Patents by Inventor Stephen M. Istvanffy

Stephen M. Istvanffy 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: 4231506
    Abstract: A method is provided for the explosive welding together of sections of large diameter metal pipe of the kind used in the construction of high volume oil and gas pipelines. In the method, internal and external band charges of welding explosive are simultaneously detonated adjacent to overlapped telescoped pipe ends. The welding charges are detonated simultaneously by means of very high detonation velocity initiation explosive charges placed along a leading edge of each welding explosive charge. The initiating explosive charges are each set off by a single detonator means. The velocity of detonation of the initiating explosive is selected so that welding charges are simultaneously detonated around the pipes while maintaining the detonation fronts at superimposed locations and at a large angle to the pipe axis. This avoids unbalancing forces on the pipes and minimizes the collision of circumferential shock waves thus preventing pipe damage and imperfect welds.
    Type: Grant
    Filed: May 21, 1979
    Date of Patent: November 4, 1980
    Assignee: Canadian Industries Limited
    Inventors: Stephen M. Istvanffy, Vonne D. Linse