Workpiece transfer apparatus

A machine tool for automated transfer and machining of workpieces comprising:

• a machine frame,
• a chuck rotatably mounted to said machine frame for supporting a workpiece during machining and defining a machining station,
• a workpiece transfer means mounted to said machine frame and defining a transfer station,
• a gripper arm including at least one gripper jaw assembly for releasably engaging and supporting a workpiece, and
• means mounting said gripper arm to said machine frame for selective movement about an axis which is fixed with respect to said machine frame, and for selective axial movement in the direction of said axis, so that said one gripper jaw assembly is moveable between said machining station and said transfer station, said mounting means comprising
• (a) a drive shaft mounted for rotation about said axis and having at least one helical thread and at least one longitudinal thread on the surface thereof,
• (b) a first nut mounted on said drive shaft and fixed against axial movement along the axis and having an internal thread engaging said one helical thread of said shaft,
• (c) a first reversible drive motor for selectively rotating said first nut so as to cause said shaft to axially advance or retract,
• (d) a second nut mounted on said shaft and fixed against axial movement along the axis and having an internal thread engaging said one longitudinal thread of said drive shaft,
• (e) a second reversible drive motor for selectively rotating said second nut and so as to cause rotational movement of said shaft about the axis.

A machine tool having provision for transferring a workpiece to and from a machining station and comprising

• a machine frame,
• a workpiece transfer means mounted to said machine frame and defining a transfer station,
• a chuck mounted to said machine frame for engaging and supporting a workpiece during a machining operation,
• at least one panel mounted to said machine frame so as to have said transfer station on one side thereof and said chuck on the other side thereof, said one panel having only one opening therethrough adjacent said transfer station,
• a gripper arm including first and second gripper jaw assemblies for releasably engaging and supporting a workpiece,
• means mounting said gripper arm to said machine frame so that said gripper arm is on the same side of said panel as said chuck and for movement between a first position wherein said first and second gripper jaw assemblies extend through said one opening and are adjacent said transfer station, and a second position wherein said first and second gripper jaw assemblies are adjacent said chuck, and
• said gripper arm and said panel having mating surfaces which form a seal surrounding said one opening when said gripper arm is in said first position and said first and second gripper law assemblies extend through said one opening so as to preclude debris from passing through the opening during the machining operation.