The present invention relates to an apparatus for mechanically treating a surface, in particular milling, scouring, grinding and/or polishing the same, using a treatment device which rotates about a horizontal axis, which treatment device is mounted on a steerable frame. The present invention furthermore relates to a method for mechanically treating a surface, in particular scouring thereof.

Such a apparatus is known per se from US patent no.

5,772,497, wherein scouring cylinders are mounted in a steerable frame, using a horizontal axis. Such a apparatus is also known from US patent no. 4,523,361, wherein two grinding devices rotate in opposite directions about a horizontal axis. Using several geometric embodiments of the grinding elements present on the grinding devices, a specific grinding treatment is carried out on a surface, for example a floor. When such an apparatus is moved across a concrete surface, exerting a force on said surface which is larger than the mechanical resistance of said surface, the surface will break into pieces. There is a danger thereby that said breaking into pieces of the surface will not take place in a uniform manner, as a consequence of which a smooth surface is not obtained. In addition, the above apparatuses are only capable of carrying out one specific treatment, for example scouring, so that another apparatus is required, for example, for polishing a surface.

The object of the present invention is to provide an apparatus and a method for mechanically treating a surface wherein the aforesaid drawbacks of the prior art are eliminated.

Another object of the present invention is to provide an apparatus and a method by means of which a surface to be treated can be smoothed in one flowing operation.

Another object of the present invention is to provide a

method and an apparatus for mechanically treating a surface, whereby a surface is obtained which exhibits the desired smoothness, density and wear resistance and which furthermore exhibits the desired optical qualities.

According to the invention, the apparatus as referred to in the introduction is characterized in that the apparatus comprises at least two cylindrical treatment devices arranged one behind another, each treatment device being circumferentially provided with its own specific wear-resistant material, which makes it possible to subject the surface to different mechanical treatments.

The use of such cylindrical treatment devices arranged one behind another makes it possible to treat the surface in one single operation. Thus the surface to be treated will first be subjected to a coarse treatment, viz. milling, so that the surface is smoothed to a certain extent, after which the surface is subjected to less coarse treatments, viz. scouring and/or grinding, as a result of which the more or less smooth surface will be made substantially smooth. In addition, it is possible to subject the surface that has thus been mechanically treated to another treatment, viz. a polishing treatment, using a cylindrical treatment device, which device is preferably provided with a different wear-resistant material than the treatment devices that have been used before, so that eventually a very smooth surface is obtained which exhibits the desired smoothness, density and wear resistance and which exhibits the desired optical qualities.

In one special embodiment, the pressure that is exerted on the surface by each treatment device is preferably individually adjustable.

Since the pressure that is exerted on the surface is individually adjustable, it is possible at all times to carry out the specifically desired mechanical treatment of the surface, whereby it should be understood, of course, that the pressure used for the first

treatment of the surface is larger than that used for the final treatment of the surface. In specific embodiments it is desirable to use substantially the same pressure that is exerted on the surface for each treatment device.

The speed of rotation and/or the direction of rotation of each treatment device are furthermore preferably individually adjustable.

The possibility of individually adjusting the speed of rotation and/or the direction of rotation of each treatment device is in particular desirable for subjecting the surface to a specific mechanical treatment, wherein it is possible at all times to meet the requirements that are made of the final product.

According to a special embodiment of the present apparatus, the present treatment device comprises a row of separate cylindrical treatment elements arranged in side-by-side relationship, wherein in particular the pressure that is exerted on the surface by each treatment element is individually adjustable. Furthermore, the speed of rotation of each treatment element is preferably individually adjustable. In addition to that, the direction of rotation of each treatment element is preferably individually adjustable. Furthermore it is desirable that each cylindrical treatment element of a row of separate cylindrical elements arranged in side-by-side relationship mechanically treats the surface to the same degree, which is realised by providing the treatment elements of said row circumferentially with the same wear-resistant material. It should be understood, however, that the present apparatus may comprise a first cylindrical treatment device and a row of separate cylindrical treatment elements disposed behind said treatment device, behind which row another cylindrical treatment device may be disposed. The combination of treatment devices and rows of separate cylindrical treatment elements arranged in side-by-side relationship is not limited to a specific number, which can be suitably selected in dependence on the intended mechanical treatment of the surface.

The use of a treatment device which, according to the present invention, can thus be considered as a row of separate cylindrical treatment elements arranged in side-by-side relationship, is in particular advantageous when large surfaces are to be treated. In addition to that, such a construction is in particular advantageous from a viewpoint of maintenance, because it is possible to exchange cylindrical treatment elements individually, whereby the apparatus as such remains usable for treating a surface. Since each cylindrical treatment element is individually adjustable as regards pressure, direction of rotation and/or speed of rotation, it is possible to treat the surface in one flowing operation by means of such an apparatus, whereby the present apparatus is in particular suitable for milling, scouring, grinding and/or polishing. The terms milling, scouring, grinding and polishing as used herein should be considered to be mechanical treatment steps, which are different from each other as regards the degree of coarseness of the surface being treated, wherein milling is considered to be a coarse treatment and polishing is considered to be a treatment aimed at obtaining a smooth and shining surface, whilst scouring and grinding are intermediate mechanical treatment steps.

Preferably, in order to be able to subject the surface to mutually different treatments, each treatment device is circumferentially provided with its own specific wear-resistant material, wherein especially diamond is used, in particular diamond exhibiting different degrees of coarseness.

In such an embodiment of the present apparatus, the first row of separate cylindrical treatment elements arranged in side-by-side relationship may thus be be circumferentially provided with very coarse diamond, for example, whilst the second row of separate cylindrical treatment elements arranged in side-by-side relationship is circumferentially provided with coarse diamond, with the possible other

rows of separate cylindrical treatment elements arranged in side-by-side relationship are circumferentially provided with a layer of diamond ranging from fine diamond to very fine diamond. When such an arrangement is used, the first row of separate cylindrical treatment elements arranged in side-by-side relationship can carry out a so-called milling operation, whilst the next rows of separate cylindrical treatment elements arranged in side-by-side relationship subject the already treated surface to increasingly finer treatments, for example scouring, grinding and/or polishing, whereby the speed of rotation, the direction of rotation and/or the pressure that is exerted on the surface may be individually adjusted. It should be understood, however, that the present apparatus is not limited to a specific number of rows of separate cylindrical treatment elements arranged in side-by-side relationship.

Preferably, the present apparatus furthermore comprises means for supplying a treatment fluid and means for discharging said treatment fluid, in which the material that has been removed from the surface is present. Such a treatment fluid assists in the mechanical treatment of the surface and facilitates the discharge of material that has been removed from the surface.

The present apparatus furthermore preferably comprises means in which the spent treatment fluid and the material that has been removed from the surface are separated.

In addition, it is desirable for the present apparatus to comprise means for storing the spent treatment fluid and means for storing the material that has been removed from the surface.

Such a construction is in particular advantageous from an ecological viewpoint, because the materials that have been removed from the surface and the treatment fluid that has been used can thus be readily discharged in a quick and efficient manner.

It is also preferred that the spacing between each treatment device of the present apparatus and the surface to be treated

be adjustable, so that the present apparatus can be moved across said surface without subjecting the surface to a mechanical treatment, for example when the apparatus is to be moved from one position to another.

Preferably, in order to achieve an efficient mechanical treatment of the surface, the present device furthermore comprises means for measuring the level and/or the surface structure of the surface, which may or may not have been mechanically treated, for which purpose several detection techniques may be used, for example ultrasonic, infrared and mechanical measurement.

The present invention furthermore relates to a method for mechanically treating a surface, which method is according to the invention characterized in that the above-described apparatus is used, wherein the following steps are carried out: i) bringing one or more cylindrical treatment devices into contact with a surface to be treated ; ii) rotating one or more cylindrical treatment devices about the horizontal axis ; iii) moving the apparatus across the surface to be treated, so that one or more cylindrical treatment devices carry out the desired mechanical treatment of the surface.

Using the present method, it is thus possible to treat the surface first with the cylindrical treatment device which is circumferentially provided with a material which exhibits a higher resistance to wear than the cylindrical treatment device that is disposed therebehind. After thus the surface to be treated fully mechanically has been treated, the already treated surface is mechanically treated anew by means of a cylindrical treatment device which is circumferentially provided with another wear-resistant material. In addition to that it is possible to change the speed of rotation and/or the direction of rotation of the cylindrical treatment device so as to obtain a different mechanical treatment. In specific embodiments it is furthermore desirable

that the pressure that is exerted in step i) on the surface to be treated be adjusted individually for each treatment device.

The present invention will now be explained in more detail by means of an example, whereby it should be noted that such an example should not be construed as being limitative.

The appended figure schematically shows at reference number 1 a special embodiment of the present apparatus for mechanically treating a surface. It should be noted that the means that are known to those skilled in this field, such as steering means, driving means, supporting means, such as wheels and the like, have been left out for the sake of clarity. In this special embodiment, apparatus 1 for mechanically treating a surface can be considered as a row of separate cylindrical treatment elements 3', 3", 3"', 3""arranged in side-by-side relationship. In this figure it is apparent that the present apparatus comprises seven rows 3', 4', 5', 6', 7', 8'and 9'of separate cylindrical treatment elements arranged in side-by-side relationship. If the present invention 1 is steered across a surface to be mechanically treated in the direction indicated by the arrow, the first row of separate cylindrical treatment elements 3'-3""arranged in side-by- side relationship will come into contact with the surface to be mechanically treated, so that a milling operation is carried out in this manner. Although each row comprises four treatment elements in this figure, it should be understood that the present apparatus is not limited to such a special number. In a second treatment, a scouring operation may be carried out, for example, by bringing the row of separate cylindrical treatment elements 4'-4""arranged in side-by-side relationship into contact with the already treated surface. It should be understood that the wear-resistant material that is used for cylindrical treatment elements 4'-4""is different from the wear-resistant material that is used for cylindrical treatment elements 3'-3"", so that first a milling operation and subsequently a scouring operation can be carried

out. The next row of separate cylindrical treatment elements 5'-5"" arranged in side-by-side relationship can be used for carrying out a grinding operation, for example, whereby the wear-resistant material that is used in this row of separate cylindrical treatment elements arranged in side-by-side relationship provides a finer mechanical treatment than the wear-resistant material of the preceding rows 4'-4"", 3'-3"".

In a special embodiment, the first two rows of treatment elements may be provided with the same wear-resistant material, with the next rows being provided with another wear-resistant material. Thus, the first two rows may be used for carrying out a milling operation, for example, whilst the other rows are used for carrying out one or more scouring, grinding and/or polishing operations. It should be understood that the apparatus that is shown in this figure merely serves to explain the present invention, and the present invention is by no means limited to such a special number of treatment devices or cylindrical treatment elements.