# US 2014/0154961 A1 · Multi-abrasive tool > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0154961 A1 - Document ID: US20140154961A1 - Status: Published application - Kind: A1 - Application number: 14/117,695 - Filed: 2011-07-07 - Published: 2014-06-05 - Earliest claimed: 2011-05-16 - Assignees: REN S.r.l. - Inventors: Nicola Fiore - Web page: https://patentgrep.com/patent/US20140154961A1 ## CPC - B24D 7/14: Zonally-graded wheels; Composite wheels comprising different abrasives - B24D 5/14: Zonally-graded wheels; Composite wheels comprising different abrasives - B24D 7/06: with inserted abrasive blocks, e.g. segmental - B24D 11/04: Zonally-graded surfaces - B24D: TOOLS FOR GRINDING, BUFFING OR SHARPENING (abrading-bodies specially designed for tumbling apparatus, e.g. abrading-balls B24B31/14; honing tools B24B33/08; lapping tools B24B37/11) ## Abstract A multi-abrasive tool is constituted by a support on which abrasive elements are present. Such abrasive elements are arranged in a manner so as to form one or more paths along which the successive abrasive elements have grain size sequentially increasing or decreasing by an arbitrary quantity when passing from on element to the next. Such principle gives rise to abrasive tools with different conformation both for polishing machines and for grindstones. For roto-orbital and planetary polishing machines, and optionally orbital, such support is circular and the grain sequence is circumferential, or radial, or in both directions. A first tool is constituted by contiguous (or non-contiguous) circular rings, that are differently abrasive. A second tool comprises differently abrasive elements arranged along the circular peripheral edge. A third tool comprises differently abrasive elements arranged along a spiral path of 360° starting from the edge. A fourth tool comprises two 180° spiral paths with reversed roughness sequences. A fourth tool comprises pairs of differently abrasive small cylinders fixed to a plate on concentric circumferences. A fifth tool is obtained directly on the plate of the polishing machine by means of reliefs and spacers for fixing differently abrasive sectors. For linear polishing machines, the abrasive support is a belt along which differently abrasive rectangular or oblique zones follow each other. For alternative polishing machines, the abrasive support is a plate shaped like the aforesaid belt. For tools to use with grindstones, the multi-abrasive element has a cylindrical rotation symmetry, or conical with rounded tip, or spherical symmetry. ## Claims ### Claim 1 An abrasive tool, characterized in that it includes on the work face at least two abrasive elements with different roughness (50, 64, 78, 86, 96, 104, 114, 140, 170, 180, 210, 218, 230, 262, 271, 290, 298, 303). ### Claim 2 (depends on 1) The abrasive tool of claim 1, characterized in that it includes more than two abrasive elements with different roughness (50, 64, 78, 86, 96, 104, 114, 140, 170, 180, 210, 218, 230, 262, 271) arranged in a manner so as to form, along at least one path between adjacent abrasive elements, a sequence that is ordered by increasing or decreasing roughness values. ### Claim 3 (depends on 1, 2) The abrasive tool of claim 1 or 2, characterized in that it has circular shape or any one regular polygonal shape (50, 64, 78, 86, 96, 104, 114, 140, 170, 180). ### Claim 4 (depends on 3) The abrasive tool (50, 64, 78, 86, 96, 104, 114, 140, 170, 180) of claim 3, characterized in that the arrangement of said abrasive elements involves a distribution of abrasive mass with respect to the center of the tool such that the abrasive elements m1, m2 whose centers of mass are aligned on opposite sides with respect to the center of the tool, respectively at distances r1, r2 therefrom, generate equivalent contributions m1·r12 and m2·r22 to the moment of inertia of the tool. ### Claim 5 (depends on 4) The abrasive tool of claim 4, characterized in that said abrasive elements (80-83; 88-93) are at the same distance from the center of the tool, being arranged in proximity to the peripheral edge. ### Claim 6 (depends on 4) The abrasive tool (96, 104, 114, 140) of claim 4, characterized in that the distance of each abrasive element from the center of the tool increases or decreases from one abrasive element to the adjacent one, depending on the clockwise or counter-clockwise direction said at least one sequence is followed. ### Claim 7 (depends on 6) The abrasive tool of claim 6, characterized in that said abrasive elements fully occupy respective concentric circular rings (52-61; 66-75) that are contiguous or arbitrarily spaced. ### Claim 8 (depends on 7) The abrasive tool of claim 7, characterized in that the grain size of the abrasive elements varies nearly continuously in a radial direction. ### Claim 9 (depends on 6) The abrasive tool of claim 6, characterized in that said abrasive elements partially occupy respective concentric circular rings that are contiguous or arbitrarily spaced. ### Claim 10 (depends on 6) The abrasive tool (96, 104) of claim 6, characterized in that said abrasive elements are arranged along a spiral path of about 360° starting from the peripheral edge of the tool. ### Claim 11 (depends on 6) The abrasive tool (114, 140) of claim 6, characterized in that abrasive elements belonging to groups of equal number are spaced along two or more spiral paths with equivalent angular opening, submultiple of 360°, and starting from the peripheral edge of the tool. ### Claim 12 (depends on 11) The abrasive tool (114, 140) of claim 11, characterized in that: a first group of abrasive elements arranged on a spiral path (116-125) or several first groups of abrasive elements arranged on adjacent spiral paths (142-146; 147-151) are ordered by increasing grain size from the periphery towards the interior; a second group of the same number of abrasive elements arranged on a spiral path (135-127) or several second groups of the same number of abrasive elements arranged on an equal number of adjacent spiral paths (152-156; 157-161) are ordered by decreasing grain size from the periphery towards the interior. ### Claim 13 (depends on 9, 10, 11, 12) The abrasive tool (96, 104, 78, 86, 114, 140) according to any claims 9 to 12, characterized in that said abrasive elements have a shape obtained by extruding, up to a same height, a circular ring sector orthogonal to the work face. ### Claim 14 (depends on 6) The abrasive tool (180) of claim 6, characterized in that it is obtained directly on the plate (181) of a polishing machine by means of reliefs (183-188) arranged in a circle in order to anchor the abrasive elements 190, 192, 194; 196, 199, 202) under pressure against the projecting peripheral edge (182), both directly and by means of spacers (198, 201, 204). ### Claim 15 (depends on 1) The abrasive tool of claim 1, characterized in that it has the shape of a belt that is closed on itself (254) or of a rectangular plate (271), said abrasive elements (258-261; 278-281) occupying contiguous strips in grain size sequence, the strips being orthogonal or oblique with respect to the longitudinal center line of the belt or plate. ### Claim 16 (depends on 1) The abrasive tool of claim 1, characterized in that it has rotational symmetry (290), said abrasive elements (291-294) being extended on the lateral surface within contiguous bands in grain size sequence, annular bands or with cylindrical helical form (F, M, G). ### Claim 17 (depends on 1) The abrasive tool of claim 1, characterized in that it has spherical symmetry (302), said abrasive elements (F, M, G) including, in grain size sequence, a spherical cap on the tip contiguous to successive spherical zones.