Head Assembly

摘要

A head assembly includes a spear head assembly and a latching system which are coupled together. The spearhead assembly includes a spear point having a proximal end pivotally coupled about a pivot axis and a sleeve that is biased in a direction toward a pointed end of the spear point. The sleeve is coupled with the spear point so that the spear point and the pivot axis can move axially relative to the sleeve. The latching system includes a latch body and two latch dogs which are coupled to the latch body and movable between a latching position where the latch dogs extend from the latch body and can engage a latching mechanism, and a release position where the latch dogs retract inwardly. The latching system is configured to enable the latch dogs to move parallel to each other rather than pivot when moving between the latch and release positions. The spear head assembly enables the head assembly to be coupled to an overshot to enable tripping through a drill string. The latching system enables the head assembly to selectively engage the latching mechanism inside the drill string to hold the head assembly in at least one axial direction relative to the drill string.