Abstract: An improved tool for removing burrs formed on the edge of drilled holes is provided and comprises a first and second elongated arm member. Each arm member includes arcuate cutting lobes formed on one axial end. The other axial end of each arm member is received within a collet so that the arm members are spaced from but substantially parallel to each other and with the cutting lobes positioned on the outer periphery of each arm member. The collet includes appropriate locking means whereby each arm member can be individually attached to and detached from the collet, and, preferably, the collet is adapted for attachment to the outwardly extending end of a tool holding rod of a tool holder.

Abstract: A combination extension and compression tool holder having a cylindrical outer housing adapted to be inserted into a chuck of a rotary drive machine. A tool holding rod is axially slidably mounted in a cylindrical recess formed in the housing for rotation about its axis of elongation. Two opposing helical springs are disposed within the cylindrical recess and bias the tool holding rod towards an intermediate position within the cylindrical recess. During the feed-in of the machine chuck during a deburring operation, one of the helical springs can be compressed to permit the deburring tool to be retracted when the deburring tool engages an unfinished hole resulting from drill breakage to thereby prevent the deburring tool from being forced into the unfinished hole and thereby broken. During the deburring operation of a normally formed hole, the compression spring will permit the deburring tool to dwell at the opening of the hole for a better deburring operation.

Abstract: A compression tool holder for use with deburring tools or the like, the tool holder having a cylindrical outer housing adapted to be inserted into a chuck of a rotary drive machine. A tool holding rod is axially slidably mounted in a cylindrical recess formed in the tool holder. A spring loaded piston is mounted behind the rod and urges the rod to its extended position. A cap member, however, defines the limit of the extended position for the rod. The rod has an outside diameter somewhat smaller than the inside diameter of the cylindrical recess in the tool holder so that the rod may compensate for misalignment by pivoting relative to the housing within the cylindrical bore, utilizing the cap member as the fulcrum point for its pivot. The end surface of the piston coacts with the end surface of the tool holding rod so as to return the tool holding rod to a central aligned position when misalignment compensation is not required.