Patent ID: 8950823
Filing Date: 2015-02-10
Classification: E21C,E21D

Abstract:
1. A method for driving tunnels or galleries with a driving rig having a movable base unit which over a support unit supports a carrying unit which in turn carries a cutting head having outwardly directed cutting elements, the method comprising: swinging the carrying unit into a first chosen mutual position with respect to the support unit; rotating the support unit into a second chosen mutual position with respect to the base unit around an axis of rotation that is a longitudinal axis of the base unit, thereby positioning the cutting head at an angle of operation; rotating the cutting head around a general axis of rotation; applying the cutting head against a rock surface to be worked, while maintaining the cutting head in the angle of operation; retracting the cutting head from the rock surface; performing tunnel side cuts essentially in parallel with said longitudinal axis, with the cutting head advancing, the cutting head being positioned in a selected angle of operation while retracted from the rock surface between performing each tunnel side cut; and transporting cut loose material away from the rock surface wherein the angle of operation of the cutting head is changed only while the cutting head is retracted from the rock surface.