Patent attributes
A mobile drilling rig is mountable on a separate drive chassis having running gear. A separate main frame may be having elongated members, each having outer end extensions and vertically adjustable support posts thereon. A slide chassis is slidable on one end of the main frame mounting a power plant, and a mast pivot support pivotally mounted on the other end of the main frame. An elongated mast has a drill head movable thereon, with the mast pivot support slidably mounting the mast thereon so that the mast may be pivoted between vertical and horizontal orientations thereon while being movable in lengthwise directions. The slide chassis, the mast and drill head are moved to positions improving the stability of the rig when traversing grades in an up or down hill direction.
