In steady control, a shaft control unit (922) adjusts rotation speed of a first support shaft (31) to cause a first roll (R1) to have peripheral speed equal to predetermined conveyance speed by maintaining a sheet storage amount in a storage mechanism (5) in a first storage amount as a reference. In storage amount adjustment control, the shaft control unit (922) accelerates the rotation speed of the first support shaft (31) to increase the peripheral speed of the first roll (R1) higher than the conveyance speed, until the sheet storage amount in the storage mechanism (5) reaches a predetermined second storage amount that is larger than the first storage amount. A calculation unit (911) calculates an outer diameter of the first roll (R1) based on the conveyance speed when the steady control is performed, and calculates the outer diameter of the first roll (R1) based on the sheet thickness calculated from a decrease amount of the outer diameter of the first roll (R1) in the steady control when the storage amount adjustment control is performed.

In steady control, a shaft control unit (922) adjusts rotation speed of a first support shaft (31) to cause a first roll (R1) to have peripheral speed equal to predetermined conveyance speed by maintaining a sheet storage amount in a storage mechanism (5) in a first storage amount as a reference. In storage amount adjustment control, the shaft control unit (922) accelerates the rotation speed of the first support shaft (31) to increase the peripheral speed of the first roll (R1) higher than the conveyance speed, until the sheet storage amount in the storage mechanism (5) reaches a predetermined second storage amount that is larger than the first storage amount. A calculation unit (911) calculates an outer diameter of the first roll (R1) based on the conveyance speed when the steady control is performed, and calculates the outer diameter of the first roll (R1) based on the sheet thickness calculated from a decrease amount of the outer diameter of the first roll (R1) in the steady control when the storage amount adjustment control is performed.

An unwinder for web material includes: a first and second reel holder, a dynamic storage device, a junction device arranged between the first or second reel holder and the dynamic storage device and configured to join an end portion of web material running out on the first reel to an initial portion of web material of the second reel, an actuator configured to pull the web material. The dynamic storage device includes: a plurality of first return rollers, a carriage mounted on a guide and free to move along the guide approaching or moving away from the first return rollers, a plurality of second return rollers mounted idly on the carriage. The return rollers define a zigzag path for the web material. The dynamic storage device includes a plurality of motorized shafts and each first return roller is mounted by means of two rolling bearings on a respective motorized shaft.

An unwinder for web material includes: a first and second reel holder, a dynamic storage device, a junction device arranged between the first or second reel holder and the dynamic storage device and configured to join an end portion of web material running out on the first reel to an initial portion of web material of the second reel, an actuator configured to pull the web material. The dynamic storage device includes: a plurality of first return rollers, a carriage mounted on a guide and free to move along the guide approaching or moving away from the first return rollers, a plurality of second return rollers mounted idly on the carriage. The return rollers define a zigzag path for the web material. The dynamic storage device includes a plurality of motorized shafts and each first return roller is mounted by means of two rolling bearings on a respective motorized shaft.

The apparatus for combining tobacco sheets (3, 4) comprises a first shaft for carrying a first bobbin (30) of tobacco sheet (3) and a second shaft for carrying a second bobbin (40) of tobacco sheet (4). The apparatus also comprises a splicing unit (2) for combining an end portion of tobacco sheet from the first bobbin (30) to a head portion of tobacco sheet from the second bobbin. The splicing unit comprises a cutting device (20) for cutting the tobacco sheets such as to provide complementary cuts to the tobacco sheets (3) from the first bobbin and from the second bobbin (4), a dispensing device (23) for dispensing water to at least one of the tobacco sheets (3, 4), and a combining device (24) for applying force onto the tobacco sheets thereby producing a spliced tobacco sheet.

The apparatus for combining tobacco sheets (3, 4) comprises a first shaft for carrying a first bobbin (30) of tobacco sheet (3) and a second shaft for carrying a second bobbin (40) of tobacco sheet (4). The apparatus also comprises a splicing unit (2) for combining an end portion of tobacco sheet from the first bobbin (30) to a head portion of tobacco sheet from the second bobbin. The splicing unit comprises a cutting device (20) for cutting the tobacco sheets such as to provide complementary cuts to the tobacco sheets (3) from the first bobbin and from the second bobbin (4), a dispensing device (23) for dispensing water to at least one of the tobacco sheets (3, 4), and a combining device (24) for applying force onto the tobacco sheets thereby producing a spliced tobacco sheet.

A method for cutting and connecting two bands end to end and which are at a stop, namely a first band ensuring the feed, and a second replacement band, in an unrolling machine including a cutting and connecting device including two connection assemblies arranged symmetrically with respect to a cutting and connection plane is provided. Utilizing the unrolling machine the method includes preparation of the second band, then immobilization of the bands in the plane, of simultaneous and transverse cutting of the latter, of disengagement of the cut portions not to be connected, and of end-to-end connecting of the cut portions thereof to be connected. A cutting and connecting device and a machine enabling the implementation of the method is also provided.

Methods and systems for preventing wrinkles in a web passing through an accumulator. The accumulator comprises a plurality of rollers including at least one roller having an axis of revolution movable toward and away from the axis of revolution of another roller to release and store varying amounts of the web. At least one of the rollers has a nominally flat outer surface and at least one of the rollers has a profiled outer surface.

Methods and systems for preventing wrinkles in a web passing through an accumulator. The accumulator comprises a plurality of rollers including at least one roller having an axis of revolution movable toward and away from the axis of revolution of another roller to release and store varying amounts of the web. At least one of the rollers has a nominally flat outer surface and at least one of the rollers has a profiled outer surface.

A splice arrangement includes an unwinding arrangement for unwinding a finite first material web from a first material roll or a finite second material web from a second material roll, a braking arrangement for applying a braking force to the unwinding arrangement and/or the finite material web being unwound, a connection arrangement for connecting the finite material webs to form an endless material web, a storage trolley for the uninterrupted conveying of the endless material web, at least one material web tension-influencing device arranged before the storage trolley, and an actuation device, which is in signal connection with the at least one material web tension-influencing device for actuating the same.