| Patents for E21B 6 - Drives for drilling with combined rotary and percussive action (930) |
|---|
| 05/29/1980 | WO1980001091A1 Device for making drillings into the rock,soil,etc |
| 05/28/1980 | EP0011287A1 Down-the-hole drill for rock, earth or the like |
| 03/18/1980 | CA1073894A1 Rock drilling method |
| 01/08/1980 | US4182421 Pneumatic rock drill |
| 12/25/1979 | CA1068676A Rock drilling apparatus |
| 10/30/1979 | US4172411 Hydraulic hammer |
| 09/04/1979 | US4166507 Percussive drilling apparatus |
| 07/24/1979 | US4161990 Rock drilling apparatus |
| 07/24/1979 | US4161989 Reciprocating hydraulic motors |
| 06/05/1979 | US4157121 Hydraulic powered rock drill |
| 05/29/1979 | CA1055477A1 Rock drill |
| 03/13/1979 | CA1050393A1 Hydraulic rotary-percussive machines |
| 12/12/1978 | CA1044116A1 Hydraulic percussive machines |
| 11/21/1978 | US4126192 Hydraulic percussive machines |
| 11/21/1978 | CA1042760A1 Rotary and percussive devices |
| 08/01/1978 | US4103746 Rotary and percussive devices |
| 06/13/1978 | US4094364 Percussion drill rod |
| 02/21/1978 | US4074771 Rock drill |
| 01/31/1978 | US4071093 Air percussion boring machine |
| 08/02/1977 | US4039033 Hydraulic rock drill |
| 07/19/1977 | US4036309 Double-piston rock drill |
| 05/17/1977 | US4023626 Self-adaptive hydraulic rock drill |
| 05/10/1977 | US4022108 Hydraulically operated percussion device |
| 02/08/1977 | US4006783 Hydraulic operated rock drilling apparatus |
| 12/21/1976 | US3998279 Air manifold and delivery passageways for rock drill |
| 11/09/1976 | US3990522 Rotary percussion drill |
| 10/19/1976 | US3986567 Hydraulic percussive-rotary machine |
| 09/21/1976 | US3981368 Coupling means in a drilling machine |
| 09/14/1976 | US3979944 Hydraulic drill, in particular a rock drill |
| 06/15/1976 | USRE28859 Rock drill |