Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 10538956 | Mine ventilation door with wings and slidable or pocket personnel door | Robert H. Chorman | 2020-01-21 |
| 9476301 | Mine ventilation door with wings and slidable or pocket personnel door | Robert H. Chorman | 2016-10-25 |
| 9181802 | Robust mine ventilation door with single actuation system | Robert H. Chorman | 2015-11-10 |
| 8884760 | Control system for mine ventilation door | Robert H. Chorman | 2014-11-11 |