Patents Examined by Robert K. Mackey
  • Patent number: 4790052
    Abstract: Method and apparatus for producing homogeneously needled three-dimensional structures formed of superposed layers of fibrous material and the needled structures produced thereby. As layers of fibrous material are added to a stack of needled layers, the needling needles are moved away from the stack so as to maintain a uniform depth of needling over the entire stack, and to achieve a uniformly needled result. To permit the same density of needling in the initial layers, a substrate layer of needle penetrable material is used to support the initial layers which can then be needled as through they were layed on top of other needled layers. For the final layers, the needling rate is reduced to compensate for the lessened clogging of the needle in having fewer layers to penetrate in the final needling.
    Type: Grant
    Filed: June 23, 1986
    Date of Patent: December 13, 1988
    Assignee: Societe Europeenne De Propulsion
    Inventor: Pierre Olry