Patents by Inventor David Morrie

David Morrie 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).

  • Plasma arc torch system with pilot re-attach circuit and method
    Patent number: 6794601
    Abstract: A plasma arc torch system, a circuit, and a method for controlling a pilot arc is disclosed. A rate of change sensor, such as a dv/dt sensor, monitors an output current signal or an output voltage signal to determine whether to close a switch to re-attach a pilot arc before a transferred arc becomes extinguished. The switch selectively connects a tip into a circuit path with an electrode and a power supply to allow the pilot arc to form between the tip and the electrode. A power supply preferably regulates the output current or voltage to a first level when a pilot arc is present, and to a second mode when a transferred arc is present.
    Type: Grant
    Filed: September 5, 2002
    Date of Patent: September 21, 2004
    Assignee: Thermal Dynamics Corporation
    Inventors: Stephen W. Norris, Roger Chamberlin, David Morrie
  • Plasma ARC torch system with pilot re-attach circuit and method
    Publication number: 20040045942
    Abstract: A plasma arc torch system, a circuit, and a method for controlling a pilot arc is disclosed. A rate of change sensor, such as a dv/dt sensor, monitors an output current signal or an output voltage signal to determine whether to close a switch to re-attach a pilot arc before a transferred arc becomes extinguished. The switch selectively connects a tip into a circuit path with an electrode and a power supply to allow the pilot arc to form between the tip and the electrode. A power supply preferably regulates the output current or voltage to a first level when a pilot arc is present, and to a second mode when a transferred arc is present.
    Type: Application
    Filed: September 5, 2002
    Publication date: March 11, 2004
    Inventors: Stephen W. Norris, Roger Chamberlin, David Morrie