Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5904444 | Propelling apparatus for underground propelling construction work | Masaya Hattori, Takashi Togawa, Yukishige Yamada, Shigeaki Okuyama, Masao Nakagawa +3 more | 1999-05-18 |
| 5878825 | Underground propelling method | Shigeaki Okuyama, Katsuhiko Mukuno, Masaya Hattori, Kazunori Tsujimoto, Takashi Togawa +3 more | 1999-03-09 |