Patents by Inventor Wilhelmus F. Knippenberg

Wilhelmus F. 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).

  • Cuvette for the atomic absorption spectrometry
    Patent number: 4629320
    Abstract: A cuvette consisting of a basic hollow member of pyrolytic graphite which is treated at least on the outside surface by a local mechanical abrasion is provided for use in atomic absorption spectroscopy. Since the mechanically treated surfaces may form the inner and outer surfaces of the cuvette, it has been found that the cuvette need not be after-coated or sealed with pyrolytic graphite, but may be of a finally finished form following this mechanical abrasion. Accordingly, cuvettes of substantially smaller wall thicknesses, and substantially smaller mass, are formed with the same or even increased rigidity than commercially available graphite cuvettes which may have or not have a pyrolytic graphite coating.
    Type: Grant
    Filed: March 8, 1983
    Date of Patent: December 16, 1986
    Assignee: U.S. Philips Corporation
    Inventors: Bernhard Lersmacher, Wilhelmus F. Knippenberg
  • Tubular cuvette for atomic absorption spectrometry
    Patent number: 4547069
    Abstract: A cuvette having a thin-walled basic member of pyrolytic graphite is provided with annular graphite components in proximity to its ends. These parts are connected to form a unit which is further coated by an enveloping pyrolytic graphite coating. This cuvette having flanged parts is simpler to electrically contact and is mechanically stable.
    Type: Grant
    Filed: March 9, 1983
    Date of Patent: October 15, 1985
    Assignee: U.S. Philips Corporation
    Inventors: Bernhard Lersmacher, Wilhelmus F. Knippenberg
  • Methods of manufacturing crucible for flameless atomic absorption spectroscopy
    Patent number: 4367246
    Abstract: A preform made of carbon, and especially electrical graphite (electro-graphite), is given a protective coating of pyrolytic graphite which, in turn, is activated by further coating with a carbon with a very low degree of orientation (soot) or by roughening. The process of activation reduces the effect of the sample to be analysed, while the protective effect of the pyrolytic graphite coating is preserved.
    Type: Grant
    Filed: February 2, 1981
    Date of Patent: January 4, 1983
    Assignee: U.S. Philips Corporation
    Inventors: Bernhard Lersmacher, Wilhelmus F. Knippenberg
  • X-ray spectrometer
    Patent number: 4280049
    Abstract: An X-ray spectrometer which is arranged inside an evacuatable housing and which comprises a wavelength dependent X-ray detection system and, for irradiating the specimen to be examined, an electron source with an electron deflection system for generating an electron beam and an X-ray source for generating an X-ray beam. The X-ray source consists of an anticathode on which the electron beam can be directed by the electron deflection system in order to generate the X-ray beam.
    Type: Grant
    Filed: May 24, 1979
    Date of Patent: July 21, 1981
    Assignee: U.S. Philips Corporation
    Inventors: Helmut W. W. Werner, Antonius W. Witmer, Wilhelmus F. Knippenberg
  • Method of making an electric resistor having a resistance body consisting of silicon carbide having a negative temperature coefficient
    Patent number: 4208449
    Abstract: A method of making an electric resistor having a negative temperature coefficient of resistance whose resistance body consists of p-type doped pyrolytic polycrystalline cubic silicon carbide.
    Type: Grant
    Filed: February 23, 1978
    Date of Patent: June 17, 1980
    Assignee: U.S. Philips Corporation
    Inventors: Wilhelmus F. Knippenberg, Gerrit Verspui, Siegfried H. Hagen
  • Cuvette for flameless atom absorption spectroscopy
    Patent number: 4204769
    Abstract: Cuvettes of carbonized laminated fabric with a surface layer of pyrolytic graphite are easy to manufacture, have a high mechanical rigidity and no memory effect and enable the operation of analysis apparatuses at normal mains voltage (220 V).
    Type: Grant
    Filed: January 17, 1978
    Date of Patent: May 27, 1980
    Assignee: U.S. Philips Corporation
    Inventors: Bernhard Lersmacher, Hans Lydtin, Karlheinz Schelhas, Wilhelmus F. Knippenberg