Patents by Inventor Henry J. Jessen

Henry J. Jessen 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: 3935792
    Abstract: In an earthmoving scraper a low volume, low pressure, pilot pump supplies fluid pressure to a pilot control valve which routes this fluid through bleed lines to a remote scraper control valve that operates the bowl jacks on the scraper from a separate source of pressurized hydraulic fluid. By manually varying the bleed rates of the output of the pilot pump with the spool of the pilot valve, proportion actuation of the control valve can be obtained through differential pressures in the bleed lines connecting it to the pilot valve. A safety valve connected in the bowl carry circuit supplies an alternate source of fluid pressure to the pilot valve if the pilot pump fails, ensuring positive fail-safe operation of the system.
    Type: Grant
    Filed: June 26, 1974
    Date of Patent: February 3, 1976
    Assignee: Caterpillar Tractor Co.
    Inventors: Joseph E. Dezelan, Henry J. Jessen