Patents by Inventor John W. Lundstrom

John W. Lundstrom 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: 7239154
    Abstract: This disclosure describes a Soil Penetrating Electrode with Conical Taper for use with instrumentation for measurement of the electrical properties of soil in situ. The Electrode shape and configuration solves problems of stable and reliable contact with the soil, repeatable contact area, and ease of use by the operator.
    Type: Grant
    Filed: March 24, 2004
    Date of Patent: July 3, 2007
    Inventor: John W. Lundstrom
  • Patent number: 6963205
    Abstract: The object of the Electrical Density Gauge (EDG) invention is to provide a low cost, portable, non-nuclear, and rugged field-use device that measures dry density in soils that have been constructed for use as road-beds and building foundations. This data is used to ensure the quality control of the constructed foundation. The electrical properties of soil are measured at a radio frequency using probes driven into the soil. To calibrate EDG, certain algorithms of these electrical properties are related to physically measured wet densities and unit weights of water for a plurality of calibration test spots. Correlation regressions are found, that are used to convert values of the electrical properties measured at unknown field test spots into values of dry density.
    Type: Grant
    Filed: August 18, 2003
    Date of Patent: November 8, 2005
    Inventors: John W. Lundstrom, Dennis Anderson, Dave Straley, William Ehni, Darrell R. Word
  • Publication number: 20040207382
    Abstract: This disclosure describes a Soil Penetrating Electrode with Conical Taper for use with instrumentation for measurement of the electrical properties of soil in situ. The Electrode shape and configuration solves problems of stable and reliable contact with the soil, repeatable contact area, and ease of use by the operator.
    Type: Application
    Filed: March 24, 2004
    Publication date: October 21, 2004
    Inventor: John W. Lundstrom
  • Publication number: 20040095154
    Abstract: The objects of the invention are to provide a low cost, stable, portable, and rugged field-use device that measures wet density, moisture content, and dry density in soils that have been constructed for use as road beds and building foundations. This data is used to ensure the quality control of the constructed foundation. The present invention integrates the complex science of soil mechanics with electrical engineering to provide efficient evaluation of soil materials that are used in civil construction.
    Type: Application
    Filed: August 18, 2003
    Publication date: May 20, 2004
    Inventors: John W. Lundstrom, Dennis Anderson, Dave Straley, William Ehni, Darrell R. Word
  • Patent number: 5808443
    Abstract: A backup battery charger measures charging capacitor voltage and charging battery current to calculate battery charging circuit resistance and open circuit float battery voltage. Microcontroller computation of the backup battery float battery voltage and battery charging circuit resistance changes enable efficient charging and monitoring of battery conditions.
    Type: Grant
    Filed: December 19, 1996
    Date of Patent: September 15, 1998
    Inventor: John W. Lundstrom
  • Patent number: 4180331
    Abstract: A method and apparatus for sampling and optically measuring a selected characteristic of flowing granular material in which an optical window located at one end of a hollow sight tube is disposed in the material stream at an angle with respect thereto. A dam is carried by the sight tube downstream of the window to retard material flow and cause material to collect on the window surface. The selected material characteristic may then be measured as a function of an optical characteristic of the material as viewed through the sight tube and window. An air nozzle is disposed adjacent the window to remove the collected material sample at the end of a measurement sequence.
    Type: Grant
    Filed: April 19, 1976
    Date of Patent: December 25, 1979
    Assignee: Bindicator Company
    Inventor: John W. Lundstrom