Issued Patents All Time
Showing 26–30 of 30 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4255000 | Rotary drill bit | Armin Olschewski, Lothar Walter, Manfred Brandenstein, Gosta Norlander | 1981-03-10 |
| 4249781 | Rotary drilling bit with conically shaped rotary cutters | Armin Olschewski, Manfred Brandenstein, Lothar Walter | 1981-02-10 |
| 4235480 | Seal ring for drill bit assemblies | Armin Olschewski, Manfred Brandenstein, Lothar Walter | 1980-11-25 |
| 4233855 | Mechanism for the axial shifting of an anti-friction bearing | Armin Olschewski, Manfred Brandenstein, Lothar Walter | 1980-11-18 |
| 4206952 | Rotary drill bit with a porous cup bearing | Armin Olschewski, Manfred Brandenstein, Lothar Walter | 1980-06-10 |