Patents by Inventor Roger John Nelson

Roger John Nelson 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: 4057109
    Abstract: The lower draft link of a tractor three-point hitch includes a sensor to sense draft loads imposed on the draft link by an earth-working implement. Variations in the draft load cause variations in the pressure of the fluid in the sensor from a preselected pressure. A pilot-operated, load control valve is connected to the sensor and is shiftable in response to pressure above and below the preselected pressure to actuate a control mechanism. The control mechanism actuates a direction control valve for directing fluid to and from a hydraulic lift cylinder for respectively raising and lowering the draft link to adjust the implement so as to maintain the preselected pressure and thus maintain the desired draft load.
    Type: Grant
    Filed: August 4, 1975
    Date of Patent: November 8, 1977
    Assignee: Deere & Company
    Inventor: Roger John Nelson