Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4747276 | Helium compressor apparatus | — | 1988-05-31 |
| 4697994 | Multistage discharge type rotary vacuum pump | Tadao Ishizawa, Hirofumi Kotaka | 1987-10-06 |
| 4622823 | Gas refrigerator | Tadao Ishizawa, Hirofumi Kotaka | 1986-11-18 |