Issued Patents 1997
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| D384669 | Remote control accessory | — | 1997-10-07 |
| 5666923 | Hydrogen enriched natural gas as a motor fuel with variable air fuel ratio and fuel mixture ratio control | Robert L. Hoekstra, David Neal Mulligan, Douglas Edward Hahn | 1997-09-16 |
| 5660602 | Hydrogen enriched natural gas as a clean motor fuel | Robert L. Hoekstra, David Neal Mulligan, Douglas Edward Hahn | 1997-08-26 |