Patents by Inventor Michael Vollmann

Michael Vollmann 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: 8855879
    Abstract: A method of operating a clutch serving as a shift element and/or starting clutch of a drive train. During engagement, the clutch will be filled by a fast filling up to a defined minimum pressure. The fast filling is at least subdivided into two phases comprising a basic filling phase and an extension and/or a cutout phase. At the end of the basic filling phase, the actual clutch pressure is measured, and then, when the actual clutch pressure is equal to or larger than the minimum pressure, the extension and/or cutout phase is activated immediately following the basic filling phase. When the actual clutch pressure is lower than the minimum pressure, activation of the extension and/or the cutout phase is at least delayed by a pressure holding phase and, if necessary, by a pressure surplus phase.
    Type: Grant
    Filed: November 24, 2010
    Date of Patent: October 7, 2014
    Assignee: ZF Friedrichshafen AG
    Inventors: Martin-Joachim Bader, Karl Locher, Robert Gronner, Olaf Moseler, Markus Terwart, Michael Vollmann
  • Publication number: 20120295760
    Abstract: A method of operating a clutch serving as a shift element and/or starting clutch of a drive train. During engagement, the clutch will be filled by a fast filling up to a defined minimum pressure. The fast filling is at least subdivided into two phases comprising a basic filling phase and an extension and/or a cutout phase. At the end of the basic filling phase, the actual clutch pressure is measured, and then, when the actual clutch pressure is equal to or larger than the minimum pressure, the extension and/or cutout phase is activated immediately following the basic filling phase. When the actual clutch pressure is lower than the minimum pressure, activation of the extension and/or the cutout phase is at least delayed by a pressure holding phase and, if necessary, by a pressure surplus phase.
    Type: Application
    Filed: November 24, 2010
    Publication date: November 22, 2012
    Applicant: ZF FRIEDRICHSHAFEN AG
    Inventors: Martin-Joachim Bader, Karl Locher, Robert Gronner, Olaf Moseler, Markus Terwart, Michael Vollmann