Patent ID: 6595278
Filing Date: 2003-07-22
Classification: E21B

Abstract:
A polished rod locking assembly, for use as part of a wellhead production pumping tree to secure a polished rod forming the upper end of a rod string extending through a vertical bore formed by the tree, comprising:body means having an outer peripheral surface means and forming a central bore, through which the polished rod may extend, and opposed first and second side openings extending between the peripheral surface means and the central bore, each side opening being formed by an internal surface threaded along part of its length; first and second locking members, each being externally threaded along part of its length and having an inner end face, adapted to thread into the first and second side openings, respectively, for frictionally engaging the polished rod, each locking member being operative to seal against the internal surface of the side opening containing it and having an outer end which will protrude from the body means; a lever arm for turning the first locking member, the arm having first and second ends, the arm's first end being connectable with the outer end of the first locking member; and mechanical means for biasing the arm's second end to turn the first locking member to increase the force with which the first locking member engages the polished rod after they are in contact, to thereby secure the polished rod.