Patents by Inventor Dennis M. Friend

Dennis M. Friend 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).

  • Temperature control system for air conditioning system
    Patent number: 4830095
    Abstract: A temperature control system for an air conditioning system that services plural zones provides priority of one or more selected zones of the conditioned air flow relative to the other unselected zones. Priority is achieved by closing those dampers associated with the unselected zones to direct the conditioned air flow into the selected zones. The temperature control system also provides for fail-safe operation by utilizing dampers biased in the open position and by preventing all dampers from being closed at the same time when conditioned air is flowing.
    Type: Grant
    Filed: March 18, 1988
    Date of Patent: May 16, 1989
    Inventor: Dennis M. Friend