Patents by Inventor Pertti Helle

Pertti Helle has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5632916
    Abstract: A method of providing by a laser beam on a bright metal surface (1) areas discernible from the surrounding surface as darker areas for producing for instance optically readable marks (5) and a metal surface provided in this manner. The procedure for producing marks not weakening the general properties of the metal surface is that the metal surface (1) is exposed to a laser beam pulse, the energy of which is 1 to 10 J/cm.sup.2, preferably 3 to 5 J/cm.sup.2 and the duration 5 ns to 1 .mu.s, preferably 15 to 30 ns; a spot of impact (7) of the laser beam pulse on the metal surface (1) is changed in such a way that a new spot of impact (8) overlaps the earlier spot of impact (7) and the metal surface (1) is exposed to a new laser beam pulse, such that an area (7a) of the metal surface, where the pulses do not overlap each other and which abuts on the spot of impact of the new pulse, gets a color contrasting with the original metal surface (1).
    Type: Grant
    Filed: May 1, 1995
    Date of Patent: May 27, 1997
    Assignee: Partek Cargotec Oy
    Inventors: Reijo Lappalainen, Sten Siren, Teijo Salmi, Pertti Helle