Patents by Inventor David Hugh Campbell

David Hugh Campbell 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).

  • Control systems for electrostatic powder spraying apparatus
    Patent number: 6274202
    Abstract: A method for controlling operation of powder spraying coating apparatus comprising automatically reducing both the discharge current and discharge voltage of the electrostatic charging means as the spray apparatus approaches a workpiece.
    Type: Grant
    Filed: October 1, 1999
    Date of Patent: August 14, 2001
    Assignee: Eurotec Surface Coating Systems, Ltd.
    Inventor: David Hugh Campbell