Patents by Inventor Karl E. Lefren

Karl E. Lefren 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).

  • Tampons and their manufacture
    Patent number: 4431427
    Abstract: A tampon having incorporated therein one or more substances, such as one or more physiologically safe organic acids that will maintain a pH of about 4.5 to 2.5 in the absorbed fluids during the use of the tampon, to create a hostile but safe environment to inhibit the growth of pathogenic bacteria, such as Staphylococcus aureus, within and on the tampon during its use.
    Type: Grant
    Filed: October 5, 1981
    Date of Patent: February 14, 1984
    Assignee: University of Delaware
    Inventors: Karl E. Lefren, Seymour Yolles