Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5852278 | Arc welding and arc plasma cutting machines having improved DC high-voltage generator | Yoshiaki Tanaka, Seigo Hagiwara, Norikazu Osaki, Naoki Kawai | 1998-12-22 |
| 5773792 | ARC welding machine and plasma cutting machine | Seigo Hagiwara | 1998-06-30 |
| 5582751 | Arc welding machine and plasma cutting machine | Seigo Hagiwara | 1996-12-10 |
| 4269714 | Activated sludge treatment method of waste water | Muneharu Ishikawa | 1981-05-26 |