Patent ID: 8641589

Claim:
An automatic tool changer configured to be installed in a precision roll turning lathe including a headstock and a tail stock, both mounted on a bed, for rotatably supporting a roll, and a tool post movably mounted for movement parallel to the roll on the bed, said automatic tool changer comprising: a change device including: a vertically movable pivot arm having a pivot axis and which pivots in a horizontal plane, a hand portion, mounted at the front end of the arm, configured for detachably gripping a tool holder, a pivot drive section configured for pivoting the pivot arm, and a lifting drive section configured for vertically moving the pivot arm; a tool holder stocker comprising a plurality of circumferentially-arranged stages disposed at a predetermined distance from the pivot axis, each stage detachably holding a tool holder; a holder base, mounted to the tool post, configured for detachably holding the tool holder to the holder base; and a clamp shaft operating device including: a clamp shaft detachably connected to the holder base; and an operating portion configured for connecting/disconnecting the clamp shaft to the holder base and clamping/unclamping the tool holder by rotating the clamp shaft from an outside of the holder base; wherein the holder base includes a cam mechanism configured for converting the rotation of the clamp shaft into clamping motions that fix the tool holder to the holder base and unfix the tool holder from the holder base.