Machine and method for the winding of strips of web material with means for transversal cutting of the strips and anchoring of the strips to the winding core

A method for winding a plurality of longitudinal strips on spools being formed in a plurality of winding stations, each spool rotating around a respective rotation axis and reciprocatingly translating parallel to said rotation axis, the method comprising the steps of:

• winding a length of the longitudinal strip on first spools being formed in the winding stations, each strip being guided around a contact roller;
• each contact roller being supported by a respective pivoting arm and rotating around a rotation axis parallel to the rotation axis of the spool and pressed against the spool;
• severing the longitudinal strips by means of cutting devices, forming trailing edges of the first spools and leading edges of second spools, each of the leading edges being held by means of a respective holding device, each holding device being supported by said pivoting arm to be movable towards and away from the axis of the rotation axis of the spool;
• removing the first spools from the winding stations;
• inserting new tubular winding cores into the winding stations;
• by means of the holding devices, moving each one of said leading edges towards the respective new tubular winding cores;
• making the leading edges adhere to the new cores;
• starting winding new spools around the new tubular winding cores.

A machine for forming spools of web material, comprising:

• an unwinding section for unwinding parent reels of web material;
• a cutting station arranged downstream of the unwinding section and comprising cutting members adapted to divide the web material coming from the unwinding section into longitudinal strips;
• a plurality of winding stations arranged in sequence downstream of the cutting station, each of which is adapted to receive a respective longitudinal strip;
• wherein each winding station comprises a winding device, to which the longitudinal strip of web material is fed, and in which a respective spool of web material is formed;
• the winding device being arranged and controlled to wind the longitudinal strip and to form the spool by rotation around a rotation axis of the spool;
• wherein each winding device comprises a winding mandrel provided with a rotation movement around the rotation axis and with a reciprocating translation movement in a direction parallel to the rotation axis, so as to helically wind the longitudinal strip around the winding mandrel;
• wherein each winding station further comprises:
• a strip cutting device for cutting the longitudinal strip transversely, thus forming a trailing edge, which remains on the spool under formation, and a leading edge;
• and a holding device for holding the leading edge of the longitudinal strip, to transfer the leading edge onto a tubular winding core of a new spool to be wound;
• wherein a contact roller is associated with each winding mandrel, the contact roller rotating around a rotation axis and being adapted to be pressed against the outer surface of a spool being formed on the winding mandrel;
• wherein the contact roller and the holding device are carried by a pivoting arm provided with a pivoting movement in order to move towards and away from the axis of the winding mandrel;
• and
• wherein the holding device is movable between a first position, where the holding device coacts with the cutting device to cut the longitudinal strip transversely, and a second position, where the holding device holds the leading edge of the longitudinal strip between the contact roller and the tubular winding core of the new spool to be wound.