Patents by Inventor Dennis A. Jennerjohn

Dennis A. Jennerjohn 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: 4728760
    Abstract: A method and apparatus is disclosed for induction heating weldable surfaces and moving the heated surfaces together with sufficient force to upset the surfaces while in a substantially inert atmosphere for thereby welding the surfaces together. The apparatus includes a rotary bus bar joint for moving the induction coil between the weldable surfaces, and also includes a clamping mechanism for handling members having weldable surfaces of different sizes and shapes. A pair of separately controlled induction coils may be used with or without laminations for heating tubular or solid members to an upsetting temperature.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: March 1, 1988
    Assignee: FMC Corporation
    Inventors: Charles A. Brolin, Dennis A. Jennerjohn, Richard E. Moeller
  • Patent number: 4717801
    Abstract: A welding control circuit for induction heating of a pair of articles to a welding temperature and for pressing the heated articles together. A pair of induction coils are positioned in a gap between the portions of the articles to be heated and a pair of temperature sensors monitor the temperature of both articles and controls heating rates so both articles reach a welding temperature at approximately the same time. The temperature sensors provide signals which cause the coils to be retracted from the gap and cause the heated articles to be pressed together to form a welded pair. When similar articles are to be welded together a single coil can be used to provide induction currents which heat the articles.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: January 5, 1988
    Assignee: FMC Corporation
    Inventors: Charles A. Brolin, Ronald L. Pike, Dennis A. Jennerjohn
  • Patent number: 4687892
    Abstract: A method and apparatus is disclosed for purging air from multiple surfaces of members to be welded together. The apparatus includes a hood with the inert gas entering the hood at about 150 cubic feet per minute at between 2-5 pounds per square inch gauge when handling approximately 21/2 inch diameter tubes. The gas is first evenly spread in the hood to fill the entire cross sectional area thereof and is then moved through a straightening section to provide laminar flow of the gas across the multiple surfaces. An induction coil is moved between hood closure means into the hood to heat the weldable surfaces to a bonding temperature and after the coils have been removed from the hood, the members are urged together to upset the heated surfaces to weld the two members together.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: August 18, 1987
    Assignee: FMC Corporation
    Inventors: Charles A. Brolin, Dennis A. Jennerjohn, Richard E. Moeller
  • Patent number: 4436169
    Abstract: An elevating and tilting mechanism for a crane cab having a sub-frame mounted to the upper works, a pair of outer arms pivotally connected to the sub-frame and to the platform, a central inner arm pivotally connected to the sub-frame and the platform to form a parallelogram linkage. A pair of elevating rams connected between the cab frame and the outer arms. A cab is pivotally mounted at its rear to the platform and has a pair of hydraulic tilting rams connected between the platform and the cab.
    Type: Grant
    Filed: January 25, 1982
    Date of Patent: March 13, 1984
    Assignee: FMC Corporation
    Inventors: Dennis A. Jennerjohn, Lyle B. Jensen