Patents by Inventor Magnus Stiefenhofer

Magnus Stiefenhofer 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: 10920876
    Abstract: A method for operating a drivetrain of a motor vehicle includes elevating a system pressure acting on a plurality of shift elements (A, B, C, D, E, F) when one of at least one positively locking shift element (A, F) is closed in a force-locking-free state, increasing a torque output by a drive assembly (15) and then subsequently reducing the torque output by the drive assembly (15) while the system pressure is elevated by an intervention with the drive assembly (15), and reducing the system pressure after reducing the torque output by the drive assembly (15). The one of the at least one positively locking shift element (A, F) closed in the force-locking-free state or another one of the at least one positively locking shift element (A, F) is opened while the system pressure is elevated and the torque output by the drive assembly (15) changes.
    Type: Grant
    Filed: March 13, 2018
    Date of Patent: February 16, 2021
    Assignee: ZF FRIEDRICHSHAFEN AG
    Inventors: Michael Sohler, Magnus Stiefenhofer, Tobias Hartmann
  • Patent number: 10443715
    Abstract: A method for operating a vehicle drivetrain (1) includes decoupling, in the presence of a demand for realizing a sailing operating state of the vehicle drivetrain (1) during which a drive machine (2) is active and the power flow between the drive machine (2) and a drive output (3) is disconnected in a gearbox (4), the active drive machine (2) from the drive output (3) by opening of one of a plurality of shift elements (A to F) that is held in a closed operating state in order to realize the operating state present before the demand for decoupling of the active drive machine (2). The method also includes then actuating the plurality of shift elements (A to F) in a manner dependent on the present operating state profile of the vehicle drivetrain (1) and with the active drive machine (2) decoupled from the drive output (3).
    Type: Grant
    Filed: May 18, 2017
    Date of Patent: October 15, 2019
    Assignee: ZF FRIEDRICHSHAFEN AG
    Inventors: Peter Schiele, Magnus Stiefenhofer
  • Patent number: 10400890
    Abstract: A method for operating a motor vehicle having a transmission (1), the method including closing a first number of shift elements and opening a second number of shift elements in each selected, force locking gear ratio of the transmission (1); closing one shift element less, and therefore opening one shift element more than in a selected, force locking gear ratio when a transmission (1) is not force locking in the sailing mode; adjusting the respectively closed and opened shift elements as a function of at least one operating condition of the motor vehicle in the sailing mode; and checking, at least on the basis of the rotational speed of the transmission input shaft (2), whether a previously closed, positively locking shift element (A, F) to be opened is actually opened in the sailing mode during adjusting of the respectively closed and opened shift elements.
    Type: Grant
    Filed: December 6, 2017
    Date of Patent: September 3, 2019
    Assignee: ZF FRIEDRICHSHAFEN AG
    Inventors: Magnus Stiefenhofer, Steffen Peine
  • Publication number: 20180266548
    Abstract: A method for operating a drivetrain of a motor vehicle includes elevating a system pressure acting on a plurality of shift elements (A, B, C, D, E, F) when one of at least one positively locking shift element (A, F) is closed in a force-locking-free state, increasing a torque output by a drive assembly (15) and then subsequently reducing the torque output by the drive assembly (15) while the system pressure is elevated by an intervention with the drive assembly (15), and reducing the system pressure after reducing the torque output by the drive assembly (15). The one of the at least one positively locking shift element (A, F) closed in the force-locking-free state or another one of the at least one positively locking shift element (A, F) is opened while the system pressure is elevated and the torque output by the drive assembly (15) changes.
    Type: Application
    Filed: March 13, 2018
    Publication date: September 20, 2018
    Inventors: Michael Sohler, Magnus Stiefenhofer, Tobias Hartmann
  • Publication number: 20180172152
    Abstract: A method for operating a motor vehicle having a transmission (1), the method including closing a first number of shift elements and opening a second number of shift elements in each selected, force locking gear ratio of the transmission (1); closing one shift element less, and therefore opening one shift element more than in a selected, force locking gear ratio when a transmission (1) is not force locking in the sailing mode; adjusting the respectively closed and opened shift elements as a function of at least one operating condition of the motor vehicle in the sailing mode; and checking, at least on the basis of the rotational speed of the transmission input shaft (2), whether a previously closed, positively locking shift element (A, F) to be opened is actually opened in the sailing mode during adjusting of the respectively closed and opened shift elements.
    Type: Application
    Filed: December 6, 2017
    Publication date: June 21, 2018
    Inventors: Magnus Stiefenhofer, Steffen Peine
  • Publication number: 20170335954
    Abstract: A method for operating a vehicle drivetrain (1) includes decoupling, in the presence of a demand for realizing a sailing operating state of the vehicle drivetrain (1) during which a drive machine (2) is active and the power flow between the drive machine (2) and a drive output (3) is disconnected in a gearbox (4), the active drive machine (2) from the drive output (3) by opening of one of a plurality of shift elements (A to F) that is held in a closed operating state in order to realize the operating state present before the demand for decoupling of the active drive machine (2). The method also includes then actuating the plurality of shift elements (A to F) in a manner dependent on the present operating state profile of the vehicle drivetrain (1) and with the active drive machine (2) decoupled from the drive output (3).
    Type: Application
    Filed: May 18, 2017
    Publication date: November 23, 2017
    Inventors: Peter Schiele, Magnus Stiefenhofer