Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4257239 | Earth coil heating and cooling system | James R. Partin, Carl W. Ledbetter | 1981-03-24 |
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4257239 | Earth coil heating and cooling system | James R. Partin, Carl W. Ledbetter | 1981-03-24 |