Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4883557 | Method for lining pipe lines with a pressurized gas | Isaburo Yagi, Hideo Maruyama, Akifumi Yamamoto | 1989-11-28 |
| 4882470 | Boring device for opening passages to branch portions of a lined main pipe line | Katsuaki Zenbayashi, Hisao Otsuga, Osamu Toyoshima, Shinji Shimokawa | 1989-11-21 |
| 4877665 | Lining material for pipe lines | Kumao Higuchi, Masahiro Seshimo, Hitoshi Saito | 1989-10-31 |