred embodiment of the invention that the weight F _G counteracting force F _D immediately before the upper stop position between 0 N and 10 N, preferably between 2 N and 5 N is and increases with increasing angle between intake manifold and adapter. At the bottom Stop position is the weight force _G F counteracting force F _D as described above usually greater and is preferably between 10 N and 30 N, more preferably between 15 N and 25 N.

In the context of the invention it can be provided that the counterforce F _D generated by the torque is less than or equal to the weight force at every possible angle between intake manifold connection and intermediate piece. For a user then initially no differences to a conventional floor nozzle to determine, except that the sliding forces are reduced in an advantageous manner. According to an alternative embodiment of the invention, however, it can also be provided that the weight force F _G and the counteracting force F _D are the same amount at an average angle. Without the additional force caused by the negative pressure, which pulls the suction head down, the suction head is located at the middle angle just on the bottom surface or floats at a small distance above the bottom surface. In a further bend then the suction head lifts off from the bottom surface. This can be tolerated, since the suction head in the usual suction against the force generated by the torque F _{D is} sucked to the ground.

With regard to the elastic element, various possibilities arise within the scope of the invention, it also being possible in principle to combine different elastic elements. Thus, for example, linear springs or coil springs may be provided between the intermediate piece on the one hand and the suction pipe connection on the other hand. In multi-layer wound coil springs, there is the advantage that they can be biased so that the torque changes only slightly over the angular range between the upper stop position and the lower stop position. Thus, for example, it can be achieved that the weight force acting on the suction head is largely compensated over the entire pivoting range. The arrangement of one or two coil springs, for example, laterally of the articulated connection between the suction pipe connection and the intermediate piece possible.

According to a preferred embodiment of the invention is provided as an elastic element leading the suction air and elastic in its longitudinal direction hose, wherein a running in the longitudinal direction of the hose center line substantially perpendicular to the horizontal hinge axis and at a distance therefrom and wherein the hose between the Intermediate piece and the Saugrohranschluss is arranged resiliently.

While in the known from the prior art designs of floor nozzles a flexible hose is usually provided to prevent or reduce false air, the elastic properties are used in the preferred embodiment rather. To produce a sufficient elasticity in the longitudinal direction can the tube may be formed, for example, as a corrugated hose or bellows, wherein usually a plastic material is used with an injected helix of spring steel. It is then particularly advantageous that the hose has permanently elastic properties. The preferred embodiment described makes use of the elastic restoring forces of the hose due to deformation in the longitudinal direction, whereby the hose can also have an additional curvature. The center line extending in the longitudinal direction of the tube extends approximately perpendicular to the horizontal hinge axis and has a distance to the hinge axis over its entire course. This is necessary so that the inventively provided torque between the suction pipe connection and the intermediate piece is generated by the elastic restoring forces of the hose.

Preferably, the center line of the hose relative to the support surface of the floor nozzle extends to a floor covering to be cleaned above the hinge axis, wherein the hose is then stretched elastically in its longitudinal direction.

As previously explained, the hose is provided as an elastic element in the described embodiment. The connection between the suction head and the first, front end of the intermediate piece can be done in a conventional manner by articulated parts. Thus, it can be provided in particular that the intermediate piece comprises a suction channel, wherein the suction head to the front end and the hose to the rear end of the suction channel.

To seal the hinged at the horizontal tilting parts parts, for example, seals, molded sealing lips or the like may be provided.

According to a preferred embodiment, the suction mouth is formed from a substantially slit suction slot. From practice, embodiments of the suction mouth are known with a suction slot or with two suction slots. While a suction head with two suction slots through the larger support surface has a lower tendency to tilt, in a design with only one suction slot a more compact design and usually higher pressure gradients and thus improved cleaning effect can be achieved. By the inventively provided elastic element, the sliding force and thus the friction on the underside of the suction head can be significantly reduced. This leads to the fact that the risk of friction-induced, uncontrolled tilting of the suction head is reduced. Finally, in one embodiment with only one suction slot in the suction direction, ie longitudinal direction, the suction head can be made comparatively short.

The support member is preferably formed as a roller to allow easy guidance of the floor nozzle. In principle it can be provided that the axis of rotation of the roller and the hinge axis coincide. The rear, second end of the intermediate piece and the Saugrohranschluss can then be connected to a pin or two pin pieces, the pin or the pin pieces then also carry the at least one roller. It is essential in the context of the invention, however, that the tube is arranged eccentrically with respect to the hinge axis in order to allow sufficient torque and thus a force on the intermediate piece. According to a preferred embodiment of the invention, the axis of rotation does not coincide with the horizontal hinge axis. So it is advantageous to provide the hinge axis as deep as possible, in which case the tube off-center can be arranged above it, without requiring an excessive height is required.

In order to avoid an uncontrolled tilting of the suction head, it can be provided to arrange the horizontal tilting axis, which connects the suction head with the intermediate piece, as deeply as possible. Alternatively, it is also possible to provide a sliding support element on the rear side of the suction head.

Fig. 1

einen vertikalen Längsschnitt durch eine erfindungsgemäße Bodendüse,

Fig. 2

eine Draufsicht auf die Bodendüse gemäß der Fig. 1,

Fig. 3

die Bodendüse gemäß der Fig. 1 in einer Ansicht von unten,

Fig. 4

ein Diagramm der an einem Saugkopf der Bodendüse wirkenden Kräfte.

The invention will be explained in the following with reference to a drawing showing only one exemplary embodiment. 10 They show schematically:

Fig. 1

a vertical longitudinal section through a floor nozzle according to the invention,

Fig. 2

a plan view of the floor nozzle according to the Fig. 1 .

Fig. 3

the floor nozzle according to the Fig. 1 in a view from below,

Fig. 4

a diagram of forces acting on a suction head of the floor nozzle forces.

The floor nozzle for vacuum cleaner shown in the figures is designed as a double-jointed nozzle. In this case, an intermediate piece 1 is tiltably connected to a suction head 2 at its front end about a horizontal tilting axis K. According to the Fig. 3 the suction head 2 on its underside a sliding sole 3 with a suction mouth 4, which is formed by a single extending in the transverse direction of the suction channel.

As can be seen from the figures, rollers are provided as support elements 5 at a second, rear end of the intermediate piece 1 laterally. At the second, rear end of the intermediate piece 1 and a suction pipe connection 6 is pivotally connected to a horizontal hinge axis G between an upper stop position (I) and a lower stop position (II) in a predetermined angular range. The two stop positions are in the FIG. 1 shown in dashed lines. The angle range can be described by an angle α formed above the horizontal joint axis G between the suction pipe connection 6 and the intermediate piece 1, which starts from a minimum angle αmin increases in the upper stop position to a maximum angle αmax in the lower stop position. The Saugrohranschluss 6 is provided in the usual manner with a rotary joint 7 and cranked. Between the intermediate piece 1 and the Saugrohranschluss 6 a suction air leading and elastic in its longitudinal direction hose 8 is provided as 15 elastic element. A center line M extending in the longitudinal direction of the tube 8 is arranged substantially perpendicular to the horizontal articulation axis G and at a distance therefrom, so that upon elastic deformation of the tube 8 in its longitudinal direction with respect to the articulated connection about the articulation axis G generates a torque D. 20 becomes. The hose 8 is resiliently clamped between the intermediate piece 1 and the suction pipe connection 6 in such a way that a torque D is generated in each angular position between the upper and the lower stop position, urging the connection of the intermediate piece 1 and the suction pipe connection 6 to smaller angles α. With a held Saugrohranschluss and the support of the floor nozzle on a flat bottom surface generates the torque D via the intermediate piece 1 as a lever arm, a force F _D , which is opposed to the force acting on the suction head 2 weight F _G.

In particular, in the sectional view of Fig. 1 It can be seen that the hinge axis G is arranged deep and does not coincide with a rotation axis of the rollers provided as support elements 5. In the illustrated embodiment, the tube 8 is elastically stretched at each angle α> α _min , whereby a tensile stress acting in its longitudinal direction is generated on the tube 8. In addition to the tube 8 or alternatively, not shown, linear springs or coil springs may be provided to produce the desired torque D.

Of the Fig. 1 Furthermore, it can be seen that the intermediate piece 1 also includes a suction channel 9, at the front end of the suction head 2 and at the rear end of the elastic tube 8 connect. The connection between the suction head 2 and the suction channel 9 about the tilting axis K is carried out in a manner known per se with double-jointed nozzles, wherein the tilting axis K is arranged comparatively deep, to avoid uncontrolled tilting of the suction head 2 in a forward or backward movement of the floor nozzle ,

As can be seen from a comparative analysis of the Fig. 1 with the Fig. 3 results, the suction head 2 brush strips 10a, 10b, which are arranged in front of and behind the suction mouth 4 and extend over the entire width of the suction head 2. The brush strips 10a, 10b are extendable on the underside of the suction head 2, for which purpose a changeover switch 11 is provided on the upper side of the suction head 2. In the Fig. 3 is further to recognize that both in front of and behind the suction mouth 4 in a conventional manner Fadenheberstreifen 12 are provided from Schrägborstenvelours.

Fig. 4 purely by way of example in a diagram shows the forces acting on the suction head 2 of the floor nozzle for various embodiments of the invention. The angle α is plotted on the horizontal axis, wherein a movement of the suction pipe connection 6 with respect to the intermediate piece 1 between the angle α _min (corresponding to the upper stop position) and the angle α _max (corresponding to the lower stop position) is possible. The amounts of the forces acting on the suction head are plotted on the vertical axis. To consider is first the weight F _G , which essentially results from the weight of the suction head 2 and proportionately also from the weight of the intermediate piece 1. In the suction operation, a negative pressure is created on the underside of the suction head 2, which causes an additional downwardly directed force F _p . The total forces acting downwards on the suction head in the vertical direction add up to F _G + F _p . While the weight force F _{G is} a size determined by the construction of the floor nozzle, the force F _p caused by the negative pressure depends on various factors, for example the nature of the floor covering and the suction power. Accordingly, the entire vertically downwardly acting force may vary to some extent depending on the operating conditions involved, which in the Fig. 4 is indicated by the curves of F _G + F _p and F _G + F _p . According to the invention, it is provided that with a fixed suction pipe connection 6 and the support of the floor nozzle on a flat bottom surface via the intermediate piece 1, a force F _{D is} exerted, which counteracts the weight F _G. This force F _D is caused by the elastic element described above and usually increases with increasing angle α. The Fig. 4 shows, by way of example for different embodiments of the elastic element, the courses of the force F _D The effective effective force thus results from the difference between (F _G + Fp) on the one hand and F _D on the other hand.

F _D1 shows a curve in which the torque D and the force generated thereby in the upper stop position at the angle αmin is 0 (F _D1 (αmin) ₌ 0). On the basis of this, the torque D and the force F _{D1 increase} uniformly, the weight force F _G and the counteracting force F _{D1 being} equal in magnitude at an angle αmid. The angle corresponds to a position III (see Fig. 1 ) of the Saugrohranschlusses, which is taken when it is held with a conventional suction tube with a length between 100 cm and 115 cm at a height between 75 cm and 85 cm. It is between 135 ° and 145 °. In a more extensive angling is lifted by the force exerted by the elastic element force F _D, the suction head 2 from the ground when no suction air flows. In the suction mode, however, the additional by the Vacuum generated downward force F _p sufficient to hold the suction head 2 on the ground or to press the ground.

F _D2 shows a course in which due to a bias of the elastic element, a force F _D2 opposite to the weight F _{G is} also produced at the angle α min. The elastic element is selected such that F _{D2 is} less than or equal to F _G at each angle. The suction head 2 is therefore so lifted in any case from the ground. Nevertheless, in a particularly advantageous manner, a very significant reduction in the force acting in the vertical direction downward force and thus a reduction of the necessary for moving the floor nozzle sliding forces is achieved.

F _D3 relates to a course with a particularly flat slope. The force F _D3 generated by the elastic element is chosen so that over the entire range between α min and α max the weight force F _{G is} largely compensated. Such a flat course can be achieved for example by a preloaded spiral spring.

Claims (10)

1. Floor nozzle for vacuum cleaners, comprising a connector (1), a suction head (2), which is joined so as to be tiltably movable about a horizontal tilt axis (K) to a first end of the connector (1), comprising at least one support element (5), which is arranged at a second end of the connector (1), and comprising a suction pipe joint (6) which is pivotally joined about a horizontal articulated axis (G) between an upper and a lower stop position in a fixed angle range to the second end of the connector (1), the angle (α) formed above the horizontal articulated axis (G) between the suction pipe joint (6) and the connector (1) increasing from the upper stop position to the lower stop position, characterised in that a resilient element is arranged between the connector (1) and the suction pipe joint (6) and generates a torque D between the upper and the lower stop position, which torque urges the connection between the connector (1) and the suction pipe joint (6) to enclose smaller angles (α).
2. Floor nozzle according to claim 1, characterised in that, when the suction pipe joint (6) is secured and the floor nozzle is applied to a planar floor surface, the torque D exerts a force F_D via the connector (1), which force opposes the weight F_G acting on the suction head.
3. Floor nozzle according to claim 2, characterised in that, directly before the upper stop position, the force F_D counteracting the weight F_G is between 0 N and 10 N, preferably between 2 N and 5 N, and increases as angle (0) increases between the suction pipe joint (6) and the connector (1).
4. Floor nozzle according to either claim 2 or claim 3, characterised in that, directly before the lower stop position, the force F_D counteracting the weight F_G is between 10 N and 30 N, preferably between 15 N and 25 N, and decreases as the angle (α) decreases between the suction pipe joint (6) and the connector (1).
5. Floor nozzle according to any of claims 2 to 4, characterised in that the weight F_G and the counteracting force F_D are of equal value in the case of a medium angle (α_mittel).
6. Floor nozzle according to any of claims 1 to 5, characterised in that a longitudinally resilient tube (8) that guides the suction air is provided as the resilient element, a centre line (M) which extends in the longitudinal direction of the tube (8) extending substantially perpendicular to the horizontal articulated axis (G) and at a spacing therefrom, the tube (8) being resiliently arranged in a sprung manner between the connector (1) and the suction pipe joint (6).
7. Floor nozzle according to claim 6, characterised in that the centre line (M) of the tube (8) extends above the articulated axis (G), the tube (8) being resiliently strained longitudinally in each pivot position of the suction pipe joint (6).
8. Floor nozzle according to either claim 6 or claim 7, characterised in that the connector (6) comprises a suction channel (9), the suction head (2) being joined to the leading end and the tube (8) to the trailing end of the suction channel (9).
9. Floor nozzle according to any of claims 1 to 8, characterised in that a roller is provided as the support element (5).
10. Floor nozzle according to claim 9, characterised in that the axis of rotation of the roller does not correspond to the horizontal articulated axis (G).

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