Patents by Inventor Kurt Koerfer

Kurt Koerfer 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).

  • Patent number: 4180418
    Abstract: A steel wire after coming from the mill is brought to a temperature between 850.degree. and 910.degree. C. This is followed by multi-stage water-cooling of the wire in such a manner that the surface of the wire is cooled to below the martensite start temperature while austenite is retained in the core of the wire. The heat retained in the core of the wire serves to partially temper the martensite formed at the surface of the wire. The wire is coiled while the temperature remains substantially constant so that the retained austenite in the core of the wire undergoes an isothermal transformation to fine pearlite. The heat of transformation serves to complete tempering of the martensite. After coiling, the wire is air-cooled to room temperature. The final wire exhibits a structure consisting of an outer layer of tempered martensite and a core of fine pearlite. This structure imparts excellent cold-working characteristics to the wire.
    Type: Grant
    Filed: September 1, 1977
    Date of Patent: December 25, 1979
    Assignee: Stahlwerke Peine-Salzgitter A.G.
    Inventors: Hans Paulitsch, Alfred Babilon, Gerhard Kiefer, Kurt Koerfer, Constantin Vlad, Ullrich Koch
  • Patent number: 4108695
    Abstract: A steel wire is rolled while in the austenitic range. Thereafter, the wire is cooled to a temperature between 850.degree. and 910.degree. C. This is followed by multi-stage water-cooling of the wire in such a manner that the surface of the wire is cooled to below the martensite start temperature while austenite is retained in the core of the wire. The latter cooling step brings the temperature of the surface of the wire to below the martensite start temperature in approximately 0.2 seconds. The heat retained in the core of the wire serves to partially temper the martensite formed at the surface of the wire. The wire is then coiled while the temperature remains substantially constant so that the retained austenite in the core of the wire undergoes an isothermal transformation to fine pearlite. The heat of transformation serves to complete tempering of the martensite.
    Type: Grant
    Filed: May 6, 1976
    Date of Patent: August 22, 1978
    Assignee: Stahlwerke Peine-Salzgitter A.G.
    Inventors: Hans Paulitsch, Alfred Babilon, Gerhard Kiefer, Kurt Koerfer, Constantin Vlad, Ullrich Koch