A grinding wheel that can rotate at high speed to grind flat plates comprised of a thin conical grindstone fastened to the open end of a rotatable inverted cup, with the grinding edge projecting outwardly from and at an inclined angle with respect to the open end. The grindstone includes a cylindrical...http://www.google.se/patents/US4545154?utm_source=gb-gplus-sharePatent US4545154 - Grinding wheel for flat plates
