A work holder assembly is disclosed for securing a workpiece on a lathe having a rotary driven shaft. The workpiece has a central hole in an end wall thereof, and said end wall will be maintained in a position substantially perpendicular to the axis of rotation of the shaft. The work holder assembly includes an arbor mount comprising a substantially cylindrical tube portion having an enlarged backing plate at one end. The arbor mount is provided with a central bore, the axis of which is substantially coincident with the axis of the tube portion, which central bore is adapted to receive the shaft in sliding engagement therewith. The tube portion of the arbor mount has an outside diameter that is smaller than the diameter of the central hole in the end wall of the workpiece, while the backing plate is larger than the central hole. The work holder assembly also includes a centering cone which has a larger end and a smaller end, which larger end has a diameter that is larger than the diameter of the central hole in the end wall of the workpiece. The cone also has a central bore, the axis of which is substantially coincident with the axis of the cone, which is adapted to receive the tube portion of the arbor mount in sliding engagement therewith. The work holder assembly also includes a compression cup having a base portion and a sidewall extending from the periphery thereof. The base portion of the cup has a central hole therethrough that is adapted to receive the tube portion of the arbor mount, and the sidewall terminates in a peripheral edge that is located so as to correspond with the periphery of the backing plate. In use, the arbor mount of the invention is positioned over the shaft, and a workpiece is positioned over the arbor mount in front of the backing plate. The cone is positioned over the tube portion of the arbor mount with its smaller end preceding its larger end and secured against the end wall of the workpiece. The compression cup is positioned and secured over the arbor mount so that compressive forces may be applied to the end wall of the workpiece between the peripheral edge of the sidewall of the cup and the periphery of the backing plate.

A kit for use in attaching and securing workpieces comprising hubless brake drums and rotors of various sizes on a lathe includes an arbor mount comprising a substantially cylindrical tube portion with an enlarged terminal member at one end. The arbor mount has a central bore adapted to receptive the shaft of the lathe. The kit also includes a pair of backing plates which can acommodate various sized workpieces. Each plate has a central hole with a diameter of sufficient size so that the tube portion of the arbor mount may pass therethrough. The first side of each plate is adapted to receive the terminal member of the arbor mount, and each plate is adapted to be positioned over the tube portion of the arbor mount with the terminal member behind a workpiece. The kit also includes a pair of centering cones which can accommodate various sized workpieces. Each of the cones has a central bore which is adapted to receive the tube portion of the arbor mount in sliding engagement therewith, and to be positioned over the tube portion of the arbor mount with the smaller end of the cone preceding its larger end and secured against the end wall of a workpiece. The kit also includes a compression cup for use with one of the plates and one of the cones. This cup has a base portion and a sidewall, and the base portion has a central hole that is adapted to receive the tube portion of the arbor mount. The sidewall terminates in a peripheral edge that is located so as to correspond with the periphery of one of the plates. The cup is adapted to be positioned and secured over the arbor mount so that compressive forces may be applied to the end wall of a workpiece between the peripheral edge of the sidewall of the cup and the periphery of the plate. A nut is used to secure a cone or the cup on the tube portion of the arbor mount.

A lathe adapter/apparatus for reshaping surfaces of a brake rotor and eliminating run-out comprising an adapter plate assembly mounted on an adapter mounting member with a first fixed plate of the plate assembly defining a first planar end surface perpendicular to the axis of adapter mounting member and a second planar end surface that forms an angle with the axis. A movable plate is mounted on the adapter mounting member adjacent the fixed plate, the moveable plate defining a first planar end surface perpendicular to the axis of the adapter mounting member and a second planar end surface that forms an angle with the axis, the angled end surface of the first movable plate member engaging the angled end surface of the first fixed plate. A second plate assembly having plates with end surfaces substantially identical to the first plate assembly is mounted on the adapter mounting member and a cone and spring centering assembly is mounted on the adapter mounting member between the first and second plate assemblies for centering a brake rotor which is mounted on the adapter mounting member between the plate assemblies.

A quick change tool holder is provided for cutter inserts on machine tools which comprises a housing which is adapted to receive and conform to the shape of a cutter insert. A pivoting arm is mounted in the insert housing and rotates about a pivot therein. The pivoting arm has a clamp portion extending from the pivot to a position over a seat portion which is adapted to engage a cutter insert. In addition, the pivoting arm has an arm extending from the pivot opposite the clamp portion. Lastly, a cam is engaged by a distal end of the arm. The cam has a clamp position which forces the clamp portion to engage a cutter insert and a release position which forces the clamp portion to disengage from a cutter insert to allow thereof. The cam moves between the release position and the clamp position.