Patents by Inventor Holger Freitag

Holger Freitag 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).

  • Publication number: 20050012483
    Abstract: The invention concerns a drive arrangement of a lifting gear and/or a traveling gear, with a pole-reversible rotary-current motor with windings for at least two different actuating speeds, with a pole switching element connecting the rotary-current motor to a voltage supply for changing between the actuating speeds of the rotary-current motor. In order to create a drive arrangement of a lifting gear and/or a traveling gear with a rotary-current motor, whose switching behavior is optimized in relation to the actuation of the rotary-current motor, it is proposed that a power switching element (3) be hooked up in front of the pole switching element (5), and it can be separated from the voltage supply via the power switching element (3) for the pole switching process of the rotary-current motor (2).
    Type: Application
    Filed: June 28, 2004
    Publication date: January 20, 2005
    Inventors: Holger Freitag, Anton Munzebrock, Burkhard Hasenack, Giuliano Persico, Erik Appel
  • Publication number: 20040239286
    Abstract: An interface circuit for actuating an electrical consumer, especially a pole-changing rotary-current induction motor, with a first contact element assigned to a signal line carrying an alternating voltage signal to generate at least two different control signals. A circuit arrangement is provided for actuating an electric motor, especially a pole-changing rotary-current induction motor, with a control switch element having an aforementioned interface circuit, which is connected via a signal line to a motor control of the electric motor.
    Type: Application
    Filed: May 21, 2004
    Publication date: December 2, 2004
    Inventors: Holger Freitag, Anton Munzebrock, Burkhard Hasenack, Giuliano Persico, Erik Appel
  • Patent number: 5818185
    Abstract: A process and a device for monitoring and/or controlling the speed of rotation of an electric drive having an asynchronous motor equipped with a braking device (11) and connected via a frequency adapter (13) to an alternating current system (12), e.g. three-phase system, to provide safe lifting and lowering of a load. The maximum torque (16) produced by the drive for lifting the load is set to be smaller than a holding torque (17) needed by the braking device (11) to hold the load in a stationary position.
    Type: Grant
    Filed: October 25, 1995
    Date of Patent: October 6, 1998
    Assignee: Mannesmann Aktiengesellschaft
    Inventors: Holger Freitag, Anton Munzebrock
  • Patent number: 5813124
    Abstract: An angle measuring device used for measuring the pendulum angle of a cable of a lifting device comprising connection components which utilize measurement value pick-ups and are connected via a cardanic-type joint to axles which are arranged at right angles to one another. To attain high precision of discrimination in measurement, the measurement value pick-ups each comprises a Hall sensor and an associated magnetic element to create a magnetic field detectable by the Hall sensor. An angle of measurement can be attained if the lower connection component is swung and causes a shift in the joint ball around the axle. This results in a change in the position of the magnets relative to the Hall sensors. This change in position results in a change in the detected Hall voltage which after appropriate adjustment can be transformed into an angle measurement.
    Type: Grant
    Filed: April 2, 1996
    Date of Patent: September 29, 1998
    Assignee: Mannesmann Aktiengesellschaft
    Inventor: Holger Freitag
  • Patent number: 5632469
    Abstract: An electric hoist with motor-speed-regulated lifting speed, in particular an electric chain hoist, including an electric motor, a gear unit, and a wheel around which the hoisting chain is looped. A load-carrying device is arranged on the hoisting chain. The motor, gear unit and wheel are connected with one another in a drive connection and the lifting speed is provided by an electric control unit for the electric motor, which control unit is connected to a manual control switch. In order to achieve suitable cooling while apportioning the space in an appropriate manner for the arrangement of all required components, the electric control unit, which has control electronics with speed sensing equipment, is arranged in an external protective housing fitted to the gear box.
    Type: Grant
    Filed: September 15, 1995
    Date of Patent: May 27, 1997
    Assignee: Mannesmann Aktiengesellschaft
    Inventors: Jurgen Heun, Holger Freitag, Anton Muller, Anton Munzebrock