Floor cleaning appliance

Abstract

The invention relates to a floor cleaning appliance comprising a suction turbine with a turbine wheel rotatingly drivable about a turbine axis, and a substantially horizontally aligned suction channel via which the suction turbine is in flow communication with a suction opening facing the floor surface to be cleaned, with the suction channel forming a container for collecting dirt and accommodating a dirt filter. In order to design the floor cleaning appliance with as low an overall height as possible, while achieving as strong a suction flow as possible in the area of the suction opening, it is proposed, in accordance with the invention, that the suction turbine be mounted on the suction channel with its turbine axis aligned at an incline to the vertical.

Description

BACKGROUND OF THE INVENTION

[0002] The invention relates to a floor cleaning appliance comprising a suction turbine with a turbine wheel rotatingly drivable about a turbine axis, and a substantially horizontally aligned suction channel via which the suction turbine is in flow communication with a suction opening facing the floor surface to be cleaned, with the suction channel forming a container for collecting dirt and accommodating a dirt filter.

[0003] Such a floor cleaning appliance is known from the international application having publication number WO 99/28800. A suction flow can be generated by the suction turbine for vacuum cleaning the floor surface to be cleaned. In the known floor cleaning appliance, the suction turbine is mounted on the substantially horizontally extending suction channel with a vertically aligned turbine axis. This enables use of a relatively large turbine wheel, but has the disadvantage that the floor cleaning appliance has a considerable overall height.

[0004] The object of the present invention is to construct a floor cleaning appliance of the kind mentioned at the outset with as low an overall height as possible, while achieving as strong a suction flow as possible in the area of the suction opening.

SUMMARY OF THE INVENTION

[0005] This object is accomplished in a floor cleaning appliance of the generic kind, in accordance with the invention, in that the suction turbine is mounted on the suction channel with its turbine axis aligned at an incline to the vertical. Owing to such alignment of the suction turbine, the overall height of the floor cleaning appliance can be kept low even when a relatively large turbine wheel is used. Moreover, such an arrangement has the advantage that the suction flow brought about by the suction turbine suffers only relatively low losses owing to changes in direction occurring in the area in which suction channel and suction turbine are joined. As a result, a relatively strong suction flow can be generated in the area of the suction opening. The floor cleaning appliance according to the invention is therefore characterized by a compact design and a particularly effective mode of operation.

[0006] It is of advantage for the turbine axis to be aligned at an angle of from approximately 15° to approximately 75° to the vertical. In particular, an angle of from approximately 20° to approximately 40° has proven particularly expedient in order, on the one hand, to keep flow losses occurring in the area of transition between the horizontally aligned suction channel and the suction turbine low, and, on the other hand, to enable use of as large a turbine wheel as possible, while taking into account as low an overall height as possible.

[0007] To achieve a particularly effective cleaning action, it is of advantage for the floor cleaning appliance to have a rotatingly drivable rotary brush arranged in the area of the suction opening. With the rotary brush, both vacuum cleaning and brushing of the floor surface to be cleaned are possible.

[0008] It is of advantage for the suction turbine to be in the form of an axial-radial fan for drawing in the working air in axial direction in relation to the turbine axis and giving it off in radial direction. The use of an axial-radial fan enables build-up of a high pressure difference so a particularly strong suction flow is achievable.

[0009] As previously explained, the floor cleaning appliance according to the invention is characterized by a relatively low overall height. This makes it possible for areas of the floor surface to be cleaned underneath radiators, pieces of furniture and the like to also be reached with the floor cleaning appliance. The working air drawn in by the suction turbine is given off to the environment again after passing through the container for collecting dirt and the suction turbine. In order to prevent the working air that is given off from whirling up dirt deposited, for example, on radiators, it is of advantage for the suction turbine to comprise an outlet channel opening into at least one air outlet opening and having an orifice area oriented at an incline to the vertical. By means of the orifice area oriented at an incline to the vertical, the exhaust air can be given off with an exhaust air flow having a correspondingly inclined orientation, which reduces the risk of dirt deposited, for example, on radiators being picked up by the flow of exhaust air when the floor cleaning appliance is positioned under the radiators.

[0010] It has proven advantageous for the orifice area of the outlet channel to be oriented at an angle of from approximately 60° to approximately 80° in relation to the vertical.

[0011] To keep the noise generated by the floor cleaning appliance low, it has proven expedient for the outlet channel to surround the turbine wheel in circumferential direction. In spite of the floor cleaning appliance being designed as compactly as possible, this makes it possible to use a relatively long outlet channel, whereby the noise made by the suction turbine can be reduced. The use of a long outlet channel also results in an increase in the pressure difference between inlet and outlet of the suction turbine, whereby the efficiency of the suction turbine is improved.

[0012] A particularly low generation of noise can be achieved by the outlet channel being of spiral configuration and widening continuously in flow direction. With such a design, the exhaust air can expand continuously, thereby avoiding an abrupt expansion of the air with a corresponding generation of noise.

[0013] In a particularly preferred embodiment of the floor cleaning appliance according to the invention, provision is made for the suction turbine to comprise an electric external rotor motor with a stator held on a carrier element, and a rotor rotatable about the turbine axis, with the turbine wheel held in a rotationally fixed manner on the rotor. The use of the external rotor motor makes it possible to position the motor on the side of the turbine wheel facing away from the suction channel without this resulting in any considerable increase in the overall height of the floor cleaning appliance. This has, in turn, the advantage that the suction channel does not have any considerable cross-sectional constrictions and is therefore characterized by as low a flow resistance as possible.

[0014] The floor cleaning appliance is preferably of automotive design. To this end, it may comprise a chassis on which two drive wheels driven by an electric motor are mounted.

[0015] The following description of a preferred embodiment of the invention serves in conjunction with the drawings for further explanation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 a schematic sectional view of a floor cleaning appliance; and

[0017] FIG. 2 a plan view of the floor cleaning appliance.

DETAILED DESCRIPTION OF THE INVENTION

[0018] The drawings show an automotive floor cleaning appliance generally designated 10 with a chassis 12 in the form of a plastic injection molded part on which there are rotatably mounted two drive wheels 13, 14, which are rotatingly drivable by an electric drive motor 15 and 16, respectively.

[0019] A cover forming a dust guard, which for reasons of clarity is not shown in FIGS. 1 and 2, may be placed on the chassis 12.

[0020] The chassis 12 forms between the two drive wheels 13, 14 a carrier plate 21 which is oriented substantially parallel to a floor surface 19 to be cleaned. The carrier plate 21 is followed in the direction of travel 22 of the floor cleaning appliance 10 via a step 23 by a supporting plate 24 which is also oriented parallel to the floor surface 19 and by a front wall 25 oriented in the direction towards the floor surface 19.

[0021] At a distance from the carrier plate 21, a base plate 26 is held on the chassis 12 so as to be detachably connectable by detent elements which are known per se and are therefore not shown in the drawings. Supporting rollers 29 are freely rotatably mounted at the front end area 27, in the direction of travel 22, of the base plate 26.

[0022] In its front area, the base plate 26 carries a sill 31 which dips into a suction opening 33 arranged in the base plate 26. A substantially horizontally aligned suction channel 35 extending between the carrier plate 21, the step 23 and the supporting plate 24, on the one hand, and the base plate 26, on the other hand, opens into the suction opening 33. A dirt filter 37 is held within the suction channel 35 so as to be aligned at an incline to the longitudinal direction thereof.

[0023] At its rear end area, the chassis 12 carries a suction turbine 40 with a turbine housing upper part 41 and a turbine housing lower part 42 accommodating between them a turbine wheel 44 and an electric turbine drive 46.

[0024] The turbine drive 46 is in the form of an external rotor motor and comprises a stator 48 held in a rotationally fixed manner on the turbine housing upper part 41 and a rotor 49 rotatably held on the stator 48. The rotor 49 is in the form of a hood 50 engaging over the stator 48 and having permanent magnets 51 fixed on its inner side facing the stator 48. The turbine wheel 44 is held in a rotationally fixed manner on the bottom wall of the hood 50 facing away from the turbine housing upper part 41.

[0025] The turbine wheel 44 is drivable by the turbine drive 46 so as to carry out a rotational movement about a turbine axis 54. The turbine axis 54 is aligned at an incline to the vertical and hence also at an incline to the longitudinal extent of the suction channel 35. An air inlet opening 56 of the suction turbine 40 is associated with the turbine wheel 44. The air inlet opening 56 is formed by a suction port 58 which is integrally connected to the turbine housing lower part 42 and establishes a flow connection between the suction channel 35 and the interior of the suction turbine 40.

[0026] As will be apparent, in particular, from FIG. 2, the turbine wheel 44 is surrounded in circumferential direction by an outlet channel 60 of spiral shape, which widens continuously in flow direction and opens into an air outlet opening 62. The orifice area 64 of the outlet channel 60 neighboring on the air outlet opening 62 is also oriented at an incline to the vertical.

[0027] By means of the suction turbine 40 a suction flow symbolized by arrows 66 can be generated within the suction channel 35 for conveying dirt from the floor surface 19 to be cleaned through the suction opening 33 into the suction channel 35. The area of the suction channel 35 arranged upstream of the dirt filter 37 forms a container 67 for collecting dirt.

[0028] In order to increase the dirt intake, a rotary brush 68 with an axis of rotation aligned transversely to the direction of travel 22 and parallel to the floor surface 19 is held for rotation on the chassis 12 in the area of the suction opening 33. The rotary brush 68 is driven by an electric brush drive 69 which is positioned on the supporting plate 24 and is coupled to the rotary brush 68 by a drive belt known per se and therefore not shown in the drawings.

[0029] As the suction flow 66 suffers only low flow losses in the area of the suction channel 35 and the suction port 58 oriented at an incline to the vertical, a strong suction flow can be achieved in the area of the suction opening 33, which in combination with the rotary brush 68 brings about effective floor cleaning. The dirt whirled up by the rotary brush 68 is picked up by the suction flow and passed into the container 67 for collecting dirt. The alignment of the suction turbine 40 with its turbine axis 54 extending at an incline to the vertical enables use of a relatively large turbine wheel 44, but the overall height of the floor cleaning appliance 10 can be kept low.

Claims

1. Floor cleaning appliance comprising a suction turbine with a turbine wheel rotatingly drivable about a turbine axis, and a substantially horizontally aligned suction channel via which the suction turbine is in flow communication with a suction opening facing the floor surface to be cleaned, with the suction channel forming a container for collecting dirt and accommodating a dirt filter, wherein the suction turbine is mounted on the suction channel with the turbine axis aligned at an incline to the vertical.

2. Floor cleaning appliance in accordance with claim 1, wherein the turbine axis is aligned at an angle of from approximately 15° to approximately 75° to the vertical.

3. Floor cleaning appliance in accordance with claim 1, wherein the floor cleaning appliance has a rotatingly drivable rotary brush arranged in the area of the suction opening.

4. Floor cleaning appliance in accordance with claim 1, wherein the suction turbine is in the form of an axial-radial fan.

5. Floor cleaning appliance in accordance with claim 1, wherein the suction turbine has an outlet channel which opens into at least one air outlet opening, and the orifice area of which is aligned at an incline to the vertical.

6. Floor cleaning appliance in accordance with claim 5, wherein the outlet channel surrounds the turbine wheel in circumferential direction.

7. Floor cleaning appliance in accordance with claim 6, wherein the outlet channel is of spiral configuration and widens continuously in flow direction.

8. Floor cleaning appliance in accordance with claim 1, wherein the suction turbine comprises an electric external rotor motor with a stator which is held on a carrier element, and a rotor which is rotatable about the turbine axis and on which the turbine wheel is held in a rotationally fixed manner.

9. Floor cleaning appliance in accordance with claim 1, wherein the floor cleaning appliance is of automotive design.