Patents by Inventor Erkki Naatanen

Erkki Naatanen 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: 5167836
    Abstract: The invention concerns a method for controlling a press filter, said press filter having electric motors for operating said press filter. At least one of said electric motors of said press filter is driven by a frequency filter. A logic control unit is used for sending a program-controlled analog signal to said frequency converter. The output current from said frequency converter having a frequency proportional to the magnitude of said analog signal received from said logic control unit is used for driving the press filter's electric motors, whose rotational speeds thereby become proportional to the drive current frequency. A desired electric motor is individually started by way of applying power to the motor via a switch element which is activated by a signal from the logic control unit.
    Type: Grant
    Filed: July 1, 1991
    Date of Patent: December 1, 1992
    Assignee: Larox Oy
    Inventors: Mauno Kylliainen, Erkki Naatanen, Petri Saira