Patents by Inventor Herbert Frohlich

Herbert Frohlich 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).

  • Patent number: 4801222
    Abstract: A steel pipeline to be driven through an earth section without disturbing the overlying earth is made up of a plurality of serially arranged axially extending pipe sections each having a leading end and a trailing end. The leading end of each pipe section abuts the trailing end of the pipe section previously driven into the earth section. A pressure-tight pipe connection between the abutting ends of the pipe sections is formed by a steel ring secured within the trailing end of the pipe section and projecting axially out of the trailing end. The steel ring has an outside diameter smaller than the inside diameter of the section. The leading end of the next pipe section has an elastic material sealing ring secured to its inside surface with the sealing ring projecting radially inwardly beyond the outside surface of the steel ring.
    Type: Grant
    Filed: July 31, 1987
    Date of Patent: January 31, 1989
    Assignee: Dyckerhoff & Widmann Aktiengesellschaft
    Inventor: Herbert Frohlich