Patent ID: 8622665

Claim:
A rotary tool accessory comprising: a base; a circular wall extending upwardly from the base about a central axis, the circular wall including an inner face, an outer face and a circular rim extending between the inner face and the outer face, wherein the rim includes a centerline defining a circumference of the circular wall; a first cutting group including a first inwardly extending tooth extending from a location directly above the circular wall to a location closer to the central axis than the inner face, the first inwardly extending tooth overlapping the centerline, a first outwardly extending tooth extending from a location directly above the circular wall to a location farther from the central axis than the outer face, the first outwardly extending tooth overlapping the centerline, and a first gullet extending downwardly along the circular wall from the rim toward the base and inclined with respect to the central axis, wherein the first outwardly extending tooth is immediatel adjacent to the first gullet and the first inwardly extending tooth is immediately adjacent to the first outwardly extending tooth and non-adjacent to the first gullet; a second cutting group including a second inwardly extending tooth extending from a location directly above the circular wall to a location closer to the central axis than the inner face, the second inwardly extending tooth overlapping the centerline, a second outwardly extending tooth extending from a location directly above the circular wall to a location farther from the central axis than the outer face, the second outwardly extending tooth overlapping the centerline, and a second gullet extending downwardly along the circular wall from the rim toward the base and inclined with respect to the central axis, wherein the second outwardly extending tooth is immediately adjacent to the second gullet and the second inwardly extending tooth is immediately adjacent to the second outwardly extending tooth and non-adjacent to the second gullet; and a first toothless expanse of the rim extending between the first cutting group and the second cutting group.