Patents by Inventor Peter N. Walker

Peter N. Walker 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).

  • Filter with dual fluid pressure actuated valves on common stem
    Patent number: 4936989
    Abstract: A filter in which liquid flows through a plurality of filter elements wherein each filter element has a pair of valves for closing off the ends of the filter elements in turn for filtering and backwashing. The valves are mounted on a common stem operated by an actuator. With the actuator on, the backwashing or cleaning valve is closed and the remaining or inlet valve is open. With the actuator off, the inlet valve closes and the backwashing valve is opened.
    Type: Grant
    Filed: May 15, 1989
    Date of Patent: June 26, 1990
    Assignee: Kalman Richter
    Inventor: Peter N. Walker