DIFF Subgroup
E21B 4/08 impact being obtained by gravity only, e.g. with lost-motion connection
Introduced: January 1980
Full Title
Full titles differ between systems:
IPC:
Drives for drilling, used in the borehole > Down-hole impacting means, e.g. hammers > impact being obtained by gravity only, e.g. with lost-motion connection
CPC:
Drives for drilling, used in the borehole > Down-hole impacting means, e.g. hammers (boring rams E21B11/02) > impact being obtained by gravity only, e.g. with lost-motion connection
No child classifications to compare. This is a leaf node in both IPC and CPC.