Patents by Inventor Gunther H. Dierssen

Gunther H. Dierssen 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).

  • Hexagonal magnetic ferrite pigment for high density magnetic recording applications
    Patent number: 5626956
    Abstract: The present invention provides a hexagonal magnetic ferrite pigment suitable for high density magnetic recording applications. The pigment is characterized by small particle size, a modified magnetoplumbite structure, and relatively high magnetic moment. The pigment is capable of being prepared by firing suitable precursor particles in air at temperatures below 850.degree. C.
    Type: Grant
    Filed: December 28, 1993
    Date of Patent: May 6, 1997
    Assignee: Imation Corp.
    Inventors: David M. Hopstock, John S. Roden, Gunther H. Dierssen, Ronald S. Sapieszko
  • Hexagonal magnetic ferrite pigment for high density magnetic recording applications
    Patent number: 5616414
    Abstract: The present invention provides a hexagonal magnetic ferrite pigment suitable for high density magnetic recording applications. The pigment is characterized by small particle size, a modified magnetoplumbite structure, and relatively high magnetic moment. The pigment is capable of being prepared by firing suitable precursor particles in air at temperatures below 850.degree. C.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: April 1, 1997
    Assignee: Imation Corp.
    Inventors: David M. Hopstock, John S. Roden, Gunther H. Dierssen, Ronald S. Sapieszko
  • Process of making hexagonal magnetic ferrite pigment for high density magnetic recording applications
    Patent number: 5378384
    Abstract: The present invention provides a hexagonal magnetic ferrite pigment suitable for high density magnetic recording applications. The pigment is characterized by small particle size, a modified magnetoplumbite structure, and relatively high magnetic moment. The pigment is capable of being prepared by firing suitable precursor particles in air at temperatures below 850.degree. C.
    Type: Grant
    Filed: September 19, 1991
    Date of Patent: January 3, 1995
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: David M. Hopstock, John S. Roden, Gunther H. Dierssen, Ronald S. Sapieszko
  • Granular silicon carbide abrasive grain coated with refractory material, method of making the same and articles made therewith
    Patent number: 4505720
    Abstract: Improved granular abrasive material comprises silicon carbide particles at least partially coated with an integral, durable surface layer of a hard refractory material comprising metal nitride or carbide. Hard refractory materials which provide a useful coating include, for example, silicon nitride or carbide, titanium nitride or carbide, sialon, and others. The surface layer is preferably provided by chemical vapor deposition, most preferably utilizing a fluidized bed. The improved granular abrasive material is particularly useful in various abrasive products such as coated abrasive products, nonwoven abrasive products and abrasive grinding wheels.
    Type: Grant
    Filed: June 29, 1983
    Date of Patent: March 19, 1985
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Thomas Gabor, David E. Broberg, Gunther H. Dierssen, Donley D. Rowenhorst
  • Thermomechanical candle snuffer
    Patent number: 4138211
    Abstract: Thermomechanical candle snuffer utilizes staff of material such as 55-Nitinol which, when heated by candle flame, elevates slideably engaged cap which falls over candle extinguishing it.
    Type: Grant
    Filed: November 4, 1977
    Date of Patent: February 6, 1979
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Robert D. Kampfer, Gunther H. Dierssen