Patents by Inventor Robert Hamilton Hartland

Robert Hamilton Hartland 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: 20130019533
    Abstract: A counter balance system for an overhead door assembly is provided. The overhead door assembly includes a door frame, an overhead door, and a door lifting assembly. The door lifting assembly includes an extension spring, a cable, and a pulley assembly. The pulley assembly guides the cable as the door is moved between a raised open position and a lowered closed position. A pulley of the pulley assembly is mounted so that an axis of rotation of the pulley remains perpendicular to a portion of the first cable extending between the pulley and a lower portion of the overhead door as the door is moved between the raised open position and the lowered closed position.
    Type: Application
    Filed: July 18, 2011
    Publication date: January 24, 2013
    Inventors: Kenneth Fletcher, Robert Hamilton Hartland