Patent attributes
For use with a power trowel, an abrasive assembly attachable to a rotatable arm of the power trowel that comprises a circular, rigid plate having a central hub projecting out from a first major surface and affixed to its second major surface is a ring of a resilient material. Adjacent the resilient ring is a molded plastic ring in which a plurality of permanent magnet members are imbedded at regularly spaced intervals. The plastic ring further includes at least, one boss projecting outward from a surface thereof and designed to fit within an aperture disposed in an outermost ring, which is entirely or partially of a ferrous metal and which carries a plurality of abrasive members on its outer surface. The resilient ring is fastened to the rigid plate by internally threaded tubular pins and the plastic ring is secured by screws that pass through the plastic ring into the lumens of the internally threaded tubular pins.