235 bit of work principle: compression gas after drill pipe into impact device, then from bit discharge, discharge of exhaust was used to row ballast. impact device of rotary movement by Rotary head provides, axis thrust by propeller provides, through soldering Rod passed to impact device Shang. card soldering sets main for to bit passed advance force and rotary movement. CLASP control bit of axis to movement, and inverse check valve is Dang stop supply pressure gas Shi, used to just check rock ballast, debris into impact device. drilling process in the, bit was advance impact device, and pressure in card soldering sets Shang, Pistons directly impact drill rock at this point, when the bit from the hole at the end of starting strong blows.