Triangular Abrasive For Floor Finishing Machine

Abstract

A drive plate for a concrete or stone grinding/polishing machine includes one or more abrasive elements in the form of short sintered metal bars having diamond crystals mixed therein. Due to the triangular profile of the abrasive elements, as the drive plate is rotated by a drive motor and the apex of the triangular abrasive element engages the floor surface being treated, the abrasive elements are able to more readily strip off mastic, sealers, glue, or most any thin film topical coating present on concrete or other hard floors.

Description

CROSS-REFERENCED TO RELATED APPLICATIONS

[0001] None

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] None

BACKGROUND OF THE INVENTION

I. Field of the Invention

[0003] This invention relates generally to motor powered floor finishing machines and, more particularly, to an improved abrasive for attachment to a drive plate for such machines, the abrasive being especially adapted for removing mastics, sealers, glue, or most any thin mil topical coating such as paint, acrylics, etc. from concrete or terrazzo floor surfaces.

II. Discussion of the Prior Art

[0004] The prior art includes many patents and publications describing tools for machining stone, terrazzo or concrete floors. Included are machines for grinding and polishing, as well as for milling or crushing floor surfaces. Further, there are machines especially adapted for cleaning hard surfaces, such as concrete, stone and terrazzo by removing coatings on them. Such machines typically carry one or more rotatably mounted, motor driven drive plates that, in turn, carry one or more abrasive elements attachable to the motor driven drive plate and adapted to be rotated in relation to a floor surface. The abrasive elements affixed to the drive disc typically include abrasive pads or bars that are made to engage the hard floor surface as the drive plate is being driven and the machine is being moved across the floor surfaces. Typical of such patents are the Van Vliet U.S. Pat. No. 7,377,838, the Palushaj U.S. Pat. No. 7,690,970 and the Anderson U.S. Pat. No. 7,563,156. A major manufacturer and supplier of concrete and stone grinding and polishing machines is Scanmaskin Sverige AB of Lindome, Sweden.

[0005] Prior art machines employ a wide variety of abrasive tools bonded, bolted or otherwise affixed to a circular disc where the abrasive tools have a planar floor-engaging surface. While such tools perform well as far as grinding and polishing concrete and stone floors, they tend not to be particularly effective in removing paint or glue that had been used in adhering commercial carpeting or tile to concrete, stone and terrazzo floors.

[0006] Once the carpeting or tile is removed, the underlying hard surface floor retains a residue of adhesive material that must be removed prior to further refining or finishing the floor.

[0007] It is the purpose of the present invention to provide an improved abrasive element attachable to a drive plate for a floor-finishing machine that is especially designed to aid in removing paint, mastic, glues, coatings, sealers, or adhesive residues that may be present on a hard surface.

SUMMARY OF THE INVENTION

[0008] In accordance with the present invention, a motorized floor finishing machine comprises one or more circular drive plates having a central hub projecting out from a first major surface of the circular plate and adapted to be attached to a motor driven drive shaft. Attached to a second major surface of the drive plate is an abrasive assembly that may comprise a mounting bracket and an abrasive member affixed to the mounting bracket. Alternatively, the abrasive element may be directly attached to the drive plate. The drive plate may rotate or vibrate or both.

[0009] The abrasive member preferably comprises a sintered metal bar of triangular cross section comprising a homogeneous mixture of metal powders, industrial diamond grit and possibly other abrasive materials.

[0010] It has been found that when triangular abrasive tools are mounted with their base affixed to the drive plate and an opposed apex contacting the floor surface they are considerably more effective in grinding away thin coatings and adhesives than are conventional abrasive tools exhibiting a flat floor engaging surface.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts.

[0012] FIG. 1 is a bottom plan view of a drive plate incorporating four triangular abrasive assemblies;

[0013] FIG. 2 is a front view thereof; and

[0014] FIG. 3 is an exploded view of one of the abrasive assemblies shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0015] The description of the preferred embodiment is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as "lower", "upper", "horizontal", "vertical", "above", "below", "up", "down", "top", and "bottom", as well as derivatives thereof (e.g., "horizontally", "downwardly", "upwardly", etc.), should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for the convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms, such as "connected", "connecting", "attached", "attaching", "join", and "joining", are used interchangeably and refer to one structure or surface being secured to another structure or surface or integrally fabricated in one piece, unless expressly described otherwise. As used herein, the term "floor treating machine" is meant to include floor grinding, floor polishing, floor burnishing, floor scrubbing and swing machines.

[0016] Referring to FIG. 1 and FIG. 2, there is indicated generally by numeral 10 one configuration of a drive plate for a concrete, stone or terrazzo floor finishing machine, such as a grinder or polisher. It is seen to comprise a steel plate 12 having a cylindrical hub 14 affixed to a first major surface 16 thereof where the hub 14 is adapted to receive a drive shaft of a motor for driving the drive plate 12 about a central axis of the hub 14.

[0017] The second major surface 18 of the drive plate 12 may have a plurality of symmetrically arranged recesses, as at 20, milled inward from the surface 18 to form pockets for receiving abrasive assemblies 22 therein. Alternatively, the second major surface of the drive plate may be flat and void of pockets.

[0018] Referring to FIG. 3, there is illustrated an exploded view of one of the abrasive assemblies 22. It is seen to comprise the bracket 24 in the form of a metal plate to which is attached one or more an abrasive elements 26. In the drawings, the mounting bracket 24 is shown as being somewhat V-shaped, but with a rounded vertex. However, the bracket shape can be changed along with the shape of the pockets in the drive plate. As seen in FIG. 3, rather than being a rectangular bar, as in the prior art, the abrasive element 26 is generally a sintered metal bar of a predetermined length dimension and having a triangular cross-section. The abrasive element 26 is preferably attached to the bracket 24 by welding or silver soldering the base 28 of the triangular abrasive element to the bracket.

[0019] In use, the apex 27 of the abrasive element opposite its base 28 is parallel to the plane of the drive plate 12. Those skilled in the art will appreciate that the abrasive elements 26 can also be directly affixed to the drive plate 12 without the use of a bracket.

[0020] The abrasive element itself is a sintered diamond grit impregnated mixture of metal powders and possibly other abrasive materials. Without limitation, the triangular abrasive element 26 may have a length dimension in a range of from 0.5 inch to 4 inch with an included angle of the apex 27 in the range of 40 degrees to 90 degrees. Without limitation, the size of the diamond grit may be in a range of from 16 to 400 on the ASTM scale.

[0021] In FIG. 1, the abrasive assemblies 22 are shown mounted in the pockets 20 of the drive plate 12 by bolts 34, which pass through apertures 36 (FIG. 3) drilled through the brackets 24 and into tapped holes (not shown) formed in the pockets of the drive plate 12. As already mentioned, the abrasive elements can be soldered or brazed directly onto the drive plate 12. The abrasive assemblies 22 may also be attached to the drive plate by alternative means known in the art.

[0022] When removing mastic, sealers, glue, or most any thin film topical coating, one of the challenges is surface contact between floor and tool, which generates heat. This heat melts the surface coating, which gums up and clogs the abrasive tool.

[0023] The use of a triangular diamond impregnated segment reduces the contact area with the floor thereby reducing generated heat. Only a line contact of the apex 27 contacts the floor. Moreover, the active contact is a line formed by the apex 27 in which a row of diamond particles, which leads to the tool performing a cutting and scraping job as opposed to grinding, the former being more desirable for coating removal. This row of diamond particles has a much greater number of cutting elements than the surface of a conventional rectangular bar segment that has diamonds sporadically embedded and is therefore more efficient and effective.

[0024] Another advantage of the triangular cross-section diamond impregnated segment is the wear pattern that occurs during use. As a prior art rectangular bar segment wears, a full rectangular side surface is in contact with the floor, which not only generates friction and heat, but also directs the abrasive action downwards. The abrasive element of the present invention more laterally interfaces with the floor, presenting a blade-like single row of diamonds to the floor surface as the tool wears.

[0025] This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself.

Claims

1. In a motorized floor finishing machine having at least one circular plate with a central hub projecting out from a first major surface of the circular plate and adapted to be attached to a motor driven drive shaft, the improvement comprising at least one abrasive member comprising a sintered metal bar of a predetermined length and having a triangular cross-section defining a base and an apex opposite said base, where the base is adapted to be joined to a second major surface of the circular plate, said sintered metal bar having diamond particles embedded therein

2. The motorized floor finishing machine of claim 1 wherein the predetermined length of the sintered metal bar is in a range of from 0.5 inch to 4.0 inches.

3. The motorized floor finishing machine of claim 1 wherein the sintered metal bar has an isosceles triangle cross-section and the included angle of the apex is in a range of from 40 degrees to 90 degrees.

4. The motorized floor finishing machine of claim 1 wherein the diamond particles have a grit size in a range of from 16 to 400.

5. The motorized floor finishing machine of claim 1 and further including a mounting bracket for interfacing the abrasive member to the second major surface of the circular plate.

6. The motorized floor finishing machine of claim 5 wherein the predetermined length of the metal bar is in a range of from 0.5 inch to 4.0 inches.

7. The motorized floor finishing machine of claim 5 wherein the metal bar has an isosceles triangle cross-section and the included angle of the apex is in a range of from 40 degrees to 90 degrees.

8. The motorized floor finishing machine of claim 5 wherein the diamond particles have a grit size in a range of from 16 to 400.

9. The motorized floor finishing machine of claim 5 wherein the base of the abrasive member is affixed to the mounting bracket by one of brazing, welding and soldering.