Patents Assigned to Grace N.V.
  • Chiral absorbing structure
    Patent number: 5229773
    Abstract: An absorbing assembly for absorbing electromagnetic radiation in the range 10 MHz to 100 GHz comprises a lossy dielectric material and chiral elements disposed outside the lossy dielectric. The chiral elements may be springs, Mobius bands, irregular tetrahedra, tapering helical springs or handed non-planar forks. The lossy dielectric material may be in the form of a shaped structure e.g. for use in an anechoic chamber.
    Type: Grant
    Filed: April 10, 1992
    Date of Patent: July 20, 1993
    Assignee: Grace N.V.
    Inventors: Jan M. A. Dauwen, August T. Timmerman, Michel A. C. Van Craenendonck, Hugo F. Pues
  • Chiral absorber
    Patent number: 5202535
    Abstract: An absorbing assembly for absorbing electromagnetic radiation in the range 10 MHz to 100 GHz comprises a lossy dielectric material and chiral elements disposed outside the lossy dielectric. The chiral elements may be springs, moebius bands, irregular tetrahedra, tapering helical springs, screws or handed non-planar forks.
    Type: Grant
    Filed: April 10, 1992
    Date of Patent: April 13, 1993
    Assignee: Grace N.V.
    Inventors: Jan M. A. Dauwen, August T. Timmerman, Michel A. C. Van Craenendonck, Hugo F. Pues
  • Internal manifold that aids in filling molds
    Patent number: 5082726
    Abstract: A process of forming buoyant structures is disclosed, whereby a manifold is positioned in a buoyant structure mold so as to define a space therein that is devoid of buoyant bodies. The mold can then be filled with a resin/microsphere mix that meets minimal resistivity in the devoid space along the length of the manifold. A reduction in mold fill-time is achieved. The resulting buoyant bodies exhibit improved quality.
    Type: Grant
    Filed: November 1, 1989
    Date of Patent: January 21, 1992
    Assignee: Grace N.V.
    Inventors: Alfons Bastiaens, Norbert Pauwels