Cutting crowns or other tools (percussion drill bits E21B10/36)

Full Title

Cutting machines, i.e. for making slits approximately parallel or perpendicular to the seam (dislodging machines with slitting means E21C27/02, E21C27/10, E21C27/18) > Machines slitting solely by one or more percussive tools moved through the seam > Cutting crowns or other tools (percussion drill bits E21B10/36)