Patents by Inventor Wilhelmus Franciscus Knippenberg

Wilhelmus Franciscus Knippenberg 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).

  • Electric resistor based on silicon carbide having a negative temperature coefficient
    Patent number: 4086559
    Abstract: An electric resistor having a negative temperature coefficient of the electrical resistance whose resistance body consists of p-type doped pyrolytic polycrystalline cubic silicon carbide.
    Type: Grant
    Filed: September 22, 1975
    Date of Patent: April 25, 1978
    Assignee: U.S. Philips Corporation
    Inventors: Wilhelmus Franciscus Knippenberg, Gerrit Verspui, Siegfried Hendrik Hagen
  • Filamentary silicon carbide crystals by VLS growth in molten iron
    Patent number: 4013503
    Abstract: A method of growing silicon carbide whiskers from a gaseous phase by means of a vapor-liquid-solid mechanism on a substrate using iron in a finely divided state as a solvent for the silicon carbide.
    Type: Grant
    Filed: July 25, 1975
    Date of Patent: March 22, 1977
    Assignee: North American Philips Corporation
    Inventors: Wilhelmus Franciscus Knippenberg, Gerrit Verspui
  • Method of manufacturing silicon carbide crystals
    Patent number: 3962406
    Abstract: A method of manufacturing silicon carbide crystals in which a core of silicon dioxide is embedded in a mass of granular silicon carbide, or materials which form silicon carbide on heating this mass being heated to a temperature at which silicon dioxide volatilizes, i.e. above about 1500.degree.C, and the silicon carbide coheres. This leaves a cavity, formerly occupied by the silicon dioxide which is surrounded by silicon carbide. Heating is then continued at a temperature, above about 2500.degree.C, at which silicon carbide crystals are formed on the walls of the cavity.
    Type: Grant
    Filed: August 15, 1972
    Date of Patent: June 8, 1976
    Assignee: U.S. Philips Corporation
    Inventors: Wilhelmus Franciscus Knippenberg, Gerrit Verspui