Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7004679 | Easily-cuttable tunnel segment structure | Ryoichi Naka, Toshihiko Yoshizumi, Shinichi Nakata, Fumio Kondoh, Osamu Ishita +2 more | 2006-02-28 |
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7004679 | Easily-cuttable tunnel segment structure | Ryoichi Naka, Toshihiko Yoshizumi, Shinichi Nakata, Fumio Kondoh, Osamu Ishita +2 more | 2006-02-28 |