Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4803859 | Tumbler wheel structure for radiological detector resistant combination lock | Stephen Helesfai | 1989-02-14 |
| 4796446 | Radiological detection resistant combination lock | Stephen Helesfai | 1989-01-10 |