Abstract: A drill rig for drilling a hole in the ground including a mast, having a longitudinal slide means at one face thereof, adapted to be set upright with the slide means facing, and being at a selected spacing from and parallel to the axis of a drill hole to be drilled with the rig; a slide frame mounted upon the mast slide means and lifter-pulldown means in the mast to move the slide frame along the longitudinal slide means; a lateral shifting means on the slide frame shiftable towards and away from the slide frame in the direction of the drill hole; a drill carrier attached to the shifting means to be shifted to a first position against the slide frame and to a second position outwardly therefrom; and a drill mechanism means including a drill pipe means mounted upon the drill carrier to effect drilling by a drill pipe means, with the drill pipe means being aligned with the drill hole axis when the drill carrier is at one of said positions.

Abstract: Multiple wall drill pipe adapted for use in a drill pipe string comprising an outer pipe member; an inner pipe member disposed within the outer pipe member; and means for releasably connecting the inner pipe member and the outer pipe member in fixed axial relationship under force loads applied in use during a drilling operation while enabling relative rotary movement between the inner pipe member and the outer pipe member during a rotary drilling operation to relieve torsional stress thereon, and for permitting the removal of the inner pipe member from the outer pipe member by relative axial displacement therebetween caused by application to the inner pipe member of only an axially directed force load in excess of the axially directed force loads applied to the inner pipe member in use during a normal drilling operation.

Abstract: Multiple wall drill pipe adapted for use in a drill pipe string comprising an outer pipe member; an inner pipe member disposed within the outer pipe member; and means for releasably connecting the inner pipe member and the outer pipe member in fixed axial relationship under force loads applied in use during a drilling operation while enabling relative rotary movement between the inner pipe member and the outer pipe member during a rotary drilling operation to relieve torsional stress thereon, and for permitting the removal of the inner pipe member from the outer pipe member by relative axial displacement therebetween caused by application to the inner pipe member of only an axially directed force load in excess of the axially directed force loads applied to the inner pipe member in use during a normal drilling operation.