Machine for machining inner or centring rings of spirally wound seals, comprising: a base (1100) which supports a column (1110) extending in a vertical direction (Z-Z); a head (1200) with machining tool (1211) movable on the column (1110) in both senses of the vertical direction (Z-Z) from a raised rest position into a lowered working position and vice versa; a rotating table (1300) attached to the base (1100) and provided with at least two means (1311a,1311b) for retaining the rings (1); said retaining means are positioned relative to each other at a suitable angular distance so as to be arranged alternately below and coaxial with the machining tool (1211) or in a loading/unloading position underneath and coaxial with gripping/releasing means (1430) of a feeding/unloading device (1400); a device (1400) for loading/unloading the rings (1), displaceable in both senses of the vertical direction from a raised position into a lowered position and rotating about the same vertical direction; at least two means for gripping/releasing the rings (1) of the feeding/unloading device and movable therewith respectively from a position for gripping a ring to be machined into a position for feeding said ring to the loading/unloading retaining means and from a position for gripping of the machined rings by the loading/unloading retaining means to a position for unloading said rings outside of the machine and vice versa.

A machine tool comprising: a first spindle; a second spindle provided on a rear headstock to face the first spindle; a barstock supply unit for supplying an elongate rod to the first spindle; and a processing means including a tool for processing the barstock, characterized in that the machine tool further comprises: a workpiece clamp device provided on the rear headstock and adapted to grip a second material comprised of the barstock that has been removed from the first spindle as an old material; and a joining means for joining opposite end portions of the second material gripped by the workpiece clamp device and of a first material gripped by the first gripping means and comprised of a barstock newly supplied by the barstock supply unit, thereby to integrate the second material and the first material into a single barstock.

A lathe capable of facilitating maintenance of a chucking mechanism. A chuck operating apparatus includes a claw and a shifter to open and close a chuck provided on a spindle. The tilt claw provided outside the spindle has a first posture to bring the chuck into the opened state and a second posture to bring the chuck into the closed state. The shifter provided outside the spindle and movable in a spindle axis direction is brought in a first position to bring the claw into the first posture and in a second position to bring the claw into the second posture. A roller is mounted on the shifter in a contact position with the claw to roll in the spindle axis direction.