DEVICE AND METHOD FOR IMPROVED COLLECTION OF DUST IN TREATMENT OF FLOOR SURFACES

Technical Field

The present invention relates to a device and a method for improved collection of dust in treatment of, for example, floor surfaces. More specifically, the present invention relates to a method and a device, which increase the efficiency of an existing dust collecting device, or which reduce the power requirement of the dust collecting device.

Background The present invention relates to machines for cutting, grinding and/or polishing treatment of surfaces, for instance hard surfaces, which may contain stone or stone-like materials, such as concrete, terrazzo or the like. Machines of this type can also be used for treatment of other surfaces, such as wood, linoleum etc. In cutting, grinding and/or polishing treatment of surfaces, particles of varying sizes are produced, which are usually collected. Such collection may occur directly in connection with the treatment, usually with the aid of a dry vacuum cleaner or, when the treatment occurs in the presence of liquid, a wet vacuum cleaner. An inconvenience in collection of grinding dust or polishing dust is that a relatively great suction power of the vacuum cleaner is necessary to collect all the grinding dust or polishing dust. In order to generate sufficient suction power, this may result in a large vacuum cleaner, which will thus by heavy and bulky. There is thus a need of providing solutions which increase the efficiency of existing vacuum cleaners, and/or which allow use of vacuum cleaners having a lower suction power.

Summary

An object of the present invention is thus to provide a device and a method which eliminate or reduce the drawbacks of prior art technique, or which at least provide a realistic alternative to prior art technique. This object is achieved wholly or partly by a device and a method according to the independent claims. Embodiments are defined in the dependent claims and by the following description and the drawings.

According to a first aspect, a device is provided for treating a floor surface, comprising a casing, which defines a treatment space. The device comprises a stirrer which is movably arranged in the treatment space and which is designed and dimensioned to stir up particles located on the floor surface.

By "stirrer" is meant a structure which is dedicated to perform stirring in the treatment space for the purpose of facilitating collection of dust. Treatment elements, and the like, which certainly have a stirring effect are not considered to constitute such stirrers.

Using such a stirrer, particles located on the floor surface are raised and can more easily be sucked up by the vacuum cleaner, whereby the suction power of the vacuum cleaner can be used more efficiently and/or be reduced. For example, it is possible to use a vacuum cleaner with a higher flow but a lower vacuum.

Tests have demonstrated that the effect of arranging a stirrer in the treatment space is striking: the floor surface will be clean immediately, with a considerable reduction of the remaining dust layer. This makes it easy for the user to estimate the result of the treatment, thus reducing the risk of redundant treatment. Furthermore the grinding/polishing effect will be improved since there remains less dust between the treatment elements and the floor surface, and since less dust thus adheres to/gets burned and stuck to the treatment element. The stirrer may be a separate stirrer. With the stirrer being separate is understood that it is separated from a treatment element, such as a cutting, grinding and/or polishing treatment element forming part of the device.

In one embodiment, the device comprises a planetary disc, which may be arranged to rotate in a plane substantially parallel to a floor surface to be treated.

The stirrer may be arranged on the planetary disc. In such an embodiment, the stirrer may be fixed relative to the planetary disc.

The stirrer may extend between the planetary disc and the floor surface.

In one embodiment, the stirrer is dimensioned and arranged so as not to extend all the way to the floor surface. It may be sufficient for the stirrer to generate an air current or air eddy, which is capable of raising the particles from the floor surface.

In another embodiment, the stirrer extends substantially all the way from the planetary disc to the floor surface. In yet another embodiment, the stirrer is dimensioned and arranged so as to touch the floor surface.

The stirrer may extend substantially transversely to a direction of rotation of the planetary disc.

The stirrer may extend substantially between a peripheral and a central portion of the planetary disc.

The stirrer may be releaseably arranged on the planetary disc. Consequently it can be made easily exchangeable.

The device may further comprise at least one treatment disc rotatably arranged on the planetary disc. In one embodiment, the device may comprise at least two treatment discs, the stirrer being arranged between the treatment discs.

The treatment discs may support at least one grinding, polishing and/or cutting tool.

The stirrer may be separate from the tool, i.e. arranged as a separate part which may be exchangeable and mountable independently of the tool or treatment disc.

The device may comprise at least two tools, in which case the stirrer may be aranged between the tools.

The stirrer may be arranged on the tool.

The stirrer may be separate from a treatment element forming part of the tool, i.e. the stirrer may be fixed to the tool itself, but not formed in one piece with that element that provides the cutting, grinding and/or polishing effect of the tool.

The device may comprise at least two treatment element, wherein the stirrer may be arranged between the treatment elements.

The stirrer may at least partly have the form of a brush.

As an alternative, or a complement, the stirrer may at least partly have the form of a rib.

The stirrer may be resiliency bendable.

According to a second aspect, a method is provided for collecting dust in connection with treatment of a floor surface. The device comprises arranging, in a treatment space, a stirrer, which is designed and dimensioned to stir up particles located on the floor surface.

The above solutions are applicable in, for example, treatment machines of the type disclosed in WO03/076131 A1 , WO9408752A1 or WO02062524A1 , the entire contents of which are incorporated herein by reference. As an alternative or complemnet, two or more stirrers may be arranged on the planetary disc, treatment disc or tool.

Brief Description of the Drawings

Figs 1 a and 1 b illustrate schematically a grinding machine with two grinding discs seen in a plan view from below, and a perspective view obliquely from below, respectively.

Figs 2a and 2b illustrate schematically a grinding machine with four grinding discs seen in a plan view from below, and a perspective view obliquely from below, respectively. Fig. 3 schematically illustrates a planetary disc as seen from below.

Description of Embodiments

Figs 1 a and 1 b illustrate a first embodiment of a floor treating device 1 , which has a casing 2 which defines a treatment space. In the treatment space

a planetary disc 4 is accommodated, which is arranged to rotate in a first direction R1 relative to the chassis of the machine (not shown). The planetary disc supports a plurality of treatment discs 5, which each are rotatable relative to the planetary disc in a second direction R2. Each of the treatment discs 5 is arranged to support one or more, usually 2-4, grinding, polishing and/or cutting tools (not shown). The planetary disc 4 and the treatment disc 5 may, as a non-limiting example, be configured to be driven by a drive motor 7 via such drive assemblies as disclosed in WO9408752A1 , or by alternative drive assemblies. The treatment space may have one or more suction openings 6, to which one or more vacuum cleaners (not shown) may be connected to suck up particles generated in the treatment, such as dust.

Figs 1 a and 1 b illustrate three stirrers 3 in the form of substantially radially extended brushes, which extend from the downward surface of the treatment disc and towards the floor surface (not shown) to be treated. Each of the stirrers 3 is arranged between two neighbouring treatment discs 5. In operation, the stirrer 5 may be fixedly arranged relative to the planetary disc. The stirrer may extend between the planetary disc and the floor surface. In one embodiment, the stirrer 5 is dimensioned and arranged so as not to extend all the way to the floor surface. For instance, it may terminate

0.5, 1.0, 1.5, 2.0 or 3.0 cm above the floor surface.

In another embodiment, the stirrer extends substantially all the way from the planetary disc to the floor surface. Moreover, the stirrer may, but does not necessarily have to, have such a vertical extent that it touches the floor surface.

The stirrer may be elongate, with a longitudinal direction at an angle to, for instance transversely to, the direction of rotation of the planetary disc.

The stirrer may extend substantially between a peripheral and a central portion of the planetary disc. For example, the stirrer may extend substantially from the periphery of the planetary disc and inwards, but not all the way, to its central portion.

The stirrer may be releaseably arranged on the planetary disc. For instance, a mechanical coupling can be arranged on the planetary disc for cooperation with a corresponding mechanical coupling on the stirrer. Such a coupling may comprise a rib, into which, or onto which, the stirrer can be moved by sliding, angling or by snap action.

In the embodiment shown in Figs 1 a and 1 b, the stirrer has the form of a brush, the bristles of which extend from the planetary disc and to the floor surface.

As an alternative, or a complement, the stirrer may be designed as a rib or fin, which extends from the planetary disc and to the floor surface.

The stirrer may be resiliency bendable so that it may yield to objects or materials located on the floor surface. A resiliency bendable stirrer also reduces the risk of damage to the floor surface if it comes into contact with the floor surface or squeezes an object between itself and the floor surface. In the case of a rib, the rib can be made of a resiliency bendable material, such as rubber or rubber-like materials, or plastic of a plastic material. Alternatively, a rigid rib can be attached to be resilient relative to the planetary disc.

The stirrer may be designed and arranged so that its movement through the treatment space generates an air current or air eddy, which helps to raise particles or dust located on the floor surface, and to keep particles that are already airborne. This means that the stirrer may, but does not necessarily have to, be designed to provide direct physical contact with particles located on the floor surface. The stirrer should have an extent in the radial direction, but may be straight or bent, and its thickness may vary. The stirrer may be continuous or discontinuous.

The stirrer may be spring loaded in the vertical direction to allow compensation for irregularities in the surface that is being treated. In different embodiments, the number of stirrers may be varied: a good efficiency is achieved even with one stirrer, but for optimal effect, it is recommended to arrange at least one stirrer between each pair of treatment discs 5, neighbouring each other in the direction of rotation.

Figs 2a and 2b illustrate a second embodiment of a floor treating machine 1 ', which resembles the floor treating machine shown in Figs 1a and 1 b, with the difference that it has four, instead of three, treatment discs 5, which are arranged to rotate in pairs in the same direction, one pair having a first direction of rotation R2 which is opposite to the direction of rotation R1 of the planetary disc, and the second pair having a second opposite direction of rotation R3.

The planetary disc 4 and the treatment discs 5 of the floor treating machine V shown in Figs 2a and 2b may have a drive assembly and may, as a non-limiting example, be designed to be driven by a drive motor 7 via such drive assemblies as disclosed in WO02062524A1 , or using alternative drive assemblies.

Fig. 3 schematically illustrates a planetary disc, as seen from below. The planetary disc 4 presents three treatment discs 5, each carrying three tools 8.

The tools 8, in its turn, have two treatment elements 9 for cutting, grinding and/or polishing treatment. In Fig. 3, it is illustrated how a stirrer 3 can be arranged on the planetary disc 4. Further, it is illustrated how a stirrer 3', as an alternative or a complement, may be arranged on the treatment disc 5. It is also illustrated how a stirrer 3" as an alternative or a complement, may be arranged on the tool 8.

What has been said concerning the arrangement and design of the planetary disc is valid analogously for those situations where the stirrer is arranged on the treatment disc and/or on the tool. The treatment discs may be formed in accordance with the disclosure of WO2004108352A1 , and thus may also carry such tools with treatment elements as are described therein.

The stirrer in Figs 2a and 2b can be designed as described above with reference to Figs 1 a and 1 b.