Abstract: Disclosed is a cutting-off machine for cutting logs of sheet material, including at least one cutting blade placed on a plane perpendicular to the axis of the logs, in order to perform transverse cuts over the same and produce rolls of smaller length than the logs, wherein the at least one cutting blade is associated with an ultrasonic device apt to generate a vibrating force on the blade.

Abstract: A rewinding machine for the production of rolls of web material wound around winding cores includes: a winding cradle, including peripheral winding members of the rolls; a feeding path of the web material towards the winding cradle; an insertion channel for inserting the winding cores towards the winding cradle, having an entrance inside which the winding cores are introduced and an exit toward the winding cradle, the insertion channel being defined between a rolling surface and a continuous flexible member, provided with a forward movement; an inserter for inserting the winding cores into the inserting channel. At the entrance of the insertion channel a pressing device is arranged, said pressing device projects toward the inside of the insertion channel and toward the continuous flexible member. The pressing device is arranged and configured to press the winding cores entering the insertion channel towards the continuous flexible member.

Abstract: A machine is shown having a winding unit (3) and a cutting unit (7) to cut a tube (T) being formed around a mandrel (5). The cutting unit (7) has a rotating cutting blade (9) provided with motion along a circular trajectory, defined by means of a system of cross guides and a fastening to a center of a circular trajectory. The position of the center (33B) of the circular trajectory of the rotating cutting blade (9) is changed according to the direction of movement of the blade with respect to the mandrel, so that the rotating cutting blade (9) cuts the tube (T) during a forward movement and is released form the tube during a backward movement. Methods for production of tubes by means of helical winding of one or more strips of web material around a mandrel are shown as well.

Abstract: A rewinding machine for the production of rolls of web material wound around winding cores includes: a winding cradle including peripheral winding members of the rolls; a feeding path of the web material towards the winding cradle; an insertion channel for inserting the winding cores towards the winding cradle, having an entrance inside which the winding cores are introduced and an exit toward the winding cradle, the insertion channel being defined between a rolling surface and a continuous flexible member, provided with a forward movement; an inserter for inserting the winding cores into the inserting channel. At the entrance of the insertion channel a pressing device is arranged, said pressing device projects toward the inside of the insertion channel and toward the continuous flexible member. The pressing device is arranged and configured to press the winding cores entering the insertion channel towards the continuous flexible member.