Patents by Inventor Struve Friedrich

Struve Friedrich 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).

  • Method of sealing lateral connections for pipe liners
    Patent number: 5223189
    Abstract: The invention provides an apparatus and method by which an opening into a lateral pipe connection for a pipeline into which a liner is being installed may be sealed and protectively lined. The invention features a bushing which is emplaced in the lateral connection by use of an expandable mandrel and a control means. The bushing includes an integral heating element for softening the thermoplastic material from which the bushing is formed. O-rings are positioned between the bushing and the lateral pipe to form a seal.
    Type: Grant
    Filed: January 7, 1992
    Date of Patent: June 29, 1993
    Assignee: Gundle Lining Systems, Inc.
    Inventor: Struve Friedrich