Rotary ball roller rock-drill chisel - has readily replaceable rollers on shanks engaging cup with central cut-out

摘要

Deep boreholes, and holes for explosive charges, are made by a drilling chisel of the rotary ball roller type, for drilling into ground and rock. A cup component (14) has one end shaped for connecting with a drill strand, while the other end has a central cutout area bounded by peripheral walling and downward-facing fitting surfaces. It is engaged by shank pieces, with chisel rollers (18) mounted on them. The pieces comprise two or more individual shanks (16) with upward-facing fitting surfaces, upward-aligned fixture area, and units for non-rotatable positioning in the cup component. They are detachably held in this component with a fixture section engaging the central cutout area. The shanks may be fixed by tongues and grooves acting together.