Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4266828 | Apparatus on drum shearer for cutting through safety wall in long wall mining | Ken Takahashi, Hajime Endo | 1981-05-12 |
| 4196933 | Safety wall cutting through method employed in long wall mining | Ken Takahashi, Hajime Endo | 1980-04-08 |