Patents by Inventor William J. Tellefsen

William J. Tellefsen 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).

  • Low emission foundry binder system
    Patent number: 4311631
    Abstract: Foundary binder, substantially free of inert hydrocarbon solvents, is comprised of a mixture of low molecular weight methylolated phenolic components and a reactive diluent. The binder is mixed with sand and cured with a polyisocyanate in the presence of a catalyst.
    Type: Grant
    Filed: September 20, 1979
    Date of Patent: January 19, 1982
    Assignee: Delta Oil Products Corporation
    Inventors: Marion M. Myers, William J. Tellefsen