ANGLE DRILLING FEATURE FOR ROTARY BLAST HOLE DRILLS

摘要

ROTARY BLAST HOLE DRILLAbstract of the DisclosureA rotary blast hole drilling apparatus having atiltable mast supported by adjustable mast braces and hav-ing a drill stem guide is described. The tiltable mast issupported by mast braces extending from the mast to a sup-porting platform, each formed of telescoping members. Aseries of openings are arranged along the length of thelower mast brace member for receiving a stop pin to beplaced at the desired point for making the mast brace of alength necessary to support it at the desired angle oftilt. A seat is placed on the stop pin and allows the mastbrace to assume the desired length to support the mast atthe desired angle. A drill stem guide assembly is providedfor substantially frictionlessly gripping the drill stem,especially as an angled drilling operation is being carriedout. The entire drill stem guide assembly is operable topivot substantially 90 degrees to permit passage of a rot-ary gear box drive assembly for the drill stem as it movestowards the lower end of the mast.