Abstract: A rotary centering device for the transfer of a bar from the guiding channel of a feeder to a lathe, comprising a supporting element and provided with at least one circular seat in which a grip element for a bar is supported, the grip element being constituted by a bush which has a tubular portion and a plurality of sectors connected to the tubular portion, elastic elements being provided which act on the bush and are designed to control its axial movement between a first stop position, in which the sectors define a circular opening whose diameter is the same as that of the bar, and a second position, in which the sectors are moved until they form an opening to allow the passage of the bar pusher.

Abstract: A rotary centering device for the transfer of a bar from the guiding channel of a feeder to a lathe, comprising a supporting element and provided with at least one circular seat in which a grip element for a bar is supported, the grip element being constituted by a bush which has a tubular portion and a plurality of sectors connected to the tubular portion, elastic elements being provided which act on the bush and are designed to, control its axial movement between a first stop position, in which the sectors define a circular opening whose diameter is the same as that of the bar, and a second position, in which the sectors are moved until they form an opening to allow the passage of the bar pusher.

Abstract: A control and management method for lathes and loaders for lathes, comprising the steps of: detecting geometric parameters and mechanical characteristics of a bar to be turned; determining development of the critical frequencies of the bar upon a rotation thereof about the longitudinal axis as the rotation rate and length of the bar vary; starting turning of the bar, avoiding the combinations of mandrel rotation rate and bar length at which the rotation rate of the bar intersects the curves that represent the development of the critical frequencies.