Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4871194 | Oil well pipe joint and manufacturing method therefor | Hisakazu Kawashima, Minoru Nishihara, Tetsuzo Arai, Kunihiro Fukui | 1989-10-03 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4871194 | Oil well pipe joint and manufacturing method therefor | Hisakazu Kawashima, Minoru Nishihara, Tetsuzo Arai, Kunihiro Fukui | 1989-10-03 |