Repetitive Rotary Broaching

A method for holding a broaching tool during the conduct of repetitive duplicate rotary broaching operations on serially presented workpieces wherein the broaching tool is engaged serially with each workpiece for rotation with the engaged workpiece during a corresponding rotary broaching operation, each workpiece having a given configuration and the broaching tool having a prescribed configuration placed at an initial orientation for establishing a broached configuration placed at a same predetermined orientation relative to the given configuration of each workpiece, the method being such that upon completion of a rotary broaching operation on a workpiece, the broaching tool is returned to the initial orientation of the prescribed configuration in preparation for a duplicate rotary broaching operation on a subsequent serially presented workpiece, the method comprising:

• providing a support assembly;
• mounting a tool holder upon the support assembly for rotation relative to the support assembly about an axis of rotation, and for translation along the axis of rotation between a first axial position and a second axial position relative to the support assembly;
• providing a reference construct carried by the support assembly at a fixed position corresponding to the initial orientation of the prescribed configuration of the broaching tool;
• coupling an orienting construct with the tool holder for rotation with the tool holder in response to engagement with the reference member;
• biasing the orienting construct and the reference construct into engagement with one another, with a biasing force for biasing the orienting construct and the tool holder into a broaching position corresponding to the initial orientation of the prescribed configuration of the broaching tool, such that upon engagement of a broaching tool held within the tool holder with a workpiece and movement of the tool holder from the first axial position to the second axial position, against the biasing force, the tool holder, and the broaching tool held therein, is free to rotate about the axis of rotation, in response to rotation of the engaged workpiece, and upon disengagement of the broaching tool from the workpiece, the tool holder is moved, in response to the biasing force, from the second axial position to the first axial position, to engage the orienting construct and the reference construct with one another so as to return the tool holder and the broaching tool to the broaching position in preparation for a duplicate rotary broaching operation on a subsequent serially presented workpiece.