Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6705648 | Pipe joint | Eiji Tsuru, Haruyuki Nagayoshi | 2004-03-16 |
| 6176524 | Oil well pipe threaded joint | Eiji Tsuru, Masaharu Oka | 2001-01-23 |
| 5725925 | Packing material for refractory | Kenji Ichikawa, Hajime Asami, Junichi Inoue | 1998-03-10 |
| 4421575 | Method of cooling steel pipes | Kyohei Murata, Heiji Morise, Yoichi Yazaki, Haruyuki Nagayoshi, Etuji Kajiki | 1983-12-20 |