Repetitive rotary broaching

A method for holding a broaching tool during the conduct of repetitive duplicate rotary broaching operations on serially presented workpieces, the method comprising:

• engaging the broaching tool serially with each workpiece for rotation with an engaged workpiece during a corresponding rotary broaching operation, each workpiece having a given configuration and the broaching tool having a 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 the corresponding rotary broaching operation on the engaged workpiece, the broaching tool is returned to the initial orientation in preparation for a duplicate rotary broaching operation on a subsequent serially presented workpiece;
• 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;
• holding the broaching tool within the tool holder;
• providing a reference construct carried by the support assembly at a fixed position corresponding to the initial orientation 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 construct;
• providing a biasing 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 broaching tool;
• engaging the broaching tool held within the tool holder with the engaged workpiece by movement of the tool holder from the first axial position to the second axial position, against the biasing force, thereby rotating the tool holder, and the broaching tool held therein, about the axis of rotation, in response to rotation of the engaged workpiece;
• and
• subsequently disengaging the broaching tool from the engaged workpiece, thereby moving the tool holder, in response to the biasing force, from the second axial position to the first axial position, whereby the orienting construct and the reference construct engage with one another to return the tool holder and the broaching tool to the broaching position in preparation for a duplicate rotary broaching operation on the subsequent serially presented workpiece.