Patent attributes
An NC automatic lathe including abase board, a headstock provided with a main spindle and so arranged as to move in a direction of Z1 axis, a back attachment provided with a sub spindle which is so arranged as to be opposed to the headstock, the back attachment being so arranged as to move in directions of Z2 axis, X2 axis and Y2 axis, a guide bush, a first turret tool post arranged at a side of the guide bush so as to move in directions of X1 axis and Y1 axis, a second turret tool post arranged at a side of the guide bush so as to move in directions of Z3 axis, X3 axis and Y3 axis, and a fixed back machining tool unit arranged at a position offset with respect to at least one of the first turret tool post and second turret tool post, to the back attachment in a direction of Z axis, and provided with tool holding portions in at least two rows and two lines in directions of X axis and Y axis.
