Patents by Inventor Donald K. Herald

Donald K. Herald 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).

  • Slag-retaining plug for metal pouring operations
    Patent number: 4725045
    Abstract: A refractory plug for blocking the tap hole of a steel making vessel or transfer ladle containing molten steel covered by a layer of slag and for minimizing turbulence caused by vortexing. The plug comprises a body having an inverted cone-shaped bottom and having an integral top portion projecting axially from a top base surface of the cone-shaped bottom portion. The plug is added to the melt just prior to or during the tapping operation to minimize vortexing and to plug the tap hole prior to egress of the slag.
    Type: Grant
    Filed: May 30, 1986
    Date of Patent: February 16, 1988
    Inventors: James R. Cutre, Donald K. Herald, Donald L. Herald, John W. Schwer