Patents by Inventor Robert B. Machen

Robert B. Machen 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).

  • Personal smoke and fire detector and warning unit
    Patent number: 4305069
    Abstract: This invention is a combination smoke and fire detection and alarm system that comprises a battery powered personal unit and an AC/DC sustaining unit. It provides audible and visual alarms and an emergency light. The personal unit plugs into the sustaining unit for battery charge and provides an additional smoke and fire detector when used in this mode.
    Type: Grant
    Filed: May 31, 1978
    Date of Patent: December 8, 1981
    Inventors: Robert B. Machen, John E. Thompson