Issued Patents 1997
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5636678 | Counterbalancing mechanism for an overhead door | Alan R. Leist | 1997-06-10 |
| 5632063 | Counterbalancing mechanism for an overhead door | Alan R. Leist, Tony Y. Lin, George S. Carper, Thomas E. Agin | 1997-05-27 |
| 5615723 | Extension spring system for an overhead door | — | 1997-04-01 |