Patents by Inventor Ralf Cremer

Ralf Cremer 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: 9702683
    Abstract: The invention relates to a method for determining the piston position of a hydraulic or pneumatic piston cylinder unit, wherein the cylinder jacket and the piston form an electrical conducting path and the piston position is determined with the aid of the inductive and/or resistive properties of the conducting path that is formed. In addition, the invention relates to a piston cylinder unit having a measuring device for carrying out such a method.
    Type: Grant
    Filed: January 23, 2014
    Date of Patent: July 11, 2017
    Assignee: Liebherr-Electronik GmbH
    Inventors: Sebastian Braun, Alfred Engler, Ralf Cremer, Ingo Nannen
  • Patent number: 9571014
    Abstract: The invention relates to a drive circuit for an electric motor having an aerodynamic bearing of the motor shaft, wherein the drive circuit comprises at least one storage means for storing electrical energy by which the electric motor can be fed with electrical energy on a failure of the supply voltage or DC-link voltage to obtain a minimum speed of the motor shaft required for the air support at least at times.
    Type: Grant
    Filed: September 2, 2014
    Date of Patent: February 14, 2017
    Assignee: LIEBHERR-ELEKTRONIK GMBH
    Inventors: Nejat Mahdavi, Ralf Cremer, Pierre Brodeau
  • Publication number: 20150130384
    Abstract: The invention relates to a drive circuit for an electric motor having an aerodynamic support of the motor shaft, wherein the drive circuit comprises at least one storage means for storing electrical energy by which the electric motor can be fed with electrical energy on a failure of the supply voltage or intermediate circuit voltage to obtain a minimum speed of the motor shaft required for the air support at least at times.
    Type: Application
    Filed: September 2, 2014
    Publication date: May 14, 2015
    Inventors: Nejat Mahdavi, Ralf Cremer, Pierre Brodeau
  • Patent number: 9027460
    Abstract: The present disclosure relates to a piston-cylinder unit with a device for determining position, the device comprising at least one exciter that is indirectly or directly electrically connected with the cylinder jacket and the cylinder piston of the piston-cylinder unit, and that excites the electrical oscillating circuit formed by the piston-cylinder unit and the contact lines to oscillate at its resonant frequency, it being possible to measure an electrical signal characterizing the resonant frequency on the piston-cylinder unit. The invention also relates to a construction machine or piece of hoisting equipment with such a piston-cylinder unit.
    Type: Grant
    Filed: January 11, 2012
    Date of Patent: May 12, 2015
    Assignee: Liebherr-Elektronik GmbH
    Inventors: Rodolphe de Maglie, Alfred Engler, Ralf Cremer, Hans-Peter Lavergne
  • Publication number: 20140218051
    Abstract: The invention relates to a method for determining the piston position of a hydraulic or pneumatic piston cylinder unit, wherein the cylinder jacket and the piston form an electrical conducting path and the piston position is determined with the aid of the inductive and/or resistive properties of the conducting path that is formed. In addition, the invention relates to a piston cylinder unit having a measuring device for carrying out such a method.
    Type: Application
    Filed: January 23, 2014
    Publication date: August 7, 2014
    Inventors: Sebastian Braun, Alfred Engler, Ralf Cremer, Ingo Nannen
  • Publication number: 20120174771
    Abstract: The present disclosure relates to a piston-cylinder unit with a device for determining position, the device comprising at least one exciter that is indirectly or directly electrically connected with the cylinder jacket and the cylinder piston of the piston-cylinder unit, and that excites the electrical oscillating circuit formed by the piston-cylinder unit and the contact lines to oscillate at its resonant frequency, it being possible to measure an electrical signal characterizing the resonant frequency on the piston-cylinder unit. The invention also relates to a construction machine or piece of hoisting equipment with such a piston-cylinder unit.
    Type: Application
    Filed: January 11, 2012
    Publication date: July 12, 2012
    Applicant: LIEBHERR-ELEKTRONIK GMBH
    Inventors: Rodolphe De Maglie, Alfred Engler, Ralf Cremer, Hans-Peter Lavergne
  • Publication number: 20120161512
    Abstract: The present invention relates to an energy supply system of an aircraft comprising a fuel cell and having one or more consumers which are or can be connected to the fuel cell such that they are supplied with energy directly or indirectly from the fuel cell in emergency operation as well has having at least one active energy store which is or can be connected to at least one of the consumers such that the consumer(s) is/are supplied with energy from the active energy store at least at times.
    Type: Application
    Filed: December 22, 2011
    Publication date: June 28, 2012
    Applicant: Liebherr-Aerospace Lindenberg GmbH
    Inventors: Dirk Metzler, Matthias Ludwig, Ralf Cremer, Jacques Herzog, Georg Ried
  • Publication number: 20090104493
    Abstract: The present invention relates to an energy supply system of an aircraft comprising a fuel cell and having one or more consumers which are or can be connected to the fuel cell such that they are supplied with energy directly or indirectly from the fuel cell in emergency operation as well has having at least one active energy store which is or can be connected to at least one of the consumers such that the consumer(s) is/are supplied with energy from the active energy store at least at times.
    Type: Application
    Filed: January 16, 2008
    Publication date: April 23, 2009
    Inventors: Dirk Metzler, Matthias Ludwig, Ralf Cremer, Jacques Herzog, Georg Ried
  • Patent number: 5693875
    Abstract: The invention relates to a measuring process for the indirect measurement of the temperature and solids content of metal workpieces during inductive heating. To this end, in a coupled coil system comprising a heating coil, the effect of alterations in the electrical conductivity of the workpiece is determined by the combination, using circuit-mathematical techniques, of a signal tapped from the exploring coil with a reference signal from the driving coil. The two signals are combined in such a way that the measurement signal obtained depends solely on the phase shift between the reference signal and the exploring coil signal and/or on the quotient of the amplitude values of the reference signal and the exploring coil signal. This facilitates measurement which is independent of the amplitude of the alternating electromagnetic field created by the driving coil.
    Type: Grant
    Filed: May 9, 1996
    Date of Patent: December 2, 1997
    Assignee: EFU Gesellschaft fur Ur-/Umformtechnik mbH
    Inventor: Ralf Cremer