Patents by Inventor Johannes Wilhelmus Antonius Krol

Johannes Wilhelmus Antonius Krol 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).

  • Method of manufacturing grid electrodes for electron tubes
    Patent number: 4120080
    Abstract: Disclosed is a method of manufacturing a pyrolytic graphite grid electrode in which after formation of the grid, the electrode is annealed at a temperature of 700.degree. to 1200.degree. C in a reactive atmosphere to remove carbon particles adhering to the electrode surface.
    Type: Grant
    Filed: March 10, 1977
    Date of Patent: October 17, 1978
    Assignee: U.S. Philips Corporation
    Inventors: Johannes Wilhelmus Antonius Krol, Bernhard Lersmacher, Horst Seifert
  • Method of manufacturing grid electrodes for electron tubes
    Patent number: 4034031
    Abstract: Method of manufacturing grid electrodes wherein a grid sleeve is produced by depositing pyrolytic graphite on a polished mandril of glassy carbon and provided with apertures by means of the laser beam, then the finished grid is provided, by means of hot gas pyrolysis, with a second layer of highly oriented pyrolytic graphite, and thermally and/or mechanically after-treated at 3000.degree. to 3800.degree. K and 10-500 bar.
    Type: Grant
    Filed: October 16, 1975
    Date of Patent: July 5, 1977
    Assignee: U.S. Philips Corporation
    Inventors: Bernhard Lersmacher, Horst Seifert, Johannes Wilhelmus Antonius Krol