Patents Assigned to Explosive Research Ltd.
  • Patent number: 4564226
    Abstract: A system and method for thickening the end of a pipe or rod for receiving tapered threads is disclosed. A metal sleeve is metallurgically bonded to the outer surface of the end portion of a well pipe by a high-energy impact of the sleeve colliding radially inward against the end of the well pipe. The impact is produced by the detonation of an explosive charge propagating uniformly around the sleeve. A castable metal having a substantially lower melting temperature than the melting temperature of the pipe is deposited within the pipe and is permitted to solidify in situ to form a core for absorbing the high-energy impact of the collision and for limiting the radial contraction of the pipe in order to preserve its inside diameter. A thread is machined along a tapered path which penetrates the metallurgically bonded interface of the sleeve and pipe.
    Type: Grant
    Filed: November 2, 1981
    Date of Patent: January 14, 1986
    Assignee: Explosive Research Ltd.
    Inventor: Alfred E. Doherty, Jr.