Abstract: A method is provided for turning a first work and a second work held on a first spindle and a second spindle, respectively. The first spindle and the second spindle are positioned on the same axis and confronting each other, so that the first work and the second work are rotated about the same axis. A tool rest is provided with a first tool and a second tool and is moved for turning the first work by the first tool. The second spindle is moved in synchronism with the movement of the tool rest for turning the second work by the second tool.

Abstract: An NC lathe includes a bed, a headstock mounted on the bed for rotating a work around C-axis, a tailstock slidably mounted on a first guide surface formed on the bed, and a carriage slidably mounted on a second guide surface formed on the bed in a direction of Z-axis parallel to the C-axis and juxtaposed with the first guide surface. The carriage has a saddle having a first slide surface for contacting the second guide surface of the bed and a second slide surface inclined at a predetermined angle with respect to the first slide surface. A slide base is slidably mounted on the second slide surface of the saddle for movement in a direction of Y-axis perpendicular to the Z-axis. A column extends from the slide base substantially perpendicular thereto and includes a column body which has a guide surface in a direction of X-axis perpendicular to the Z-axis and to the Y-axis. A cross slide is slidably mounted on the guide surface of the column body in the direction of the X-axis and includes a driving device.

Abstract: A centering device in a machine tool having a chuck for clamping a work includes a clamp device for clamping and centering the work at a different position with respect to the chuck. The clamp device has an actuator driven by a pressure medium and a holder operable by the actuator for clamping the work with a pressure corresponding to the pressure of the pressure medium and for releasing the work. A control device is provided for controlling the pressure of the pressure medium to a value which is appropriate to center the work by the clamp device and which is previously determined according to a diameter of the work to be clamped.

Abstract: An NC lathe includes a bed, a headstock mounted on the bed for rotating a work around C-axis, a tailstock slidably mounted on a first guide surface formed on the bed, and a carriage slidably mounted on a second guide surface formed on the bed in a direction of Z-axis parallel to the C-axis and juxtaposed with the first guide surface. The carriage has a saddle having a first slide surface for contacting the second guide surface of the bed and a second slide surface inclined at a predetermined angle with respect to the first slide surface. A slide base is slidably mounted on the second slide surface of the saddle for movement in a direction of Y-axis perpendicular to the Z-axis. A column extends from the slide base substantially perpendicular thereto and includes a column body which has a guide surface in a direction of X-axis perpendicular to the Z-axis and to the Y-axis. A cross slide is slidably mounted on the guide surface of the column body in the direction of the X-axis and includes a driving device.