Patents by Inventor Frank-Werner Hoffmann

Frank-Werner Hoffmann 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: 9538587
    Abstract: A method and a device for closed-loop control of an electrode gap in a vacuum arc furnace subjects an electrode gap of a melting electrode from the surface of a melt material to closed-loop control as a function of a droplet short-circuit rate. For this purpose, a histogram of detected droplet short-circuits is created on the basis of at least one droplet short-circuit criterion. The histogram is subdivided into sub-areas, a characteristic sub-area of the histogram is selected for closed-loop control purposes. The electrode gap is subjected to closed-loop control on the basis of the droplet short-circuits which can be associated with the selected sub-area.
    Type: Grant
    Filed: October 6, 2011
    Date of Patent: January 3, 2017
    Assignee: ALD VACUUM TECHNOLOGIES GMBH
    Inventors: Ralf Oehler, Harald Scholz, Frank-Werner Hoffmann
  • Publication number: 20130282158
    Abstract: The invention relates to a method and device (40) for filtering supply network failures (84) out of an electrode signal (82) in a metallurgical electric remelting process, in particular for the electrode gap closed-loop control of a system for closed-loop control of an electrode gap (48) of a melting furnace (10). For this purpose, said device also comprises at least one electrode sensor device (44) for measuring an electrode signal (82), in particular electrode current and/or electrode voltage of the electrode (30), a network sensor device (46) for measuring a network signal, in particular network current and/or network voltage, and a filter device (50) for filtering network failures (84) of the network signal out of the electrode signal (82), such that an electrode signal (80) with no network failures can be emitted.
    Type: Application
    Filed: October 6, 2011
    Publication date: October 24, 2013
    Inventors: Ralf Oehler, Harald Scholz, Frank-Werner Hoffmann
  • Publication number: 20130279535
    Abstract: The invention relates to a method as well as a device for closed-loop control of the electrode gap in a vacuum arc furnace (10), wherein an electrode gap of a melting electrode from the surface of a melt material is subjected to closed-loop control as a function of a droplet short-circuit rate. For this purpose, a histogram (70) of detected droplet short-circuits (80) is created on the basis of at least one droplet short-circuit criterion (76), the histogram (70) is subdivided into sub-areas (72), a characteristic sub-area (74) of the histogram (70) is selected for closed-loop control purposes, and an electrode gap is subjected to closed-loop control on the basis of the droplet short-circuits (80) which can be associated with the selected sub-area (74).
    Type: Application
    Filed: October 6, 2011
    Publication date: October 24, 2013
    Inventors: Ralf Oehler, Harald Scholz, Frank-Werner Hoffmann