Rewinding machine for the production of logs of paper material, including a winding station in which is fed a paper web and, in sequence, more tubular cores, and in which station winding are arranged a first, a second and a third winding roller cooperating with each other to wind a predetermined amount of said paper web onto each core. The machine includes a fourth winding roller which is connected to respective moving elements adapted to arrange it in a first inoperative position until the diameter of a log in the winding station is lower than a first predetermined value and a second operating winding position when the diameter of the log being formed is equal to said first predetermined value, the moving elements being controlled to maintain the fourth roller in the second operating winding position until the diameter of the log reaches a second final value higher of the first predetermined value.

A device for rewinding and forming a paper roll in a rewinding machine comprising three rollers with parallel axes and perpendicular to the paper feeding direction, wherein two lower and upper winding rollers supported on a frame cooperate with a third swivel roller in pressure on a roll being formed, the paper being wound provided with a series of transverse piercing and weakening lines spaced apart according to regular intervals along their longitudinal development passing on the upper winding roller and finished roll exiting from an output opening defined between the lower roller and the third roller, the cores for the rolls fed one after the other by a conveyor, wherein mechanical tearing means are placed in the upper roller along its development facing towards the side of the paper facing towards the upper roller to positively act directly at a piercing line and cause the tearing of the paper.

A rewinding machine winds a web material into a log about a core. The web material to be wound is directed about a rotating winding drum. A continuous loop is spaced from the winding drum and with the winding drum defines a nip through which the core is inserted and through which the web material is directed. A surface of the continuous loop opposite the winding drum across the nip is configured to move in a direction generally opposite of the winding drum for winding the web material about the core. A rider roll defines a winding space with the winding drum and the continuous loop. The rider roll is movable relative to the continuous loop and the winding drum to allow for an increase in a diameter of the log in the winding space during winding of the web material about the core.

Rewinder for the production of paper logs adapted to guide and transversely pre-cut a paper web along a predetermined path, adapted to wind a predetermined amount of the paper web on a core in a winding station, and including a threading mechanism for threading the web along said path. The threading mechanism includes a dragging unit provided to engage the web to drag it along the path with a predetermined feed direction and at least one dragging member to engage a respective flap of the web preceding the production of the logs. The dragging unit is located downstream of the winding station and is adapted to release the flap of the web from the dragging member, the release means being arranged downstream of the dragging so as to intercept the flap of the web and disengage it from the dragging while the web is fed.

The rewinding machine includes a first winding cradle, formed between a first winding roller, a second winding roller and a third winding roller, and a second winding cradle formed between the first winding roller, the second winding roller and a fourth winding roller. The first winding roller and the second winding roller define a nip through which nip the winding cores, around which the web material is found, pass and the web material is fed towards a roll being formed in the second winding cradle. A severing member is furthermore provided, acting on the web material between a winding core and the nip, to sever the web material thus generating a tail edge of a completed roll and a leading edge of a new roll to be wound.

A surface winder for winding a web material around a core to obtain a log is disclosed. The surface winder provides a core inserter for inserting a core into an introductory portion of a winding cradle defined by an upper winding roller, a concave cradle, a lower winding roller, and a third oscillating roller. The concave cradle has a leading edge device having a surface with at least one channel disposed therein. The at least one channel has a single entry point and a single exit point and extending from a position external to the leading edge device and a first location disposed upon the surface capable of receiving a fluid from the at least one channel. The fluid is fluidically displaced onto the core from the at least one channel when the core is in contacting engagement with the first location disposed upon the surface.

Method for rolling up definite lengths of a mats in a unidirectional rolled roll, where mats are advanced one after another into a rolling mechanism in flattened out condition and released from the mechanism in rolled up condition. A rolled up mat is ejected from the rolling mechanism and caused to roll out therefrom on top of a succeeding flattened out mat which advances towards the rolling mechanism. A mat rolling station for performing the method is provided, where a ramp conveyer is provided which advances a flattened mat towards the rolling mechanism. At the rolling mechanism, bending conveyers are provided for advancing the forwardly moving mat sections into a circular bend on the ramp conveyer. A difference of surface speeds of the bending conveyers and the ramp conveyer is controllable by a signal provoked by the advance of a succeeding mat on the ramp conveyer before the rolling mechanism.

A leading edge device for incorporation into an introductory portion a concave cradle is disclosed d. The concave cradle is associated with an upper winding roller of a surface winder to form a winding cradle for winding a web material having a velocity, v, around a core having a radius, R, inserted therein to obtain a log. The leading edge device has a surface having a texture provided thereto for contacting the core.

An introductory portion for a surface winder is disclosed. The introductory portion comprises a surface. The surface has at least one channel disposed therein. The at least one channel has a single entry point and a single exit point and extends from a position external to the introductory portion and a first location disposed upon the surface. The first location is disposed upon the surface and is capable of receiving a fluid from the at least one channel. The fluid is fluidically displaced onto the core from the at least one channel when the core is in contacting engagement with the first location disposed upon the surface.

A rewinding machine winds a web material into a log about a core. The web material to be wound is directed about a rotating winding drum. A continuous loop is spaced from the winding drum and with the winding drum defines a nip through which the core is inserted and through which the web material is directed. A surface of the continuous loop opposite the winding drum across the nip is configured to move in a direction generally opposite of the winding drum for winding the web material about the core. A rider roll defines a winding space with the winding drum and the continuous loop. The rider roll is movable relative to the continuous loop and the winding drum to allow for an increase in a diameter of the log in the winding space during winding of the web material about the core.