Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4865367 | Safety door with counterweight locking | — | 1989-09-12 |
| 4838587 | Mechanism for controllably deadlocking a door to a door frame, for panic release | — | 1989-06-13 |
| 4824150 | Fire responsive safety door assembly | Gregg Smith | 1989-04-25 |