Patents by Inventor David B. Swift

David B. Swift 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).

  • A valve arrangement
    Patent number: 5280803
    Abstract: An hydraulically assisted inlet valve is disclosed having a by-pass passage (32) which is permanently open. Preferably the valve has a valve body (13) reciprocally mounted in the inlet (4) and carried by a diaphragm (23). The by-pass passage preferably extends through the valve body (13) to apply inlet pressure to one side of the diaphragm.
    Type: Grant
    Filed: August 9, 1991
    Date of Patent: January 25, 1994
    Assignee: Caroma Industries Limited
    Inventors: David B. Swift, David Chelchowski