CPC Main Group
E21B 1/00 Percussion drilling
4 direct subcodes
Child Classifications
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- E21B 1/02 Surface drives for drop hammers , e.g. with a cable
- E21B 1/12 with a reciprocating impulse member (E21B1/02, E21B1/38 take precedence)
- E21B 1/36 Tool-carrier piston type, i.e. in which the tool is connected to an impulse member
- E21B 1/38 Hammer piston type, i.e. in which the tool bit or anvil is hit by an impulse member