by rotary drills with breaking-down means, e.g. wedge-shaped drills

Full Title

Machines which completely free the mineral from the seam > Mineral freed by means not involving slitting > by rotary drills with breaking-down means, e.g. wedge-shaped drills

Classification Context

Section:

FIXED CONSTRUCTIONS

Class:

EARTH OR ROCK DRILLING; MINING

Subclass:

MINING OR QUARRYING