Patent ID: 6758732
Filing Date: 2004-07-06
Classification: B24B,B24D

Abstract:
A combination abrasive disc and backing plate, comprising:an abrasive disc having opposed first and second major surfaces, the first major surface being at least in part an abrasive surface, and having at least one non-concentric viewing aperture through the disc; and a backing plate having a bottom major surface which supports the abrasive disc and an opposed top surface, and correspondingly having at least one non-concentric viewing aperture through the plate such that coordinated alignment of the viewing apertures of the disc and plate allows observation of a workpiece collectively through the disc and plate during driven rotation thereof about a rotation axis substantially perpendicular to the bottom major surface; wherein the plate's viewing aperture is bounded by a peripheral boundary and, during rotation of the plate, the plate's viewing aperture orbits the rotation axis such that the boundary is characterized by a leading portion and a spaced trailing portion, said plate further comprising a scooping formation on the top surface that is arranged around the trailing portion for scooping air from an environment above the plate's top surface and deflecting such in a current through the aligned viewing apertures of the disc and plate to provide an air current onto the workpiece; and wherein the plate's viewing aperture's boundary further comprises spaced inboard and outboard portions extending between and linking up the leading and trailing portions thereof, said scoop formation being arranged partly curling around the outboard portion as well.