Crawler rigs working when promoting regulating agencies to drills with continuous advancement, and turned around and always rock of hole bottom contact. Slewing mechanism for continuous rotary drill. Meanwhile, mounted on the front of the drill pipe of shock in the air under its piston impact drill bit got energy after impact, dive into the hole, squeezed the rock impact. Drilling tool Rotary avoided on the bit is repeated against the same Chiseled, and thus lead to the rock of hole bottom scraping effect of shearing force, impact shock piston and Rotary mechanism of shear force, rocks are crushed and shredded. Compressed air from the air fitting into and through the hollow end of drill pipe through the hole, after cutting rock slag, from the annular space between wall and blew out of the hole, creating holes, this is the working principle of crawler rigs, hope the small summary can bring you that understanding.