DIFF Subgroup
E21B 3/02 Surface drives for rotary drilling
Introduced: September 1968
Full Title
Rotary drilling > Surface drives for rotary drilling
Of 5 combined children, 4 exist in both systems.
1 codes are CPC-only extensions.
Child Classifications
Navigate with arrow keys, Enter to open
- E21B 3/03 with an intermittent unidirectional rotation of the tool since 2000 IPC+CPC Available in IPC and CPC