Abstract: Cutting-off machine for the transversal cutting of logs of paper material, comprising: a structure (SC) on which are moved the logs; a cutting unit (CU) with a blade (2); a grinding unit for sharpening the blade; a device for positioning the grinding wheels with respect to the blade (2); wherein the positioning device comprises a primary carriage (4) and two secondary carriages (42, 43) driven by respective actuators; there is an optical sensor (100) that detects a cutting edge (200) of the blade (2); in a phase of operative positioning of the grinding wheels which involves sharpening the blade following the contact of the grinding wheels with the blade, the abrasive side of the grinding wheels is pushed against the blade with a thrust having a predetermined value.

Abstract: A cutting machine for the transversal cutting of paper material logs, including: a structure on which are moved the logs; a cutting unit including a blade; at least one sharpening unit with two grinding wheels; a positioning device for positioning the grinding wheels with respect to the blade. The positioning device includes: a primary carriage and two secondary carriages supported by the primary carriage; a sensor for detecting the radius of the blade and configured to stop the primary carriage when the grinding wheels are arranged with the respective axes at a given distance from the axis of the blade. In a second phase of positioning the grinding wheels, the secondary carriages are controlled so as to bring the abrasive side of the wheels into contact with the blade.

Abstract: Rewinder for making paper logs of paper material including a detection system with optical means adapted to detect, in a succession of predetermined detection times, a succession of diameters assumed in such times by a log being formed in a winding station and a programmable electronic unit which compares the diameters measured by the optical means with a succession of corresponding preset diameters and to calculate a sequence of differences. The processing unit receives a signal relating to the value of the actual diameter of the completed log and determines a parameter related to the trend over time of the differences. Elements for adjusting the thickness of the paper web automatically adjust said thickness if the parameter is between predetermined values.

Abstract: Rewinder for producing paper logs, comprising a winding station with a first winding roller, a second winding roller and a third winding roller driven by corresponding electric motors, including a detection system capable to detect a succession of diameters of the log being formed in the winding station and a programmable electronic unit connected to the electric motors. The system compares the measured diameters with a succession of corresponding diameters of predetermined value and to calculate a sequence of differences between these values. The electronic unit determines a parameter (a) related to the trend over time of the values. The electronic unit changes the relative speed of the first and second roll depending on the value of the parameter.

Abstract: A cutting machine for the transversal cutting of paper material logs, including: a structure on which are moved the logs; a cutting unit including a blade; at least one sharpening unit with two grinding wheels; a positioning device for positioning the grinding wheels with respect to the blade. The positioning device includes: a primary carriage and two secondary carriages supported by the primary carriage; a sensor for detecting the radius of the blade and configured to stop the primary carriage when the grinding wheels are arranged with the respective axes at a given distance from the axis of the blade. In a second phase of positioning the grinding wheels, the secondary carriages are controlled so as to bring the abrasive side of the wheels into contact with the blade.

Abstract: Rewinder for making paper logs, including a winding station with a first winding roller and a second winding roller delimiting a nip and a third winding roller downstream of the other rollers. The rewinder includes optical elements for detecting, at a predetermined time, an actual position of each log in said winding station and an electronic unit connected to the optical elements and programmed to compare the actual position with a theoretical position of the log at the time, the electronic unit being connected to at least one motor driving the rollers and programmed to modify the speed of the at least one motor when a deviation between the actual and theoretical positions exceeds a pre-established value, the electronic unit being also programmed to operate said optical elements at the time.

Abstract: A cutting-off machine for the transversal cutting of logs of paper material, including a structure on which the logs to be cut are moved and a cutting unit including a support plate for a blade arranged along a lying plane. The machine includes at least one sharpening unit with two grinding wheels for sharpening the blade on opposite sides of the plane and equipped with an abrasive side and a grinding wheel positioning device with respect to the blade, arranged on each sharpening unit, by which each grinding wheel is placed in a position of contact with the blade in a phase of sharpening the latter starting from a position initial inoperative. The positioning device is equipped with automatic elements for detecting the wear of the abrasive side of the grinding wheels.

Abstract: A cutting machine for the transversal cutting of logs of paper material, including a cutting unit, at least one sharpening unit with two grinding wheels and a device for positioning the grinding wheels. The device includes a primary carriage and two secondary carriages. The primary carriage has a surface arranged at a predetermined distance from the plane of the blade and forming a surface for controlling the run of the secondary carriages. In a first step of positioning the grinding wheels, the secondary carriages bring the abrasive side of the grinding wheels into contact with the surface. In a second step, the secondary carriages bring the abrasive side of the grinding wheels to the plane. In a third step, the primary actuators move the primary carriage until the abrasive side of the grinding wheels contacts the blade.

Abstract: Rewinder for producing paper logs, comprising a winding station with a first winding roller, a second winding roller and a third winding roller driven by corresponding electric motors, including a detection system capable to detect a succession of diameters of the log being formed in the winding station and a programmable electronic unit connected to the electric motors. The system compares the measured diameters with a succession of corresponding diameters of predetermined value and to calculate a sequence of differences between these values. The electronic unit determines a parameter (a) related to the trend over time of the values. The electronic unit changes the relative speed of the first and second roll depending on the value of the parameter.

Abstract: Rewinder for making paper logs of paper material including a detection system with optical means adapted to detect, in a succession of predetermined detection times, a succession of diameters assumed in such times by a log being formed in a winding station and a programmable electronic unit which compares the diameters measured by the optical means with a succession of corresponding preset diameters and to calculate a sequence of differences. The processing unit receives a signal relating to the value of the actual diameter of the completed log and determines a parameter related to the trend over time of the differences. Elements for adjusting the thickness of the paper web automatically adjust said thickness if the parameter is between predetermined values and.

Abstract: Rewinder for making paper logs, including a winding station with a first winding roller and a second winding roller delimiting a nip and a third winding roller downstream of the other rollers. The rewinder includes optical elements for detecting, at a predetermined time, an actual position of each log in said winding station and an electronic unit connected to the optical elements and programmed to compare the actual position with a theoretical position of the log at the time, the electronic unit being connected to at least one motor driving the rollers and programmed to modify the speed of the at least one motor when a deviation between the actual and theoretical positions exceeds a pre-established value, the electronic unit being also programmed to operate said optical elements at the time.

Abstract: Plant for the production of paper logs, including a number of operating units configured to produce logs of paper material starting from a web of paper material unwound from one or more corresponding reels and slaved to a control unit that, in turn, is configured for driving the operating units such that each of them has a predetermined production speed. The said control unit is programmed to process data contained in a database individually associated with each reel and representative of defects classified according to a predictive classification based on the effects of the defects in the production of the logs and further representative of the location of defects on the web unwound from the reel. The control unit receives position data related to the instantaneous diameter of the reel from a corresponding detection means. The control unit is programmed to modify the production speed in function of the instantaneous position and of the class of each of the defects.

Abstract: Rewinder for the production of logs. A feeding element adapted to supply a paper web. A guide element adapted to guide sequentially several cores along a predetermined path between a station for feeding the cores and a winding station in which a predetermined amount of the web is wound on each core. A winding element adapted to wind the paper web on the cores in the winding station. The guide element includes a guide with a curved end section that ends in the winding station and in cooperation with the winding element, delimits a channel crossed by each core before reaching the winding station.

Abstract: Rewinder for the production of logs. A feeding element adapted to supply a paper web. A guide element adapted to guide sequentially several cores along a predetermined path between a station for feeding the cores and a winding station in which a predetermined amount of the web is wound on each core. A winding element adapted to wind the paper web on the cores in the winding station. The guide element includes a guide with a curved end section that ends in the winding station and in cooperation with the winding element, delimits a channel crossed by each core before reaching the winding station.