The invention relates to a flat mop device with the features of the introductory part of claim 1. Further, the invention relates to a mop head cover for use with such a flat mop device.

A usual flat mop device comprises a mop frame, a handle joined to the upper side of the mop frame, preferably by means of a universal joint, and a removable flat mop cover from woven or non-woven textile material with attachment means on the upper side thereof for attachment to the mop frame. The mop frame as such is either a metal frame-construction or a plate-like construction from metal or plastics, mostly of a fold-away type (WO 03/020100 Al).

Numerous flat mop covers for application with a fiat mop device of this kind are used in practice. A comprehensive overview is given in US 5,887,311 A which forms an important background art to the present invention. Those flat mop covers are suitable for dry cleaning of floors. Their particular advantage, however, lies in its good retention properties for cleaning liquid, in particular for water. Such a flat mop cover is expected to take up the cleaning liquid quickly, to allow transportation of a substantial amount of cleaning liquid without dripping, to transfer the cleaning liquid gradually to the floor and to take up soiled cleaning liquid quickly as well. In addition such flat mop cover is expected to take up a large amount of solid soil particles and to glide easily over the floor. Washing of such a flat mop cover takes place frequently and is done at relatively high temperatures. So flat mop covers of this kind are expected to withstand a large number of washing cycles.

Modern flat mop covers which are widely used in practice consist entirely of a synthetic microfiber material, preferably of polyester-microfibers. For the definition of microfiber material and for the complete background of this prior art, reference is again made to US 5,887,311 A, the disclosure of this document being included here by reference. However, in contrast to the disclosure of this prior art a microfiber material with microfϊbers of less then 1 dtex is indeed suitable for wet cleaning, because such material has a substantial water retention capacity.

An alternative approach to a flat mop device uses a fully disposable, single-use material of synthetic microfibers. This prior art combines a mop head cover designed as a simple, thin, cloth-like material of woven or non-woven fabric with a cushioning pad on the underside of the mop frame (GB 2 031 039 A). A cushioning pad forms the backing structure for the mop head cover and provides a substantial retention capacity for cleaning liquid. This cushioning pad is made from synthetic sponge material fixedly attached to the underside of the plate-like mop frame. Whereas this prior art flat mop device is primarily used for dry cleaning, it is also applicable for wet cleaning applications.

This prior art (GB 2 031 039 A) forms the starting point of the invention. It discloses a large number of examples for cloth-like material for use as a mop head cover on a cushioning pad. As the thin, cloth-like material has only a low weight, washing is simple, fast and cost-saving. However, attaching the thin mop head cover to the mop frame needs specific means like clips or brackets.

Similar prior art is disclosed in US 4,823,424 A.

The content of both above mentioned prior art documents is incorporated into the present application herewith by reference, too.

Although both systems, the system with the removable flat mop cover of woven or non- woven textile material on the one hand (WO 03/020100 A) and the system with cushioning pad on the underside of the mop frame and a disposable, thin, cloth-like mop head cover on the other hand (GB 2 031 039 A) are existing in parallel for decades, both systems have still been considered as alternative approaches to floor cleaning. One system would be abandoned in favor of the other system.

The object of the present invention is to provide a flat mop device that combines the advantages of both systems and gives full flexibility to the user.

This object is met in a flat mop device with the features of the introductory part of claim 1 by providing the features of the characterizing part of claim 1. A corresponding mop head cover is the subj ect matter of claim 13.

The main idea of the present invention is to combine the folly disposable or semi-disposable mop head cover with a removable standard flat mop cover from woven or non-woven textile material, i.e. to use a removable standard flat mop cover in place of the cushioning pad of the prior art flat mop device (GB 2 031 039 A). So the features of the back-up cushioning pad on the one hand and the water retention properties on the other hand are provided by a flat mop cover, whereas the fully disposable or semi-disposable mop head cover from thin sheet- like material is used to take up all dirt and soil from the floor. Surprisingly, the flat mop cover remains rather clean for a long time, but can then be removed from the mop frame, too, to be washed for further use. Moreover, the flat mop device can also be used without the folly disposable or semi-disposable mop head cover just as a traditional flat mop device with standard flat mop cover. The user can choose between two alternative ways to clean the floor.

As explained in claim 2 it is preferable that the removable standard flat mop cover that is used in place of the cushioning pad has a substantially smooth underside. A planar surface as a back-up surface for the fully disposable or semi- disposable sheet-like material that forms the mop head cover leads to the required even cleaning results on the floor. In particular, it is preferable that the flat mop cover comprises, forming the main cleaning surface or trimming of the flat mop cover, a synthetic microfiber material with microfibers cut to a rather uniform average fiber-length of about 10 mm to 15 mm or less. Examples for such material can be obtained from the prior art mentioned in the introductory part of the descriptions and incorporated herein by reference. A preferred range of microfiber-size is given in claim 4.

A particular product that is manufactured by the applicant and is on the market right now is sold under the brand "Rasantec Mono". This product is particularly suitable as a flat mop cover for a flat mop device according to the present invention. Such kind of flat mop cover has the properties of claim 5 and claim 6 and is a preferable choice for the present application.

In the flat mop device according to the invention the usual attachment means for flat mop covers can be used. Insofar, see US 5,887,311 A and WO 03/020100 A.

The simple sheet-like material for the mop head cover allows that the piece of sheet-like material forming the mop head cover is cut off or otherwise separated from a supply of sheet-like material, in particular from a supply roll. Such a supply of sheet-like material can be carried along with a cleaning trolley so that the person using this flat mop device has always the possibility to use a fresh mop head cover.

Specific attachment means are the subject matter of claim 9.

Of course, it is possible to use a fully disposable, single-use material, in particular a specific paper material as the mop head cover. Such paper should have a substantial tensile strength and good dirt retention properties. Paper used for filter material may be a good choice for this kind of mop head cover as well.

In an alternative approach it is possible that the mop head cover is made from a semi-disposable material, namely a thin, washable textile material, preferably a synthetic mircofiber material. This is the material already used in the prior art, too, in particular see GB 2 031 039 A. This material provides a high cleaning efficiency, because the semi-disposable mop head cover can be washed and re- used many times up to 600 to 700 times. In spite of this, the complete weight of such mop head cover of a suitable size will be around 20 g for a small mop frame (40 cm x 10 cm) and about 30 g for a larger mop frame (55 cm x 20 cm).

Reference is made to claims 13 and 14 as far as a mop head cover for use with such a flat mop device as such is concerned.

Now, further advantages and features of the invention will be described with reference to the preferred embodiment as shown in the drawings.

Fig. 1 shows the three items forming a full flat mop device according to the invention,

Fig. 2 shows the items of Fig. 1 combined and

Fig. 3 shows a supply roll of cloth, this cloth forming the mop head cover of the flat mop device according to this embodiment of the invention.

Fig. 1 shows all items of a flat mop device of a preferred embodiment of the invention. On top there can be seen a mop frame 1. A socket 2 for a handle is joined to the upper side of the mop frame 1 by means of a universal joint 3 which allows movement of the mop frame 1 backwards or forward in all directions. Below the mop frame 1 a cushioning pad is indicated that is adapted to be positioned on the underside of the mop frame 1 and will be explained later.

The third item shown in Fig. 1 is an easily removable mop head cover 4 that, in practice, covers the underside of the cushioning pad and is adapted to be attached to the mop frame 1 during floor cleaning. The mop head cover 4 is designed as a simple, thin sheet-like material. In Fig. 1 it is a cloth of non-woven fabric of synthetic microfiber material. This will be explained later, too.

The cushioning pad to be seen in the middle of Fig. 1 is formed as a removable standard flat mop cover 5 from woven or non- woven textile material. This kind of flat mop cover 5 is well known by prior art, in particular US 5,887,311 A and WO 03/020100 A. Here, however, it has the main function of a cushioning pad for the mop head cover 4 and also the function of retaining cleaning liquid if wet cleaning is desired. Soil-removing, however, is done by the mop head cover 4. The standard flat mop cover 5 has the usual attachment means 6 on the upper side thereof for attachment to the mop frame 1.

In order to provide an even cushioning effect the flat mop cover 5 has a substantially smooth, planar underside. To this effect the flat mop cover comprises, forming the main cleaning surface, synthetic microfiber material with microfibers cut to a rather uniform average fiber-length of about 10 mm to 15 mm or less. In particular, the flat mop cover 5 comprises microfiber material with microfibers of about 0,5 dtex to about 0,9 dtex, preferably of about 0,6 dtex. In the preferred embodiment the microfiber material is made from polyester- microfibers.

Fig. 2 shows the three items of Fig. 1 now combined to a complete flat mop device ready to use. It is provided in this preferred embodiment that the flat mop cover 5 of an average size of the main cleaning surface of about 40 cm in length and about 10 cm in width is used and has a weight of about 60 g to about 100 g,

preferably of about 80 g. This kind of product is on the market by the applicant of the present patent application under the brand "Rasantec mono". The microfiber material of this flat mop cover 5 provides a water retention capacity of up to 500 %, even up to 700 % of the dry weight of the flat mop cover 5. In practice this means a water retention capacity of up to 560 g based on the weight of the flat mop cover 5 in the dry state of 80 g. This flat mop cover 5 of microfiber material is therefore particularly suitable as the cushioning pad of a flat mop device according to the invention. Another version for a larger mop frame 1 of 55 cm x 20 cm has a weight of up to 160 g with a preferable weight of about 100 g.

The prior art discloses a large number of alternatives for a flat mop cover 5 that are basically suitable for the present application as well. Insofar please refer to US 5,887,311 A disclosing cotton fiber material for flat mop covers 5 as well.

As explained before the flat mop cover 5 needs the usual attachment means 6 to be attached to the mop frame 1. In the present embodiment those attachment means 6 are narrow holding strips running across the plate like mop frame 1.

Fig. 3 shows a specific embodiment of the invention where a piece of sheet-like material forming a mop head cover 4 is cut off or otherwise separated from a supply of sheet-like material, in particular from a supply roll 7. Fig. 3 shows the particular attachment means 6 of this mop head cover 4, namely a single, lengthwise extending insertion pocket 8. Fig. 2 shows how the mop frame 1 with the flat mop cover 5 attached to the mop frame 1 by the attachment means 6 can be slid into the insertion pocket 8 at the edge of the mop head cover 4.

In the present embodiment it is important to realize that only one insertion pocket 8 is provided. This takes into account that a flat mop device according to the invention will normally be moved in a unidirectional, however crosswise extending movement. So one insertion pocket 8 on one lengthwise extending side will be sufficient for use for a short period at it is usual with fully disposable or semi-disposable mop head covers 4 according to the present invention.

In Fig. 3 the supply roll 7 of sheet-like material provides a fully disposable, single-use material, in particular a strong paper. It has already been explained

that it is particularly convenient for the user to carry such supply roll 7 along on a transportation trolley. Fig. 3 shows a cut-off line that can be indicated optically or by a perforation.

An alternative lies in the use of a mop head cover 4 made from a semi-disposable material, namely a thin, washable textile material, in particular a synthetic microfiber material. Those semi-disposable mop head covers 4 can be washed at 6O ⁰ C many times, up to about 700 times. Washing costs are low, because of the low weight which is about 20 g to 30 g or even only 10 g for a standard piece of cloth forming such semi-disposable mop head cover 4.

Altogether the invention acknowledges the fact that washing costs for fiat mops shall be reduced. Usual flat mop covers pick up dirt only at the surface. So for dirt removal it is not necessary to use a flat mop cover with a high weight as such. This flat mop cover 5, however, is helpful to carry the cleaning liquid. The weight is needed to achieve good holding properties for cleaning liquid. So this is combined with a fully disposable or semi-disposable, however very thin mop head cover 4. Washing only the mop head cover in case of a semi-disposable material reduces the washing costs to a third or even a quarter of the washing costs of the washing costs for the traditional flat mop cover 5. Using the traditional flat mop cover 5 instead of the traditional cushioning pad from sponge material leads to a cushioning pad that as such is washable as well and can be used in a second version of application of the flat mop device.