Patents Assigned to Helmut Rehlen
  • Sound-insulated flow duct and process for the manufacture thereof
    Patent number: 4615411
    Abstract: A sound-insulated flow duct is provided with walls made up of a composite of an elastic thermoplastic, predominantly closed-cell foam material as the outer layer and an open-cell, elastic soft foam material as the inner layer.
    Type: Grant
    Filed: May 24, 1983
    Date of Patent: October 7, 1986
    Assignees: Dynamit Nobel AG, Helmut Rehlen, Jurgen Roellinghoff
    Inventors: Hans-Ulrich Breitscheidel, Cosmas Lorry, Helmut Rehlen, Jurgen Roellinghoff