Patents by Inventor John D. Hanson

John D. Hanson 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).

  • Vacuum check valve
    Patent number: 4499916
    Abstract: A vacuum check valve comprising a single umbrella valve responding to vacuum differences between the input and output of the check valve. The check valve directs the output line to feed a vacuum operated device with either the vacuum source or reference air through a bleed passage. The umbrella shaped valve eliminates the requirement for a diaphragm operated poppet valve.
    Type: Grant
    Filed: January 31, 1983
    Date of Patent: February 19, 1985
    Assignee: Allied Corporation
    Inventors: John D. Hanson, John E. Cook