Apparatus for positioning deflection wedges

摘要

A deflection wedge is positioned in a long horizontal drill hole by securing it with a shear pin to an extension on a drill string. The extension is turned independently of the drill string to enable a droparm mechanism to actuate a trigger which stops rotation at a predetermined orientation. Rotation is effected by means of a rifle bar mechanism. The rifle bar presses against the bottom of the hole to cause rotation and the trigger declutches the rifle nut when the droparm drops.