Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5634740 | Large-depth underground drainage facility and method of running same | Kunio Takada, Kenji Otani, Masayuki Yamada, Sumio Sudo, Sadashi Tanaka | 1997-06-03 |
| 5624226 | Underground drainage facility, vertical-shaft multi-stage adjustable vane pump, and method of running drainage pump | Masayuki Yamada, Sumio Sudo | 1997-04-29 |