Patents by Inventor Larry D. Robertson

Larry D. Robertson 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).

  • Duct notching template apparatus
    Patent number: 5083380
    Abstract: The disclosure relates to a duct notching template apparatus having slidably positionable and settable end templates and a center template. The end templates have hooked or tabbed edges for engaging the edge of a piece of sheet metal to be scribed for notching. The templates contain windows for viewing the measuring indicia on the longitudinal element on which they are disposed.
    Type: Grant
    Filed: April 23, 1990
    Date of Patent: January 28, 1992
    Inventor: Larry D. Robertson