Abstract: A drill stem especially adapted for use in a boring machine which drills upwardly, having pin and box joints on its respective ends, having a circumferential collar that is utilized for both vertical and rotational support of the drill stem section, and additionally having a spline connection on its lower end which is utilized for imparting rotating drive.

Abstract: A vertical drill rig having a drive kelly, a drilling tool supported from the lower end of the drive kelly, a rotary table, and a friction crowd for imparting via the drive kelly to the drilling tool a vertical driving force which is in excess of that provided by gravity alone. The disclosed friction crowd assembly includes concentric inner and outer sleeves, the outer sleeve being supported from the rotary table while the inner sleeve is vertically movable relative both to the outer sleeve and to the drive kelly. Rotary movement is imparted by means of first interengaging rib and keyway means from the outer sleeve to the inner sleeve, and by means of second interengaging rib and keyway means from the inner sleeve to the drive kelly. Crowding of the kelly is accomplished by applying a separate vertical driving movement to the inner sleeve.