Patents by Inventor Alfred L. Duncan

Alfred L. Duncan 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).

  • Device for controlling the pouring of molten materials
    Patent number: 5286009
    Abstract: A device for controlling the pouring of a molten material from a crucible or other container. The device (10) includes an annular retainer ring (12) for mounting in the drain opening in the bottom of a conventional crucible (16), the retainer ring defining a opening (14) therethrough. The device (10) also includes a plug member (22) having an annular forward end portion (24) for force-fit reception in the opening (14) of the retainer ring (12) to selectively seal the opening (14) and for being selectively forced through the opening (14). The plug member (22) has a rear end portion (26) for being positioned within the crucible (16), the rear end portion (26) including stop means for prohibiting the rear end portion from passing through the opening (14) in the retainer ring (12) when the forward end portion (24) is selectively forced through the opening.
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: February 15, 1994
    Assignee: Martin Marietta Energy Systems, Inc.
    Inventors: Alan F. Moore, Alfred L. Duncan