Patents Assigned to Frederick William Johnson
  • Patent number: 5154452
    Abstract: A tubular connection employing two separate non-concurrent threaded sections, each of which nearly decays, that is, runs out on a tubular surface, one on the outside diameter of the male tubular member, and one on the inside diameter of the female tubular member, thus providing a joint with nearly the strength of the tubular body in tension without the use of a coupling. The female tubular member is expanded through a cold swaging operation before being finished with the two threaded sections. Additionally, the connection features a torque stop and cylindrical seal in the middle of the two thread steps, where stresses may be kept low. The thread elements are reverse angle locking with S-shaped load flanks which reduce stress concentrations and provide a clamping action on the centralized seal. Because of this unique seal, the connection can take cyclic application of external and internal pressure without leaking, a feat non-coupled and non-upset connections of prior art have not achieved.
    Type: Grant
    Filed: September 18, 1991
    Date of Patent: October 13, 1992
    Assignee: Frederick William Johnson
    Inventor: Fred W. Johnson