Laser scribing installation for the superficial treatment of magnetic sheets with spots of elliptic section

A laser scribing installation for treatment of grain oriented magnetic sheets, as strip advancing along a longitudinal direction of movement, comprising a laser generator, a cylindrical telescopic optical group with variable focus for formation of a laser beam of elliptic section, a rotating mirror scanner for scanning the laser beam of elliptic section according to a pre-defined angle and a cylindrical optical focusing device,

• wherein said cylindrical optical focusing device is extended transversally to the strip and in proximity of the strip for receiving the laser beam from the scanner and focusing the laser beam on the strip along a treatment path as elliptic spot;
• wherein the rotating mirror scanner has planar mirrors on polygonal faces and sharp corners between the mirrors;
• wherein the laser beam incident on the strip is provided for moving along the treatment path according to a beam sense of movement from an initial extremity to a terminal extremity of the treatment path while said elliptic spot defines a leading edge and a trailing edge in the beam sense of movement along said treatment path;
• and
• wherein the telescopic optical group has a focus downstream of the mirror rotating scanner and a sense of rotation of the mirror scanner is such that, during the incidence of the elliptic sectioned laser beam on a corner of the scanner and in a commutation between two adjacent ones of the mirrors, the laser beam scanner by the mirror scanner is convergent and divided as two beams through the cylindrical optical focusing device directed, respectively, to the initial extremity and the terminal extremity of the treatment path, with the trailing edge of the spot at the terminal extremity of the treatment path and the leading edge at the initial extremity of the path.

A laser scribing installation for treatment of grain oriented magnetic sheets, as strip in longitudinal movement on a planar surface, comprising a generator of laser beam, a scanner for scanning the laser beam and an optical focalizing device and wherein the focalizing device is extended transversally to the strip and in proximity of the strip for receiving the scanned beam and focusing the beam on the strip along a treatment path;

• the installation further comprising
• a tray or basin for lodging the scanner and the optical focalizing device, an air filtering and ventilating unit in connection with said tray or basin, and a protection device;
• said tray or basin includes, as a bottom, a limiting plate between the surface of the strip and the optical focalizing device and which defines a window for the laser beam directed to the treatment path of the strip;
• the air filtering and ventilating unit is provided for maintaining in a dry and clean environment the scanner and the optical focalizing device;
• and
• wherein said protection device is pre-set for generating a gaseous lamina between the limiting plate and the strip, adjacent to the window, with function of gaseous barrier tangent to the window for protecting the optical focalizing device from contamination.

A laser scribing installation for treatment of grain oriented magnetic sheets in shape of a strip advancing along a longitudinal direction of movement, by means of a laser beam transversally scanned with respect to the strip, the installation further comprising a support frame with a surface of reference for said strip, two groups of laser treatment, including each one a generator for a laser beam, a scanner for scanning a laser beam from said generator, an optical focalizing device extended transversally to the strip and in proximity of the strip for receiving a scanned beam from said scanner and focusing the scanned beam on a treatment path of the strip transversal to said longitudinal direction of movement, a tray or basin for lodging the generator, the scanner and the optical focalizing device, and wherein:

• said strip has a longitudinal axis delimits two longitudinal halves of the strip and defines a geometric surface perpendicular to said strip and passing through said longitudinal axis,
• the scanner and the optical device of said groups of laser treatment are arranged offset and specularly to one another with respect to said geometric surface to an end of treating said two longitudinal halves of the strips according to a predetermined angle with respect to the longitudinal direction of movement of the strip;
• each tray or basin is rotatably mounted on said support frame around a respective axis perpendicular to said surface of reference;
• and
• said scribing installation further comprises means for rotating the tray or basin of the groups of laser treatment in order to modify the angle of the treatment path with respect to a transversal direction of the strip.

A laser scribing installation for treatment of grain oriented magnetic sheets, as strip in longitudinal movement, comprising a generator of laser beam, a scanner for scanning the laser beam and an optical focalizing device, wherein the optical focalizing device is extended transversally to the strip and in proximity of the strip for receiving the scanned beam and focusing the beam on the strip along a treatment path;

• said installation further comprising:
• a tray or basin for lodging the scanner and the optical focalizing device, an air filtering and ventilating unit in connection with said tray or basin, and a protection device, and in which said tray or basin includes, as a bottom, a limiting plate between a surface of the strip and the optical focalizing device;
• wherein said air filtering and ventilating unit is provided for maintaining in a dry and clean environment the scanner and the optical focalizing device
• wherein said limiting plate defines a window for the laser beam directed to the treatment path of the strip and openings upstream and downstream of said window;
• and
• wherein said protection device is provided for generating a gaseous lamina between the limiting plate and the strip, adjacent to the window, with function of gaseous barrier for protecting the optical focalizing device from contamination;
• wherein said protection device comprises a boxed cover mounted on the limiting plate and an exhausting fan;
• wherein said cover defines a slit in registration with the window for passage of the laser beam directed to the treatment path of the strip, and
• wherein said exhausting fan generates an airflow with input and output through said openings with the clean environment of said tray or basin, and forming said gaseous barrier between the limiting plate and the boxed cover, tangent to the window and the slit.