The invention relates to an apparatus for grinding a concrete floor surface according to the preamble of the independent claim directed thereto, in order to perform grinding with a manual , a pullable and/or a drive-on concrete scrubbing machine .

It is known to use in the above mentioned purpose e.g. as shown in figure 1 , a manual or, as shown in figure 2, a drive -on type of concrete scrubbing machine . A driving end or a so called rotor in this type of a concrete scrubbing machine typically consists of four coupling arms perpendicular to each other, having e.g. elongated scrub wings , as shown in figure 1, or a uniform scrub plate, as shown in figure 2 , fastened thereto .

Especially in connection with a scrub plate it is known to use porous washing, polishing or waxing disks e.g. being affixed to its scrubbing surface with a sticker coupling and having diamond disks fastened in a circle thereon especially for grinding a concrete floor surface In this case thorough cleaning of the scrub plate is required before the sticker tapes are being attached thereto, as well as cleanness of the sticker surfaces, in order to keep the disk provided with diamond disks reliably attached to the scrub plate .

On the other hand, e.g. patents US 7, 255, 513 and US 7,481,602 disclose solutions for the diamond grinding of a concrete surface that differ from the above described, whereby in the former patent there is presented a diamond coating to be attached onto a scrubbing surface of a scrub wing with a suitable middle layer . In the latter patent , for its part , there is presented a corresponding solution as described above being used in connection with a circular scrub plate , as well as a coupling arrangement for coupling the diamond disks rotatably onto the scrubbing surface of the scrub plate with three backing discs and rotation mechanisms .

Arranging a diamond grinding surface straight onto the sc ubbing surface of scrub wings or a scrub plate is disadvantageous first of all in that respect that scrubbing tools executed with such scrubbing organs are single-use and only applicable for diamond grinding . On the other hand, diamond disks to be used on the principle according to patent US 7,481,602, are being attached onto the scrubbing surface of the scrub plate with multiple middle layers , due to which the actual diamond grinding surface remains quite far apart from the scrub plate . Thus , coupling thereof causes both mechanical strain and vibration, which is why the efficient service life of the diamond grinding equipment in question remains short even despite the fact that they are able to rotate on the scrubbing surface .

Because the rotation speed of the concrete scrub ing machines may be considerably high, there is also a risk in the diamond grinding with present solutions that the fastening of the diamond grinding equipment gives way in a way that bigger or smaller particles may get thrown out from the scrubbing surface with a high speed causing thus a work safety hazard in addition to other possible damages .

It is an aim of the apparatus for grinding a concrete floor surface according to the present invention to bring about a decisive improvement particularly in the problems described above and thus to raise essentially the level of prior art . In order to carry out this aim, the apparatus for grinding a concrete floor surface according to the invention is mainly characterized by what has been presented in the characterizing part of the independent claim directed thereto .

As the most important advantages of the apparatus according to the invention may be mentioned simplicity and efficiency of the parts and subsystems related thereto as well as use thereof first of all thanks to the fact that the diamond grinding equipment may be attached in a fast and reliable manner to the concrete scrubbing organ, such as a scrub plate or scrub wings , without the risk e.g. of the diamond disk or parts thereof getting loosened involuntarily during grinding . As an advantageous embodiment of the invention, a coupling arrangement of the diamond grinding arrangement therefore comprises a perforation through e.g. the scrub plate or the scrub wing, wherein a fastening part going through the perforation and being coupled with a fastening frame of the diamond grinding arrangement is arranged to be affixed to the scrubbing organ . In this way it is made possible first of all that the actual diamond grinding surface is as close as possible to the scrubbing surface of the scrub plate or the scrub wing and on the other hand that a reliable coupling of the grinding equipment in question in a removable manner in connection with each scrubbing organ is achieved, wherein the scrubbing organs may be constantly used, when necessary by changing the diamond disks when necessary, and wherein the scrubbing organs are furthermore suitable also for grinding to be performed without diamond disks . Furthermore , when implementing the inven ion advantageously, the fastening frame is coupled in connection with the diamond disk utilized on the scrubbing surface of the scrubbing organ chemically, such as by gluing, mechanically, such as by a sticker gripping or a snap joint coupling, melting , such as by welding or injection moulding and/or in a corresponding manner, thanks to which it is possible to ensure a uniform, compact and an as "low" as possible diamond grinding equipment entirety, from which parts cannot get loose involuntarily . Attachment of the diamond grinding arrangement , such as the diamond disk, can be made even more efficient e.g. by utilizing as the fastening frame ' s fastening part arrangements that get locked against the scrubbing organ' s back surface . Furthermore, as an advantageous embodiment , spring means are being utilized in the invention in order to make possible deflection motions of the diamond disks with respect to the concrete scrubbing organ .

Other advantageous embodiments of the apparatus according to the invention have been presented in the dependent claims directed thereto . In the following description the invention is being illustrated in detail with reference to the appended drawings , in which in figure 1

is shown a typical manual concrete scrubbing machine, having scrub wings attached to the rotor thereof , in figure 2

is shown furthermore a typical drive-on concrete scrubbing machine , having a scrub plate attached to the rotor thereof , in figures 3a and 3b

are shown as perspective views a scrub plate and a scrub wing equipped with a concrete grinding equipment according to the invention, in figures 4a-4d

are shown first of all a perspective view of a scrub plate to be used in the apparatus according to the invention and with consecutive phases the coupling of a diamond disk equipped with a fastening frame onto the scrubbing surface of a scrub plate in a manner enabling a deflection motion of the diamond disk, in figures 5a and 5b

are shown furthermore some alternative spring and fastening arrangements of the diamond disk's fastening frame, in figures 6a-6c

are shown furthermore an advantageous alternative spring arrangement of the diamond disk' s fastening frame and the fastening thereof to the scrub plate in a manner enabling a deflection motion of the diamond disk, in figures 7a-7c

are shown views corresponding to figures 6a- 6c of a further alternative fastening of the diamond disk in connection with a scrub plate or a scrub wing, in figure 8

are shown as exemplary perspective views a rotor with multiple arms and the scrub plate to be used in connection therewith, and as a cross section an advantageous fastening principle of a diamond grinding arrangement belonging to the apparatus according to the invention, in figure 9

is shown an alternative embodiment with respect to figure 8 of two alternative fastening arrangements of a diamond disk having a fastening part with a wedge-like cross section, and in figures lOa-lOc

are shown first of all as a perspective view a rotor to be used as a concrete scrubbing organ, and on the other hand as views from above diamond disks coupled to the fastening arms thereof with two alternative coupling arrangements .

The invention relates to an apparatus for grinding a concrete floor surface , in order to perform grinding e.g. as shown in figure 1 with a manual , a pullable or e.g. as shown in figure 2 a ride-on concrete scrubbing machine . The apparatus comprises a concrete scrubbing organ 1 to be used with the concrete scrubbing machine and a diamond grinding arrangement 2 , such as one or several diamond disks 2a or like , to be coupled in connection with the concrete scrubbing organ removably by means of a fastening arrangement . The fastening arrangement 3 for coupling the diamond grinding arrangement 2 in connection with the concrete scrubbing organ 1 comprises e.g. with reference to figure 4b a fastening frame 3a, being in connection with the diamond grinding arrangement 2 that exists on a scrubbing surface hp of the concrete scrubbing organ, and a fastening part 3b extending from the fastening frame and getting supported on the concrete scrubbing organ 1 while going through the same .

As an advantageous embodiment of the apparatus according to the invention, the concrete scrubbing organ 1 comprises a metallic scrub plate la or scrub wings lb, wherein back surfaces thereof are provided with a coupling arrangement (that has not been shown in more detail in the drawings) for the coupling of the concrete scrubbing organ with a concrete scrubbing machine ' s rotor R e.g. having customarily four or as shown in figures 8-10 more than four arms . In figure 3a is shown as a perspective view a scrub plate 1; la equipped with concrete grinding equipment according to the invention to be coupled with the rotor of the concrete scrubbing machine and in figure 3b respectively a scrub wing 1 ; lb to be coupled with each coupling arm of the concrete scrubbing machine ' s rotor .

The fastening arrangement 3 comprises e.g. with reference to figure 4a a perforation 3c that goes at least through the concrete scrubbing organ 1, such as the scrub plate la or scrub wings lb, in order to fasten the diamond grinding arrangement 2 to the scrub ing organ 1 e.g. on the principle manifesting itself in figures 4c, 6b and 7b by the fastening part 3b of the diamond grinding arrangement ' s 2 fastening frame 3a that goes through the perforation 3c in the scrubbing organ 1.

Furthermore , in figure 8 is shown an embodiment implemented in the above described manner, wherein the fastening part 3b of the fastening f ame of the diamond grinding arrangement is arranged long enough , so that the diamond grinding arrangement 2 is supported on the concrete scrubbing organ 1 through perforations 3c, 3c' being present both therein and in the rotor R .

As a furthermore advantageous embodiment of the apparatus according to the invention, the fastening frame 3a is arranged in connection with the diamond grinding arrangement 2 , such as the diamond disk 2a, chemically, such as by gluing, mechanically, such as by a sticker gripping joint or a snap- joint , melting, such as by welding or inj ection moulding, and/or in a corresponding manner . As a furthermore advantageous embodiment of the apparatus according to the invention, the fastening arrangement 3 comprises e.g. with reference to figures 4b and 8 an expansion assembly 3b' at an end of the fastening part 3b in order to lock the diamond grinding arrangement 2 , such as the diamond disk 2a, against the back surface tp of the scrub plate la or the scrub wing lb.

Especially in the type of embodiments as shown in figures 9 and lOa-lOc, the fastening part 3b of the diamond grinding arrangement 2 is formed wedge-like by its cross section in order to couple the diamond grinding arrangement e.g. with the fastening parts 3b of the left hand sided diamond disks 2 in figures 9 and 10a through triangle shaped perforations 3c, 3c' in the scrub plate la and/or the rotor R against the back surface tp of the scrub plate la or the rotor R. The right hand sided diamond disks in figures 9 and 10a are for their part arranged to be coupled in place with an interference fit between the fastening frames 3b and the perforations 3c, 3c' in the scrub plate la and/or the rotor R, wherein the diamond disks 2a are forced into the perforations 3c, 3c' with a tight fit . As a furthermore advantageous embodiment of the apparatus according to the invention e.g. with reference to figures 4b-4c , the fastening arrangement 3 includes spring means 3d in order to enable deflection movements of the diamond grinding arrangement 2 , such as the diamond disk 2a, with respect to the concrete scrubbing organ 1, regarding which some advantageous exemplary alternatives of the spring means are shown in figures 5a, 5b, 6a-6c and 7a-7c . As a furthermore advantageous embodiment of the apparatus according to the invention, a cross section area of one or more holes 3c, 3c' for the fastening part 3b in the concrete scrubbing organ 1, such as the scrub plate la or the scrub wing lb, is/are arranged essentially larger than a cross section area of the fastening part 3b, which enables e.g. a deflection motion of the diamond grinding arrangement 2 as shown in figures 4d, 6c and 7c without the need to manufacture the fastening part necessarily from elastic material , or when utilizing the wedge-like form of the fastening part as shown in figures 8, 9, lOa-lOc, the locking and releasing motions thereof in the radial direction as shown in figure 10b . In figure 10c is shown for its part a fastening part 3b of the diamond disk 2; 2a that is locked in place immovably with an interference fit . According to figure 10a, the invention may also be applied by using the concrete scrubbing machine ' s rotor R together with its perforations 3c directly as the concrete scrubbing organ 1.

As a furthermore advantageous embodiment of the apparatus according to the invention, the spring means 3d are arranged e.g. according to figures 4b-4d or 5a, 5b with a flexible formation of the fastening frame ' s 3a back surface, being made of elastic and/or flexible material , wherein as a furthermore advantageous embodiment especially with reference to figures 6a- 6c and 7a- 7c, the spring means 3d are arranged with a spring rib or a spring ring structure made of elastic and/or flexible material on the back surface of the fastening frame 3a.

As a furthermore advantageous embodiment of the apparatus according to the invention, the fastening part 3b is arranged e.g. on the principle as shown in figures 4b, 5a, 6b, 7b and 8 with an end 3b' of the fastening part 3b that gets locked against the back surface tp of the concrete scrubbing organ 1 with a snap- lock j oint . The principle described above manifests itself also in the left hand sided diamond disks 2; 2a presented in figures 9 and 10a .

As a furthermore advantageous embodiment of the apparatus according to the invention, the fastening part 3b is arranged with a counterpart that gets supported against the back surface tp of the concrete scrubbing organ 1 and that is to be fastened removably to the fastening part 3b. As an example of the above described, reference is made to the embodiment according to figure 5b, wherein a screw coupled with the fastening frame by its head is supported against the back surface tp of the scrubbing organ with a nut 3b' to be screwed on the thread part of the screw . It is clear that the invention is not limited to the embodiments shown or described above , but it may be altered in very many ways within the basic idea of the invention, e.g. by using the embodiments shown in the appended drawings mixed with each other etc . Thus e.g. the "rotor embodiment" shown in figure 10a may also be utilized by coupling the same with a customary rotor of a concrete scrubbing machine . Also the types of implementations shown in the appended drawings may be carried out with structures and appearances differing from what has been shown in order to bring about the same basic purpose of the invention . Additionally, components or parts thereof belonging to the apparatus according to the invention may also be manufactured from the most different kinds of materials by utilizing the most different kinds of manufacturing techniques e.g. by using plastic , ceramic , composite, carbon fibre and/or the like, not to mention metal structured, such as light alloy implementations .