Patents by Inventor Robert J. Campbell

Robert J. Campbell 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: 4197995
    Abstract: An agricultural spraying assembly including a plurality of nozzles divided into groups with each group being supplied liquid through a solenoid valve with a motorized proportioning valve being adjustable to control the pressure supplied to the solenoid valves and, in turn, to the plurality of nozzles. The assembly includes a main control box which is normally situated on a spraying trailer and a remote control box which is normally situated on the pulling tractor and is supplied power from the tractor's battery. Each of the control boxes includes switches for each of the solenoid valves as well as a pressure adjusting switch for adjusting the pressure supplied to the nozzles. Each control box has a pressure gauge for indicating the operating pressure supplied to the nozzles.
    Type: Grant
    Filed: November 13, 1978
    Date of Patent: April 15, 1980
    Assignee: McCord Corporation
    Inventors: Robert J. Campbell, Paul D. Gray
  • Patent number: 3992900
    Abstract: The invention is directed to an apparatus and method of purifying contaminated water by means of a two-step freeze crystallization process. The method and apparatus overcomes the serious problem caused by the freezing of water on the screen of the wash column. The solution comprises means and method of reducing the temperature difference between the concentrate and the wash water in the wash column.
    Type: Grant
    Filed: December 27, 1974
    Date of Patent: November 23, 1976
    Assignee: Avco Corporation
    Inventor: Robert J. Campbell