Three piece coupling arrangement for a turret indexing mechanism for a machine tool assembly and an air bearing assembly for the same

An indexing tool turret for a machine tool, comprising:

• a tool turret assembly rotatably supported on the machine tool, said tool turret assembly including at least one of a stationary tool assembly and a live tool assembly supported thereon;
• an indexing assembly capable of rotating said tool turret assembly to a desired location;
• and
• a lock that locks the location of the turret assembly at the desired location, comprising:
• a rotating portion constructed and arranged to rotate with the tool turret assembly;
• a fixed portion;
• and
• a moveable coupling that is moveable between (1) a first position in which the moveable coupling member operationally engages the fixed portion and the rotating portion, thereby preventing rotation of the tool turret assembly, and (2) a second position in which the moveable coupling is operationally disengaged from the fixed and the rotating portions, thereby allowing the tool turret assembly to rotate;
• wherein the fixed and rotating portions have respective pluralities of teeth constructed and arranged to engage a corresponding plurality of teeth on the moveable coupling when the moveable coupling is in the first position;
• and further comprising a fluid bearing assembly constructed and arranged to selectively separate rotating portions of the tool turret assembly from the fixed coupling member when the moveable coupling member is in the second position.

A method of indexing a rotatable tool turret assembly of a machine tool to rotate the tool turret assembly to a desired location such that a tool located on the tool turret assembly can perform a machining operation on a workpiece, the tool turret assembly being connected to a locking assembly, the method comprising:

• disengaging teeth of a coupling portion of a lock on the turret assembly from teeth of fixed and rotating portions of the lock;
• separating the tool turret assembly from the locking assembly using a fluid bearing;
• rotating the tool turret assembly with an indexing assembly;
• and
• engaging the coupling portion of the lock with the fixed and rotating portions;
• and
• reconnecting the tool turret assembly to the locking assembly.