Method and machine for cutting logs of wound web material

1. A cutting machine for cutting logs of web material comprising: a feeding path for logs to be cut; a cutting head arranged along the feeding path, said cutting head comprising a coupling for a disc-shaped cutting blade which is configured to impart the disc-shaped cutting blade a rotary motion around an axis thereof and a cyclic movement to cut the logs into rolls, and to allow the logs to move forward along the feeding path; at least one store unit for disc-shaped cutting blades associated with the cutting head; at least one handling member to remove the disc-shaped cutting blade from the cutting head when the disc-shaped cutting blade is a worn disc-shaped cutting blade to be replaced, and to replace the worn disc-shaped cutting blade with a new disc-shaped cutting blade taken from the store unit; wherein the store unit comprises a blade-holder rotating around a rotation axis substantially orthogonal to the feeding path for the logs and provided with a plurality of seats for the disc-shaped cutting blades, and wherein the plurality of seats are adapted to support the disc-shaped cutting blades in the blade-holder with their axis substantially orthogonal to the feeding path and the at least one handling member is adapted to pivot the disc-shaped cutting blades into a position with the rotation axis parallel to the feeding path and attach the new disc-shaped cutting blade to the cutting head.

2. The cutting machine according to claim 1 , wherein the plurality of seats for the disc-shaped cutting blades are arranged and configured to keep the disc-shaped cutting blades coaxial with one another.

3. The cutting machine according to claim 2 , wherein the plurality of seats are arranged and configured to keep the disc-shaped cutting blades with the rotation axis thereof substantially parallel to the feeding path and/or parallel to the axis of the disc-shaped cutting blade when the latter is mounted onto the cutting head, the blade-holder being provided with a translation movement substantially parallel to an alignment direction of the disc-shaped cutting blades held in the store unit.

4. A cutting machine for cutting logs of web material comprising: a feeding path for logs to be cut; a cutting head arranged along the feeding path, said cutting head comprising a coupling for a disc-shaped cutting blade which is configured to impart the disc-shaped cutting blade a rotary motion around an axis thereof and a cyclic movement to cut the logs into rolls, and to allow the logs to move forward along the feeding path; at least one store unit for disc-shaped cutting blades associated with the cutting head; at least one handling member to remove the disc-shaped cutting blade from the cutting head when the disc-shaped cutting blade is a worn disc-shaped cutting blade to be replaced, and to replace the worn disc-shaped cutting blade with a new disc-shaped cutting blade taken from the store unit, wherein the store unit comprises a blade-holder rotating around a rotation axis substantially orthogonal to the feeding path for the logs and provided with a plurality of seats for the disc-shaped cutting blades, and wherein each seat of said plurality of seats is provided with a pivoting motion from a first position, wherein a respective disc-shaped cutting blade is stored, to a second position, wherein the respective disc-shaped cutting blade is transferred; in the first position the disc-shaped cutting blade is arranged with the rotation axis thereof substantially orthogonal to the feeding path for the logs; in the second position the disc-shaped cutting blade being arranged with an axis thereof being substantially parallel to the feeding path.

5. The cutting machine according to claim 4 , wherein the store unit comprises a single actuator to control the pivoting motion of all the plurality of seats with which the store unit is provided.

6. A method for cutting logs of wound web material comprising steps of:

providing a feeding path for logs to be cut;

arranging along the feeding path a cutting head with at least one disc-shaped cutting blade, the cutting head moving the disc-shaped cutting blade with a cyclical motion to cut the logs and allow a forward movement of the rolls along the feeding path;

providing at least one store unit for disc-shaped cutting blades associated with the cutting head;

moving logs of web material sequentially along the feeding path in a direction parallel to a log axis;

cutting the logs by the disc-shaped cutting blade mounted on the cutting head and severing the logs into small rolls having an axial length smaller than the logs;

periodically grinding the disc-shaped cutting blade;

when the disc-shaped cutting blade is so worn that the cutting blade is a worn disc-shaped cutting blade to be replaced:

temporarily stopping forward movement of the logs; removing the worn disc-shaped cutting blade from the cutting head; taking a new disc-shaped cutting blade from the store unit by a handling member, transferring the new disc-shaped cutting blade to the cutting head and mounting the new disc-shaped cutting blade on the cutting head;

once the new disc-shaped cutting blade has been mounted on the cutting head, re-starting the forward movement of the logs along the feeding path;

wherein the store unit is adapted to support the disc-shaped cutting blades with axes of the cutting blades being substantially orthogonal to the feeding path, and the handling member is adapted to attach the new disc-shaped cutting blade to the cutting head; and wherein the store unit includes a blade-holder having a plurality of seats and each seat of said plurality of seats is provided with a pivoting motion from a first position, wherein a respective disc-shaped cutting blade is stored, to a second position, wherein the respective disc-shaped cutting blade is transferred; in the first position the disc-shaped cutting blade is arranged with the rotation axis thereof substantially orthogonal to the feeding path for the logs; in the second position the disc-shaped cutting blade being arranged with an axis thereof being substantially parallel to the feeding path.

7. A method for cutting logs of wound web material, comprising steps of:

moving logs of web material sequentially along a feeding path in a direction parallel to axes of the logs;

cutting the logs by a disc-shaped cutting blade mounted into a cutting head and severing the logs into rolls of an axial length smaller than that of the logs, the cutting head moving the disc-shaped cutting blade with a cyclical motion to cut the logs and allow a forward movement of the logs along the feeding path;

periodically grinding the disc-shaped cutting blade;

when the disc-shaped cutting blade is so worn that the cutting blade is a worn disc-shaped cutting blade to be replaced:

temporarily stopping the forward movement of the logs, removing the worn disc-shaped cutting blade from the cutting head, taking a new disc-shaped cutting blade from a store unit, transferring the new disc-shaped cutting blade to the cutting head and mounting the new disc-shaped cutting blade on the cutting head;

once the new disc-shaped cutting blade has been mounted on the cutting head, re-starting the forward movement of the logs along the feeding path;

wherein the store unit is adapted to support the disc-shaped cutting blades with axes of the disc-shaped cutting blades being substantially orthogonal to the feeding path, and a handling member is adapted to attach the new disc-shaped cutting blade to the cutting head; and wherein the store unit includes a blade-holder having a plurality of seats and each seat of said plurality of seats is provided with a pivoting motion from a first position, wherein a respective disc-shaped cutting blade is stored, to a second position, wherein the respective disc-shaped cutting blade is transferred; in the first position the disc-shaped cutting blade is arranged with the rotation axis thereof substantially orthogonal to the feeding path for the logs; in the second position the disc-shaped cutting blade being arranged with an axis thereof being substantially parallel to the feeding path.

8. A cutting machine for cutting logs of web material comprising: a feeding path for logs to be cut; a cutting head arranged along the feeding path, said cutting head comprising a coupling for a disc-shaped cutting blade which is configured to impart the disc-shaped cutting blade a rotary motion around an axis thereof and a cyclic movement to cut the logs into rolls, and to allow the logs to move forward along the feeding path; at least one store unit for disc-shaped cutting blades associated with the cutting head; at least one handling member to remove the disc-shaped cutting blade from the cutting head when the disc-shaped cutting blade is a worn disc-shaped cutting blade to be replaced, and to replace the worn disc-shaped cutting blade with a new disc-shaped cutting blade taken from the store unit; and wherein the store unit comprises a blade-holder provided with a plurality of seats for a plurality of disc-shaped cutting blades, arranged and configured to keep the disc-shaped cutting blades aligned according to an alignment direction substantially parallel to the feeding path; wherein the disc-shaped cutting blades in the store unit are adapted to move substantially parallel to the alignment direction thereof; and wherein the at least one handling member is adapted to position a worn disc-shaped cutting blade removed from the cutting head into one empty seat of the store unit, and is adapted to pick up a new disc-shaped cutting blade from another seat of the store unit and attach the new disc-shaped cutting blade to the cutting head.