Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5943890 | Cylinder lock and key assembly and hierarchical system therefor | Peter Field | 1999-08-31 |
| RE35518 | Restricted key system | — | 1997-05-27 |
| 5176015 | Restricted key system | — | 1993-01-05 |
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5943890 | Cylinder lock and key assembly and hierarchical system therefor | Peter Field | 1999-08-31 |
| RE35518 | Restricted key system | — | 1997-05-27 |
| 5176015 | Restricted key system | — | 1993-01-05 |