Abrading Disc

Abstract

A rotating circular disc attaches to a rotary motion abrading tool and converts the rotary motion to a random orbital motion. The disc has a center and has an axis of rotation that is off center and that forms a center of gravity. One embodiment of the disc is a backing plate. A second embodiment of the disc is a polishing pad. A third embodiment of the disc is a combination of a backing plate and a polishing pad.

I claim: 
     
         1 . An abrading disc for attachment to a rotary motion abrading tool that converts the rotary motion to a random orbital motion, the disc having a center, an axis of rotation that is off center and that forms a center of gravity, and a means for attachment to a rotary motion abrading tool. 
     
     
         2 . The abrading disc of  claim 1  wherein the disc comprises a backing plate having a working face for attachment of a polishing pad and an opposed face with an arbor extending outwardly from the opposed face that defines the axis of rotation and that attaches to a rotary motion abrading tool. 
     
     
         3 . The abrading disc of  claim 1  wherein the backing plate has a crescent shaped recess in the opposed face. 
     
     
         4 . The abrading disc of  claim 1  wherein the disc comprises a polishing pad having a working face with an abrasive surface and an opposed face having a means for attachment to a backing plate. 
     
     
         5 . The abrading disc of  claim 1  wherein the means for attachment comprises a hook and loop fabric. 
     
     
         6 . A backing plate for a rotary motion abrading tool that converts the rotary motion to a random orbital motion, the backing plate comprising a circular plate having a center, a working face for attachment of a circular polishing pad, an opposed face with an arbor extending outwardly from the opposed face that defines an axis of rotation, the axis of rotation being off center and forming a center of gravity when a circular polishing pad is attached to the working face. 
     
     
         7 . The backing plate of  claim 6  wherein the opposed face has a crescent shaped recess. 
     
     
         8 . The backing plate of  claim 6  wherein the working face comprises a hook and loop fabric. 
     
     
         9 . The backing plate of  claim 6  wherein the axis of rotation forms the center of gravity when a circular polishing pad with a uniform weight distribution is attached. 
     
     
         10 . The backing plate of  claim 6  wherein the axis of rotation forms the center of gravity when a circular polishing pad with a non-uniform weight distribution is attached. 
     
     
         11 . An assembly for a rotary motion abrading tool that converts the rotary motion to a random orbital motion, the assembly comprising:
 (a) a backing plate comprising a circular plate having a center, a working face for attachment of a circular polishing pad, an opposed face with an arbor extending outwardly from the opposed face that defines an axis of rotation, the axis of rotation being off center; and   (b) a circular polishing pad attached to the working face of the backing plate, the pad being of substantially the same size as the working face;   
       wherein the assembly has a center of gravity that is on the axis of rotation. 
     
     
         12 . The assembly of  claim 11  wherein the working face of the backing plate comprises a hook and loop fabric. 
     
     
         13 . The assembly of  claim 11  wherein the opposed face of the backing plate comprises a crescent shaped recess. 
     
     
         14 . The assembly of  claim 11  wherein the opposed face of backing plate comprises an arbor on a cone shaped platform. 
     
     
         15 . The assembly of  claim 11  wherein the polishing pad has a uniform weight distribution.