Abstract: This invention relates to a chuck assembly for a drill box of a mine drill for releasably securing a mining tool including a working end and a depending rod-like member for roof bolting and roof and face drilling operations and a method of using the chuck assembly. The drill box includes a source of rotary power and a drive member operatively connected to the source of rotary power to rotatably drive the chuck assembly. The chuck assembly includes a spindle, a collet closer and a collet. The spindle is operatively connected to the drive member and has a sleeve of a cylindrical shape including a threaded collar end and a bottom end and an opening extending a selected distance from the collar end to the bottom end. The collet closer includes an annular housing having an aperture threaded for threadingly engaging the threaded collar end of the spindle.

Abstract: A contour miner has walker means carrying an external deck outside the formation being mined having power supply and control means for movement along the periphery of a coal seam with a reciprocating carriage having a rotary cutter for removing the coal from a work face extending inwardly below the overburden perpendicular to the seam periphery; a conveyor extends adjacent the work face and conveys the removed coal out beyond the external deck; an internal roof support-walker assembly is positioned inwardly of the formation and has hydraulic cylinder actuated movable roof supports and ground pads and hydraulic cylinders for walking forward toward the work face with dragline means moving prefabricated roof supports behind the support-walker assembly as it is moved toward the work face.