Patents by Inventor Rolf P. Janssen

Rolf P. Janssen 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: 4598055
    Abstract: A method of manufacturing ceramic sintered bodies. A basic starting material corresponding to the sintered body is mixed with compounds which form a melting phase with the starting material during sintering. Prior to the sintering, presintered starting material nuclei having an average crystallite size which corresponds at least three times the average crystallite size of the basic starting material are added to the basic material and melt-forming compounds. The nuclei are added in a quantity of at least 0.1% by weight of the starting material to be sintered. By this addition the grain size and grain distribution in the ceramic sintered body of materials with discontinuous grain growth can be effectively checked and controlled.
    Type: Grant
    Filed: April 8, 1985
    Date of Patent: July 1, 1986
    Assignee: U.S. Philips Corporation
    Inventors: Detlev F. K. Hennings, Rolf P. Janssen, Piet Reijnen