Patents by Inventor Dwight E. Zongker

Dwight E. Zongker 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).

  • Patent number: 4709618
    Abstract: A self-leveling series type hydraulic system including boom and bucket valves which separately control boom and bucket cylinders and a flow divider valve positioned in the exhaust flow path of the rod end of the boom cylinder. The flow divider valve splits the flow sending a portion of it to the cap end of the bucket cylinder so as to maintain the bucket in a level condition during raising of the boom with the remaining flow connected to one of the boom valve motor ports. An improved boom lower circuit which bypasses the flow divider valve as the boom is lowered to achieve a faster boom lower rate and the inclusion of an unloading valve in the bucket circuit which includes the dual function of preventing cavitation and relieving high pressure.
    Type: Grant
    Filed: October 2, 1985
    Date of Patent: December 1, 1987
    Assignee: The Cessna Aircraft Company
    Inventor: Dwight E. Zongker