Patents by Inventor Bertram D. Robertson, Jr.

Bertram D. Robertson, Jr. 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: 4819819
    Abstract: A tamper evident closure for a container generally having a cylindrical upstanding neck or throat, the neck having an external thread. The closure comprises an annular element which slides into and mates with the throat of the container, a cylindrical cup which frictionally engages the end of the annular element that extends into the container, the bottom of the cup constituting a flat disc having frangible lines which begin at the outer edge of the disc and wind spirally to the center of the disc ending in a pull tab which extends upwardly in the cup, and a clear cap the internal threads of which mate with the external threads of the neck. The annular element is made of rigid plastic material that is suitable for ultrasonic welding to the throat to create an integrity of the throat and closure.The cup is made of a softer deformable material such that when the pull tab is pulled to open the closure the unwound portion will be so deformed that it cannot be replaced in its original condition.
    Type: Grant
    Filed: March 28, 1988
    Date of Patent: April 11, 1989
    Inventor: Bertram D. Robertson, Jr.