Patents by Inventor Lake H. Johnson

Lake H. Johnson 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).

  • Centrifuge tube seal
    Patent number: 4222513
    Abstract: A vertically oriented centrifuge tube is placed in a rotor cavity and the open end sealed with a tapered plug. A resilient O-ring is placed in an annular groove formed in the top of the tapered plug and a retaining disc, secured to the open end of the cavity, wedges the plug into the open end of the centrifuge tube. The O-ring, being resilient, maintains an axial force which aids in retaining the tapered plug properly seated within the open end of the centrifuge tube, even during and following the stresses of centrifugation.
    Type: Grant
    Filed: December 12, 1978
    Date of Patent: September 16, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Donald A. Webster, Lake H. Johnson, William A. Romanauskas