Patent ID: 7108594

Claim:
An abrasive disc for use with an orbital sander fitted with a dust extraction system having a plurality of exhaust ports on said orbital sander, comprising: a circular abrasive disc having a major abrading surface provided with an annular zone, intermediate between the center and the circumference of the circular disc wherein the radial distance from the center of the disc to the annular zone is from one third to one half of the radius of the disc and the radial distance from the circumference of the disc to the zone is from one quarter to one third the radius of the disc, and, exclusively within the annular zone, a plurality of perforations, each having a diameter less than one quarter the width of the annular zone and being essentially uniformly spaced in the zone such that the distance between any pair of adjacent perforations is less than twice the greatest dimension of either perforation and at least two perforations are in register with each exhaust port on an orbital sander.