Patents by Inventor Jack E. Washburn

Jack E. Washburn 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: 4424039
    Abstract: A mathematics teaching device wherein a display surface is divided into eight regions. The first region contains one hundred colored and numbered plaques removably mounted in ten rows. Plaques are within five color groupings and the rows are color-coded as are receiving pockets. Two regions have another set of plaques with an adjacent receiving pocket to permit simple mathematical operations to be performed therein. The other regions are marked for additional operations to be performed therein.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: January 3, 1984
    Inventor: Jack E. Washburn