Patents by Inventor Mark Peter Krefta

Mark Peter Krefta 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).

  • Linear position sensing system and coil switching methods for closed-loop control of large linear induction motor systems
    Patent number: 6952086
    Abstract: A control system for a linear motor adapted to accurately supply a moving window of power to the stator coils. A plurality of individually switched stator coils run the length of a linear motor to move a rotor down the long axis of the stator. Accurate inductive-based position sensors continuously provide position data for the moving rotor. A processing unit calculates a proper time delay from a source voltage peak in order to apply power to the next stator coil in the moving direction of the rotor such that no DC offshoot/undershoot occurs. The linear motor control system optionally includes a failure prevention switching scheme in which pairs of individual stator coils on opposite sides of a double-sided stator are switched together.
    Type: Grant
    Filed: October 10, 2003
    Date of Patent: October 4, 2005
    Assignee: Curtiss-Wright Electro-Mechanical Corporation
    Inventors: Mark Peter Krefta, David Jonathan Hall, Kenneth Martin Eichler, Jiing-Liang Wu, Robert E. Strickler, Michael Barnaby Brennen
  • Trapezoidal shaped magnet flux intensifier motor pole arrangement for improved motor torque density
    Patent number: 6879075
    Abstract: A permanent magnet synchronous machine with improved torque and power characteristics. A circumferential-oriented rotor assembly is provided with alternating permanent magnets and magnetic pole pieces. In order to reduce the amount of leakage flux in the rotor and increase the effective length of the permanent magnet, a trapezoidal or otherwise tapered permanent magnet structure is used. By alternating trapezoidal permanent magnet, and magnetic pole pieces, a higher intensity magnetic field is created in the air gap utilizing the same radial space in the motor without altering the weight or volume of the motor compared to conventional machines.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: April 12, 2005
    Assignee: Curtiss-Wright Electro-Mechanical Corporation
    Inventors: Raymond Mark Calfo, Mark Peter Krefta
  • Trapezoidal shaped magnet flux intensifier motor pole arrangement for improved motor torque density
    Publication number: 20040150283
    Abstract: A permanent magnet synchronous machine with improved torque and power characteristics. A circumferential-oriented rotor assembly is provided with alternating permanent magnets and magnetic pole pieces. In order to reduce the amount of leakage flux in the rotor and increase the effective length of the permanent magnet, a trapezoidal or otherwise tapered permanent magnet structure is used. By alternating trapezoidal permanent magnet, and magnetic pole pieces, a higher intensity magnetic field is created in the air gap utilizing the same radial space in the motor without altering the weight or volume of the motor compared to conventional machines.
    Type: Application
    Filed: January 31, 2003
    Publication date: August 5, 2004
    Inventors: Raymond Mark Calfo, Mark Peter Krefta