Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
E21C31/00—Driving means incorporated in machines for slitting or completely freeing the mineral from the seam
E21C31/02—Driving means incorporated in machines for slitting or completely freeing the mineral from the seam for cutting or breaking-down devices
E21C31/04—Driving means incorporated in machines for slitting or completely freeing the mineral from the seam for cutting or breaking-down devices imparting both a rotary and reciprocating motion