Patents by Inventor Robert C. Postma

Robert C. Postma 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).

  • Flexible writing surface
    Patent number: 4978568
    Abstract: A flexible writing surface including a coated flexible substrate having a dust collecting cuff around the perimeter thereof to prevent the scattering of chalk dust during use.
    Type: Grant
    Filed: February 22, 1989
    Date of Patent: December 18, 1990
    Assignee: Hach Associates, Inc.
    Inventor: Robert C. Postma