Patents by Inventor Keith D. Ramthun

Keith D. Ramthun 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).

  • Complaint investment casting mold and method
    Patent number: 5297615
    Abstract: A high melting point and/or low ductility metal or alloy is investment cast in a refractory mold including a facecoat layer and a plurality of back-up layers wherein at least one back-up layer is a relatively weak, sacrificial layer. This latter layer is crushed as necessary as the casting cools below its ductile-to-brittle transition temperature to avoid hot tearing or cracking of the solidified metal or alloy during cooling in the mold.
    Type: Grant
    Filed: July 17, 1992
    Date of Patent: March 29, 1994
    Assignee: Howmet Corporation
    Inventors: Paul R. Aimone, Bart M. Kilinski, Keith D. Ramthun