Patent ID: 7458538

Claim:
An unwinding device for unwinding reels of web material wound around a central shaft and delivering said web material to a converting line, comprising: supports to support at least a reel in an unwinding position; at least a peripheral drive mechanism which acts on a cylindrical surface of the reel being unwound and peripherally transmits to said reel a torque to draw the reel in rotation; at least a center drive mechanism which transmits centrally to said reel an auxiliary torque to draw the reel in rotation in combination with the torque transmitted by said peripheral drive mechanism; a control system to reciprocally coordinate operation of said peripheral drive mechanism and of said center drive mechanism; and a detection system to detect, during unwinding, angular displacement of an outermost web material on the reel in relation to the central shaft of the reel, operation of said center drive mechanism being controlled so as to correct said angular displacement.