Patents by Inventor John A. Zwald

John A. Zwald 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).

  • Removable subdie
    Patent number: 3949589
    Abstract: There is described a subdie assembly adapted for easy removal from a larger die apparatus. The assembly comprises a die retention means, die means, guide means, tool retention means and workpiece engaging means both movably oriented on said guide means for aligned movement toward and away from the die retention means, and first and second resilient spacing means for maintaining the tool retention means in spaced relationship with the workpiece engaging means and the die retention means respectively.
    Type: Grant
    Filed: February 5, 1975
    Date of Patent: April 13, 1976
    Assignee: GTE Sylvania Incorporated
    Inventors: Robert R. Johnson, Robert E. Jones, John A. Zwald