DISTANCE COMPENSATING DEFLECTED LIGHT BEAM PATTERN PROJECTOR

摘要

A method in rock blasting operations for marking out drill holes when drifting tunnels while making use of a direction reference beam which is projected in a direction in accordance with a predetermined lay out, at least part of said reference beam being passed to a scanning means by means of which said part-beam in accordance with a predetermined drill hole pattern is directed onto the rock to present thereon images of the beam at locations of intended drill holes on the rock surface. Correspondingly, a device for executing said method comprises means for deflecting at least part of a reference light beam onto locations for holes to be drilled in accordance with a predetermined pattern onto the rock wall.